DE69737686T2 - VASCULAR CATHETER SYSTEM FOR HEATING WOVEN FABRICS - Google Patents

Description

Background of the invention

These The invention relates to a catheter-based positioning system an electrode for applying energy to a vein intraluminal to shrink the fluid flow dynamics to change and the ability of Venous valves and proper function restore the vein using a minimally invasive procedure.

The human venous system of the lower extremities consists essentially from the superficial venous System and the deep venous system, where perforating veins connect the two systems. The superficial System includes the long or large saphenous vein and the short one Saphenous vein. The deep system closes the front and rear Shin veins that unite to the knee vein, which in turn becomes the femoral vein when united with the short saphenous vein.

The venous System contains numerous one-way valves to direct blood flow back to the heart. Venous valves are common bicuspid flaps, with each flap sail a sac or a Reservoir for Blood forms, under pressure, which forces three surfaces of the valve sails together, a backward one To prevent flow of blood and a forward flow to the heart to allow. When in the flow path of the backward river to Full down an inoperative Flap is located, the flap can not close because the leaflets form no proper seal and the reverse Blood flow can not be stopped.

Functional flaps can in the venous System occur in venous dilation. The separation of the flap sails The venous valves at the commissure can occur as a result. The leaflets are due to the dilatation of the vein and the accompanying increase in the vein diameter, the leaflets pull through, stretched. An extension of the leaflets of the venous valve allows it to loose leaves to fold yourself and leave the flap open. This prolapse can the reflux allow blood in the vein. Finally, the venous valve fails, the pressure on the lower venous Sections and above increased tissue becomes. Two venous ones Diseases that are common Venous dilatation are varicose veins and chronic venous insufficiency.

The Varicose veins closes Dilatation and tortuosity of the superficial veins of the lower veins extremities one that in unsightly discoloration, Pain and ulcers result. Varicose veins often involve inoperability of one or more venous ones Flaps that return of blood from the deep venous system to the superficial System, or reflux within the superficial Allow system. Current treatments include such invasive, open surgical procedures such as venerexhairesis, sclerotherapy and sometimes vein grafting, venous valvuloplasty and implantation of various prosthetic devices. The distance from Varicose veins from the body can be an annoying, time-consuming Be a procedure that causes a painful and slow healing process Has. Complications, scarring and loss of the vein for future cardiac and other by-pass procedures also occur. In addition to the complications and risks of invasive, open Surgery can Varicose veins persist or recur, especially when the flap problem is not corrected. Because of the long, arduous and annoying Nature of the surgical procedure, can be the treatment of multiple venous sections exceed the physical endurance of the physician and therefore the Make total treatment of varicose vain unusable.

chronic venous Insufficiency (CVI) is a problem caused by hydrodynamic forces being on the body tissues, especially the legs, ankles and feet, works. When the veins increased because of Pressure dilate, fail the valves in the veins. This leads to a Increase of Pressure on the next Flap and the next lower one Vein segment, which causes that these veins dilate and, if this continues, fail the valves in the veins finally all. If they fail, they grow the effective height the blood column over the feet and ankles and the weight and the hydrostatic pressure acting on the tissues of the ankle and the foot exercised will, increase. If the weight of this column is a critical point Achieved from the venous failure, ulcers of the ankle begin to form, which start deep and eventually come to the surface. These ulcers do not heal easily because the weight of the blood that caused them persists and they tend to enlarge the ulcer.

Chronic venous insufficiency often consists of hypertension of the lower extremities in the deep, perforating and often superficial veins and can result in discoloration, pain, swelling and ulceration. Existing treatments for chronic venous insufficiency are often less than ideal. These treatments include elevation of the legs, external compression of veins with elastic support stockings and surgical repair by transplantation from vein sections with healthy valves from the arm to the leg. These methods have a different effectiveness. Furthermore, invasive surgery has its accompanying complications with life and cost risks. Likewise, the relief therapies require the patient to make major lifestyle changes. For example, ulcers will recur if the patient does not continue to lift his legs and use the support stockings continuously for his entire life.

Because of the time-consuming and invasive nature of the current surgical Treatments, such as vein grafts, typically become only one flap during treated every single procedure. This severely limits the ability of the physician to the patients suffering from chronic venous insufficiency completely to treat. However, every invasive surgical procedure has its own accompanying complications with life and cost risk.

The Tying of the vascular Lumens by attaching a surgical suture around it, cauterization or coagulation using electrical energy from one Electrode has been used as an alternative to venerexhairesis or the surgical removal of such veins. Abbindeprozeduren shut down but lumen off and destroy it essentially their functional abilities. For example it is known to insert an electrode into the leg of a patient and the electrode to the outside to position the varicose vein to be treated. By A small stitch cut will be a probe through the subcutaneous layer forced between the fascia and the skin and then to the various to be destroyed Veins. Electrodes at the outer end The probe is placed adjacent to the varicose veins. After more correct Positioning an alternating current of 500 kilohertz is created to destroy the adjacent varicose veins. The veins lose the Function to allow blood to flow through and are no longer available use. For example, would a saphenous vein clogging this vein unavailable for removal in other surgical procedures like coronary by-pass operations. Tying techniques that functionally destroy the vein lumen, would inappropriate for corrective procedures for the restoration and maintenance of the function of the vein appear.

hemorrhoids are dilated veins in and around the anus and lower rectum. Dilation can be increased by one Pressure in the hemorrhoidal vein originate. Constipation including the frequent Tension to pass hard chair increases pressure in hemorrhoidal veins and is a common one reason for Hemorrhoids. Other contributing factors include pregnancy, low fiber nutrition and obesity. When the hemorrhoidal vein is affected by the increased pressure still can, can the venous valves of the hemorrhoidal vein start to fail and become inoperative. This can the dilation of the hemorrhoidal vein worse, there is a reflux of blood in the vein is made possible by the open, non-functional valve. The vein finally can a bag-like bulging form when the state is allowed to stop. hemorrhoids are generally classified as either internal or external, dependent from their location relative to the serrated line. The serrated line can be easily identified as the demarcation between the pink Mucous membrane that forms the anoderm. The serrated line separates the internal and external haemorrhage system. Internal hemorrhoids are over in the anus the toothed Line isolated. External hemorrhoids are below the toothed Line isolated. Both can to extend from the anus.

strain or irritation caused by passing stool can the sensitive surface an internal hemorrhage hurt and lead to bleeding. If the pressure and dilation of the hemorrhoidal vein persists, can the internal hemorrhoids Collapse and through the anal opening are forced. If a hemorrhoidal vein collapses can be considerable Malaise, including Itching and bleeding occur. The blood supply to these occurred hemorrhoids can through the sphincter be cut off, resulting in strangulated hemorrhoids. thrombosis can arise where the blood clumps inside the prolapsed vein. This extremely painful Condition can be edema and inflammations cause.

Increased pressure In the portal vein system can also increase the pressure of the upper hemorrhoidal vein (SHV) lead, what an increased Diameter of the hemorrhoid leads. The portal vein system allows venous drainage of the intestinal tissues to the liver and can become hypertensive if the liver is cirrhotic is.

The Treatment method for Hemorrhoids include invasive Surgery to remove the hemorrhage, Bonding by means of elastic ring, sclerotherapy and the application of ointments and suppositories one. Surgical removal of large and heavy hemorrhoids is as a hemorrhoidectomy known. This surgical procedure can be used in both internal and also external hemorrhoids be used. However, such a surgical procedure involves typically a long recovery period, along with the associated ones Risks and costs of invasive surgery.

Internal hemorrhoids can be made by means of gum bandbinding are treated, wherein a Abbinder is inserted through an area in the anal canal. The hemorrhoid is gripped with tweezers in the ligator and held in position. The ligator contains a cylinder that is pushed up and releases one or more rubber bands around the base of the hemorrhoid. A typical diameter for the rubber band is one millimeter. The tape cuts the blood circulation to the hemorrhage and the hemorrhage begins to shrink away. Provided that the rubber band stays in place, the hemorrhage typically falls off within seven to ten days.

sclerotherapy, another form of treatment for Hemorrhoids, involves injecting a solution, such as sodium morrhuate or Phenol oil, submucoulär into the areolar tissue around the hemorrhoidal vein, to an inflammation and causing scarring to eliminate the hemorrhage. Other external Treatments induce combustion or coagulation hemorrhoids to destroy. at Infrared coagulation can be applied to infrared light a small tissue-destroying burn around the base of the hemorrhoid to cut off the blood supply to the hemorrhoid. electrocoagulation, sometimes referred to as bipolar diathermy, can be done in a similar way be used. In laser therapy, also known as vaporization, A laser beam generates a superficial combustion around the To seal blood vessels and the hemorrhoids to hold in a non-occurred position.

The previous treatments for hemorrhoids involving external ligation or hemorrhage excision can do not affect the underlying causes that were originally related to that Hämorridenleiden led. Therefore, the suffering can recur.

varicose veins, called oesophageal Varices, can in the venous System form along the submucosa of the lower esophagus and bleeding out the dilated veins can occur. Blood flows from the portal vein system through the veins surrounding the esophagus to the heart back. Unlike other veins, such as the saphenous vein in the lower leg, have the esophagus surrounding veins typically have no valves to bring blood back to the heart bring to. The venous pressure in these esophageal Veins are relatively high and blood can flow without the help of venous valves back flow to the heart.

oesophageal Varices can of portal hypertension and other abnormalities in the portal vein system, such as Liver cirrhosis. Bleeding or bleeding that is hard to stop can, can be from esophageal Varices are caused and could, if left untreated, to life-threatening conditions develop. Such varices can simply erode and cause a massive gastrointestinal bleeding to lead.

The Treatment of esophageal Varices close portal-caval shunts, endoscopic variceal ligation, sclerotherapy and electrocoagulation of an electrode within the esophagus as from a tamponade aid. The portal shunt involved the surgical joining of two veins, the portal vein and the lower vena cava to relieve pressure in the vein, the blood in the Liver leads. Although effective in preventing recurrent bleeding from Varices, there are still the associated risks and complications of one such invasive surgery, including encephalopathy and postshunt hepatic failure, for the portal shunt operation.

The Endoscopic variceal ligation works analogously to rubber band ligation in the treatment of hemorrhoids. The esophageal Varices are made with elastic bands umgarnt to eradicate the varices. An endoscope is placed in the patient introduced and gets to the oesophageal to be treated Varice placed adjacent. The varize is pulled into a drum, which is attached to the tip of the endoscope. One on the drum mounted elastic band is then released through the varix. Endoscopic variceal ligation can not complete fibrosis the inner wall of the esophagus reach and a recurrence of the varices can result. Close other complications Bleeding of elastic and ligament-induced ulcers and oesophageal Blockage due to obstruction of the lumen due to ligated oesophageal Varices.

at sclerotherapy becomes a solution like sodium morrhuate or ethanolamine, submucosal into the tissue injected, which is located around the varicose vein in the esophagus, around inflammation and To cause scarring to complete the vein and to reduce the likelihood of bleeding. sclerotherapy may ulcers that produce esophageal Lead to constrictions can.

electrocoagulation was also used to oesophageal To treat varices. A tamponade tool with a metallized Surface becomes in the esophagus brought in. The metallized surface becomes with the mucosalen Membrane of the esophagus brought into contact. An electric current is then applied to the metallized surface designed to cause thrombosis of the esophageal varices.

EP 0,205,851 discloses a catheter comprising at least one lumen, closed at the front end, for the local treatment of internal Body structures, especially stenoses. The catheter includes at least one opening in the catheter wall disposed in a front end treatment section and extending from the lumen to the outer wall of the catheter. The catheter further comprises an extensible and extensible member disposed in the treatment section of the catheter end, having at least one electrically conductive zone forming part of the extension of that member. The electrically conductive zone is disposed on the outer surface of this part of the catheter.

The Previous treatments for oesophageal Varices typically involve external coagulation or desolation of the veins and need often several treatment sessions. Treat such forms of treatment The varicose veins are not direct and can not be based on the underlying causes that originally gave rise to the esophageal Varices gave.

It there is a need for a system to treat dilated veins, such as those in varicose veins result or from venous Insufficiency, which is the patency of the veins for the venous Function receives and yet restore the competence that relates to the valves. There is also a need to treat dilated hemorrhoidal veins the venous Pressure on the hemorrhoidal Reduce the region. Such treatment should be functional continuity maintain the vein and the competence concerning the valves at the origin of hemorrhoids, as well as within the hemorrhoid self, restore. There is a need that dilated Treat veins that are esophageal Cause varices and the venous Pressure on the esophageal To reduce region of the portal vein system, without the concomitant risks invasive surgery. There is also a need for a less invasive one Procedure available too represent several venous ones Can handle jobs quickly and easily. The need exists Restoring flow pictures, dynamics and pressure and sections dilated veins to a normal or reduced diameter to shrink. Where bleeding occurs, there is a need for hemostasis in bleeding varices and the recurrence of bleeding to minimize.

Summary of the invention

In Brevity and in general terms The use of the present invention makes a less invasive and faster procedures ready to address the underlying problems of varicose veins and venous To solve insufficiency and uses a novel repair system, including one Catheter for placement of an electrode for application of radiofrequency energy.

According to the present Invention provides an apparatus for applying energy to reduce the diameter of a vein as claimed in claim 1.

The Method of using the apparatus of the present invention includes the steps: insert a catheter with a functional end and means for heating, localized at the functional end to treat a site in a vein; Positioning the means for heating at the treatment site in the vein; Application of energy from the means for heating, to controllably heat up the treatment site and shrink to cause the vein; and stopping the energy emission from the Means for heating, after a sufficient shrinkage of the Vein has taken place, so that the competence related to the valves or so that the vein stays consistent, to continue the function as a blood channel. The procedure is a minimal one invasive procedure that eliminates the need for open surgical Procedure for venous Repair eliminated, including venous Valvuloplasty and the transplantation of a arm vein in the leg.

One Apparatus applies radiant energy to the shrinkage of a vein to cause. The heating unit may contain RF electrodes to heat and shrink the vein. Feedback control systems can be applied to control the application of energy, around the venous To heat tissue to control the extent of shrinkage.

characteristics The present invention includes recovery the competence of the venous valves, the normalization of flow patterns, dynamics and the pressure and reduction of sections of dilated Varicose veins to a normal diameter for cosmetic purposes. The treated veins remain consistent and can continue to function and bring blood back to the heart.

A Procedure is for restoring venous valve competence Controllable shrinkage of the otherwise dilated lumen of a vein to the desired Diameter.

One Another advantage is controlling or adjusting the effective one Diameter of the catheter or electrode configuration to the extent to control the circumferential shrinkage from the vein wall is experienced. An extendable element that connects to the functional end The catheter is located adjacent to the effective diameter of the catheter and limit the shrinkage of the vein.

Advantageous a catheter electrode is provided which is a radio frequency field created around the circumference of the catheter, surrounding the vein wall and shrink all around while the longitudinal contraction is minimized when the catheter electrode is intraluminal within the vein is positioned.

One Field can be generated at a certain frequency around the catheter to minimize coagulation within the vein and around the Spread of heating within the venous tissue.

The venous valve leaflets by minimizing the heating effect on the venous valves protected by selectively positioning the electrodes within the vein.

Preferably becomes cooling liquid delivered to the bloodstream to reduce the likelihood that the blood is heated to the point of coagulation.

Preferably the contraction of the vein is over the end of the catheter is prevented.

Advantageous The electrodes are held in line with the venous tissue to ensure that the heat is too venous Tissue is released and not to the blood that flows through the Vein is moving.

The flexible elements become radial after Outside bent to maintain contact with the venous tissue. The bendable Elements are conductive, longitudinal Electrodes essentially covered with an insulating film are, except that Part which is to be attached to the venous tissue in alignment.

In another arrangement is a balloon on one side of the catheter with electrodes on the opposite Page isolated. Inflating the balloon moves the electrodes in line with the vein wall on the opposite side.

One Advantage of using the apparatus according to the present invention is there a procedure available to put several venous ones Can handle jobs quickly and easily.

One Advantage of the present invention is that no foreign object or no prosthesis remains in the vasculature after treatment.

in the Method of using the apparatus according to the present invention, contains the step of positioning the heater at the treatment site preferably further comprising the step of placing the heater adjacent to the venous valves at the treatment site to venous valve competence restore.

Advantageous includes the step of positioning the heater further the Step of aligning the heater to a circumferential To achieve shrinkage of the vein and an axial shortening too minimize.

Advantageous includes the step of positioning the heater continues to Step of moving the heater in alignment with the vein wall at the treatment site.

Advantageous includes the step of positioning further comprises the step of increasing one effective diameter of the catheter to the heater to be brought in line with the vein wall; and the step of mooring of energy closes continue the step of reducing the effective diameter of the catheter in a controlled manner, so that the sequencer remains with the vein wall while the vein wall shrinks, to a diameter for reached the vein that restores vein function.

Advantageous The method further comprises the step of limiting the Shrinkage of a vein to a diameter through the heater is defined. Preferably, the method further comprises the Step of moving the heater radially outward from the catheter with one bendable element to the heater in line with the vein bring to. Preferably closes the step of applying energy continues to be the step of control the energy from a heater to the depth of heating at the treatment site of the vein.

Advantageous The method further comprises the step of determining the extent of shrinkage the vein.

Advantageous The method further comprises the step of determining the extent of shrinkage the vein using fluoroscopy.

Advantageous The method further comprises the step of determining the extent of shrinkage the vein using ultrasound.

These and other aspects and advantages of the present invention will become apparent from the following, more detailed description when they are seen in conjunction with the accompanying drawings, exemplifying the principles of the invention.

Brief description of the drawings

1 Figure 10 is a cross-section of a dilated lower limb vein having incompetent venous valves to be treated using the present invention;

2 shows a representative view of a venous section 1 along lines 2-2 to be treated using the present invention;

3 shows a partial cross section of a catheter having electrodes that is antegradically administered to a venous treatment site;

4 shows a partial cross section of a venous section of 2 after treatment using the present invention;

5 shows a partial cross section of the catheter and the vein, which in 3 shown to be administered to another venous treatment site;

6 shows a partial cross-section of a catheter being delivered retrograde and laterally flexed to a venous treatment site;

7 shows a partial cross-section of an assembly of the catheter having a bulbous tip and ring electrodes for treating a dilated vein according to the present invention.

8th shows a partial cross-section of an assembly of the catheter having a flush end at the functional end and ring electrodes for the treatment of a dilated vein;

9 shows a partial cross-section of an assembly of the catheter having a cap electrode for treating a dilated vein;

10 Figure 12 is a partial cross-sectional view of another catheter assembly having a cap electrode and a balloon for centering the placement of the electrode within the vein to be treated;

11a . 11b and 11c 12 partially depict cross-sections of other arrangements of the catheter having a flexible tip that is laterally flexed to effect an alignment between the electrodes of the catheter and the venous wall;

12a . 12b and 12c Figure 12 shows side and elevational views in partial cross-section of another catheter assembly having a balloon on one side of the catheter and longitudinal electrodes on the other side at the functional end of the catheter for bringing the electrodes into abutting contact with the venous wall;

13 shows an embodiment of the catheter having flexible electrodes which are deflected outwardly to increase the effective diameter at the functional end of the catheter according to the invention;

14 shows another arrangement of the catheter having a balloon and a flexible member with electrodes that are deflected outwardly to increase the effective diameter at the functional end of the catheter;

15a shows a cross section of an arrangement of the catheter, which in 14 shown having four equally spaced electrodes;

15b shows a cross section of an arrangement of the catheter, which in 14 4, which is preferably distributed to give two pairs of electrodes;

16 shows a partial cross-section of another arrangement of the catheter, which has four equidistant electrodes and which is administered retrograde to a venous treatment site;

17 shows a partial cross section of another arrangement of an over-the-wire balloon catheter having four equidistant distributed electrodes on the surface of the balloon

18 Figure 12 shows a cross section taken along lines 18-18 of the over-the-wire balloon catheter 17 ;

19 shows a partial cross-section of another arrangement of the catheter having electrodes located within the balloon member;

20 Fig. 3 is a side view of an embodiment of a catheter having flexible electrodes according to the invention coupled with a block diagram of a heat treatment system;

21 FIG. 4 is a partial side view of the functional end of the catheter used in FIG 20 and having electrodes bent outwardly to increase the effective diameter at the functional end of the catheter according to the present invention;

22 is a cross section along the lines 22-22 of the electrode for the in 21 shown Catheter;

23 is a cross-section along lines 23-23 in FIG 20 and Figure 4 shows a catheter having four equidistant electrodes according to the present invention;

24 is a cross section of another embodiment of the in 23 This embodiment has four electrodes preferably distributed according to the present invention to give two pairs of electrodes;

25 is a cross section of another embodiment of the in 23 shown catheter, this embodiment has two pairs of opposing electrodes according to the present invention;

26 is a cross-section of the catheter taken along lines 26-26 in FIG 20 ;

27 Figure 4 is a partial side view of the functional end of another catheter assembly having a balloon and a flexible member with electrodes;

28 is a cross-section of the catheter taken along lines 28-28 in FIG 26 ;

29 shows a partial cross-section of the venous system of the hemorrhoid region to be treated using the present invention;

30a . 30b and 30c 10 are side views of an embodiment of the catheter treating a venous treatment site within a dilated vein according to the present invention;

31 Figure 10 is a partial profile view of the anatomical region of the esophageal region, including a vein to be treated using the present invention;

32a . 32b and 32c Figures 10 are side views of an embodiment of the catheter constructed and administered to a venous treatment site within a dilated vein for treatment using the present invention.

Detailed description the embodiments

As shown in the exemplary drawings, the invention relates on the intravenous treatment from veins using a catheter to at least one electrode to a venous To bring treatment site. As used herein, similar reference numbers will be similar elements in the various embodiments of the refer to the present invention to be discussed. In addition, unless otherwise stated, the term functional ends on the direction towards the treatment site in the patient and the term connection end refers to the direction of away from the treatment site in the patient. The invention is related to the treatment of the venous System of lower extremities to be discribed. It is understood, however, that the invention not limited to this and can be used to repair veins in other parts of the body, such as hemorrhoids, oesophageal Varices and venous Drainage Impotence of the penis to treat intraluminally. Farther It is understood that although the invention as RF energy from the electrode also other forms of energy, such as Microwaves, ultrasound, direct current, circulating heated liquid, bright light and laser can be used, and that of one Resistance coil or Curie point element generated thermal energy can also be used.

A partial cross section of a dilated lower limb vein, which has incompetent valves, is in 1 shown. These veins are often located in muscle tissue. Veins have bicupsidal valves, and in a normal, competent valve, each valve leaflet forms a sac or reservoir for blood, with each valve leaflet forming a sac or reservoir of blood which, under pressure, forces the three surfaces of the valve leaflet together, one backward To prevent flow of blood and to allow a forward flow to the heart. The arrow leading out of the top of the vein represents the forward blood flow back to the heart. The venous valves prevent the backward flow while pushing the blood forward through the venous lumen and back to the heart.

When an incompetent flap encounters reverse flow, the valve is unable to close, the valve leaflets do not seal properly, and backward blood flow can occur. Incompetent valves may result from dilation of dilated veins. When the valves fail, increased pressure is exerted on the lower veins and lower valves of the veins, which in turn aggravates the failure of these lower valves. A cross-sectional view of a dilated vein taken along lines 2-2 of FIG 1 is in 2 shown. The leaflets can undergo a slight separation at the junction because of the thinning and stretching of the venous wall at the valve leaflets.

The method of using the present invention for the minimally invasive treatment of venous insufficiency may be accomplished using a catheter 10 be performed to electrodes 12 to the venous treatment site to restore the competence of a vein. An arrangement of the catheter 10 to the electrodes 12 to bring to the venous treatment site is in 3 shown. The electrodes 12 can use two RF ring electrodes 14 and 16 to be at the functional end 11 of the catheter 10 are localized. These and other arrangements of the catheter 10 will be described later in more detail. It is further contemplated to use the method with any suitable apparatus for applying radiant energy, thermal energy, or other forms of energy to heat and shrink the venous tissue in the repair or reconfiguration of the incompetent veins to restore venous function or valve competence , A particular discussion will be directed to the treatment of incompetent and varicose veins in the legs, although the method of the present invention is well suited to treat veins in other parts of the body.

at In the treatment of lower limb veins, the patient typically becomes placed on a treatment table, with drooping Feet, to to fill the veins of the leg. The leg of the patient is pretreated with antiseptic solution. A percutaneous insertion gets into the vein using the well-known Seldinger technique introduced, to gain access to the saphenous vein or deep venous system. Alternatively, a venous shortening used to gain access to the vein to be treated. The Procedure for repair of incompetent veins may be from a qualified Doctor with or without fluoroscopic or ultrasound observation or under direct visualization performed become. Furthermore could The doctor will touch the treatment site to locate the patient Catheter and the treatment site during the procedure to determine if the superficial Venous system is treated.

The catheter 10 could be run within the vein after introduction through the introducer and be advanced through this to the venous site. The wire is advanced antegrade to the venous treatment site, such as the height of the next incompetent venous site to be repaired. The catheter is then inserted over the wire and led up the leg through the vein to the level of the venous portion where backward flow occurs. In any case, the catheter brings 10 the electrodes 12 to the venous treatment site. Fluoroscopy, X-ray, ultrasound or similar visualization techniques can then be used to direct the specific placement of the catheter and confirmation of position within the vein. X-ray contrast material may be injected through or around the catheter to identify the incompetent vein sections that are to be repaired.

From the antegrade approach, the catheter can be pushed through the venous valve so that the electrodes are positioned over the flap of the incompetent vein segment that is to be treated. The catheter 10 moves antegrade through the venous valves, as in 3 shown, and is positioned so that the electrodes 12 near a dilated section of the vein to be treated. The electrodes can be positioned so that they protrude beyond the incompetent venous valve. When the electrodes 12 of the catheter 10 are positioned at the venous treatment site, the RF generator is activated to provide suitable RF energy, preferably at a selected frequency from a range of 250 kHz to 350 MHz. A suitable frequency is 40 MHz. A criterion for the selection of the applied frequency is the minimization of coagulation in the vein. Another criterion is the control of the spread and depth of the thermal effect in the tissue. The extent of heating or the depth of penetration into the tissue generally increases with lower frequencies and decreases as the frequency increases. A microprocessor may be used to select a frequency for the treatment of various veins according to the above criteria. For example, the microprocessor may include a table stored in memory to associate particular frequencies for treating varicose veins and venous diameters according to the criteria for minimizing coagulation with control of the spread and depth of the heating effect. The energy emitted by the electrodes is converted to heat within the venous tissue. As the temperature of the venous tissue increases, the venous tissue begins to shrink. The shrinkage is due in part to dehydration and structural transfiguration of the collagen fibers in the vein. Although the collagen is compressed during this process, the collagen still retains some elasticity. When RF energy is applied near the location of the dilated vein and venous valve, the shrinkage of the vein can restore valve competence by reducing dilatation, which prevents the proper functioning of the venous valve.

The functional end 11 of the catheter 10 near the electrodes 12 physically limits the extent of shrinkage. The functional end 11 is preferably sufficiently dimensioned or enlarged to prevent complete ligation of the vein. Other measures, such as an inflatable balloon, may be used to mechanically limit the extent of vein shrinkage.

Venous dilation is reduced after the application of RF energy from the electrodes 12 the surrounding venous tissue is heated to cause shrinkage. RF energy is no longer applied after sufficient vein shrinkage has occurred to relieve dilation of the vein near the valves to restore venous function or valve competence. Sufficient shrinkage can be detected by fluoroscopy, external ultrasound scanning, intravascular ultrasound scanning, impedance monitoring, temperature monitoring, direct visualization using an angioscope, or any suitable method. For example, the catheter 10 be configured to provide X-ray contrast medium to allow visualization by fluoroscopy to assess the state of the vein and the ratio of the catheter to the treatment area of the vein during the shrinking process. As an alternative to fluoroscopy, external ultrasound techniques such as B-scanning using certain ultrasound signals from different angles or intravascular ultrasound may be used to obtain a multidimensional view of venous shrinkage at the treatment site, which enhances the detection of uneven shrinkage in the vein , An angioscope can also be used to directly visualize and determine the extent and level of venous shrinkage.

After treatment, the junction and valve leaflets of the venous valves should be closer together, with less clearance or prolapse, indicating restoration of valve competence. A cross section of the venous valve after treatment with RF energy is in 4 shown. Flap competence can be determined by contrast injection or Doppler probe measurement.

A Considerable shrinkage can be achieved very quickly, depending on the specific treatment conditions. As the shrinkage with At a fairly fast rate, RF energy becomes energy preferably applied at low levels. As previously discussed, The frequency of RF energy is selected to minimize coagulation and the propagation of the heating effect at the treatment site to control. The properties of the treatment site, such as temperature, can be monitored be to a feedback control for the RF energy available to minimize coagulation. Other techniques like impedance monitoring and ultrasound pulse echo be used in an automated system, which the application of RF shuts off energy from the electrodes to the vein section, when a sufficient shrinkage of the vein is detected and overheating and to avoid cauterization of the vein. Monitoring these values in an automated feedback control system for RF Energy can also be used to spread, including Depth to control the heating effect. In all cases will The application of RF energy so controlled that the venous tissue is sufficiently shrunk to restore the competence of the venous valve and to get.

After treatment of the vein section in 3 shown is the catheter 10 moved to the next lower venous valve, which suffers from insufficiency, as in 5 shown. The electrode 12 Can be used in conjunction with 3 discussed being placed over the venous valve. However, an alternative placement of the electrode 12 be used. For example, as in 5 shown is the electrode 12 positioned just below or retrograde to the valve leaflets of the venous valve. The placement of the electrode under the valve when RF energy is applied may be beneficial in minimizing the effect of localized RF heating of the thin valve leaflets of the venous valve while still achieving vein shrinkage to restore vein function or valve competence.

If the catheter with a fluid delivery lumen equipped, can be a cooling fluid through the delivery lumen during RF heating to the bloodstream of the treated vein become. The administered coolant Minimizes any heating effect on the blood and reduces it the risk of heating the blood to the point of coagulation. The liquid can through openings, along the side of the catheter near the end of functioning and the Are formed electrodes are administered.

While the method has hitherto been described as restoring the valve competence, it is not limited thereto. A contiguous axial portion of a dilated vein can be treated by application of RF energy along the dilated venous segment, even if the segment is extensive. The dilated vein is shrunk and reduced to a normal diameter under the controlled application of RF energy in accordance with the present invention. Such a treatment can be used in the cosmetic treatment of varicose veins. Furthermore, a thickening of the vein can occur during treatment, which may reduce the likelihood of varicose veins recurrence and venous insufficiency.

The catheter 10 can be repositioned to treat as many vein sections and valves as necessary. RF energy is applied to each section of the vein that is to be repaired until all of the desired vein sections have been repaired and the flaps have been made competent. Multiple incompetent valves and insufficient or dilated vein segments can be treated and repaired during a single minimally invasive procedure. If desired, a second introducer can be inserted into the limb of a patient to reach either the deep or superficial venous system, which still needs to be treated. The catheter can then be used to treat the incompetent vein sections in the other venous system.

Instead of the antegrade approach, as in 3 and 5 As shown, the catheter may also deliver the electrodes from a retrograde direction to the venous treatment site. The catheter 10 is introduced through the skin and into a vein in a retrograde direction. The catheter 10 can penetrate the vein above and adjacent to the incompetent vein segment to be treated. The electrodes are advanced until contact with the valve leaflets of the venous valve is observed by fluoroscopy, ultrasound, or other detection technique. The catheter is then gently withdrawn to allow treatment of the dilated vein segment. The electrodes are activated to deliver RF energy to the venous tissue and shrink the vein. The shrinkage of the vein can be limited to prevent ligation and allow continued vein function. The outer diameter of the catheter or an extendible member can be controlled to limit the size of venous shrinkage.

More specific delivery of RF energy to the venous valve connecting junctions can be effective in restoring venous function and valve competence. The catheter 10 may be configured to position the electrodes within the vein and to place the electrodes against the vein portion to be repaired. The catheter is capable of being bent, twisted or otherwise moved to allow proper placement of the electrode. Alternatively, a permanent bend may be formed near the functional end of the catheter, which may then be rotated and twisted to achieve the desired abutment. Manipulation of the functional end of the catheter allows for preferential heating along the venous wall that is treated, if desired, where the electrodes are placed closer to one side of the venous wall.

The electrodes 12 on a curved catheter, as in 6 can be placed in close proximity to the venous walls near the junction in a retrograde approach. The catheter may also be manipulated to place the electrodes in close proximity to the venous valve junctions to achieve local shrinkage near the junctures to treat any separation of the junctions for venous dilation and restore venous function and valve competence. After the treatment of one end of the valve junction, the catheter can then be moved to place the electrodes near the junction at the opposite end of the valve. Therefore, upon selective application of RF energy to one side of the venous wall, the catheter can be rotated 180 degrees to apply energy to the other side of the venous wall to promote venous function recovery. Alternatively, an asymmetric balloon, as in 12 or any other such positioning member may be used to string the electrodes to the vein portion to be treated. The balloon may be deflated and then inflated to allow for easier movement and repositioning of the catheter.

To Treating one section of the vein allows the catheter to advance to the next level the next Section of the vein to be repaired. The same procedure then would for each subsequent instance the venous repair are repeated. The treatment can be several Repeat times until adequate venous shrinkage is achieved is to the venous Restore function and flap competence while the Vein throughout remains. After completion of the treatment the incompetent vein sections will the catheter containing electrodes removed from the vein.

An arrangement of the catheter 10 with electrodes 12 at the end of the function 11 , which causes local heating of the surrounding venous tissue and shrinkage of the vein as described, as shown 3 and 5 , is more detailed in 7 shown. The electrodes 12 close two ring electrodes 14 and 16 one. The end ring electrode 14 can act as the active electrode and the ring electrode 16 can act as the return electrode or vice versa. The end ring electrode 14 is preferably removed from the tip of the functional end of the catheter, which may be made of plastic or other non-conductive material. That through the ring electrodes 14 and 16 RF field generated should not extend beyond the end of the catheter. The inert non-conductive tip of the functional end of the catheter helps to prevent shrinkage beyond the end of the catheter by limiting the extent and formation of the RF field. This non-conductive tip acts as a shrinkage limiting mandrel to prevent veins from shrinking to a diameter less than the catheter tip, and may be 2 to 25 mm across the electrode 14 transcend. Both electrodes 14 and 16 are preferably made of stainless steel. An insulator material 18 is located between the end electrode and the ring electrode. The catheter 10 and the electrodes 12 should be made of materials that allow visualization under fluoroscopy, X-ray, ultrasound or other imaging techniques. For example, the catheter 10 be configured to administer an X-ray contrast medium to allow visualization by fluoroscopy. Contrast media injected into the vein can be used to determine the state of the vein and the ratio of the catheter to the area of treatment of the vein by means of phlebography during the shrinking process.

The catheter 10 closes a stranded, twisted center conductor 20 surrounded by an insulation layer 22 a, which is preferably made of TFE Teflon ^® . A silver-coated copper shield 24 surrounds the isolated center conductor and gives the catheter shaft flexible and twistable properties. A scabbard 26 covers the copper shield 24 from. The scabbard 26 is preferably made of an electrically lofted, biocompatible material with a low friction coefficient, such as Teflon ^®, manufactured. The center conductor 20 is at a power source 64 , such as the RF generator, connected to deliver RF energy to the electrodes.

While the electrodes 12 As ring electrodes have been described, other electrode configurations and arrangements may be used. For example, equidistantly distributed longitudinal electrodes can be used to provide omnidirectional and circumferential shrinkage and minimize longitudinal contraction of the vein. The electrodes form a circumferential RF field around the electrode.

It is understandable, that although a bipolar arrangement is described, also a monopolar arrangement can be used. In a monopolar Application is an internal electrode, such as a grid or wire electrode, into a hollow of the body introduced by the patient. An outer electrode with a much larger surface than the inner electrode is placed on the outer surface of the patient's body, near the treatment site. For example, an external metal plate to the skin over the region to be treated by the inner electrode is placed. The electrodes are connected to an RF generator, which is an electrical generator Field within the patient's body generated. Because the surface the inner electrode is much smaller than that of the outer electrode is the Density of electric field around the inner electrode around much higher. The electric field reaches its highest density between the two Electrodes in the region near the inner electrode. The increased Density of the field around the inner electrode allows a local Heating the tissue surrounding the inner electrode. The extent of heating can be dependent be of factors such as the impedance and the dielectric constant of the treated tissue.

The end ring electrode 14 and the ring electrode 16 are preferably between the sensors 60 , for measuring the values such as impedance, localized. When measuring the impedance, as will be described in more detail later, the area between the electrodes often provides the most relevant data. It is understandable that the sensors 60 can be used to measure other values including temperature and ultrasonic signals. Furthermore, the positioning of the sensors 60 on the catheter 10 vary, depending on the measured value. For example, if the temperature is being measured, it may be desirable to place the sensor on or immediately adjacent to the electrode. The temperature sensor can measure the temperature of the tissue around the electrodes. When echo signals from pulsed ultrasound are measured, the sensors can be placed between the electrodes or at the tip of the catheter. In the measurement of pulse neuroprotective signals, the catheter is preferably rotated to resolve an image of the environment surrounding the catheter and sensors.

The sensors 60 Measure parameters that can be used to determine the extent of venous shrinkage. For example, the sensors 60 Sensor electrodes that are the impedance of the venous tissue, in contact with the terminal electrode 14 and the ring electrode 16 stands, measure. A constant RF current is supplied by the active end electrode 14 to the return electrode 16 emitted. The impedance can continue directly between the electrodes 14 and 16 be measured. The voltage across the electrodes is measured by the sensor electrodes to detect the impedance of the volume between the electrodes. The measured voltage is proportional to the impedance Z between the electrodes, where Z = V / I and the current I is constant. The impedance changes as a function of the diameter of the vein, as there is less with decreasing venous diameter blood and less conductivity. As the volume decreases due to shrinkage, the amount of conductive volume between the electrodes decreases and the increased impedance causes a corresponding increase in the measured voltage. This technique makes it possible to measure venous shrinkage in relative terms. The signals of the sensor electrodes can be in a monitor or microprocessor 62 be guided, the control signals to the RF generator 64 to control the application of RF energy to the electrodes according to the measured relative impedance. Alternatively, the signals from the sensor electrodes can be visually displayed on a monitor to allow manual control by the physician.

In an alternative arrangement, the sensors 60 instead, be temperature sensors, such as thermistors. The temperature sensors may be included on the catheter near the electrodes on the functional end to monitor the temperature surrounding the electrodes and the treated venous section. The application of RF energy from the electrodes may be halted when the monitored temperature reaches or exceeds the specific temperature at which the venous tissue begins to shrink. The signals from the temperature sensors can be in the microprocessor 62 to control the application of RF energy to the electrodes according to the monitored temperature.

Instead of sensor electrodes or thermistors, another arrangement includes ultrasonic piezoelectric elements serving as sensors 30 emit pulsed ultrasonic waves. The piezoelectric elements are operated in a pulse-echo fashion to measure the distance to the venous wall from the catheter shaft. Again, the signals of the pulse echo would be in the microprocessor 63 or in a monitor to allow manual control, and the application of RF energy would be controlled according to the calculated distance between the catheter and the vein wall.

The functional end 11 of the catheter 10 , as in 7 is rounded to provide an atraumatic tip that minimizes any accidental injury while manipulating the catheter in the vein. The functional end 11 of the catheter 10 may have increased dimensions limiting the extent of local venous shrinkage. An enlarged atraumatic tip can be achieved by using a bulbous shape as the functional end 11 be achieved. Various great functional ends 11 and electrodes 12 Can be separate from the catheter 10 for later assembly with the shaft of the catheter 10 can be made, so that a single catheter shaft can be used with functional ends that have a variety of diameters. A functional end with a specific size or shape could then be catheterized 10 be used, depending on the type of vein treated. For example, certain larger veins have a diameter of seven to eight millimeters (mm), while other veins only have a diameter of 2 to 3.5 mm. Alternatively, the functional end 11 and the ring electrodes 14 and 16 flush with the stem of the catheter, as in 8th shown. Other methods, such as monitoring the extent of shrinkage by fluoroscopy, can be used to control the extent of shrinkage. In other respects, the structure of the catheter is in 8th similar to the one in 7 as discussed previously.

Another arrangement of the catheter 10 closes an end electrode 14 one which is a cap electrode which is on the top of the working end 11 of the catheter 10 is formed. As in 9 shown is the end electrode 14 preferably made of stainless steel. The end electrode 14 acts as the active electrode and the ring electrode 16 acts as the return electrode. The cap electrode 14 of the catheter 10 is rounded to provide an atraumatic tip to minimize any injury to the surrounding venous tissue while manipulating the catheter through the vein. The outer diameter (OD) of the electrodes 14 and 16 is in an example size 7 French, or about 2.3 mm. Alternatively, the cap electrode and the functional end 11 of the catheter 10 have enlarged dimensions from the rest of the catheter. The electrodes and the function end essentially close as in 9 shown flush with the rest of the catheter. The shielding sheath 26 covers the silver-coated copper shield 24 of the catheter and the sheath is flush with the outer diameter of the ring electrode 16 , An insulation tube 18 is located between the end electrode and the ring electrode. At the functional end of the catheter becomes a filling with solder 28 between the center conductor 20 and the end electrode 14 educated. The center conductor 20 is from the ring electrode 16 by means of insulation 22 isolated. The end cap electrode in 9 does not limit the shrinkage of the vein adjacent to the tip of the catheter and therefore may allow the vein to shrink completely if desired.

In another arrangement, an inflatable balloon 40 coaxially placed over the shielded shaft, the catheter 10 and electrodes 14 and 16 center within the venous lumen to prevent unwanted electrode contact with the venous lumen, which could otherwise result in uneven heating of portions of the venous lumen. As in 10 shown is the balloon 40 to the electrode 16 located adjacent, which is closer to the connection end of the catheter. The balloon 40 is preferably extendable and compliant and made of an elastic material, such as latex, which can provide intermediate diameters. The balloon may be filled with saline or other conductive solutions.

As in connection with 6 For example, it may be desirable to maintain selective sequencing between the electrodes and the venous tissue at the treatment site. An arrangement of the catheter 10 , shown in 11a . 11b and 11c , is able by a shaft bending wire 29 to be bent. The catheter contains a silver-coated copper shield 24 and an outer insulation layer. The electrodes 12 may be four circumferentially distributed longitudinal electrodes, as previously discussed. 11a and 11c show only two of the four longitudinal electrodes. The catheter 10 also contains a stiffening jacket 25 which is formed around the catheter shaft except for the functional tip of the catheter. A central hollow wire lumen 27 runs through the length of the catheter. The shaft bending wire 29 has a stiff bend formed near its working end and is passed through the wire lumen 27 of the catheter. The end of the wire 29 after the stiff bend that extends through the tip of the functional end of the catheter is preferably flexible and flexible. The stiffening jacket 25 prevents the catheter shaft from passing through the shaft bending wire 29 is bent until the bending wire reaches the functional end of the catheter. The bend in the bend wire 29 moves the function end 11 of the catheter to one side. The electrodes can then be selectively placed in alignment with the specific venous tissue to be treated. A contrast medium may also be delivered to the treatment site through the lumen 27 be administered. Furthermore, a cooling fluid or liquid may be delivered to the treatment site through the lumen 27 to be brought. side openings 30 for the lumen can be at the functional end near the electrodes 12 be formed to administer the contrast agent and the cooling liquid. Alternatively, the lumen could 27 be closed at the top of the working end of the catheter, to allow it, that an injection of contrast or cooling fluid from the side openings 30 is forced. A closing of the lumen 27 At the top, continue to allow the bend wire 29 can be made stiffer without concern that the stiffer wire extends beyond the catheter.

Another arrangement uses an asymmetric balloon 40 to the electrodes 12 at the end of the function 11 of the catheter to one side. The electrodes 12 are a pair of longitudinal electrodes located on one side of the catheter. As in 12a and 12b shown is the balloon 40 located on the opposite side of the catheter. If the balloon 40 is inflated, becomes the opposite side of the function end 11 , which receives the longitudinal electrodes, moved in tandem with the venous tissue to be treated. After treatment of the dilated vein section, the balloon may be deflated and the catheter removed from the vasculature. It should be noted that other mechanisms for bending the functional end of the catheter can be used. For example, a flexible actuation wire may be used on one side of the catheter to perform a function similar to that of the asymmetric balloon. The catheter further includes the sheath 26 , the shielding 24 and the TFE insulation 22 and is similar in structure to the previously discussed embodiments.

In one embodiment of the present invention, as in 13 shown, the catheter closes 10 bendable electrodes 12 in the form of four conductive, elongated elements. The bendable electrodes 12 are similar to longitudinal electrodes formed around the circumference of the catheter, but are not attached to the catheter. The catheter itself may fit for the procedure through a sheath of suitable size. For example, a French sheath approximately 3mm in diameter may be used. The functional end 11 the catheter closes a moving tip 31 one manually through a diameter actuator 33 , which is located at the connecting end of the catheter, is controlled. The moving tip 31 is with the diameter actuator 33 by means of a central wire (not shown) passing through the catheter. The diameter actuator 33 may be threaded onto the connecting end of the catheter. Maneuvering the actuator 33 into and out of the connecting end of the catheter causes a corresponding movement in the movable tip 31 at the functional end of the catheter. When the moving tip 31 through the diameter actuator 33 is pulled in the direction of the connection end, the electrodes 12 bent outwards. The bendable electrodes 12 preferably expands to treat veins up to 8 mm. When the moving tip 31 by means of the diode actuator 33 are pushed out, the bendable electrodes 12 withdrawn to the shaft of the catheter. Permanent contact of the electrode with the venous wall can be maintained.

The extent of shrinkage can be controlled by the effective diameter of the catheter and electrode combination. The electric the 12 can be bent radially outward as part of the effective diameter of the catheter to come in alignment with the vein wall. When RF energy is applied, the vein begins to shrink to the effective diameter of the catheter. The effective diameter of the catheter is lowered under the physician's control to control the extent of shrinkage. When the effective diameter is lowered, the electrodes retain the lining to the venous tissue. As before, the extent of venous shrinkage can be monitored by fluoroscopy or any suitable method. After shrinking the vein to the desired diameter, the application of RF energy from the electrodes is adjusted. The desired diameter may be the final effective diameter of the catheter passing through the bent electrodes 12 is defined.

The electrodes 12 can be made of spring steel or nitinol, so that the electrodes 12 inclined to be biased to return to a reduced diameter profile. If the entire length of the flexible longitudinal electrode is conductive, insulation may be sufficient 35 over the majority of the electrode surface to prevent any unwanted heating effects. The ends of the electrodes are isolated from each other to prevent generation of variable field densities at the ends, especially as the effective diameter increases, which could generate even greater field inequalities between the ends and the arcuate center section. The insulation 35 may be polyimide or another type of insulating film. Insulation provided along the back of the electrodes away from the vein wall 35 It also prevents the heating of the blood that flows in the vein, which should also reduce the likelihood of coagulation. The remaining exposed area of the electrode is preferably the area that contacts the vein wall during the alignment. The heating effect is then focused along the wall of the vein. The exposed surface of the electrode should be as large as possible while maintaining continuous distance between exposed portions of the electrode along the perimeter of the effective diameter. The larger the exposed surface of the electrodes that are lined up against the vein wall during shrinkage, the larger the surface of the venous wall that is affected by the electric field generated by the electrodes.

Another arrangement of the catheter 10 , as in 14 shown, includes flexible, elongated elements 32 one whose one end in the functional end 11 anchored to the catheter and the other end is slidably connected to the catheter in the direction of the connection end. The catheter in 14 is similar to that shown in FIG 13 is shown with the exception that instead of the elongate elements acting as electrodes themselves, the electrodes 12 on the elongated elements 32 are localized. The elongated elements 32 preferably close a flat central area 34 for the electrodes 12 one. The central area 34 remains essentially flat while the elongated elements 32 be deflected outwards and bent. The essentially flat central area allows a more even contact with the vein wall. The flat area creates a larger surface area to make contact between the electrode 12 on the elongated element and the vein wall. It is understandable that the flat area 34 not centrally on the elongated element 32 must be localized. The flat area should be located so that it is the first area that contacts the wall of the vein. The elongated elements 32 , in the 14 are shown are with the sliding sheath 36 connected along the exterior of the catheter shaft. When the electrodes 12 moved radially outward and inward becomes the slidable shroud 36 moved to and from the end of the function.

The balloon may be between the catheter shaft and the elongated element 32 be located. Manual manipulation of the slidable shroud is not necessary in this arrangement and the shroud does not have to travel a substantial distance along the catheter. The balloon 40 is inflated and comes with the elongated elements 32 in contact. If the balloon 40 continues to be inflated, the electrodes are 12 moved outward in a radial direction, while the elongated elements through the expanding balloon 40 be distracted and bent. The balloon is preferably inflated using a nonconductive liquid, especially when the elongate elements contain the electrodes, or when the elongate elements themselves are conductive to act as electrodes. When the correct diameter for the electrodes is reached, inflation of the balloon stops and the application of RF energy begins. The balloon 40 Covers a larger surface area of the venous treatment site and ensures proper electrode placement relative to the vein wall while controlling the extent of venous shrinkage. More precise control over the shape and circumference of the balloon may also be possible using bendable elements. When RF energy is applied, the vein begins to shrink. The effective diameter of the catheter is reduced under the physician's control to control the extent of shrinkage. When the effective diameter is lowered, the electrodes keep the start hung on the venous tissue at. The application of RF energy is stopped after the vein has been shrunk to the desired diameter, which is the final effective diameter, determined by the diameter of the balloon 40 and the deflected elongated elements 32 is defined. The balloon 40 is then emptied to a minimum profile. The elongated elements 32 are preferably made of spring steel or Nitinol, so that the elongated elements have a bias to return to a reduced diameter profile when the balloon is deflated.

A cross-sectional view of the electrodes 12 out 14 along lines 15-15 will be in 15a shown. In the four-electrode configuration, it is a preferred arrangement, the electrodes 12 equidistant along the circumference of the catheter. The polarity of each electrode is preferably opposite to the polarity of the immediately adjacent electrode. Therefore, the alternate electrodes would create a uniform RF field along the circumference of the catheter. In a different arrangement, as in 15b As shown, two effective pairs of active electrodes of opposite polarity would be formed along the circumference of the catheter as adjacent electrodes moved closer together. While one RF field would still be formed along the entire circumference of the catheter, the RF field would be strongest between the closest adjacent electrodes of opposite polarity. The shrinkage of the vein would be concentrated where the RF field was strongest.

In one of the in conjunction with 14 discussed alternative arrangement, the outer sheath may be 36 extend along the length of the catheter to allow the operator or clinician to mechanically control the effective electrode diameter during the application of RF energy, such that it has its own balloon 40 is not necessary. A movement of the displaceable sheath in the direction of the functional end 11 The catheter causes the electrodes to deflect and flex radially outward to an increased diameter. The outer sheath 36 For example, a preset distance can be moved to cause the electrodes to bow outward to a known diameter. An outward bending of the electrodes also places the electrodes in line with the venous tissue to be treated. Moving the sheath 36 in the direction of the connecting end of the catheter, the electrodes pull out into or out of the vein prior to insertion or withdrawal and push it against the catheter. Sheath movement controls the diameter of the catheter assembly for proper treatment of venous lumens of varying diameters and for providing varying degrees of venous shrinkage. For example, the electrodes could be brought into contact with the venous tissue and the effective diameter mechanically reduced to control shrinkage while applying RF energy.

In another arrangement, instead of the outer sheath, the ends the elongated one Elements that are otherwise attached to the outer shell would, slidably located within longitudinal slots or channels, which are arranged along the circumference of the catheter. The ends the bendable elements would within these channels slide in the direction of the functional end while the elements deflected outwards or bowed, and would to retreat towards the end of the connection to its original position Configuration to return.

In an alternative arrangement could the electrodes and the elongated ones Elements through a single wire grid or a screened one Electrode are replaced, preferably when RF energy in one monopolar configuration is administered. As before, the Balloon expand the grid electrode radially outward, in alignment with the vein wall. The balloon can also reduce the extent of venous shrinkage check.

An alternative method of changing the effective diameter of the catheters in 13 and 14 it is the electrodes 12 to move into direct contact with the vein wall. As the electrodes emit RF energy, the vein wall shrinks and pushes the electrodes inward toward the catheter. Venous shrinkage directly reduces the effective diameter, rather than the physician's active control, eliminating the need for sustained fine mechanical adjustments to the effective diameter. A mechanism such as a push rod or a fixed diameter balloon may be included to prevent further radial contraction of the electrodes at a specific effective diameter, thereby controlling and limiting the extent of venous shrinkage. This has the advantage of maintaining the alignment of the electrodes with the venous tissue so that the tissue is heated more than the surrounding blood without the physician having to constantly adjust the effective diameter of the catheter while using RF energy.

Other elements that are controllably expandable or extendible may be used to limit the shrinkage of the vein to a desired size. For example, spikes may pop out of the sides of the catheter ben to define a diameter limit for the shrinkage of the venous section. As another example, a bendable, conductive deflection wire may be located in one side of the catheter to achieve vein wall alignment. Furthermore, the non-expandable catheter shaft and the electrodes used in 7 can be used to limit the extent of venous shrinkage during the procedure. The vein would only shrink to the fixed diameter of the catheter.

Other Procedures can used with the catheter to maintain a sequencing. For example, a pressure cuff can be used to external Put pressure on the leg, to compress the treatment site, leaving the vein wall in contact with the electrodes. The arrangement of the electrodes with the venous tissue would maintained by the applied external pressure. Such External compression can be used when the superficial Veins are treated. Other than the aforementioned mechanical methods can also used to increase the size of the vein shrinkage check. Such non-mechanical methods include Control the time and temperature of venous RF treatment.

The functional end of the catheter 10 could be designed to have a diffraction near the working end, as in 11 so that the catheter can be rotated to create a stirring effect within the vein to achieve more uniform heating of the venous tissue for even greater shrinkage. Instead of permanent flexion, the catheter can also be made to provide a controllable flexion near the end of functioning. For example, the diffraction may be made of a shape memory metal, manipulatable by a system of wires, a rotatable shield, or a permanent bend in the catheter.

One another method of controlling the heat transfer to a more uniform To achieve heating is the use of an external constrictor bandage, to reduce the blood flow and the vein around the catheter at the venous To compress the treatment site. By reducing blood flow, either by external compression or by an intravenous inflated occlusive Balloon, the influence of blood flow through the vein, the heat away from the treatment site minimized. The heat transfer to the venous tissue during The procedure is less affected by blood flow and the rate of shrinkage the vein would therefore become more predictable. A sufficient pressure can also through the external constrictor bandage be prepared to cause the vein to be sequenced with the electrodes.

In a different arrangement, as in 16 shown becomes a closing centering balloon 40 used to restrain a stagnant accumulation of blood near the venous treatment site. A single occluding balloon 40 can be used in conjunction with the venous valve to hold back an accumulation of blood that is supposed to be heated, taking the electrodes 12 between the venous valve and the occluding balloon 40 are localized. Two occluding balloons (not shown) may be formed at each end of the electrodes to create a stagnant accumulation of blood at the venous treatment site away from the venous valve. Such an arrangement isolates and protects the venous valve when treatment of the valve is not desired. The occluding balloon may also be used to center the electrode within the venous lumen.

Although not on the arrangement of the occluding balloon, shown in 16 , limited, may be the catheter 10 continue electrodes 12 contained in a longitudinal manner around the circumference of the catheter around. This arrangement is similar to the embodiments used in conjunction with 13 and 14 In this case, however, the electrodes are fixed on the catheter and do not bend outward. This fixed diameter arrangement allows an RF field to be created along the circumference of the catheter. Such an arrangement may allow for contraction all around and avoid the elongated contraction of the vein. The particular positioning and orientation of the longitudinal electrodes is preferably as in FIG 15a shown.

An expansible balloon assembly, as in 17 shown contains the four longitudinal electrodes 12 that are in a longitudinal manner around the perimeter of the balloon 40 of the catheter 10 are arranged around. This arrangement is similar to the embodiments used in conjunction with 13 and 14 have been disclosed and described to allow for all-around shrinkage and minimize the elongated contraction of the vein. The particular positioning and orientation of the longitudinal electrodes is preferably equidistant, as in FIG 15a shown. The in 17 The catheter shown is an over-the-wire type in which the catheter passes over a guidewire 42 through a guide wire lumen 52 running. The catheter 10 also includes the braided shielding 24 holding the guidewire lumen 52 surrounds. A braided tube 54 is about the braiding 24 educated. The lumen 56 for the balloon 40 and the balloon tube 55 , surround the braided tube. The braid tube forms a sealing barrier against the guidewire lumen 52 Licking inflation fluid from the balloon lumen. The exterior of the catheter contains a restraint tube 57 that the connecting wires 20 that holds the electrodes 12 connect to an RF generator. A cross section of the shaft of the catheter 10 along the lines 18-18 in 17 , is in 18 shown.

In another arrangement, the electrodes are under the balloon 40 of the catheter 10 localized. This arrangement, she in 19 is shown and similar to that in the 17 and 18 shown, allows the conductive heating of the venous tissue. The in 19 The catheter shown is of an over-the-wire type, with the catheter over the previously inserted guidewire 42 running. This balloon is inflated and expands to contact the venous tissue. As previously discussed, the inflated balloon 40 Used to reduce the size of the vein shrinkage to the outer diameter of the inflated balloon 40 to control or restrict. The effective diameter can be achieved by selectively inflating and deflating the balloon 40 to be controlled. The inflator of the balloon 40 is preferably a conducting fluid, such as saline, so that a significant amount of RF energy is still transferred to the surrounding venous tissue. However, the inflator may absorb a certain amount of RF energy, which is then converted to heat. This diffusion of RF energy could provide greater control over the vein's shrinkage. Alternatively, a heating coil or a Curie point element could be used instead of the electrodes 12 used to directly heat the inflator, which in turn would conductively transfer the heat to the venous tissue.

An embodiment of the catheter 10 of the present invention with electrodes 12 at the end of the function 11 , causing a local heating of the surrounding venous tissue and the shrinkage of the vein, is in 20 shown. The catheter 10 includes electrodes 12 in the form of four conductive, elongated elements that can be bent outwards. The bent electrodes are formed along the circumference of the catheter, but not fixed to the catheter. The catheter itself is inserted through a sheath suitable for the procedure. For example, a French sheath having a diameter of about 2.3 millimeters (mm) may be used. The sheath is made of a biocompatible material with a low friction coefficient. The functional end 11 of the catheter includes a tip 15 attached to one end of each electrode, and the other end of each electrode is with the slidable sheath 36 connected along the exterior of the catheter shaft. The outer sheath extends down the length of the catheter to allow the physician to control the effective electrode diameter directly and mechanically during the application of RF energy. When the sliding sheathing 36 in response to a control actuator 33 moving forward and away from the working end, the electrodes become 12 radially outward or forced inward. The summit 15 remains substantially stationary while the slidable shroud is moved. Moving back the jacket 36 toward the junction end of the catheter, the electrodes retract before insertion or removal into or out of the vein and flatten them against the catheter. Moving the jacket 36 Forward in the direction of the functional end of the catheter causes a deflection and radially outward bending of the electrodes to an increased diameter. The contact area of the electrodes is bent outward while the opposite ends of the longitudinal electrode are moved closer to each other. The outer sheath may be moved a preset distance to cause the electrodes to bow outward to a known diameter. An outward bending of the electrodes also brings the electrodes in line with the venous tissue to be treated. By manipulating the slidable sheath to adjust the effective diameter of the catheter defined by the radii of the electrodes, the contact between the electrodes and the venous wall can be maintained while the vein is shrinking. The control actuator 33 is a switch, lever, wind-up control knob or any other suitable mechanism, preferably one that allows precise control over the movement of the sliding shroud. By using the control actuator to move the slidable sheath, the effective diameter of the electrode can be controlled to treat venous lumens of different diameters and to allow for varying degrees of venous shrinkage.

The summit 15 has a tip-like shape or may have any shape that allows movement of the catheter over the guidewire and through the bends in the venous vascular system. The tip-shaped tip can be made of a polymer with a low hardness, such as 70 Shore A. Alternatively, the tip may be made of a spring covered with a thin layer of polyethylene shrink tubing.

The extent of shrinkage is through controls the effective diameter of the catheter and electrode combination. The electrodes 12 are flexed radially outward, as part of the effective diameter of the catheter, so that they come in line with the vein wall. After contacting with the venous tissue and the effective diameter could be mechanically reduced to control the shrinkage while applying RF energy. The electrodes 12 are preferably operated as bipolar electrodes. When RF energy is applied to the electrodes, an RF field is created around the effective diameter of the catheter defined by the diffracted electrodes and the vein is heated and begins to shrink. The effective diameter of the catheter is reduced under the physician's control to control the extent of shrinkage. When the effective diameter is lowered, the electrodes remain in line with the venous tissue. The extent of venous shrinkage is monitored by fluoroscopy or any other suitable method. After shrinking the vein to the desired diameter, the application of RF energy from the electrodes 12 set. The desired diameter of the vein is the effective final diameter of the catheter, as by the deflected electrodes 12 Are defined.

The electrodes 12 have an elongated shape and can be made of stainless steel, spring steel, or nitinol, so that the electrodes 12 have a bias to return to a reduced diameter profile. The electrodes are rounded wires to allow flexing of the catheter at the functional end as it passes through the thin venous vasculature. The diameter of the electrodes is preferably between about 0.12 to 0.35 mm (about 0.005 to 0.015 inches), but may be up to 0.7 mm (about 0.03 inches). Other shapes, including rectangular wires with relatively large flat surfaces for contacting the vein wall may be used. Such rectangular wires have widths in the range of 0.12mm to 1.2mm (0.005 to 0.05 inches) and preferably between 0.35mm to 0.7mm (0.012 and 0.030 inches) to allow four to eight electrodes around the catheter shaft.

The entire length of the bendable longitudinal electrode is conductive and insulation 35 is provided over the majority of the electrode surface, as in 21 and 22 shown to avoid any unwanted heating effects. Only a small portion of the conductive surface is exposed to act as the electrode. The heating effect is greater as the electrodes are closer together because the electric field density (force density) is greatest at this point. The ends of the electrodes are insulated from each other to avoid the generation of electric field densities that are larger at the ends compared to those around the center of the electrode. As the effective diameter increases, greater field inequalities could be created between the ends and the outwardly-bowed center sections if there were no insulation. The insulation 35 may be polyimide, parylene or another type of insulating material. The insulation 35 Also, which is attached along the sides and rear of the electrodes opposite to the vein wall prevents the heating of blood flowing in the veins, which should also decrease the likelihood of coagulation. If the wire had a rectangular shape, then the exposed area, which functionally acts as an electrode, would occupy only one side of that wire. As in 22 shown, the insulation can 35 surrounding the electrode, further covering the peripheral edges of the exposed side of the electrode to further isolate the blood flow from unwanted heating effects.

Of the exposed area of the electrode is preferably the area that the vein during the baying directly contacted. The heating effect then becomes focused in the vein wall. The exposed surface area the electrode should be as big as possible be while a stable one Distance between the exposed areas of the electrode along the extent of the effective diameter is maintained. The bigger the exposed surface area of the electrodes during the the shrinkage are lined up to the vein wall, the larger it is the surface area the vein wall, which is generated by the electric generated by the electrodes Field is affected. The exposed surface area for the electrode may be essentially flat to the uniform contact with the vein wall to improve and to control the diameter of the vein.

A sensor 60 and a small thermocouple for measuring the temperature is applied to the electrode 12 appropriate. As in the cross-sectional view in 22 shown is the temperature sensor 60 soldered through a hole in the electrode, so that the sensor is substantially flush with the exposed surface of the electrode. The sensor can accurately measure the temperature of the venous wall in alignment with the exposed electrode surface. The wirings to the sensor are mounted on the opposite side of the electrode, which is insulated.

A cross-sectional view of the electrodes 12 out 20 along lines 23-23 is in 23 shown. In the four-electrode configuration, it is a preferred embodiment, the electrodes 12 evenly spaced along the circumference of the catheter. Although the catheter described It is understood that the catheter may include a different number of electrodes, for example, six, eight or more bendable electrodes, to reduce the gap between the electrodes and reduce the amount of current flowing through the electrodes it is necessary to heat the venous tissue. The polarity of each electrode is preferably opposite to the polarity of the directly adjacent electrodes to permit in all directions and circumferential shrinkage of the vein. Therefore, the alternating electrodes would create a relatively uniform RF field along the circumference of the catheter. In another embodiment, as in 24 As shown, two effective pairs of opposite polarity active electrodes would be formed along the circumference of the catheter as the adjacent electrodes moved closer together. While one RF field would still be generated along the entire circumference of the catheter, the RF field would be strongest between the closest adjacent electrodes of opposite polarity. The shrinkage of the vein would be concentrated where the RF field would be strongest.

In another embodiment, the RF field may be focused using two pairs of electrodes arranged to be isolated from each other. For example, as in 25 As shown, the positive electrodes of each pair of electrodes would be adjacent and no field would be formed along the perimeter of the effective diameter between the two pairs of electrodes. Opposing RF fields are made by the two electrode pairs to create two discrete heating zones along the circumference. These heating zones may be aligned to cause heating of isolated areas within the veins (ie, not circumferential) to direct treatment to the specific area of variceal bleeding of the vein. Specific or isolated occurrences of variceal bleeding may be treated by such directed application of RF energy to the vein.

The functional end of the catheter further includes a guidewire lumen 39 to the guide wire 13 take. The tip of the guidewire 13 is preferably rounded. The guidewire lumen 39 is preferably insulated to avoid or minimize any coupling effects affecting the electrodes 12 could have on the guidewire. The guidewire may be removed prior to application of RF energy to the electrodes. A cross-sectional view of the catheter 10 along lines 26-26 in 20 is in 26 shown. The guidewire 13 becomes central within a guidewire lumen 38 shown localized. The guidewire lumen 38 is surrounded by a layer of insulation material 22 , which in turn is surrounded by a Kupferschirmung 24 for stability and rigidity, as well as for enabling flexible twistability of the catheter. An insulation sheath 26 covers the copper shield 24 and also contains the conductive connections 20 to the electrodes. In a bipolar arrangement, the conductive connections 20 an opposite polarity. In an over-the-rail type of catheter, the guidewire is on the outside of the catheter until it reaches the functional end of the catheter, whereupon the guidewire merges into the guidewire lumen. The guidewire lumen 39 is preferably within the insulation material 22 localized to the guidewire 13 electrically from the electrodes 12 to isolate. The guidewire lumen may also allow the administration or perfusion of a drug or cooling fluid during the application of RF energy to the treatment area.

Another arrangement of the catheter 10 , as in 27 shown, includes bendable elongated elements 32 one with the end in working end 11 anchored to the catheter and the other end are slidably connected to the catheter, in the direction of the connection end. The in 27 shown catheter is similar to that in 20 with the exception that instead of elongate elements which themselves act as electrodes, the electrodes 12 on the elongated elements 32 are localized. The elongated elements 32 preferably include a flat central area for the electrodes 12 one. The central area remains essentially flat, while the elongated elements 32 deflected and bent outwards. The essentially flat central area allows a more even contact with the vein wall. The flat area creates a larger surface area to the contact between the electrode 12 on the elongated element and the vein wall. It is understood that the flat area is not central on the elongated element 32 must be localized. The flat area should be located so as to be the first area that contacts the vein wall. The elongated elements 32 at the functional end of the catheter are connected to a movable tip, which is manually controlled by a diameter actuator located at the connecting end of the catheter. The moving tip 17 is with the diameter actuator via an actuation wire 37 connected, which runs centrally through the catheter, as in 28 shown. The diameter actuator may be wound onto the connection end of the catheter. Maneuvering the diameter actuator into and out of the connection end of the catheter causes a correspondence over the actuation wire rende movement in the movable tip at the functional end of the catheter. When the moving tip 17 through the diameter actuator 33 is pulled in the direction of the connection end, the electrodes 12 bent outwards. The bendable electrodes 12 preferably expand to treat veins up to a diameter of ten millimeters or more. When the moving tip 17 by means of the actuation wire 37 pushes forward, the bendable electrodes 12 then withdrawn to the shaft of the catheter. Contact of the electrode with the venous wall can be maintained while the vein is shrinking.

In one embodiment, the balloon is 40 between the catheter shaft and the elongated element 32 localized. The manual manipulation of a slidable sheath or a movable tip is not required in this embodiment, and the slidable sheath, if used, need not travel a substantial distance along the catheter. The balloon 40 can either be made of elastic material such as latex or non-compliant material. The balloon 40 is inflated and comes with the elongated elements 32 in contact. If the balloon 40 continues to be inflated, the electrodes are 12 moved outward in a radial direction, while the elongated elements through the expanding balloon 40 be distracted and bent. The balloon is preferably inflated using a nonconductive liquid, especially when the elongated elements contain electrodes or when the elongated element itself is conductive to act as an electrode. When the correct diameter for the electrodes is reached, inflation of the balloon stops and the application of RF energy begins.

The balloon 40 Covers a larger surface area of the venous treatment site and ensures proper electrode placement relative to the vein wall while controlling the extent of venous shrinkage. More precise control over the shape and circumference of the balloon may also be possible using bendable elements. The balloon can also be used to control the effective diameter of the catheter at the functional end. When RF energy is applied, the vein begins to shrink down to the effective diameter of the catheter. The effective diameter of the catheter is reduced under the physician's control to control the extent of shrinkage. When the effective diameter is lowered, the electrodes retain the lining to the venous tissue. The application of RF energy from the electrodes 12 is terminated after the vein has shrunk to the desired diameter, which is the final effective diameter, which is determined by the diameter of the balloon 40 and the deflected elongated elements 32 is defined. The balloon 40 is then emptied to a minimum profile. The elongated elements 32 can be made of spring steel or Nitinol, so that the elongated elements 32 have a bias to return to a reduced diameter profile when the balloon is deflated.

In another embodiment are the ends of the elongated ones Elements are instead slidable within longitudinal slots or channels located along the circumference of the catheter. The ends of the bendable elements would travel within these channels in the direction of Functional slip while the elements abroad distracted or bowed, and would to retreat towards the end of the connection to its original position Configuration to return.

In an alternative arrangement could the electrodes and the elongated ones Elements through a single wire grid or a screened one Electrode are replaced, preferably when RF energy in one monopolar configuration is administered. As before, the Balloon expand the grid electrode radially outward, in alignment with the vein wall. The balloon can also reduce the extent of venous shrinkage check.

One alternative method of modifying the effective diameter of the catheters is to direct the electrodes To move or distract contact with the vein wall and then it to allow the vein wall to change the effective diameter. If the electrodes emit RF energy, shrinking the vein wall and presses the electrodes inward towards the catheter. The venous shrinkage directly reduces the effective diameter instead of the active one Control of the doctor, eliminating the need for persistent fine Mechanical adjustments of the effective diameter are eliminated. One Mechanism like a push rod or a balloon with a fixed diameter can be involved in a further radial contraction of the electrodes to prevent at a specific effective diameter the extent of Venous shrinkage is controlled and limited. This has the advantage maintaining the alignment of the electrodes with the venous tissue, making the tissue stronger is heated as the surrounding blood, without the doctor persistently must adjust the effective diameter of the catheter while RF Energy is applied.

The method of using the present invention for the minimally invasive treatment of venous insufficiency may be performed using a catheter, at least To deliver an electrode at the functional end of the catheter to a venous treatment site to restore proper function of a vein leading to the hemorrhoidal region. An over-the-wire or rail-guided catheter can be used to deliver one or more electrodes through the tortuous bends of the venous system to the hemorrhoidal treatment site.

The Electrode applies RF energy at a suitable frequency for the minimum Coagulation for Sufficient time to shrink, stiffen the vein and to fix and yet maintain venous function or valve competence to obtain. This intraluminal approach avoids the risks and Mortality associated with more invasive surgical techniques such as hemorrhoidectomy are while the blood reflux is significantly decreased in the areas without causing necrosis or remove the venous tissue.

at The treatment of veins of the lower hemorrhoidal region becomes the site of access prepared and a percutaneous introducer is inserted into the vein. The Procedure for repair of incompetent veins may be from a qualified Doctor with fluoroscopic or ultrasound observation or under direct visualization performed become. A guidewire gets into the vein through the insertion aid introduced and pushed on to the venous treatment site. Alternatively, the catheter can be inserted directly into the vein and without a guide wire be manipulated. Preferably, the guide wire has a spring-wound Top. The guidewire becomes retrograde to venous Advanced treatment site, such as the incompetent venous site, which is located very distally and should be repaired. Various intravenous Ways can to the hemorrhoidal Treatment site to be taken.

A partial cross-sectional view of the venous system leading to the hemorrhoidal region is in FIG 29 shown. Hemorrhoids are generally defined as internal or external, depending on whether they are over or under the toothed line (DL). Internal hemorrhoids are usually formed when smaller veins leading to the upper haemorrhoidal vein SHV or the middle hemorrhoidal vein MHV are dilated. External hemorrhoids are usually formed when the smaller veins leading into the lower haemorrhoidal vein IHV are dilated.

A method of administering the catheter 10 and guidewire 13 , it is the guidewire 13 to introduce into the external iliac vein EI on the opposite side to the dilated vein of the hemorrhoid. The guidewire is controlled via the forked branch of the lower vena cava IVC to the lower iliac vein II. The guidewire is then maneuvered into either the middle hemorrhoidal vein MHV for treatment of internal hemorrhoids or the pudendal vein PV and the lower hemorrhoidal vein IHV for the treatment of external hemorrhoids. The guidewire is inserted and maneuvered into the middle hemorrhoidal vein MHV to treat internal hemorrhoids. The guidewire 13 is maneuvered through the venous system until it reaches the dilated vein of the hemorrhage. The catheter 10 is then over the guidewire 13 brought to the venous treatment site, as in 29 shown. The functional end 11 of the catheter 10 includes one or more electrodes for applying RF energy once properly positioned at the venous treatment site to cause vein shrinkage. The functional end of the catheter further includes a flexible tip tip to allow tracking of the catheter over the guide wire and through the bends in the vascular system. Fluoroscopy, x-ray, ultrasound, or similar imaging techniques could be used to direct the specific placement of the catheter and to verify the position within the vein. X-ray contrast agent may be injected through or around the catheter to identify the incompetent vein segments that are to be repaired. This approach advantageously allows the guidewire or catheter to avoid sharp bends or curves while being controlled to the venous treatment site. It is understood that other access points can be used to treat either internal or external hemorrhoids.

One another method of administering the catheter and guidewire is it, the guidewire in the upper hemorrhoidal vein introduce and the guidewire through the upper Hömorrhoidalvene SVH to the hemorrhoidal region to maneuver. The guidewire is positioned and the catheter is then placed over the guidewire to the venous Treatment site for the internal hemorrhage brought. The venous Treatment site is within the lumen of a dilated vein.

When the electrodes 12 of the catheter 10 At the venous treatment site, an RF generator is activated to provide suitable RF energy, preferably at a low energy level, and preferably at a selected frequency in the range of 250 kHz to 350 MHz. For example, a suitable frequency is 510 kHz. Another suitable frequency is 460 kHz. An example of the choice of applied frequency is speed control the depth, the thermal effect in the tissue. Another criterion for selecting the applied frequency is the ability of the filter circuits to eliminate RF noise from the thermocouple signals.

The Energy emitted by the electrodes will be within the venous tissue converted into heat. When the temperature of the venous tissue increases, The venous tissue begins to shrink. The shrinkage is partial due to dehydration and structural transfiguration of the collagen fibers in the vein. Although the collagen compresses during this process will, keep the collagen nevertheless adds some elasticity.

RF Energy can be applied to the dilated vein sections a hemorrhoid to heat. The dilated vein is under controlled use from RF energy that heats the venous tissue to a normal one or reduced diameter shrunk. The venous pressure on the lower vein sections of the hemorrhoid can be lowered because of the decrease in the cross-sectional area of the vein. The flap competence in the lower venous Sections may also be indirect by lowering the venous pressure be restored. A thickening of the vein occurs during the Treatment also on what the likelihood of recurrence reduce venous dilation. The temperature and energy the RF energy can also be controlled to shrink the hemorrhage both as well as to cause the wall of the hemorrhoidal vein to be adjacent Tissue is attached.

Even though the application of RF energy the venendilatation near the formation Hemorrhoids shrinkage, the extent of shrinkage can also be higher venous sections to be beneficial, the effect of higher and increased venous pressure to the hemorrhoidal system too Reduce. A coherent one axial section of a dilated vein can be made using RF energy can be treated along the dilated vein section, even if this section is big. For example, there are hemorrhoids sensitive to pressures from the portal system affecting hemorrhoids through the upper hemorrhoidal vein SHV can be transferred. A treatment of the upper hemorrhoidal vein due to general shrinkage along an extensive section of the Vein over Hemorrhoids can the dilating forces pick up that raised from any Press the Portal systems arise. Such a treatment can be even then desirable be if there is no significant dilatation in the upper hemorrhoidal vein SHV gives.

The catheter 10 will, as in 30a shown over the guide wire 13 introduced through the venous system. The summit 15 the functional end 11 of the catheter 10 has the shape of a tip that is flexible to slide over the guide wire and through the bends in the venous system. As in 30b shown, becomes the catheter 10 placed in the dilated venous section, which may contain an incompetent flap. The electrodes are then positioned in line with the vein wall, preferably by mechanically bending the electrodes 12 away from the catheter 10 , as in 30c shown. The application of RF energy from the electrodes causes vein shrinkage and the effective diameter of the catheter, as defined by the outwardly bent electrodes, is mechanically reduced to control the extent of venous shrinkage. The bent electrodes become as in 30d shown held in position to define a specific effective diameter and to prevent occlusion of the vein. The catheter may be moved along the length of the dilated vein to cause a generalized shrinkage where extensive dilation is present.

RF Energy is no longer applied after a sufficient shrinkage the vein has taken place to relieve the dilation of the vein. A considerable shrinkage can be achieved very quickly, dependent from the specific treatment conditions including the energy level the applied RF energy. The properties of the treatment site, like temperature, can be monitored be to a feedback control for the RF energy available to deliver. Other techniques, such as impedance monitoring and ultrasound pulse echo, can be used in an automated system, which the application of RF shuts off energy from the electrodes to the vein section, when a sufficient shrinkage of the vein is detected and overheating and to avoid cauterization of the vein. Monitoring these values in an automated feedback control system for RF Energy can also be used to control the energy level and to control the heating effect.

Sufficient vein shrinkage can be detected by fluoroscopy, venography, external ultrasound scanning, intravascular ultrasound scanning, impedance monitoring, temperature monitoring, direct visualization using an angioscope, or any suitable method. For example, the catheter 10 be configured to administer an X-ray contrast agent to allow visualization by fluoroscopy to assess the condition of the vein and the relationship between the catheter and the treatment area of the vein during shrinkage process. As an alternative to fluoroscopy, external ultrasound techniques such as B-scanning using certain ultrasound signals from different angles or intravascular ultrasound may be used to obtain a multi-dimensional view of venous shrinkage at the treatment site, which enhances the detection of uneven shrinkage in the vein. An angioscope can also be used to directly visualize and determine the extent and level of venous shrinkage.

If the catheter with a fluid delivery lumen equipped, can be a cooling fluid through the delivery lumen during RF heating of the treated vein into the blood stream. The liquid can contain radiodense contrast material. The administered coolant Minimizes any heating effect on the blood and reduces it the risk of heating the blood to the point of coagulation. The liquid can through openings administered along the side of the catheter near the catheter Functional and the electrodes are formed.

The functional end 11 of the catheter 10 near the electrodes 12 can be used to physically limit the extent of shrinkage. The functional end 11 is preferably sufficiently dimensioned or enlarged to prevent complete occlusion of the vein. Other measures, such as an inflatable balloon, may be used to mechanically limit or control the extent of vein shrinkage or to displace blood from the treatment site. Such mechanical means may also be used to ensure alignment between the electrodes and the venous tissue during treatment.

While the catheter allows a general contraction of the vein, it can also be used to more directly treat the venous valves. The hemorrhoidal veins have bicupuncture valves and in a normal and competent valve, each valve leaflet forms a sac or reservoir of blood that forces the surfaces of the valve leaflets together under pressure to prevent a backward flow of blood and to allow a forward flow to the heart. The arrows, from the top of the lower vena cava IVC and the upper haemorrhoidal vein SHV as in 29 Lead out, representing the antegrade blood flow back to the heart. The venous valves prevent the retrograde flow as blood is forced forward through the venous lumen and back to the heart. In an incompetent valve, the valve leaflets do not close properly and retrograde blood flow can occur. Incompetent valves may result from dilation of dilated veins. When the valves fail, increased pressure is exerted on the lower veins and lower valves of the veins, which in turn aggravates the failure of these lower valves. As a result, hemorrhoids may occur or worsen. The leaflets can undergo a slight separation at the junction because of the thinning and stretching of the venous wall at the valve leaflets. When RF energy is applied within the dilated vein adjacent to the incompetent venous valve, shrinkage of the vein can restore valve competence by reducing the dilation that prevents the proper functioning of the venous valve.

at In the treatment of venous valves, the electrodes are placed on the catheter pushed forward until contact with the valve leaflets of the venous valve by means of fluoroscopy, ultrasound or another detection method is observed. The catheter is then slightly withdrawn, to allow treatment of the dilated portion of the vein. The electrodes are activated to deliver RF energy to the venous tissue to give up and shrink the vein. The application of RF energy should be controlled to prevent unintentional heating of the leaflets to avoid. The shrinkage of the vein can be restricted to a closure avoid the vein and maintain a continuous function of the vein to allow. The outer diameter of the catheter or an extendable element can be controlled be to the size of the venous shrinkage to restrict.

To The treatment should be the junction and the leaflets the venous valves are closer together, with little distance or incident, which indicates a restoration of valve competence. The flap competence can be determined by contrast injection or Doppler probe measurement become.

To the Example may be a radiopaque contrast agent The catheter lumen will be infused to decrease the valve competence over descending To determine venography. It should be mentioned that a reduction vein dilatation by means of general shrinkage in a section above of the section that contains the incompetent venous valves, the Recover valve competence by reducing venous pressure on the flap and the dilation of the vein, giving the necessary span the flap sail is reduced. Also, the direct placement of the electrodes over a Venous valve can lead to a shrinkage of the loose, flabby leaflets, which to prevent prolapse and reflux of blood through the valve leads.

The catheter 10 can be repositioned within the vein to treat as many vein sections and valves as necessary. RF energy is applied to each section of the vein to be repaired until all of the desired venous sections have been repaired and the flaps have been made competent. Multiple incompetent valves and dilated venous sections can be treated and repaired in a single minimally invasive procedure. If desired, a second introducer can be introduced into the patient to treat incompetent venous sections in the other venous system, such as the upper hemorrhoidal vein.

One other area of the venous Insufficiency that is suitable according to the present invention Being treated involves oesophageal varices. Varicose veins, called oesophageal Varices, can in the venous System forming along the submucosa of the lower esophagus and bleeding can occur from the swollen veins. Properly dimensioned Catheters can according to the present Be used to place the electrodes in place of the venous Insufficiency along the esophageal To bring varices. endovascular Access for The catheter is preferably through the upper mesenteric vein or Portal vein available to shrink the branches of the portal vein, the to the lower esophagus to lead. Proper positioning The electrode inside the vein can be made using fluoroscopic or ultrasound techniques confirmed become. The electrodes use RF energy or other radiant Energy at a suitable frequency to shrink the vein and the swelling and transmission of high portal venous Pressure on the esophagus to reduce surrounding veins, while the function of the vein is maintained. The extent of the shrinkage of the vein can be limited by the diameter of the catheter, or the Electrodes themselves can be extended to a predetermined diameter, the shrinkage the vein is limited to this diameter.

Varicose veins, called oesophageal varices, can form in the venous system along the submucosa of the lower esophagus and bleeding can occur from the swollen veins. A properly sized catheter 10 is used to the electrodes 12 to take the place of venous dysfunction along the esophageal varices. Endovascular access for the catheter is preferably provided through the superior mesenteric vein or portal vein to shrink the branches of the portal vein leading to the lower esophagus. Proper positioning of the electrode within the vein can be confirmed using fluoroscopic or ultrasound techniques. The electrodes apply RF energy or other forms of energy at an appropriate energy or frequency to shrink the vein and reduce the swelling and transmission of high portal venous pressure to the veins surrounding the esophagus while maintaining vein function. The extent of vein shrinkage may be limited by the diameter of the catheter itself, and the catheter or electrodes themselves may be expanded to a predetermined diameter which limits the contraction of the vein to that diameter.

In the treatment of veins of the lower esophageal region, the access site is prepared and a percutaneous introducer is inserted into the vein. The procedure for repairing the incompetent veins may be performed by a qualified physician with or without fluoroscopic or ultrasound observation or under direct visualization. A guidewire 13 is inserted through the introducer into the vein and advanced to the venous site. The wire is advanced to the treatment site, such as the height of the most proximal site of an incompetent vein to be repaired. Preferably, the guidewire and catheter are advanced antegrade to the esophageal site. Alternatively, the catheter can be inserted directly into the vein and manipulated without a guidewire.

As in 31 In a partial view of the venous system leading to the esophageal region, the catheter becomes 10 over the guide wire 13 pushed to a dilated section of the vein. One method of administering the catheter and guidewire is to insert the guidewire through the upper mesenteric vein SMV to the portal vein PV and coronal vein CV, which divides and leads to the lower esophagus E to form the esophageal veins EV. As an alternative route, the guidewire could be inserted into the lower mesenteric vein and directed through the splenic vein SV, portal vein PV, and coronary vein CV to arrive at the esophageal varix to be treated.

The guidewire is inserted and manipulated to reach the treatment site for the treatment of the esophageal varices. The venous treatment site is preferably within the lumen of a dilated vein. The catheter 10 is then delivered to the venous treatment site via the guidewire 13 , as in 31 shown, brought. Fluoroscopy, x-ray, ultrasound, or a similar imaging technique can be used to direct the specific placement of the catheter and the position within the vein to check. X-ray contrast agents can be injected through or around the catheter to identify the dilated venous sections that are to be treated. Bleeding or bleeding of the esophageal varices can also be identified in this way.

Once the dilated venous section is reached, the one or more electrodes become 12 activated to deliver RF energy to the dilated venous section. While the electrodes are held in the middle of the vein, the electrodes are preferably placed in line with the vein wall. The electrodes placed in line with the venous tissue ensure that the heating effect is delivered in the direction of the venous tissue and not to the blood moving through the vein and allow control over the contraction of the vein. One method of achieving a sequencing is to flex the electrodes outwardly away from the body of the catheter. This will be in 32a . 32b and 32c shown. The electrodes have an elongated, longitudinal structure with opposite ends fixed to a fixed or movable part at the functional end of the catheter. The bendable electrodes are operated by moving the outer sheath of the catheter while the tip of the catheter remains fixed. Alternatively, a center wire could be used to move the tip while holding the opposite end of the bendable electrode in place.

The one or more electrodes 12 at the end of the function 11 of the catheter 10 Apply RF energy as soon as it is properly positioned and attached to the venous line to cause vein shrinkage. An RF generator is activated to provide a suitable RF energy to the electrodes, preferably at a low energy level and preferably at a selected frequency in a range from 250 kHz to 350 MHz. For example, a suitable frequency is 510 kHz. A criterion for the selection of the applied frequency is the control of the propagation including the depth of the thermal effect in the tissue. Another criterion is the compatibility with the filter circuits that can be used to eliminate RF noise from the thermocouple signals.

The Energy emitted by the electrodes will be within the venous tissue converted into heat. When the temperature of the venous tissue increases, The venous tissue begins to shrink. The shrinkage is partial due to dehydration and structural transfiguration of the collagen fibers in the vein. Although the collagen compresses during this process will, keep the collagen nevertheless adds some elasticity.

A Considerable shrinkage can be achieved very quickly, depending on the specific treatment conditions, including the diameter the treated vein and the energy level of applied RF energy. The properties of the treatment site, such as temperature, can be monitored be to a feedback control for the RF energy available to deliver. Other techniques, such as impedance monitoring and ultrasound pulse echo, can be used in an automated system, which the application of RF shuts off energy from the electrodes to the vein section, when a sufficient shrinkage of the vein is detected and overheating and to avoid cauterization of the vein. Monitoring these values in an automated feedback control system for RF Energy can also be used to increase the heating effect to control.

Sufficient shrinkage can be detected by fluoroscopy, external ultrasound scanning, intrasuscular ultrasound scanning, impedance monitoring, temperature monitoring, direct visualization using an angioscope, or any suitable method. For example, the catheter 10 be configured to provide X-ray contrast medium to allow visualization by fluoroscopy to assess the state of the vein and the ratio of the catheter to the treatment area of the vein during the shrinking process. As an alternative to fluoroscopy, external ultrasound techniques such as B-scanning using certain ultrasound signals from different angles or intravascular ultrasound may be used to obtain a multi-dimensional view of venous shrinkage at the treatment site, which enhances the detection of uneven shrinkage in the vein. An angioscope can also be used to directly visualize and determine the extent and level of venous shrinkage.

The functional end 11 of the catheter 10 near the electrodes 12 physically limits the extent of shrinkage. The electrodes 12 at the end of the function 11 are bent outward in line with the vein wall and then slowly reduced inward towards the catheter during the application of RF energy. The final effective diameter of the electrodes 12 at the end of the function 11 is preferably sufficient to prevent complete occlusion of the vein. Other systems, such as an inflatable balloon, may be used to limit or control the extent of shrinkage in the vein to a desired diameter. RF energy is no longer applied by the electrodes after sufficient vein shrinkage has occurred has to relieve the dilation of the vein. Other methods than the aforementioned mechanical methods can also be used to control the extent of venous shrinkage. Such nonmechanical procedures include the control of the time and temperature of venous RF treatment.

Of the dilated venous Section will be under the controlled application of RF energy according to the present Invention heated and to a normal or reduced diameter shrunk. A coherent one axial section of a dilated vein can by application be treated by RF energy along the dilated venous section, even if the section is extensive. To an extensive vein section To treat, the catheter is moved at intervals to the venous section progressively shrink, or along the extensive section while the application of RF energy moved back and forth. Furthermore, a Thickening of the vein during the treatment will occur and the likelihood of recurrence reduce venous dilation and bleeding.

The Application of RF energy shrinks the dilation of esophageal Varices and the extent of shrinkage on other sections in the portal vein system may be beneficial to the effect of increased venous pressure on the esophageal varices to further reduce. oesophageal Veins can sensitive to pressures be from the portal system. A treatment of branches of the portal vein in front of the esophagus due to general shrinkage along an extensive area of the vein in front of the esophagus can exert the dilating effect on the esophageal veins, resulting from increased pressures the portal vein system is caused to reduce.

It is understandable, that other mechanisms can be used to insert the electrodes into or with the venous to be repaired To position or line section without bending or stretching of the electrodes away from the catheter itself. The catheter can be designed for that be distracted, twisted or otherwise moved to a proper placement to allow the electrode. The catheter can be made to a controllable bend near the working end put. For example, the bend may be of a shape memory metal manufactured, manipulatable by means of a wire system, a twistable cord or a permanent bend in the catheter. The manipulation the functional end of the catheter allows, if desired, the preferred heating along the vein wall being treated where the electrodes are closer placed to one side of the vein wall. The preferably Heating the vein can also be used to treat the hemostasis to accomplish.

It is understandable that although a bipolar arrangement is described, also a monopolar arrangement can be used. In a monopolar Arrangement becomes an inner electrode such as a grid or wire electrode in the body introduced by the patient. An outer electrode with a much larger surface than the inner electrode is placed on the outer surface of the patient's body, near the treatment site. For example, an external metal plate to the skin over the region to be treated by the inner electrode is placed. Alternatively, a metallized balloon enters the esophagus introduced and inflated to make contact with the mucosal lining of the esophagus to come and as an inactive feedback electrode to act. The electrodes are connected to an RF generator, which generates an electric field within the patient's body. There the surface the inner electrode is much smaller than that of the outer electrode is the Density of electric field around the inner electrode much higher. The electric field reaches its highest density between the two Electrodes in the region near the inner electrode. The increased Density of the field around the inner electrode allows a local Heating the tissue surrounding the inner electrode. The extent of heating can be dependent be of factors such as the impedance and the dielectric constant of the treated tissue. It is understandable that different electrodes different number and configuration can be used to the wished to produce any heating effect.

As can be readily ascertained from the present disclosure, The procedure of the present invention may be without the need for one longer Hospitalization or postoperative recovery accomplished become. The curative restoration of venous function is possible without the need for constant changes in the lifestyle, how common Raising the legs, wearing relatively uncomfortable support stockings or prolonged treatment of recurrent venous stasis ulcers. Moreover, the surgical transplantation not necessary from veins.

Early treatment for venous disease may prevent more serious complications such as ulcer, thrombophlebitis, and thromboembolism. Treatment costs and complications due to venous disease would be significantly reduced. There would be no need for extended hospitalization for this procedure and the need for subsequent treatment or hospitalization would be required in view of what is currently required is also reduced. Furthermore, the minimally invasive nature of the disclosed methods would allow the physician to repair or treat multiple vein segments in a single procedure and a relatively short period of time.

It It should be understood that the type and dimensions of the catheter and the electrodes are selected according to the size of the vein to be treated can. Although the present invention is for the treatment of venous insufficiency the lower extremities, As varicose veins in the leg have been described, the present may be Invention used to treat venous insufficiency in others Areas of the body to treat intraluminally.

One other area of venous insufficiency refers to erectile Impotence of the penis. A significant number of all physically induced Cases of impotence result from excessive outflow of blood from the venous system of the penis. Venous outflow impotence can be treated using the present invention. Catheters of sufficiently small diameter can be used to treat the Electrodes to ring through you dorsal vein of the venous system of the penis, around this venous Outflow path to shrink. Fluoroscopic or ultrasound techniques can used to properly place the electrode within the incompetent Position vein. RF energy or other radiant energy is applied by the electrodes at an appropriate frequency, to shrink the surrounding venous tissue to the excessive amount to reduce runoff from the penis while the venous function or Flap competence is maintained. The extent of shrinkage The vein can be limited by the diameter of the catheter itself or the catheter or the electrodes themselves can open the reasonable size will be extended. The ligature of these veins should be avoided to ensure proper drainage Allow blood from a swollen penis, allowing for proper penile Function is needed.

While numerous certain forms of the invention have been illustrated and described are, it is obvious that a lot of modifications can be made without departing from the scope of the invention. Accordingly, it is not intended that the invention be limited is intended, except as by the appended claims.

Claims (15)

A device for using energy to reduce the diameter of a vein, the device comprising: a catheter ( 10 ) with a functional end and an outer diameter, wherein the outer diameter of the catheter can be adjusted to be smaller than the inner diameter of the vein, wherein the catheter ( 10 ) further comprises a movable outer shell ( 36 ) having; a heating device ( 12 ) for heating a treatment area in the vein to reduce the diameter of the vein, wherein the heating device at the functional end of the catheter ( 10 ) is arranged; and at least one flexible element ( 32 ) for moving the heating device ( 12 ) along the catheter ( 10 ) to the outside, wherein the flexible element ( 32 ) is conductive and further comprises an insulating film ( 35 ) having the surface of the conductive flexible element ( 32 ), except for a non-covered part which contacts the wall of the vein when the flexible element is placed along the catheter (FIG. 15 ) is moved outwards, wherein the flexible element ( 32 ) includes a first end and a second end, the first end having the functional end of the catheter and the second end having the movable outer sheath ( 36 ), so that the uncovered part of the flexible element can be positioned by manipulation of the outer sheath in the vein, wherein the heating device ( 12 ) includes the uncovered portion of the conductive flexible member, and the flexible member has sufficient structural strength to prevent a reduction in the diameter of the vein below an effective diameter determined by the flexible member, wherein the effective diameter is greater than that outer diameter of the catheter is. Device according to claim 1, further characterized in that the conductive flexible element ( 32 ) has a rectangular shape with a flat portion between the first end and the second end, the flat portion containing the non-insulated part. Device according to one of the preceding claims, further comprising a balloon ( 40 ) between the flexible element ( 12 ) and the catheter ( 10 ), wherein the balloon acts on the flexible element during inflation and pushes it radially outward. Device according to one of the preceding claims, wherein the heating device ( 12 ) comprises at least one electrode. The device of claim 4, further characterized in that the at least one electrode further comprises a plurality of longitudinal electrodes disposed along the circumference the functional end ( 11 ) of the catheter are arranged to cause an omnidirectional heating along a portion of the catheter (FIG. 10 ) to effect. Apparatus according to claim 5, further characterized that each longitudinal electrode has an opposite polarity to the has immediately adjacent longitudinal electrodes. Device according to claim 5, further characterized in that on the catheter ( 10 ) an even number of longitudinal electrodes is arranged to provide cooperative pairs of longitudinal electrodes. Device according to claim 5, further characterized in that on the catheter ( 10 ) an even number of longitudinal electrodes is arranged to provide cooperative pairs of longitudinal electrodes, each electrode having opposite polarity to the immediately adjacent electrodes. Device according to claim 5, further characterized in that on the circumference of the catheter ( 10 ) an even number of electrodes is arranged to provide cooperative pairs of electrodes, wherein a first electrode has a first polarity, a second electrode disposed adjacent to the first electrode has a second polarity, that of the first polarity and a third electrode disposed adjacent to the first electrode has the same polarity as the first polarity, with an even number of electrodes disposed on the catheter to provide cooperative pairs of electrodes for energy in a directional form. Device according to one of the preceding claims, further comprising a positioning device ( 40 ) to the heater ( 12 ) with the treatment area in the vein. Device according to one of the preceding claims, further comprising an occlusion balloon arranged at the functional end of the catheter ( 40 ), which causes an occlusion of the vein when inflating. Device according to one of the preceding claims, further comprising one at the functional end of the catheter ( 10 ) arranged sensor ( 60 ), and a microprocessor capable of receiving a signal from the sensor, the signal reflecting a condition on the treatment surface, the microprocessor comprising means for controlling the heating device ( 12 ) such that the propagation of the heating effect in the venous tissue is controlled in response to the signal from the sensor. Device according to one of the preceding claims, further comprising a microprocessor with a device for selecting the frequency of the heating device ( 12 ), so that the propagation of the heating effect in the venous tissue is controlled. Device according to one of the preceding claims, further characterized in that the catheter contains a lumen, through which liquid can be injected into the vein. Apparatus according to any of claims 5 to 14, further characterized characterized in that the catheter includes a guide wire which in an isolated lumen for the guidewire is located, with the lumen for the guidewire is adapted so that an electrical coupling between the guide wire and the electrode is prevented.