KR19980018457A - Braided reinforcement injection catheter assembly with inflatable membrane - Google Patents

Abstract

The present invention relates in particular to a perfusion catether having an inflatable membrane or ballon located at the distal end of the catheter shaft. The catheter shaft consists of an outer tube assembly and an inner tube assembly separated by an annular opening for expanding and contracting the inflatable membrane. The assembly further includes an inflatable membrane that can be separated. The outer tube assembly consists of at least one polymer layer and a braid of superelastic alloy, which may be a polymer or a metal. At least a portion of the inner tube assembly consists of at least one polymer layer, preferably of a superelastic metal braid. The inner tube assembly includes a lumen through which the guidewire may pass. The inner tube assembly generally includes a coil member coaxial with the instrument along its axis. This lumen is preferably lined with a lubricating polymer. The outer tube assembly allows the shape of the catheter to be minimized but provides significant tremor resistance to the inner tube assembly. The structure of the inner tube assembly prevents hasty expansion while introducing the injection through the inner lumen.

Description

Braided reinforcement injection catheter assembly with inflatable membrane

The present invention relates to a surgical device. In particular, the present invention relates to a perfusion catheter having an inflatable membrane or device located at the distal end of the catheter shaft. The catheter shaft consists of an outer tube assembly and an inner tube assembly separated by an open annulus to inflate and deflate the inflatable membrane. These assemblies may further comprise an inflatable membrane that can be separated. The outer tube assembly consists of at least one polymer layer and a braid of superelastic alloy, which may be a polymer or a metal. At least a portion of the inner tube assembly consists of at least one polymer layer and preferably of a superelastic metal braid. The inner tube assembly includes lumens through which the guide wire can pass. More preferably, the inner tube assembly includes a coil member extending substantially the same as the instrument along its axis. This lumen is preferably lined with a lubricating polymer. The outer tube assembly provides significant twist resistance to the inner tube assembly while allowing the shape of the catheter to be minimized. The structure of the inner tube assembly provides resistance to hasty expansion while introducing the injection through the inner lumen.

The present invention generally relates to a catheter having an inflatable membrane or device at its distal tip. The catheter is configured to have two lumens, one of which is a central lumen for use with a guidewire or for introducing a drug or vascular occlusion material or device, and the other is located coaxially around the inner lumen and for distal expandable membrane. Used only for the purpose of inflation and deflation. This instrument has a very narrow overall diameter and is preferably designed in such a way that it is constructed using a compliant instrument as a membrane. In other words, the instrument section located remotely on the catheter of the present invention is of the same general diameter as in the catheter shaft close to the neighbor of the inflatable membrane and will expand by four or five times the diameter of the instrument when inflated. Since the instrument is of a very narrow structure, conventional instrument catheter may be used for parts of the human body in which it is not suitable. In other words, the instrument may be used for flexible organs, such as the liver, as well as for vascular structures in the brain and surroundings. The instrument is of sufficiently small enough diameter that it can be used in several genitourinary passages without causing excessive pain to the patient. In addition, an important fact in the present invention is the use of a metal or polymer thread braid, preferably in the outer tube assembly. At least one portion, generally the proximal portion, of the inner tube assembly of the catheter of the present invention comprises a metal braid, sometimes a metal or superelastic alloy ribbon braid. Such superelastic alloy braids provide exceptional twisting provisions for the inner tube assembly rather than for the tube assembly in which it is installed. The inner braid prevents the instrument from expanding while the fluid is introduced through the inner lumen or prevents the inner lumen from collapsing if the instrument expands. The inner tube assembly also preferably includes a coil section in the area of the inflatable membrane to provide improved flexibility.

Catheters having a coaxial structure are known. Many such catheters are used in procedures such as percutaneous translucent angioplasty (PTA). However, in this process, the instrument is noncompliant. In other words, the instrument is of a particular size set at the time of its manufacture. The instrument itself is thereby collapsed or collapsed into a rather large and rigid area that is difficult to steer towards the treatment area through the guide catheter in which the instrument is installed and through various vessel lumens. In this process, an intraocular catheter, typically having a preformed distal tip, is introduced into the patient's vasculature. The catheter then advances into the aorta from the entry zone in the femur artery. Once the tip of the catheter approaches the aorta, the distal end of the catheter is twisted or twisted to bend the preformed distal tip of the intraocular catheter into the opening of the desired coronary artery. The instrument support catheter then advances through the intraocular catheter until the instrument of the inflation catheter extends across the site to be treated so that its distal tip exits. The instrument is then expanded to a predetermined size by using radiopaque liquids, often at relatively high pressures. At the end of this process, the instrument is then contracted so that blood flow can recover through the treated artery after the dilation catheter is removed.

In another procedure, an instrumentally supported catheter of somewhat smaller diameter than the catheter typically used in PTA procedures may be used. In a universal sense, this procedure may be considered similar because the intraocular catheter is initially installed such that its distal end is positioned near the site to be treated or diagnosed. The instrument catheter will then be placed at that site through the lumen of the intraocular catheter. The instrument support catheter with guidewires extending through the existing central lumen can then extend through the distal side of the intraocular catheter to the treatment or diagnostic site. The instrument will then be inflated, and upon completion of this process, the instrument will contract and be removed from the human body. In certain cases, the instrument may be of a more compliant characteristic than the fixed diameter form found in conventional PTA instruments.

The benefit of interventional radiology and its subexecution, neuroradiology, as an alternative to feasible treatment in various parts of the human body with curved vasculatures often surrounded by soft organs, is not installed on devices used in PTAs. It provided a demand for catheterization equipment. There is a need for devices of relatively small diameter and in particular devices with varying flexibility and capable of resisting tremor.

US Pat. No. 5,338,295 to Cornelius et al. Discloses an expansion mechanism catheter with a shaft formed of a tubular braid of stainless steel material. The proximal outer tube section is inserted into the polyimide material. The terminal outer tube section forming the instrument is made of a polymeric material such as polyethylene.

Another similar device is shown in US Pat. No. 5,451,209 to Ainsworth et al. Einsworth's patent discloses a complex tubular element useful for endovascular catheter. In particular, such composite tubular elements are known to be useful as elements of a fixed wire expansion catheter or to be useful in intraocular or vascular graphics catheter. The structure of this mechanism is formed by braided twisted yarns. The twisted yarn is formed from a mixture of polymer matrix materials (eg fibers or powder). The polymeric matrix material has a relatively low melting point in high strength reinforcing fibers with a relatively high melting point. This fiber is woven into tubular elements. The finally braided tubular element is heated to melt the matrix material, allowing the matrix material to flow around reinforcing fibers with high melting points. This process forms a matrix. The thermoplastic jacket or coating is then extruded or otherwise applied onto the exterior of the braided tubular element thus produced.

Demello US Pat. No. 5,429,597 discloses an instrument catheter with a tremor resistance. In general, the catheter appears to be made of an outer polymer covered over a cross-wound multi-chamber (CWMF) in an unfixed removable core wire. The CWMF coil is a pair of spiral coils wound in opposite directions to provide torque transfer while using the catheter. This patent does not appear to suggest the winding of CWMF materials with a braid.

The PCT application of Prey et al. (International Patent WO93-20881), assigned to SciMed Medical Systems, discloses an expansion catheter with a stainless steel braid tube and a shaft with a proximal section of a composite of polymeric material. Suggesting. The distal section of the catheter is formed of a flexible polymer tube. In one embodiment, the braid fabric of the proximal section of the shaft has a variable pick count that increases in the distal direction. This provides for increased terminal flexibility.

Published British Patent Application Publication No. 2,233,562 A to Hanam et al. Discloses an instrument catheter with a hollow inner shaft and a braided outer shaft with the instrument. This mechanism is inflated using a fluid introduced between the inner shaft and the outer shaft. The inner shaft is fixed to the outer shaft at both ends so that the outer shaft contracts when the instrument is inflated. The excess length of the inner shaft is accommodated by the process of bending the inner shaft in the form of a coil in the outer shaft lumen. Braids are commonly referred to as fibers of polyester floss. This extends the entire length of the outer shaft but may clearly include a variable pick rate near the instrument. The appliance is made of the same material as the braided layer and has a flexible elastic polyurethane sheath.

Burns, US Pat. No. 5,032,113, shows a partial coaxial catheter with a range of instruments with coaxial properties. The innermost lumen is used for the passage of the guidewire. The outer annular lumen is used to inflate the instrument in hydraulic communication with it. The outer annular lumen is also in hydraulic communication with the inner lumen. The outer annular lumen is also in hydraulic communication with the inner lumen. Several flow reduction means are shown to be in the intermediate catheter to allow passage of fluid at a somewhat controlled rate into and out of the instrument.

U. S. Patent No. 5,460, 607 shows another coaxial catheter in which a conventional instrument is opened in an annular space between an inner tube and an outer tube. One variation of this instrument includes an instrument made of a material such as polyurethane (column 12). In this variant, the inner tube 130 is made of a rigid tube, a metal spring reinforcement tube, a fine stainless steel tube, or the like.

US Pat. No. 5,460,608 to Rodin et al. Shows an instrument catheter having an outer tube shaft and an inner tube shaft configured in a manner that prevents the inner shaft from collapsing or breaking during use. This is referred to as the dilation catheter used for PTA in large peripheral vessels. The inner tube is reinforced using reinforcement coils. The apparatus is preferably made of polyurethane terephthalate.

US Pat. No. 5,470,313 to Crocker et al. Illustrates another variation of an instrument catheter with inner and outer tube assemblies partially separated to form a region between the two assemblies. The mechanisms mentioned in connection with this device are generally not compliant, but are designed in such a way that they have a variable diameter when inflated. This is done by installing bands in various zones around the circumference of the instrument.

US Pat. No. 5,480,383 to Bagaoisan et al. Discloses an instrument catheter with inner and outer tubular members having a proximal end of an inner tubular member formed of a virtual elastic alloy. This section appears to be tubular.

Martin, US Pat. No. 5,480,380, discloses a double lumen catheter with orifices in the inner and outer lumen allowing the filling of the material installed in the catheter into the selected treatment site.

None of the foregoing patents disclose a catheter with the structure specified herein.

The present invention relates to a catheter used for insertion into some lumen of the human body. Generally, this catheter is used in the lumen of the vessels, which is a desirable feature of high flexibility without shaking. Such vascular lumens will usually be found in the brain, liver, and any peripheral site of the human body. Nevertheless, the catheter of the present invention is conjugated to the treatment of other human lumens as found in the urogenital system.

The physical structure of the catheter of the present invention includes an inner and outer tube assembly separated by an annular space. At the distal end of the outer tubular member an expandable membrane may be found, typically in the form of a plastic or compliant instrument. Preferably, the diameter of the unexpanded instrument is equal to the diameter of the outside of the catheter shaft at the proximal end of the instrument region. The inner tube assembly is opened from the proximal end through the distal end. The annular space between the two tube assemblies is not in fluid communication with the inner lumen and is used only for the purpose of expanding and contracting the inflatable end membrane. The essence of some variations of the present invention is the use of a superelastic ribbon braid integrated into the desired form at least as part of the inner and outer tube assemblies. The outer tube assembly with this ribbon braid acts as a member to prevent shaking of both the inner and outer assemblies that are part of it.

Another very preferred variant of the invention includes the outer tube assembly using a polymer member braided at least at the distal end of the member instead of the superelastic alloy ribbon member.

The inner tube assembly also preferably includes a superelastic ribbon braid integrated into the polymer tube wall. This prevents instrument shaking and improper inflation while performing other procedures.

In one variant of the invention, the braid in the outer tube member extends to a point immediately proximate to the interior of the inflatable membrane. The braid in the inner tube assembly thus provides the overall hardness of the catheter assembly, particularly in the distal region.

The braid itself in the outer tube assembly may be used as a cured product in the entire catheter assembly by extending the braid through the inner space of the inflatable membrane. In this variant, the expansion fluid will agglomerate into the instrument itself from the annular space between the tube assemblies through the gap in the brae structure. In another preferred variant, the inner tube assembly uses coils in the area of the inflatable membrane.

The catheter most preferably has an inner layer of lubricating polymer tube positioned as the innermost surface of the inner tube assembly. This inner lubrication layer extends all the way from the proximal end toward the distal tip.

The instrument member used in the catheter assembly of the present invention is either elastomeric or radially compliant to provide a variety of functions not typically attempted by using polyethylene or PET instruments. This instrument member may also be a noncompliant instrument. However, if noncompliant devices are used, the catheter assembly loses some flexibility substantially and figuratively. The present invention includes the presence of a detachable mechanism mounted on the distal end of the internal lumen.

It is highly desirable that the overall structure of the instrument is that the most proximal end of the instrument is cured, the central portion is more flexible and the distal end is more flexible. If desired, multiple or minor regions of intermediate flexibility may be used.

Finally, soluble and flowable polymers, such as polyurethanes, are highly desirable to be used to penetrate several braids and provide some bonding to any inner layer of the outer tube assembly. This provides a very thin walled catheter assembly with a wall that is lubricious on its own but capable of supporting the joint with more lubricating polymer.

The concept of the instrument catheter of the present invention is to provide a highly flexible, compliant instrument catheter suitable for use in the very terminal vasculature. Despite the fact that it is very flexible, it is also designed in a way that resists tremors, especially in the immediate vicinity of the instrument.

1A is a plan view of a conventional catheter made in accordance with the present invention,

1B is a cross-sectional view of the proximal end of the catheter assembly shown in FIG. 1A;

2A and 2B are enlarged plan views of the distal end of the catheter shown in FIG. 1A, illustrating the unexpanded (FIG. 2A) and expanded (FIG. 2B) states of the expandable membrane, respectively;

3 is a partial cutaway cross-sectional view of the inner and outer tube assemblies forming at least one section of the catheter as shown in FIG. 1A, FIG.

4 is a cross-sectional view taken along the section line shown in FIG. 3;

5 is another partial cut cross-sectional view of another modification of the present invention;

6 and 7 are cross-sectional views each showing another variation of the inflatable mechanism,

8 is a partial cross-sectional view showing that the instrument is attached to an outer section of the outer tube assembly;

9 is a partial cross-sectional view of another variation of the present invention in which the braid traverses the opening under the inflatable membrane and the instrument joins the inner tube assembly with the narrow nose;

10 is a partial cross-sectional view of another variation of the present invention showing the coil traversing an opening under the inflatable membrane;

11A, 11B and 11C are partial cross-sectional views showing one variation of the inflatable membrane using an inflatable marker band to show when the instrument is properly inflated;

12A and 12B are partial cutaway side and end views of the distal tip of the catheter assembly of the present invention showing a bleeding port for removing gas from the catheter of the present invention;

13A, 13B and 13C show partial cutaway side views, respectively, of the distal tip of the catheter assembly of the present invention showing an inverted inflatable membrane and a removable instrument.

Explanation of symbols for main parts of the drawings

100: catheter assembly

108: inflatable membrane

112: guide wire

118: Luer

220: inflatable flexible membrane

232: inner tube assembly

362: braid member

404 instrument

1A is a side view illustrating a typical structure of a catheter assembly 100 in accordance with the present invention. The catheter assembly 100 has various areas with different flexibility for illustrative purposes only. In the example shown in connection with FIG. 1A, the more distal end 106 of the catheter assembly 100 is more flexible than the proximal end 102. Areas of medium intensity are also shown. These strengths and methods of providing these lengths will be described in more detail below. However, it should be understood that the present invention is not limited to catheters having operating shafts with two or three regions of different flexibility. That is, the entire length of the operating shaft of the catheter assembly 100 may be single flexible or three or more individual flexibles, or in addition, the flexibility may vary in a wide variety of ways not specified herein. For example, the flexibility of the catheter assembly 100 may vary as a function similar to the distal end. When such a catheter is used in a weak organ such as the liver or brain, it is more common that the distal end of the catheter is more flexible. This flexibility is higher in certain instances but may appear to be numerically variable, although it may be desirable to have a specific flexible end region.

Nevertheless, the catheter assembly 100 is shown with three separate portions of the catheter shaft. The distal end 102 is the strongest in this variant. The intermediate shaft 104 of the catheter assembly 100 is more flexible than the proximal shaft 102 and at the distal end 106 of the catheter assembly 100 as the most flexible portion of the shaft proximal portion of the inflatable membrane 108. It leads. Radiopaque marker 110 is shown on the proximal and distal ends of inflatable membrane portion 108.

As will be described in more detail below, this catheter assembly 100 is entirely so that the guidewire 112 can pass through the proximal end of the guidewire assembly 100 and extend beyond the distal end of the catheter assembly 100. It is an assembly with an open lumen along its length. A radiopaque coil 114 is surrounded on the illustrated guidewire 112. The structure of the guidewire is not important in the present invention. Nevertheless, the catheter is designed to guide the guidewire into the twisted vasculature of a weak organ of a person, such as the brain or liver.

In addition, the subject matter of the present invention and the details described below relate to an annular lumen that forms a closed system with an instrument or membrane 108. The membrane expands and contracts through this lumen and separates from the central or lumen with guidewires. This annular lumen is filled with an expandable liquid through a device such as the side arm 116 of luer 118. 1b shows in more detail the hydraulic communication of the luer assembly. The side arms 116 and luer 118 are customary for attachment to the source of expansion fluid, radiopaque liquids for monitoring the catheter's passage through the vasculature, salt solutions for cleaning the guidewire lumen and others. Has a threaded container or fitting.

2A and 2B show one very preferred aspect of the catheter of the present invention. Unlike most other instrument catheters currently in use today, such catheters include the use of an expandable flexible membrane 220. The membrane 220 is a flexible member and has an elastomeric characteristic. A membrane is a device or membrane that matches the shape of the interior of the device within the vascular structure. 2A illustrates a preferred variant of the present invention in which the expanded membrane 220 has the same diameter as the distal end of the intermediate portion 104. This allows the catheter to operate in a much simpler form than a catheter with an inflatable, fixed sized instrument that is folded before introduction into the vasculature. The latter catheter often has a longitudinally folded instrument during its transverse movement through the vasculature to reach its intended site, the folded instrument being of polyethylene. 2B shows the membrane 220 in its expanded state. Although the instrument is shown as having a constant diameter in the flat shape or toward the middle of its inflation shape, the instrument may be in other shapes. Also shown in FIGS. 2A and 2B are guidewires 112 having distal and proximal radiopaque bands 110 and radiopaque (possibly similar) coils 114 attached to their distal tips. Is shown.

3 and 4 illustrate one preferred variant of the invention. These FIGS. 3 and 4 are partially cut cross-sectional views, wherein the main portion of the catheter assembly may form the working shafts (102, 104, 106 in FIG. 1A) of the catheter. In particular, FIG. 3 shows outer tube assembly 230, inner tube assembly 232 and guidewire 112 for illustrative purposes. These figures are not drawn to scale so that the various parts forming the catheter assembly may be clearly shown.

The outer tube assembly 230 is typically comprised of three parts: outer cover 234, inner cover 236 and braid 238. Braid 238 may be discontinuous if desired.

Although not required, the inner tube assembly 232 typically includes an outer tube cover 240, an inner braid 233, and an inner tube liner 242. Finally, the guidewire 112 is shown in the inner lumen of the inner tube assembly 232.

4 is a cross-sectional view of the catheter portion shown in FIG. 3, showing the central portion of the present invention. In particular, an annular space 244 is shown positioned between the outer tube assembly 230 and the inner tube assembly 232. The outer diameter of the inner tube assembly 232 is sized such that the gap for the flow of the expansion liquid between the outer diameter of the inner tube assembly 232 and the inner surface of the outer tube assembly 230 is small. The annular space 244 is hydraulically separated into the inner lumen of the catheter 236. The inner tube assembly 232 is spaced apart from the outer diameter of the outer tube assembly 230. Although this concept is preferred in some variations, in the variations of the invention described herein, no physical spacers are located in the annular space 244. Such spacers similarly inhibit the flow of liquid from the outside of the catheter to the inflatable membrane and affect the flexibility of the catheter by adding small points of significantly higher intensity. Although it is common for the inner tube assembly 230 to be spaced from the inner lumen of the outer tube assembly 230, it is preferred that the two are fixed to each other only at the very distal tip of the catheter or at the distal end of the catheter assembly 100. As is common, there is a possibility of side to side or radial movement of the inner tube assembly 232 in the annular space 244 to the point of contact with the inner wall of the outer tube assembly 230. This, of course, does not allow the annular space 244 to become annular at the point of contact and in the area surrounding it, but for the purposes of the present invention the area for the purpose of the present invention may be annular.

Another major aspect of this portion of the invention is the presence of a braid 238 that is part of the outer tube assembly 230. The presence of this braid 238 in the outer tube assembly 230 has a good arrangement advantage. The individual strands that make up the braid 238 may be a polymeric fibrous strand (eg, polyester such as polyethylene terephthalate, such as Dacron, polyimide such as nylon, LCP, etc.) or stainless steel. The outer tube assembly 230 also includes an outer tube assembly 230 and an inner tube assembly 232 because it consists of a superelastic alloy containing one of nickel and titanium such as nitinol and is a ribbon rather than a wire. ) Provide twist resistance. Because the outer tube is twist-resistant and fairly flexible, the vascular catheter prepared for the neurological size of the size described below is an area where the passage of liquid injection through the lumen of the inner tube assembly 232 has not previously reached easily. To reach me. In addition, since the expandable membrane can be used as a temporary occlusion device to block blood flow through the luminal lumen, the introduction of a particular drug is much more precise, and the concentration of drug at this entry site is improved. This braid allows the distal tip of the catheter to be stabilized during high pressure liquid injection through the innermost lumen and to inject a viscous liquid or a liquid containing a large amount of solids or particles. The presence of the ribbon braid 238 in the outer tube assembly 230 allows for the temporary occlusion of the very terminal vascular segments for physiological testing as well as for the introduction of various therapeutic agents. Finally, the central lumen design is shown to provide a rapid expansion / contraction reaction. In addition, the instrument diameter is controlled with increasing and decreasing pressure.

Outer tube assembly 230 need not include braid 238 along its entire length. The braid 238 was found to extend at least about 25% of the distance from the proximal end of the inflatable membrane.

In some examples, introducing liquid under pressure into the inner lumen 246 can cause expansion of the wall of the inner tube assembly 232 when the braid member 233 is not present, thereby causing the outer tube assembly 230 And the acceptable volume in the annular space 246 between the inner tube assembly 232. This expansion causes the instrument to expand at an inappropriate time. Thus, to alleviate this problem, the braid member 233 in the inner tube assembly 232 is introduced at least with respect to the length typically found in the guide catheter.

Referring again to FIGS. 2 and 3, the material of the structure is as follows. For the outer tube assembly 230 the outer cover 234 preferably comprises polyurethane. The polyurethane is easily placed on the outside of the braiding by the lamination technique described below. It is preferable to use polyurethanes with different modules of flexibility and strength (eg durometer values) when forming a catheter such as that shown in FIG. 1A with multiple flexible parts. For example, in three flexible variations of the catheter assembly 100 shown in FIG. 1A, the outer sheath 234 may be polyvinyl acetate or ethylene acetate; Various nylons, polyesters such as polyethylene terephthalate (PET); Polyvinyl chloride; Polysulfones including polyethersulfone, polyphenolsulfone; Alloys of various ketone base resins such as polyaryletheretherketone (PEEK) and variants such as PEKK, PEKEKK and the like, and non-alloyed polyethylene (LLDPE and LDPE) polymers of different families such as polyolefins such as polypropylene. have. These are suitable because they are located along the outer surface of the braid 238. The stronger material may be located in the proximal region on the catheter assembly 100 shown in FIG. 1A. More flexible material may be located on the exterior of the portion 104 in FIG. 1A and on the most flexible portion on the distal portion 106 of FIG. 1A. By varying the composition of the material in this way, a catheter with a fairly constant diameter can be formed and has the desired flexibility. Again, the most preferred polymeric material used on the outer surface 234 of the outer tube assembly 230 is polyurethane. Suitable polyurethanes include commercially available products such as Pelethane (Dow Chemicals) and Carbothane (Thermedics).

Braid 238 is preferably made of a plurality of polymeric multi-threaded ribbons. The polymer may be polyester (e.g. PET, such as Dacron), liquid crystalline polymer (LCP), polyamide (e.g. nylon), polyolefin (e.g. polypropylene), polyaramid [e.g. Kevlar) ], And the like can be selected from known materials. In addition, the braid 238 may be made of stainless steel or a superelastic alloy as described elsewhere. Dacron is preferred.

The braid 233 is preferably made of a plurality of metallic ribbons. Especially preferred are superelastic alloys containing nickel and titanium. Particularly important materials are materials commonly known as nitinol. These alloys were found by the U. S. Naval Ordnance Laboratory. Such materials are fully described in US Pat. No. 3,174,851 to Bueller et al., US Pat. No. 3,351,463 to Rosner et al. And US Pat. No. 3,753,700 to Hays et al. Typical alloys include some amount of the member selected from the iron group, such as Fe, Cr, Co, and the like. These are suitable for use in the kind of superelastic alloys predicted by the present invention. In addition, the Nitinol family of alloys most preferably contains a small amount of chromium (up to about 5%). These small amounts of iron group-containing metals in superelastic alloys retain good shape after heat treatment. The braid shown in the figure was squeezed onto a stainless steel mandrel and added with a braid on the mandrel for several minutes in combination with a heating step of 600 ° C to 700 ° C. This heat treatment causes the braid shape to stabilize, but the alloy forming the braid keeps its superelasticity.

The ribbons forming the braids 233 and 238 are preferably 0.25 to 3.5 mils thick and 2.5 to 12.0 mils wide. The term ribbon includes an elongate shape, the cross section of which is not square or circular, but may be rectangular, oval or semi-elliptical. They should have an aspect ratio (thickness / width) of at least 0.5. The thickness and width for the superelastic alloy including nitinol and variants containing small amounts of iron group metals can range from 0.25 mils and 1.0 mils, respectively, towards the bottom. Current useful and preferred ribbons include sizes of 0.5 mil x 3 mils, 0.75 mil x 4 mils, 2 mil x 6 mils and 2 mil x 8 mils.

Most of the ribbon forming the braid 233 is most preferably a superelastic alloy. A small portion (less than 35%) of the ribbon can be made of auxiliary material. Synthetic and natural fibers can be used, such as performance polymers such as polyaramid or carbon fibers. In certain applications, more malleable metals such as gold, platinum, palladium, rhodium may be used. In these examples, a very preferred alloy is platinum containing a few percent of tungsten. Braids used in the present invention can be made using commercially available tubular braders. The term braid refers to a tubular structure in which the ribbon forming the structure is woven into and out of shape to intersect to form a tubular lumen defining a single lumen. Braids may be made of any suitable number, typically six or more ribbons. It is a braid with 8 or 16 ribbons that is easy to manufacture by a commercial brader.

The braids 233 and 238 shown in FIG. 3 have a nominal pitch angle with a braid axis of 45 °. Since the braid may have elements that move clockwise and counterclockwise around the tubular braids 233, 238, the angle between the two elements is shown at a typical 90 °. For the catheter of the type described herein, the braid angle with respect to the catheter axis is preferably 45 degrees or less. In these situations, the pitch angle of either side of the catheter changes in function of the catheter axis (or to vary the strength of the catheter in shape by changing the composition of the polymer layer adjacent to the braid 233 or 238). You can simply change to different angles.

The inner sheath 236 enclosed about the tube assembly 230 may be a lubricious material, such as polytetrafluoroethylene or other suitable fluorocarbon polymer, another lubricious material, such as polyylene, and the like. Moreover, the inner liner 236 may be a polyurethane adjacent to a braid and a stack of polyfluorocarbons therein.

Polyurethane and TFE combinations are highly preferred, and the outer surface of the TFE tube used can be chemically etched using a solution such as a mixture of metallic sodium and ammonia such that the TFE tubing forms a strong mechanical bond with the adjacent polyurethane. When using the above-described methodology described below, preferred polyurethanes are melted in place using instant shrink wrap tubes as molding members. The polyurethane flows through the gaps in the braid and adheres to the polyurethane formed on the etched polypulocarbon surface or on the other surface of the braid.

Inner tube assembly 232 includes outer tube cover 240 of polyurethane or other suitable polymer, such as the members described above, braid 233 of the material described elsewhere, and inner tube liner 242 of lubricious material, such as TFE. It is a construct of. In certain circumstances, the polyurethane layer may be omitted as shown in other variations of the present invention described below.

Finally, the interior of the parts shown in FIGS. 3 and 4 can be seen on the guidewire. Suitable guidewires for this portion are described in US Pat. No. 4,884,579 to Engelson. As mentioned above, the specific physical shape of the guidewire does not form an important part of the present invention, although it is very clear that the described catheter assembly is for the specific purpose of advancing or retracting the guidewire through the twisted vasculature. Typical size ranges for the parts of the invention shown in FIGS. 3 and 4 are shown in the table below.

Typical Dimensions (Inches) Outer diameter of outer tube assembly 230 0.025 to 0.045 Inner diameter of outer tube assembly 230 0.020 to 0.045 Wall thickness of outer covering 234 0.001 to 0.004 Wall thickness of inner covering 236 0.0005 to 0.003 Outer diameter of annular space 244 0.020 to 0.045 Inner diameter of annular space 244 0.016 to 0.040 Outer diameter of inner tube assembly 232 0.016 to 0.040 Inner diameter of inner tube assembly 232 0.010 to 0.035 Wall thickness of outer covering 240 0.0005 to 0.003 Wall thickness of inner covering 242 0.0005 to 0.003

These dimensions are provided only as a guideline to assist in understanding the small catheter accepted and accomplished as a result of the present invention.

Figure 5 shows another variant of the working shaft of the catheter of the present invention. In this variant, the catheter section 300 is formed similar to the sector 230 in FIGS. 3 and 4. However, outer tube assembly 302 includes only outer tube cover 304 and braid 238. Inner tube assembly 232 is manufactured in the same manner as the inner tube assembly of FIG. Guidewire 112 remains in the center. Unlike the above-described modification, the overall structure of the assembly 300 is the same as that shown in FIGS. 3 and 4. The composition of the outer tube assembly 302 and its outer sheath 304 may be basically the same as described with respect to the outer sheath 234 in FIGS. 3 and 4. The material forming this braid 238 is the same as the configuration in the previous figures.

6 shows a variant of the device of the present invention, where the braid 238 is disposed at the contact surface between the inner tube 322 and the outer tube 324. For most catheters made in accordance with the present invention, the braid 320 of the inner assembly 318 axially overlaps the braid 318 in the outer tube assembly 230 by an inch or two inches. In this way, the instrument section is given a level of strength that leaves the inflatable membrane region sufficient to follow the guidewire, but provides a good degree of transition from the proximal region to the stiffer, more flexible instrument section. do. As can be determined from this view, the braid or coil 320 installed in the variant shown in FIG. 6 is more flexible than the braid 318 installed in the outer tube assembly 230.

In this respect, the inner sheath 236 extends to the area of the inflatable membrane 312 all the way towards the distal tip 318. Multiple orifices 316 allow fluid to flow from annular space 244 to inflatable membrane 312.

7 illustrates another variation of the present invention, wherein the inner covering 236 of the outer tube assembly 230 terminates at the end of the inflatable membrane 312. This is a simple variant of the embodiment shown in FIG. 6. The braid 320 again extends all the way towards the distal end 330 of the catheter assembly. Since the inner covering 236 of the outer tube assembly 230 is cut at the proximal end of the inflatable membrane 312, the outer diameter of the distal tip 330 may be very small. On the other hand, the variant shown in FIG. 7 is very similar to that shown in FIG. Braid 320 overlaps superelastic alloy braid 238 by at least one inch to provide sufficient strength, transition, and overall pressure on the catheter assembly.

6 and 7 illustrate the materials that make up the inflatable membrane 312, which contact the outer sheath 234 of the outer tube assembly 230, respectively. A preferred variant is shown in FIG. In this case, the tubes that make up the inflatable membrane 340 are disposed outside the outer cover 234 of the outer tube assembly 230 and overlap several inches on the outer cover 234 of the outer tube assembly 230. This provides a tighter seal between the inflatable membrane 340 and the outer tube assembly. Similarly, FIG. 9 illustrates a variation including proximal overlap features of inflatable membrane 340, with the distal end of inflatable membrane 340 being the outer sheath of inner sheath 236 and inner tube assembly 232. 234 is connected. This deformation causes the distal tip to be many smaller than most of the variations described herein. Nevertheless, the central lumen remains open for the guidewire injection passage.

FIG. 10 shows a variant of the device of the present invention that requires a coil member 368 in the region of the inner tube assembly 369 overlapping the distal and proximal regions of the inflatable membrane 370. As described, the rest of the inner and outer assemblies are herein. Coil 368 is particularly useful for small French catheter to provide added measure of flexibility to the distal end of the overall catheter assembly, but still provides anti-twist protection when using soft, compliant instruments or membranes. to provide. Coil member 368 is preferably a metal ribbon, one of the materials described. However, it is preferably a superelastic alloy.

11A, 11B and 11C illustrate the concept and use of elastomeric band 240 lying in the proximal region of inflatable membrane 318 in a manner that acts as an indicator of proper expansion of the device.

FIG. 11A shows an unexpanded inflatable membrane 318 bound to the proximal end by a band of warning strip material 340, which has a higher durometer ratio than the material used for the inflatable membrane 318. And is fairly radiopaque. Radiation impermeability in such materials is provided by various methods. In particular, the band 340 may comprise barium sulphate, bismuth trioxide, bismuth carbonate, powdered tungsten, powdered tantalum or a radiopaque filler such as It can be filled with, and contrasted with the material is shown. For example, it is within the scope of the present invention to include such things as radiopacity in some of the polymers used herein. It is almost always desirable to be able to see the contours of the catheter inserted into various parts of the body, at least in minor ways. Most of the tubes used in the devices of the present invention are so small that fluoroscopy cannot provide a good outline of such devices. Simply appearing of radiopaque materials is not enough. Although the body parts are somewhat dense in fluoroscopy, the present invention shown in FIGS. 13A-13C is very valuable for the present invention to provide a proximal shape for the device, wherein the device is suitably inflated with an expandable membrane or Almost overexpansion.

As can be seen in FIG. 11B, the inflatable membrane 318 at normal expansion rests comfortably along the inner sheath 236 of the outer tube assembly 230. When the radiopaque band 240 emerges from the braid 238 and provides a device having a shape generally as shown in FIG. 11B, the physician using the device as an expanded membrane approaches the design limitations of the device. . If a larger diameter is needed, a new catheter with a larger diameter inflatable membrane 318 can be used, or if such is acceptable, the expansion of the inflatable membrane should be slightly reduced.

12A and 12B are partial cutaway side and partial cutaway end views of a distal tip of a catheter made in accordance with the present invention. In particular, this figure shows the most preferred structure and method for removing air from the annular region of the present invention.

12A has an outer tubing assembly and purging sheath 352 made of an outer polymeric covering and braid member 356 and an inner polymer layer 358. The distal end of the catheter assembly 350 is shown. The catheter assembly 350 also includes an inner tube assembly consisting of a polymer layer 360, a braid member 362, and an internal lubricity polymer layer 364. In the case of the device described above, the inner tube assembly and the outer tube assembly are separated from each other such that an annular region 366 is formed between the two tube assemblies. In this variant, a number of orifices 368 are formed starting from the annular region 366, which is used to expand the inflatable membrane 370.

At the heart of this variant of the invention is the presence of a small bleed port 372 passing through the end of the annular region 366. This port is sized to allow the expansion of the instrument to close the bleed port or port 372 when the inflatable membrane 370 actually expands by flowing fluid from the annular region 366 through the filling port 368. Has Although only one bleed port 372 is shown in FIGS. 12A and 12B, the present invention may use one or more such openings. Bleed restraint sheath 352 is shown disposed in place on the exterior of catheter assembly 350. While this sheath 352 is in place, the bleed port 372 is opened. This allows a person to fill the annular region 366 with liquid, releasing all air found in the annular region 366 before the catheter is inserted into the patient. As soon as air is removed through the bleed port 372, the confinement sheath 352 may be removed. The catheter may then be placed into the intraocular catheter or introducer to orient the catheter to the desired site.

Otherwise, the catheter assembly 350 shown in FIGS. 12A and 12B has the same advantages and structures as described elsewhere herein.

13A, 13B and 13C show another variant of the catheter 400 of the present invention. In this variant, the inflatable membrane also extends distal, not just extending outwardly from the axis of the catheter assembly 400. This particular variant has an outer mechanism 402. In addition to the description of the extraneous mechanism 402, the variant shown in FIGS. 13A-13C provides a removable mechanism with a self-sealing valve 406.

13A shows a detachable instrument 404 seated on catheter 400. This catheter assembly 400 includes an inner tube assembly 408 and an outer tube assembly 410 in much the same way that the above-described variations have such variants. Annular region 412 opens into the instrument 402 via one or more small passageways, such as 414. 12A-12C show a variant in which the detachable instrument 404 may be inflated after introduction of the assembly 400 into the body. Inflation of the detachable instrument 404 may be performed independently of inflation of the catheter instrument 402. The extensible instrument 402 is present on the catheter for the purpose of deployment of the removable instrument 400.

The development takes place in the following way. After the volume interior of the removable device 404 is filled via the lumen 414, fluid is introduced into the interior space of the device 402 through the annular region 414. As shown in FIG. 13B, the instrument 402 begins to extend distal to push the removable instrument 404 from the distal end of the catheter. The platypus spout shaped self-closing valve 406 is almost closed in FIG. 13B.

FIG. 13C shows the instrument without the distal end of the inner tube assembly 408 and the self-closing valve fully closed. The self-closing valve 406 may be a platypus spout or other type of self-closing valve. For example, a valve much like that found in the heart operates the same and is configured to close when the tubular assembly is removed from its interior.

Removable instruments are suitable for a variety of applications. They may be used in other variations of embolic materials such as embolic coils or cyanoacrylate adhesives, glass or polyester beads or fibers and the like. The removable device 404 may be made of various kinds of materials that exhibit similarly broad characteristics. For example, the use of silicone or other expandable compliant instrument material allows the user of the catheter assembly to slightly select the instrument size even after the instrument is introduced into the body. When using instruments made of non-expandable material, for example polyethylene, the size of the instrument is set prior to introducing it into the body. Selecting a specific size may be highly desirable when the instrument is used in vulnerable vessels.

Generally, modifications of the above-described modifications for carrying out the present invention, which will be apparent to those skilled in the art of medical device design, particularly in catheter devices, are intended to fall within the scope of the following claims. .

The catheter of the present invention is suitable for use in the terminal vasculature, and prevents tremor and improper expansion of the instrument while performing other procedures, and particularly resists tremor in the region immediately adjacent to the instrument.

Claims (19)

In a catheter assembly, (a) an outer tube assembly having a proximal end and a distal end and an axis extending therebetween, the outer tube assembly comprising an outer polymeric cover extending from the proximal end to the distal end and for at least a portion of the shaft the outer polymeric cover; The outer tube assembly having a ribbon braid disposed therein; (b) an inner tube assembly having a proximal end and a distal end and a lumen extending therebetween, the inner tube assembly comprising an outer polymeric cover extending from the proximal end to the distal end and the outer polymeric cover for at least a portion of the shaft; A superelastic alloy ribbon braid member disposed within the interior of the interior tube assembly, wherein the inner tube assembly is positioned spaced therefrom within the outer tube assembly to form an annular space between the outer tube assembly and the inner tube assembly. The inner tube assembly; (c) a membrane assembly having a proximal end and a distal end expandable membrane, wherein the expandable membrane is at the distal end of the outer tube assembly and extends distal to the distal end of the inner tube assembly such that A catheter assembly comprising the tube assembly forming an expandable cavity in fluid communication with the annular space therebetween. The method of claim 1, The outer tube assembly further includes an inner polymeric tube member positioned inside the ribbon braid member. The method of claim 1, The inner tube assembly further includes a lubricating inner polymeric tube member inside the braid member. The method of claim 1, The superelastic alloy ribbon braid member extends beyond the distal end of the outer tube assembly to the distal end of the inner polymeric tube assembly. The method of claim 1, The outer tube assembly further includes an inner polymeric tube member positioned inside the superelastic alloy ribbon braid member, wherein both of the superelastic alloy ribbon member and the inner polymeric tube member have a distal end of the outer tube assembly. An extension extending beyond the distal end of the inner polymeric tube assembly, the inner polymeric tube member having a tube wall having at least one orifice, in fluid communication with the annular space between the outer tube assembly and the inner tube assembly A catheter assembly to allow fluid communication through tube walls between possible cavities. The method of claim 1, And the superelastic alloy ribbon braid member terminates at the proximal end of the membrane assembly. The method of claim 3, wherein And the braid member extends proximally from the distal end of the membrane assembly to a point at the proximal end of the membrane assembly. The method of claim 1, The outer polymeric sheath of the outer tube assembly includes at least two sections with different stiffness. The method of claim 8, The outer polymeric sheath of the outer tube assembly comprises a proximal section with relatively low flexibility, a distal section with relatively high flexibility, and an intermediate section with flexibility between the proximal and distal sections. The method of claim 1, The catheter assembly of the outer tubular assembly comprises a polyurethane. The method of claim 1, The inner polymeric tubular member of the outer tubular assembly comprises a lubricity polymer. The method of claim 11, And the polymeric tubular member of the outer tubular assembly comprises polyfluorocarbons. The method of claim 1, The catheter assembly of the inner tube assembly of the inner tube assembly comprises polyfluorocarbons. The method of claim 1, The expandable membrane further expands to the distal end upon inflation. The method of claim 14, And a mechanism releasably attached to the distal end of the inflatable membrane to release upon expansion of the inflatable membrane. The method of claim 15, The releasable instrument further includes a one-way valve suitable for receiving fluid from the inner tube assembly lumen. The method of claim 1, And at least one bleed port for opening said annular space between said outer tube assembly and said inner tube assembly, said at least one bleed port being sealable upon expansion of said inflatable membrane. The method of claim 1, And the outer tube assembly braid member comprises a polymeric ribbon. The method of claim 18, And the outer tube assembly braid member comprises a polyethylene terephthalate ribbon.