WO2016199117A1

WO2016199117A1 - Improved balloon catheter and method of use

Info

Publication number: WO2016199117A1
Application number: PCT/IL2015/050582
Authority: WO
Inventors: Eran Harari; Gal MEISTER; Gil Bernstein; Alexander Barash; Roy Feig
Original assignee: Angioslide Ltd
Priority date: 2015-06-09
Filing date: 2015-06-09
Publication date: 2016-12-15

Abstract

A balloon catheter comprising an inflatable balloon at a distal end of a lumen for allowing passage of a fluid to said inflatable balloon for inflating said balloon, the balloon catheter further comprising a bell shaped sleeve covering the balloon of the balloon catheter such that inflation of said balloon causes said sleeve to dilate, whereas subsequent deflation of said balloon by extraction of the fluid, causes the balloon to separate from the dilated bell shaped sleeve, and a bell shaped sleeve having a circumferential wall for covering a balloon with a circumferential wall of a balloon catheter that is inflatable by a lumen; the bell shaped sleeve having a closed proximal end closely surrounding the lumen, and an open distal end, such that inflation of the balloon causes dilation of the bell shaped sleeve, whereas deflation of the balloon separates the wall of the balloon from the dilated bell shaped sleeve.

Description

IMPROVED BALLOON CATHETER AND METHOD OF USE

BACKGROUND

The present invention relates to devices and methods for angioplasty and for the biopsy of artery clogging material, and more particularly to catheters having a balloon with an open sleeve.

Atherosclerosis, the clogging of arteries, is a leading cause of coronary heart disease. Blood flow through the peripheral arteries (e.g., carotid, femoral, renal, etc.), is similarly affected by the development of atherosclerotic stenotic lesions (narrowings). One existing method of removing or reducing the effect of stenotic narrowings in blood vessels is known as angioplasty.

Angioplasty is the technique of mechanically widening narrowed or obstructed arteries, which may become blocked a result of atherosclerosis.

A variety of minimally invasive interventional procedures have been developed for opening stenosed or occluded blood vessels in a patient caused by the build up of plaque or other substances on the walls of the blood vessel. Such procedures usually involve the percutaneous introduction of the interventional device into the lumen of the artery, usually through a catheter.

One widely known and medically accepted procedure is balloon angioplasty in which an inflatable balloon is introduced within the stenosed region of the blood vessel to dilate the occluded vessel. The balloon catheter is initially inserted into the patient's arterial system and is advanced and manipulated into the area of stenosis in the artery. The balloon is inflated to compress the plaque and press the vessel wall radially outward to increase the diameter of the blood vesselln order to help deliver balloon catheters and stent devices, special guiding catheters or sheaths are often used. These guiding catheters or sheaths are placed upstream from the targeted lesion or stenotic area. A guide wire may be advanced past the stenotic area, allowing the subsequent balloon catheters and stents to be advanced through the guiding catheter or sheath to the target area of the blood vessel.

A typical coronary angioplasty procedure consists of accessing a peripheral artery (usually femoral) and then advancing a guide catheter to the ostium of the coronary artery. A long coronary guidewire is then advanced through the guide catheter and the distal end of the guidewire is maneuvered through the coronary artery to a point beyond the stenotic lesion. A balloon angioplasty catheter with an inflatable balloon at its distal end is then advanced over the guide wire until the balloon is positioned across the stenotic or occluded area. The balloon is then inflated to dilate the constricted area. The angioplasty balloon is then deflated and a controlled injection of radiopaque contrast material is made in order to confirm successful dilation of the stenotic area. The balloon angioplasty catheter is then removed and an ultrasonic catheter may then be advanced over the guide wire to confirm proper stent deployment. The guide wire is subsequently removed from the body at the end of the procedure.

Rapid exchange ("monorail" or RE) catheters typically comprise a relatively short guide wire lumen provided in a distal section thereof, and a proximal guide wire exit port located between the catheter's distal and proximal ends. This arrangement allows exchange of the catheter over a relatively short guide wire, in a manner which is simple to perform and which can be carried out by a single operator. Rapid exchange catheters have been extensively described in the art, for example, in U.S. Pat. Nos. 4,762,129, 4,748,982 and EP0380873.

Rapid exchange catheters are commonly used in Percutaneous Transluminal Coronary Angioplasty (PTCA) procedures, in which obstructed blood vessels are typically dilated by a distal balloon mounted on the catheter's distal end. A stent is often placed at the vessel's dilation zone to prevent restenosis (reoccurrence of obstruction). The dilation balloon is typically inflated via an inflation lumen which extends longitudinally inside the catheter's shaft between the dilation balloon and the catheter's proximal end.

In another widely practiced procedure, the stenosis can be further treated by placing a device known as a stent into the stenosed region to hold open and sometimes expand the segment of the blood vessel or other arterial lumen. Stents are particularly useful in the treatment or repair of blood vessels after a stenosis has been compressed by balloon angioplasty or removal by atherectomy or other means.

The above interventional procedures, when successful, avoid the necessity of major surgical operations. However, there is one common problem associated with all of these minimally invasive procedures: the potential release of embolic debris into the bloodstream which can occlude distal vasculature and cause significant health problems to the patient.

Medical devices have been developed to attempt to deal with the problem created when debris or fragments enter the circulatory system following treatment utilizing any one of the above-identified procedures. One approach which has been attempted is the cutting of any debris into minute sizes which pose little chance of becoming occluded in major vessels within the patient's vasculature. However, it is often difficult to control the size of the fragments which are formed, and the potential risk of vessel occlusion still exists, making such procedures in the carotid arteries a high-risk proposition.

Other techniques which have been developed to address the problem of removing embolic debris include the use of catheters with a vacuum source which provides temporary suction to remove embolic debris from the bloodstream. However, there have been complications with such systems since the vacuum catheter may not always remove all of the embolic material from the bloodstream, and a powerful suction could cause problems to the patient's vasculature.

Further techniques which have had some limited success include the placement of an embolic protection device such as a filter or trap downstream from the treatment site to capture embolic debris before it reaches the smaller blood vessels downstream. Such embolic protection devices enable the filtering of embolic debris which may be released into the bloodstream during the treatment to the vessel, and yet allow a sufficient amount of oxygenated blood to flow past the device to supply vital organs downstream from the treatment site.

There have been problems associated with embolic protection devices, particularly during the assembly, insertion, and deployment thereof. The device may be mounted on the guide wire in an inconvenient manner so as to be fixedly secured thereto. Also, the mounting of the device on the guide wire, such that the device is affixed to and rotatable with the guide wire, may result in the entangling of the device in a delivery sheath as the device is being directed in the delivery sheath through the patient's anatomy to the position distal to the interventional procedure site. Further, the expansion and deployment of the embolic protection device may not result in full and complete expansion of the device, and consequently may not seal off the inner wall of the blood vessel about its entire circumference, which can result in embolic material bypassing the device. The formation of the embolic protection device also may not be such as to enable the device to maintain vessel wall opposition upon expansion thereof, which can also result in embolic material bypassing the device. The length of the device may further result in difficulty in navigating tortuous vasculature. A need exists for a catheter procedure not requiring an embolic filter.

United States Patent Number US 6,491,712 titled "Double walled balloon debris collector" relates to a device for collecting debris flowing in an artery downstream from a percutaneous coronary intervention. The device includes a hollow guidewire, a double walled balloon connected to the guidewire, and a filter secured to the balloon and to the guidewire, all of which are inserted into the artery downstream of the intervention. Prior to the intervention, the double walled balloon is inflated to occlude the blood vessel except for the open area of the filter. Any debris flowing downstream from the intervention is caught in the filter. When the intervention is completed, the balloon is deflated causing it to collapse away from the vessel wall, permitting blood flow past itself and trapping any debris caught by the filter between itself and the guidewire. Multiple inflation and deflation cycles may be performed if multiple interventions are required upstream. The entire device can then be removed from the artery

United States Patent Number US 7,097,440 titled "Embolic protection systems" describes a system for enabling the insertion and removal of an embolic protection device, for capturing and retaining embolic debris which may be created during the performance of a therapeutic interventional procedure in a stenosed or occluded region of a blood vessel. The system, in an embodiment thereof, enables the device to be snap-fitted so as to engage the distal end of a guide wire, to be pre-formed for its expansion so as to seal off the inner surface of a blood vessel, to inhibit the forming of a gap therein, for inhibiting embolic material from passing therethrough, and to be foreshortened to enable its insertion through confined spaces. Another embodiment of the system enables expandable material to be formed into an expandable configuration of an embolic protection device for capturing embolic material, which is capable of sealing off the inner surface of the blood vessel.

United States Patent Number US 7,189,250 titled "Aspirating balloon catheter for treating vulnerable plaque" relates to devices and methods for extracting core material contained in plaque deposits inside a blood vessel. A device in accordance with one embodiment of the invention includes a catheter having an elongate shaft, a collection array of a plurality of collection lumens disposed about the distal portion of the elongate shaft, a means for radially extending and/or collapsing the collection array, and a suction means for extracting material from the lumen of the blood vessel. A method in accordance with one embodiment includes the steps of inserting the distal portion of the catheter into a lumen of the blood vessel, positioning the distal end of the collection array proximate plaque deposits, extending the collection array to rupture the plaque deposits and to urging core material therefrom, and to extract the material using a suction means fluidly coupled to the proximal end of the collection array.

United States Published Application Number USSN 2007/135832 titled "Vascular Catheter with Aspiration Capabilities and Expanded Distal Tip" describes a vascular catheter and method of use of the catheter for aiding in balloon angioplasty and stent placement procedures. The vascular catheter has a retrieval catheter with an expanded distal portion. The expanded distal portion has aspiration holes which allow aspiration of embolic debris during recovery of the embolic filter. A guide sheath may be used to guide the retrieval catheter past a stent and into position for aspiration and retrieval of the filter after stent placement.

United Kingdom Patent Application Number GB2426457 (A) titled "Balloon angioplasty device with distal protection capability" describes a balloon angioplasty device for dilating a region of a vessel of a patient which has been occluded by a stenotic lesion comprises an inflatable element comprising a dilatation balloon and a membrane located around the distal end of an elongate catheter shaft. The membrane has at least one flushing opening at or near its distal end. In use, the dilatation balloon is inflated to cause the inflatable element to dilate the stenotic lesion. As the balloon is partially deflated the membrane continues to be pressed against the treated stenotic lesion by the pressure of flushing fluid which is pumped along an antegrade flushing fluid flow path between the dilatation balloon and the membrane, the pressurized flushing fluid entering the treated vessel through the flushing fluid opening(s). The membrane remains pressed against the treated lesion until the pressure of fluid in the vessel distal to the inflatable element increases to a pressure where the flushing fluid is forced to flow in a retrograde direction between the treated stenotic lesion and the membrane when the membrane moves away from the treated lesion thereby providing at least one retrograde fluid flow path for the retrograde flushing fluid entraining debris released from the treated lesion.

United States Published Application Number US2007/073332 titled "Intraluminal filter having a cover sleeve" describes a temporary filtering device for collecting debris in a body lumen. An embolic filter is utilized that is expandable and collapsible by a push-pull action. A filter proximal end is attached to a proximal shaft portion and a filter distal end is attached to a distal shaft portion. The proximal and distal shaft portions are slidably engaged within the filter, such that relative longitudinal movement between the proximal and distal shaft portions either moves the filter ends closer together to expand the filter, or moves the filter ends farther apart to collapse the filter. The filtering device includes a cover sleeve coaxially disposed about the filter that is attached to the distal shaft portion for aiding in the collapse of the filter. The cover sleeve may be attached to the distal shaft portion by one or more connecting rods, and is sized to slide over the filter and at least partially cover the filter openings, when the filter is being collapsed and when the filter is in its collapsed configuration. The temporary filtering device may be utilized without a distal shaft portion, wherein the filter distal end and connecting rods are attached or slidable relative to a core wire and relative movement between the core wire and proximal shaft reconfigures the filter between the expanded and collapsed configurations.

United States Patent Number US 4,921,478 titled "Cerebral balloon angioplasty system" describes an occlusion catheter for use during the therapeutic intervention of a cerebral blood vessel for flushing away fluid and debris from the area of the therapeutic intervention. The catheter carries an inflatable occlusion balloon capable of being formed into a funnel with the larger end of the funnel facing distally. The funnel-shaped occlusion balloon seals the walls of the vessel to establish retrograde flow of blood. The peripheral walls of the funnel meet the vessel walls at an oblique angle and channel fluid and debris flowing proximally into the funnel to efflux ports at the base of the funnel.

German patent application number DE 10145138 titled "Intervention instrument for internal widening comprises first stented balloon and second balloon downstream with expandable collecting diaphragm for freed debris collection and capture" describes a catheter that carries a first balloon with a fitted stent and with a device distally downstream of the balloon whose expandable diaphragm catches particulate debris freed by the expansion of the first balloon or stent. The diaphragm then closes round the debris to secure it. The device controllably inflates the balloon and collecting device in a manner such that the diaphragm is expanded before the balloon. The diaphragm should be semi-permeable to let the contrast agent and blood through but block the debris particles and has holes of several microns. A second balloon distally downstream of the balloon is responsible for expanding the collecting diaphragm. The guide wire lumen opens into the second distal balloon.

Published International Application Nos. WO 2005/102184 discloses a catheter having a rollable expandable element. Published International applications, Publication Nos. WO 2007/004221, WO 2007/042935 , WO 2008/004238 and WO 2008/004239, all five published international applications are incorporated herein by reference in their entirety for all purposes, disclose various types of catheters and catheter systems having intussuscepting balloon-like inflatable members which may be used, inter alia, to treat plaque by balloon inflation while efficiently and safely collecting plaque debris and other particulate matter from the lumen of pathologically-involved blood vessels and to remove such particles and particulate matter from the blood vessel.

WO 2008/004238 discloses several types of rapid exchange catheters having an intussuscepting balloon-like inflatable member which may be used for treating plaque in stenosed vessels and for collecting and for removing from the body plaque debris and other particulate matter resulting from the distention of the vessel wall and the compaction of plaque during the inflating of the balloon within the blood vessel.

While the various types of rapid exchange catheters with intussuscepting balloons disclosed in WO 2008/004238 may be efficiently and safely used for treating patients, their construction is based on the use of a segmented tubular inner conduit having several segments. Some segments of the inner conduit are slidably disposed within other segments of the inner conduit in order to enable the distal part of the inner conduit to move proximally during the intussuscepting of the balloon. In order to keep the segmented inner conduit sealed, WO 2008/004238 discloses the use of sealing gaskets designed to withstand the inflation pressure of the balloons. While sealing gaskets are well known in the art their use may pose several technical difficulties, due mainly to the fact that the implementation of sealing gaskets may require expensive and time consuming construction techniques as well as the use of time consuming and expensive testing and quality control procedures. This is especially challenging when the diameters of inner conduit and of the necessary gaskets are relatively small.

While the cavity forming intussuscepting balloons are quite efficient for trapping debris and/or particulate matter or secretions from the treated site, the construction of a movable inner conduit that slides within an outer conduit and the operation of mechanisms to move the inner conduit as combined with an intussuscepting balloon are fairly complex and require expertise to construct and to operate. In particular rapid exchange (monorail) catheters with intussuscepting balloons are not simple to construct.

International published applications WO 08/004238 and WO 08/004239 disclosed a sleeve collecting device having a tube with a sleeve suitable for passage of a debris collecting catheter therethrough. However, such sleeve devices are separate from the debris collecting catheter, require the handling and operating of two separate devices (a sleeve collecting device and a separate debris collecting catheter which is separate from the sleeve device that are longitudinally or axially freely movable relative to each other). The debris collecting catheter is based on an intussuscepting balloon which is first inserted through the lumen of the sleeve device and then operated at the treatment site and only after the capturing of the debris by the catheter the catheter is withdrawn proximally to enter the sleeve of the separate sleeve device.

U.S. Patent 5,092,839 to Kipperman discloses a system including an angioplastic balloon catheter which is movably disposed within a hollow thrombectomy catheter. The thrombectomy catheter has a distal end which may be expanded by inflating the balloon catheter. However, the balloon catheter is axially (longitudinally) movable with respect to the thrombectomy catheter and the system requires moving the balloon catheter distally outside of the thrombectomy catheter in order to perform angioplasty on the lesion followed by proximal movement of the balloon catheter into the thrombectomy catheter in order to collect debris.

There is therefore a need for simple and efficient catheters capable of collecting debris and particulate matter and/or secretions at a treatment site in a body cavity.

SUMMARY OF THE INVENTION

The present invention relates generally to improvements in balloon angioplasty and embolic protection systems and methods whose deployment enables the efficient capture of embolic material, which may be created and released into the bloodstream during the performance of the interventional procedure in a stenosed or occluded region of a blood vessel,. The system further enables the embolic protection device to be inserted through a patient's vasculature and to effectively navigate confined spaces therein, for deployment thereof at the location distal to the interventional procedure site.

The present invention particularly relates to an improved system and method for embolic protection angioplasty The expandable configuration of the device formed thereby provides a substantially uniform maximum outer diameter portion upon expansion, to maintain vessel wall opposition upon deployment, for preventing embolic material from bypassing the embolic protection device.

Aspects of the present invention provide improved systems and methods for treating stenosis in blood vessels which enable embolic protection The same device preforms both balloon angioplasty and captures embolic material, and minimizes the embolic material bypassing the embolic protection device and continuing downstream thereof. The improved systems and methods of the present invention further enable the efficient formation of expandable material into an embolic protection device.

A first aspect is directed to providing a bell shaped sleeve having a perimeter wall for covering a balloon with a perimeter wall of a balloon catheter that is inflatable by a lumen; the bell shaped sleeve having a closed proximal end closely surrounding the lumen, and an open distal end, such that inflation of the balloon causes dilation of the bell shaped sleeve, whereas deflation of the balloon separates the wall of the balloon from the dilated bell shaped sleeve. Optionally, the bell shaped sleeve comprises a material that is viscoelastically or plastically stretched by inflation of the balloon.

Optionally, the bell shaped sleeve comprises a folded bell shaped sleeve that is furled around the balloon, such that inflation of the balloon causes the bell shaped sleeve to unfurl and dilate.

In some embodiments, the bell shaped sleeve comprises perforations for elution of an active preparation therethrough.

Optionally, the active preparation is selected from the group comprising at least one of the group consisting of medicaments, bioselective solvents, blood clotting factors, radioactive markers, contrast enhancing fluids, blood thinning factors, platelets and plasma.

In some embodiments, the bell shaped sleeve further comprises ribs for holding the bell shaped sleeve open.

In some embodiments, the ribs are selected from the group consisting of spokes, rings, open rings and a helical coil.

A second aspect is directed to providing a balloon catheter comprising an inflatable balloon at a distal end of a lumen for allowing passage of a fluid to the inflatable balloon for inflating said balloon, the balloon catheter further comprising a bell shaped sleeve covering the balloon of the balloon catheter such that inflation of the balloon causes the bell shaped sleeve to dilate, whereas subsequent deflation of the balloon by extraction of the fluid, causes the balloon to separate from the dilated bell shaped sleeve.

Typically, the balloon catheter is further advanced on a guide wire.

Typically, the balloon catheter further comprises a second lumen surrounding the guide wire.

Typically, at least one of the following limitations is true: (i) the first and second lumens are coaxial; (ii) the first and second lumen are coextruded adjacent lumens separated by a common wall, and (iii) coextruded, cylindrical lumens.

Optionally, the balloon catheter further comprises a third lumen connectively coupled to the bell shaped sleeve and to a suction device for applying suction pressure to the bell shaped sleeve.

Optionally, a retractable sheath covers the compacted bell shaped sleeve and the compacted balloon.

Optionally, the balloon catheter further comprises a dilatable stent surrounding the bell shaped sleeve, such that insertion of the balloon catheter into a body cavity and its inflation causes dilation of the bell shaped sleeve and of the stent, and subsequent removal of the balloon catheter with the bell shaped sleeve, leaves the dilated stent within the body cavity.

Optionally, the bell shaped sleeve of the balloon catheter is perforated with perforations, and a pharmaceutical preparation is disposed between the balloon and the bell shaped sleeve, such that inflation of the balloon elutes the preparation through the perforations.

Optionally, the preparation comprises at least one of a blood clotting factor, a blood thinner, a selective biological solvent, a radioactive marker, an aesthetic, a disinfectant, collagen, platelets and antibiotics or an antiproliferative drug, such as sirolimus.

In some embodiments, the balloon catheter further comprises a cap at a distal end of the balloon for holding the distal end of the balloon around the guide wire.

Optionally, at least one of the following limitations is true: (i) the cap holds the mouth of the bell shaped-sleeve around the guide wire prior to inflation of the balloon, however inflation of the balloon releases the mouth of the sleeve from the cap; (ii) the cap comprises a soft material, and (iii) the cap comprises a material selected from the group comprising silicone, latex and polybutadienestyrene.

Typically, the balloon catheter is selected from the group comprising over the wire catheters and rapid exchange catheters.

In some embodiments, the bell shaped sleeve comprises ribs.

Optionally, the ribs are selected from the group consisting of spokes, rings, open rings and a helical coil.

Optionally, the fluid is selected from the group comprising gases and liquids.

Typically the fluid is selected from the group comprising water, plasma or blood.

The bell shaped sleeve may be used employed with balloon-over-wire catheters and / or with rapid exchange catheters.

The term lumen and conduit are used interchangeably to refer to a cavity or channel within the tubular structure of the catheter.

DESCRIPTION OF FIGURES

For a better understanding of the invention and to show how it may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings.

With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only, and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention; the description taken with the drawings making apparent to those skilled in the art how the several forms of the invention may be embodied in practice.

In the accompanying drawings:

Fig. 1 is a schematic longitudinal section through a prior- art balloon-over- wire catheter in its deflated configuration;

Fig. 2 is a schematic longitudinal section through the prior art balloon at the distal end of a balloon-over- wire catheter of Fig. 1, in its inflated configuration;

Fig. 3 is a schematic cross-section through the distal end of a prior art balloon-over- wire catheter in its deflated configuration showing dislodged debris

Fig. 4 is a schematic radial cross-section showing the balloon fabricated from a substantially non-stretchable material that is furled around the guide wire for insertion into the body in accordance with one embodiment;

Fig. 5 is a schematic longitudinal section through a prior-art rapid exchange balloon- over- wire catheter in its deflated configuration;

Fig. 6 is a schematic longitudinal cross-section through one embodiment of a balloon- over-wire catheter incorporating a bell shaped sleeve, after the balloon has been deflated, leaving the bell shaped sleeve in a dilated configuration, showing how debris gets sucked into the low pressure cavity between the bell shaped sleeve and the deflated balloon wherein in this embodiment, the catheter is divided into a first pathway for a guide-wire and a second pathway for forcing air under pressure, by a curved dividing wall;

Fig. 7 is a schematic longitudinal cross-section through a distal end of a balloon-over- wire catheter incorporating the bell shaped sleeve, prior to the balloon being inflated and the bell shaped sleeve being dilated;

Fig. 8 is a schematic cross-section through a furled balloon and bell shaped sleeve prior to inflation of the balloon and dilation of the sleeve;

Fig. 9 is a schematic cross-section through a furled compliant balloon and elastic bell shaped sleeve prior to inflation of the balloon and dilation of the sleeve;

Fig. 10 is an embodiment of an over-the-wire catheter incorporating a bell shaped sleeve, after the balloon has been deflated, leaving the bell shaped sleeve in a dilated configuration, showing how debris gets sucked into the low pressure cavity between the bell shaped sleeve and the deflated balloon, in this second embodiment, the catheter is divided into a first pathway for the guide- wire and a second pathway for forcing air under pressure, by a straight dividing wall;

Figs. 11-13 show typical cross-sections of embodiments of the catheter, such that Fig. 11 shows a double lumen catheter wherein the catheter has a cylindrical profile and the first and second lumens are separated by a curved wall;

Fig. 12 shows a cross-section through a double lumen catheter wherein the catheter has a cylindrical profile and the first and second lumens are separated by a straight dividing wall;

Fig. 13 shows a cross-section through a three lumen catheter wherein the catheter has a cylindrical profile and the first and second lumens are separated by a par of straight dividing walls, the purpose of which is discussed hereinbelow;

Fig. 14 is a schematic cross-section through a rapid exchange catheter incorporating a bell shaped sleeve of Fig. 10, with the balloon and bell shaped sleeve deflated;

Fig. 15 is a schematic cross-section through the distal end of a balloon catheter incorporating a bell shaped sleeve of Fig. 10, wherein the balloon is inflated, dilating the bell shaped sleeve, such that the balloon tapers distally and the sleeve opens into a tulip shaped bell, the bell being substantially the length of the balloon;

Fig. 16 is a schematic cross-section through the distal end of a balloon catheter incorporating a bell shaped sleeve of Fig. 10, wherein the balloon is inflated, dilating the bell shaped sleeve, such that the balloon is inflated into a tubular shape with substantially parallel walls and the sleeve opens into a bell with substantially cylindrical walls, the bell being shorter than the balloon;

Fig. 17 is a schematic longitudinal cross-section through the distal end of a balloon catheter wherein the balloon and the bell shaped sleeve both are stepped, with regions having different cross-section;

Fig. 18 is a schematic longitudinal cross-section through the distal end of a balloon catheter wherein the balloon and the bell shaped sleeve have similar lengths;

Fig. 19 is a schematic longitudinal cross-section through the distal end of a deflated balloon catheter wherein the bell shaped sleeve has reinforcement ribs and is shown in its pre-dilated compacted configuration,;

Fig. 20 is a longitudinal section through the balloon catheter of Fig. 19, with the balloon inflated, dilating the bell shaped sleeve; Fig. 21 is a schematic longitudinal section through the distal end of a balloon catheter of Fig. 19 and 20, with the balloon deflated leaving the dilated bell shaped sleeve, showing how reinforcement ribs support the dilated bell shaped sleeve;

Fig. 21 is a schematic longitudinal section through the distal end of a balloon catheter with a compacted, bell shaped sleeve over the deflated balloon, wherein the sleeve is porous for drug elution therethrough, the balloon catheter further comprising an impregnated layer between the balloon and the sleeve;

Fig. 22 is a schematic longitudinal section through a balloon-of-wire catheter having a third lumen for coupling to a pump for active evacuation;

Fig. 23 is a schematic longitudinal section through a rapid deployment catheter having a third lumen for coupling to a pump for active evacuation, and

Fig. 24 shows how the deflated balloon may crumple up, away from the dilated sleeve.

DESCRIPTION OF EMBODIMENTS

Balloon angioplasty is well established. With reference to Fig. 1 a schematic longitudinal section through a prior art balloon 2 at the distal end of a balloon-over-wire balloon catheter 5 is shown in its deflated configuration. The wire 4 and its lumen or conduit 6 are fed into an artery 8 to a location where there is some plaque buildup or a blockage 10. The artery 8 may be a carotidal artery or another artery. The wire 4 is typically introduced via a large artery in the wrist or groin, and is fed through the branching arterial structure to where there is a blockage 10 or an artery narrowing. The end of the catheter may have a soft tip 12. A soft tip 12 may facilitate the navigation of the catheter through a tortuous body cavity such as an artery without damaging the side walls of the cavity. Such a tip is optional however. The tip 12 may be configured to engage and retain the end of the balloon 2. The tip may include radio-opaque fillers to help track the course of the tip through the body.

With reference to Fig. 2, the balloon 2' may be inflated by forcing a fluid into the balloon 2'. Typically, saline solution with or without contrast media is used. It must be pumped into the balloon 2' at a pressure which is typically but not limit to about 2- to 25 atmospheres. The inflated balloon pushes the blocking material 10 into the walls of the artery and expands the walls of the artery 8, providing a passage for blood flow.

The inflation fluid is introduced into the balloon 2' via a conduit or lumen 14 that, as shown may surround the conduit 6 of the guide wire 4, possibly coaxial therewith, but may simply be adjacent thereto. The balloon 2 may be fabricated from an elastomeric material such as silicone rubber, latex, polyethylene butadiene styrene, polyamides, oriented polyamides such as Grilamid L25, Grilamid L55, Rilsan B, Esno, Polyether block amides PEBA such as PEBAX 7233, PEBAX 7033, PEBAX 6333, PEBAX 5533, which may be oriented or non oriented, Grilf ex ELG 6260, Polyethylene Tetraphthalate (PET), such as Mylar, High, Low or other density polyethylene, and the like. In such cases, the balloon 2 is inserted in its deflated state and is inflated in situ to form the inflated balloon 2. After use, it may be deflated again reassuming the deflated configuration 2'.

Alternatively, with reference to Fig. 3, showing a cross section through a distal end of another prior art catheter system 15', the balloon 12 may be a folded balloon that is furled around the wall 7 of the lumen 6 of the guide wire 4 and which is inflated by being unfurled by water pressure introduced thereinto.

Referring to Fig. 4, it is known that sometimes debris 16 becomes dislodged by the invasive balloon angioplasty procedure. Such debris 16 may be carried by the bloodstream into ever narrower arteries until it eventually causes a blockage. It is therefore preferable for such debris 16 to be removed. Prior art attempts to remove debris 16 includes filters positioned on the catheter wire 4, downstream of the balloon 2.

Referring to Fig. 5 showing both the proximal and distal ends of a rapid-exchange balloon catheter, in some prior art systems, the guide wire 24 is introduced not far from the distal end 25 of the balloon angioplasty catheter system 20. At the proximal end 30 of the balloon angioplasty catheter system 20, outside of the body, the lumen 14 for the inflation fluid extends to an outlet 32, and may be connected to a syringe or pump for introduction of the inflation fluid.

The present invention is directed to an improved angioplasty catheter system and technique for clearing blockages 10 and for widening narrowed arteries 8 that enables removal of debris 16 dislodged by the balloon angioplasty procedure.

Removal of dislodged debris 16 not only prevents it from causing blockages and thromboses, but also is a technique for performing a biopsy in that the dislodged material is extracted and may be used to clarify the cause of the blockage.

With reference to Fig. 6, a first embodiment of an improved balloon catheter is shown. The balloon catheter is a balloon-over-wire catheter 100 comprising a first lumen 102 for a guide-wire 104, and a second lumen 106 for introducing pressurized fluid into the balloon to inflate the balloon 108. The improvement consists of a bell shaped sleeve 110 positioned around the balloon 108. As shown in Fig. 6, the bell shaped sleeve 110 is fully dilated. This is the situation after the balloon 108 is inflated and then deflated leaving the sleeve 110 dilated. Debris 112 dislodged from the walls 114 of a blood vessel such as an artery, are sucked into the bell shaped sleeve 110 by the pressure differential. Thus Fig. 6 is a schematic longitudinal section through the deflated balloon 108 and wire 104 of a balloon catheter device 100 having a bell shaped sleeve 110 around the deflated balloon 108.

With reference to Fig. 7, showing the distal end of the pre-inflated balloon catheter 108' and pre-dilated bell 110', as inserted into the body cavity, the pre-dilated bell 110' is only slightly larger than the pre-inflated balloon 108' and so the catheter 100 may be inserted into the body in the same way along a guide wire 102 as the catheters of the prior art.

The catheter with tightly furled or deflated balloon 108' and sleeve 110' as shown in

Fig. 8 is introduced into the artery as in conventional balloon angioplasty techniques. When a blockage or artery narrowing is encountered, the balloon 108 is inflated and this dilates the bell shaped sleeve 110 pushing it against the artery wall 114. Everything is similar to conventional balloon angioplasty, except that by virtue of the bell shaped sleeve 110, the balloon 108 comprises two layers instead of one. The balloon 108 is configured to be inflated and to deflate back to a fairly compact state, albeit often not necessarily identical to that as when inserted into the body. However, the sleeve 110 is configured to remain dilated when the balloon 108 is deflated. In some embodiments, the sleeve 110 is fabricated from a plastic material that may be expanded by the balloon 108 therewithin, but which remains plastically deformed after the balloon 108 is deflated.

Referring back to Fig. 6, a low pressure cavity 120 is formed between the deflated balloon 108' and the dilated sleeve 110. The mouth 125 of the cavity 120 faces downstream, and so there is a considerable pressure difference between the blood flow around the sleeve 110 and that within the cavity 120 of the sleeve 110 which is more or less stagnant. This pressure difference results in solid matter 1112 being sucked into the sleeve 110. A significant proportion of the material from a blockage or clot is thus trapped between the balloon shaped sleeve 110 and the balloon 108 and may be removed on removal of the catheter 100. It will be appreciated that the material 112 removed cannot cause clotting downstream, and may also be examined to ascertain the underlying pathology of the blockage, the system and procedure of the invention, providing a convenient biopsy technique.

Fig. 8 is a schematic cross-section through a compliant balloon 108' and bell 110' furled around the two lumen catheter 103. The two lumen catheter 103 is typically cylindrical for ease of passage through body cavities, particularly blood vessels. It consists of two lumens. A first lumen 102 for a guide wire 104 and a second lumen 106 for a pressurizing fluid. As shown, the two lumens 102, 106 may be separated by a curved dividing wall 107.

With reference to Fig. 9, a bell 110' furled around the lumen 103 and enclosed in an elastic sleeve 210 is shown. The bell shaped sleeve 210 may be fabricated from a compliant material that that deforms elastically, or from a non-compliant material that may be deformed plastically after exposure to an overload. In some embodiments, bell shaped sleeve 110 may be fabricated from silicone rubber, latex, polyethylene butadiene styrene, polyamides, oriented polyamides such as Grilamid L25, Grilamid L55, Rilsan B, Esno, Polyether block amides PEBA such as PEBAX 7233, PEBAX 7033, PEBAX 6333, PEBAX 5533, which may be oriented or non-oriented, Grilflex ELG 6260, Polyethylene Tetraphthalate (PET), such as Mylar, High, Low or other density polyethylene, and the like.

Essentially, the balloon catheter of the invention is introduced into the body, typically into the cardiovascular system and most typically into an artery, with the bell shaped sleeve in its pre-dilated, contracted state around the pre-inflated balloon.

With reference to Fig. 10, showing a further embodiment of the catheter 200 of Fig. 6, mutatis mutandis, in some embodiments, the dividing wall 207 may be straight. Indeed, the shapes and relative sizes of the two lumens 202, 206 are fairly arbitrary. To facilitate smooth passage of the guide-wire 204 it may be preferable for the double lumen 203 to have a smooth rounded external profile. In general the catheter 200 itself will generally have a cylindrical external profile for ease of passage through the blood vessels. It could, of course, have an elliptical profile.

With reference to Fig. 11, a section through one embodiment of the catheter 303 is shown, showing a curved dividing wall 307. As shown in Fig. 12, in a second embodiment of catheter 403, the dividing wall 407 is straight. With reference to Fig. 13, in yet a further embodiment of catheter 503, there are three lumens 502, 504, 506 separated by two dividing walls 505, 507. The purpose of the third lumen is to allow actively reducing the pressure inside the bell by coupling to a pump.

With reference to Fig. 14, in addition to use with balloon-over-wire catheters, the bell 510 of the invention may be used with rapid-exchange balloon catheters 500 with short guide wires 524.

With reference to Fig. 15, although typically the balloon is designed to fully inflate into a sausage shape with parallel walls, the bell shaped sleeve 210 need not have a constant cross-section, and may taper towards the catheter tip 215 (or away from it). In some embodiments, the balloon may inflate into a tapering shape 208 and typically the bell 210 is fabricated from a material that retains its shape when the balloon 208 is deflated, and thus may assume a tulip shape.

Referring to Figs. 16, the balloon 308 and the bell shaped sleeve 310 may be stepped along their length, having 2 or 3 sections, each with a different diameter.

As shown in Figs. 17, in some embodiments, the sleeve 410 may extends past the balloon 408 and be longer than the balloon 408.

The mouth of the bell shaped sleeve is a wide aperture that remains open and gaping after the balloon is compacted. Sometimes, a gasket is provided over and around the distal and proximal ends of the balloon to keep these tight around the lumen. Sometimes a gasket is provided around the proximal end of the bell shaped sleeve to help it withstand the pressure differentials.

The dimensions of the bell shaped sleeves may vary considerably in different embodiments for different applications and the sleeves may be 2 to 15 mm in diameter and may be 8 mm to 300 mm long. Typically they are no more than 120 mm long.

With reference to Figs. 18-20, in some embodiments, the sleeve 610 has reinforcement ribs 605 that, once dilated, prevent it from being contracted when the balloon 610 is deflated.

With reference to Fig. 21, in some embodiments the bell shaped sleeve 710 may be perforated with perforations 711 that may be from 1 to several hundred microns in size, and an intermediary absorbent layer 709 of some generally absorbent material such as a felt or fabric may be provided, between the balloon 708 and sleeve 710, wherein the intermediary layer 709 is impregnated with an active material such as a drug, a radioactive marker, a selective bio-solvent, a blood thinning or a blood clotting factor. Other elutable materials may include one or more diagnostic substances, therapeutic substances, drugs, living cells, DNA, RNA, nucleic acids, vectors for delivering genetic material, anti-inflammatory agents, anti- restenosis agents, anti cell proliferation agents, anti smooth muscle proliferation agents, vasoactive and vaso-dilating agents, vaso-constricting agents, antiobiotics, anticoagulatives, anti fibrosis, platelet aggregation inhibitors, lipid based vehicles or pharmaceutically acceptable vehicles. Inflation of the balloon both dilates the bell shaped sleeve 710 and squashes the intermediate layer 709 between the balloon 708 and the sleeve 710 to elute the active ingredient through the perforations or pores 711 of the sleeve.

With reference to Fig. 22 in one embodiment, the balloon and bell catheter apparatus 800 consists of three lumens 802, 806 and 807 extending the length of the catheter 805. The first lumen 802 allows passage of a guide wire 804. The second lumen 806 allows pressurizing of the balloon 808. Outlet 830 of the third lumen 807 may be coupled to a pumping device, which may be a syringe for example, for active depressurizing of the cavity 820 within the bell shaped sleeve 810. This sucks debris 812 through the mouth 825 of the bell shaped sleeve 810.

Referring to Fig. 23, a similar three lumen catheter configuration 905 may be utilized with a rapid exchange balloon catheter 900. Outlet 930 may be coupled to a syringe or pump thereby enabling the cavity 920 to be actively evacuated, decreasing the pressure therein and more effectively sucking in debris 912.

With reference to Fig. 24, in some embodiments, the post-inflation deflated balloon 248 does not collapse to its pre-inflation dimensions. It does, however, collapse away from the sleeve 250, perhaps linking and crumpling, but, nevertheless creating a debris collecting low pressure cavity between the deflated balloon 248' and the sleeve 250.

In the various embodiments, a stent may be positioned around the bell shaped sleeve. Inflation of the balloon causes dilation of the bell shaped sleeve and expansion of the stent. When the bell shaped sleeve is removed together with the rest of the catheter, the expanded stent is left behind and serves to keep the artery widened.

Thus embodiments of the present invention are directed to a balloon catheter having a bell shaped sleeve over the balloon that is closed around the catheter wire at the proximal end, and is open at the distal end.

The bell shaped sleeve is dilated by inflation of the balloon, and remains dilated when the balloon is deflated. This creates an open mouthed bell at the narrowing or blockage site, facing downstream. Due to the collapsing and deflation of the balloon, the blood pressure within the open mouthed bell is lower than the surrounding blood pressure. Debris such as white blood cells, clot and plaque deposits are sucked into the bell through the open mouth. On retraction of the catheter, such debris is removed together with the bell and collapsed balloon.

It will be appreciated that every piece of debris from a clot or blockage that is removed from the body cannot cause a clot or blockage downstream in the narrower arteries. Furthermore, the material thus removed in a biopsy and may be examined, enabling a better understanding of the causes of the blood clotting and early diagnosis of cancer cells and the like.

The bell shaped sleeve may be coupled to a lumen or conduit for active evacuative pumping to increase the pressure difference. It will be appreciated that there are a very large number of angioplasty catheters, with which the bell shaped sleeve may be used as a retrofittable addition or may be covended therewith.

In some embodiments, the bell shaped sleeve is shorter than the balloon and only partially covers the deflated balloon. In other embodiments, the non-inflated balloon and the sleeve have similar lengths. In yet other embodiments, the bell shaped sleeve is longer than the balloon and extends beyond the balloon.

In some embodiments, the bell shaped sleeve is fabricated from a relatively stiff resilient material, and, after the balloon is deflated, the sleeve is self-supporting by virtue of the relatively stiff resilient material from which it is fabricated. On other embodiments, the bell shaped sleeve includes reinforcing ribs that provide rigidity and form. In some embodiments, the reinforcing ribs are spoke-like. In some embodiments, the reinforcing ribs are separate rings which may be open rings or closed rings. In some embodiments, the reinforcing ribs are a continuous helical structure.

The bell shape sleeve may be fabricated from a compliant material or from a noncompliant material. It may be deployed with a wide range of catheters including rapid exchange catheters and balloon-over- wire catheters.

Although described in relation to angioplasty catheters, it will be appreciated that the bell shaped sleeve over a balloon of the present invention may be deployed to biopsy and / or unblock other cavities in the body, such as the urethra, intestine, lymphatic vessels and the like.

Features shown or discussed with one embodiment may be combined with features shown in other embodiments.

Thus persons skilled in the art will appreciate that the present invention is not limited to what has been particularly shown and described hereinabove. Rather the scope of the present invention is defined by the appended claims and includes both combinations and sub combinations of the various features described hereinabove as well as variations and modifications thereof, which would occur to persons skilled in the art upon reading the foregoing description.

In the claims, the word "comprise", and variations thereof such as "comprises",

"comprising" and the like indicate that the components listed are included, but not generally to the exclusion of other components.

Claims

1. A bell shaped sleeve having a perimeter wall for covering a balloon with a perimeter wall of a balloon catheter that is inflatable by a lumen; the bell shaped sleeve having a closed proximal end closely surrounding the lumen, and an open distal end, such that inflation of the balloon causes dilation of the bell shaped sleeve, whereas deflation of the balloon separates the wall of the balloon from the dilated bell shaped sleeve.

2. The bell shaped sleeve of claim 1 comprising a material that is viscoelastically or plastically stretched by inflation of the balloon.

3. The bell shaped sleeve of claim 1 comprising a folded bell shaped sleeve that is furled around the balloon, such that inflation of the balloon causes the bell shaped sleeve to unfurl and dilate.

4. The bell shaped sleeve of claim 1 comprising perforations for elution of an active preparation therethrough.

5. The bell shaped sleeve of claim 4 wherein the active preparation is selected from the group comprising at least one of the group consisting of medicaments, selective solvents, blood clotting factors, radioactive markers blood thinning factors, platelets and plasma.

6. The bell shaped sleeve of claim 1 further comprising ribs.

7. The bell shaped sleeve of claim 6 wherein the ribs are selected from the group consisting of spokes, rings, open rings and a helical coil.

8. A balloon catheter comprising an inflatable balloon at a distal end of a lumen for allowing passage of a fluid to said inflatable balloon for inflating said balloon, the balloon catheter further comprising a bell shaped sleeve covering the balloon of the balloon catheter such that inflation of said balloon causes said sleeve to dilate, whereas subsequent deflation of said balloon by extraction of the fluid, causes the balloon to separate from the dilated bell shaped sleeve.

9. The balloon catheter of claim 8, further comprising a guide wire.

10. The balloon catheter of claim 9, further comprising a second lumen surrounding the guide wire.

11. The balloon catheter of claim 10, wherein at least one of the following limitations is true:

(i) the first and second lumen are coaxial;

(ii) the first and second lumen are coextruded adjacent lumens separated by a common wall;

(iii) coextruded, cylindrical lumens.

12. The balloon catheter of claim 10, further comprising a third lumen connectively coupled to the bell shaped sleeve and to a suction device for applying suction pressure to the bell shaped sleeve.

13. The balloon catheter of claim 8, further comprising a dilatable stent surrounding the bell shaped sleeve, such that insertion of the balloon catheter into a body cavity and its inflation causes dilation of the bell shaped sleeve and of the stent, and subsequent removal of the balloon catheter with the bell shaped sleeve, leaves the dilated stent within the body cavity.

14. The balloon catheter of claim 8 wherein the bell shaped sleeve is perforated with perforations, and a pharmaceutical preparation is disposed between the balloon and wherein the bell shaped sleeve is perforated with perforations, and a preparation is disposed between the balloon and the bell shaped sleeve, such that inflation of the balloon elutes the preparation through the perforations.

15. The balloon catheter of claim 14 wherein the pharmaceutical comprises at least one of a blood clotting factor, a blood thinner, a selective solvent factor, a radioactive marker, an aesthetic, a disinfectant, collagen, platelets and antibiotics.

16. The balloon catheter of claim 8 further comprising a cap at a distal end of the balloon for holding the distal end of the balloon around the guide wire.

17. The balloon catheter of claim 16 wherein at least one of the following limitations is true:

(i) the cap holds the mouth of the bell shaped sleeve around the guide wire prior to inflation of the balloon, however inflation of balloon releases the mouth of the sleeve from the cap;

(ii) the cap comprises a soft material, and

(iii) the cap comprises a material selected from the group comprising silicone, latex and poly-butadiene-styrene.

18. The balloon catheter of claim 8 being selected from the group comprising over the wire catheters and rapid exchange catheters.

19. The balloon catheter of claim 8 wherein the bell shaped sleeve comprises ribs.

20. The balloon catheter of claim 19 wherein the ribs are selected from the group consisting of spokes, rings, open rings and a helical coil.