WO2010001405A1

WO2010001405A1 - Corrugated balloon catheter and methods of use thereof

Info

Publication number: WO2010001405A1
Application number: PCT/IL2009/000668
Authority: WO
Inventors: Eran Harari; Doron Besser
Original assignee: Angioslide Ltd.
Priority date: 2008-07-02
Filing date: 2009-07-02
Publication date: 2010-01-07
Also published as: JP2011526530A; EP2306910A4; EP2306910A1; CA2728773A1; CN102131470A

Abstract

lA balloon catheter including an outer conduit, an inner conduit disposed within the lumen of the outer conduit. The distal tip of the inner conduit extends beyond the distal tip of the outer conduit. The inner conduit is capable of being longitudinally moved within the outer conduit. An inflatable balloon has a proximal margin attached to the outer surface of the outer conduit's distal tip, and a distal margin attached to the outer surface of the portion of inner conduit extending beyond the distal tip of the outer conduit. The balloon has at least one corrugated portion. The distal end portion of the balloon is capable of intussuscepting upon proximal movement of the inner conduit within the outer conduit. The catheter has a fluid port for introducing an inflation fluid into the space formed between the outer conduit and the inner conduit and into the lumen of the balloon.

Description

CORRUGATED BALLOON CATHETER AND METHODS OF USE THEREOF

FIELD OF THE INVENTION

This invention relates in general to the fields of medical balloon catheters and more particularly to systems and catheters having inflatable intussusceptible corrugated balloons and methods of their manufacturing and use.

CROSS-REFERENCE TO RELATED US APPLICATIONS

This application claims priority from and the benefit of US Provisional Patent Application Serial Number 61/077,520 filed on July, 02, 2008 and entitled "CORRUGATED BALLOON CATHETERAND METHODS OF USE THEREOF" and US Provisional Patent Application Serial Number 61/143,847 filed on January, 12, 2009 and entitled "BALLOON AND CATHETER SYSTEM AND METHODS FOR MAKING SAME" both of which are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

Catheters are used in various interventional procedures for delivering therapeutic means to a treated site (e.g., body organ or passageway such as blood vessels). In many cases, a catheter with a small distal inflatable balloon is guided to the treated site. Once the balloon is in place it is inflated by the operator for affixing it in place, for expanding a blocked vessel, for placing treatment means (e.g., stent) and/or for delivering surgical tools (e.g. knives, drills etc.) to a desired site. In addition, catheter systems have also been designed and used for retrieval of objects such as stents from body passageways.

Two basic types of catheter have been developed for intravascular use: over-the-wire (OTW) catheters and rapid-exchange catheters.

OTW catheter systems are characterized by the presence of a full-length guide wire, such that when the catheter is in its in situ working position, said guide wire passes through the entire length of a lumen formed in, or externally attached to, the catheter. OTW systems have several operational advantages which are related to the use of a full length guide wire, including good stiffness and pushability, features which are important when maneuvering balloon catheters along tortuous and/or partially occluded blood vessels. U.S. Pat. No. 6,039,721 to Johnson et al. describes a balloon catheter system comprising two concentrically-arranged conduits, with a balloon connected between the distal regions thereof. The catheter system permits both expansion/deflation of the balloon and alteration in the length of the balloon when in situ, such that the balloon may be moved between extended and intussuscepted conformations. The catheter system is constructed in order that it may be use for two main purposes: firstly, treatment (i.e. expansion) of different-length stenosed portions of blood vessels with a single balloon and secondly, the delivery of either stents or medication to intravascular lesions, wherein the stent or medication is contained within the distally-intussuscepted portion of the balloon. When used for multiple, differing-length lesion expansion, the balloon is inserted into blood vessel in a collapsed, shortened, intussuscepted conformation, and is advanced until it comes to rest in the region of the shortest lesion to be treated. The balloon is then inflated and the lesion treated (i.e. expanded). Following deflation of the balloon, the distal end of the catheter system is moved such that the balloon becomes positioned in the region of the next—shortest lesion to be treated. The effective length of the balloon is then increased by moving the inner conduit in relation to the proximal conduit, following which the balloon is again inflated and the lesion treated. In this way, a series of different length stenoses, in order from the shortest to the longest, may be treated using a single balloon. When used for stent delivery, the stent is pre-loaded into a proximal annular space formed as a result of balloon intussusception. The balloon is then moved to the desired site and the stent delivered by means of moving the inner conduit distally (in relation to the outer tube), thereby "unpeeling" the stent from the catheter.

WO 2000/38776 discloses a dual-conduit balloon catheter system similar in basic design to that described above in relation to U.S. Pat. No. 6,039,721. This catheter system is intended for use in a vibratory mode in order to break through total occlusions of the vascular lumen. In order to fulfill this aim, the outer conduit has a variable stiffness along its length, while the inner conduit. In addition, the inner conduit while being intrinsically relatively flexible is stiffened by the presence of axial tensioning wires. These conduit design features are used in order to permit optimal translation of vibratory movements of the proximal end of the inner conduit into corresponding vibration of the distal tip thereof. Rapid exchange ("monorail") 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, 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 reoccurrences of obstruction therein. 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.

The guide wire lumen passes within a smaller section of the catheter's shaft length and it is accessed via a lateral port situated on the catheter's shaft. This arrangement, wherein the guidewire tube is affixed to the catheter's shaft at the location of its lateral port, usually prevents designers from developing new rapid exchange catheter implementations which requires manipulating its inner shaft. For example, extending or shortening the catheter's length during procedures may be advantageously exploited by physicians to distally extend the length of the catheter into a new site after or during its placement in the patient's artery, for example in order to assist with the passage of tortuous vessels or small diameter stenoses, or to allow in-situ manipulation of an inflated balloon at the distal end of the catheter.

Published International Patent Application, Publication No. WO 2005/102184 discloses a catheter having a reliable expandable element. Published International Patent 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.

A problem frequently encountered in the use of inflatable balloons to treat atheromatous plaque in blood vessels is that inflation of the balloon against the wall of the blood vessel may cause some damage to the blood vessel wall in the region of contact between the balloon and the blood vessel walls. Physicians are therefore usually reluctant to use balloons longer that the length necessary for treating most of the plaque. However, when the intussuscepting balloons as disclosed, inter alia, in WO 2005/102184 and WO 2007/004221 are used for treating plaque (by expanding the balloon placed inside the plaque region or by other methods) and for trapping and internalizing debris particles or secretions and fluids from inside a treated blood vessel, one would like to increase the capacity of the balloon to trap and include debris particles in it's intussuscepted (invaginated) state without increasing the length of the balloon above the length that is recommended by the physician for the purpose of safe plaque treatment.

Another problem which may be encountered in the use of intussuscepting balloons, such as, for example, the balloons disclosed in WO 2005/102184 and WO 2007/004221 is that it is important to ensure that the distal end of the balloon (the end attached to the inner tube of the catheter) collapses preferentially at a lower pulling force than the force required to collapse the proximal end of the balloon (the end of the balloon attached to the outer tube of the catheter) to ensure proper intussuscepting of the balloon. (The proximal and distal ends of the balloon are defined as described in WO 2005/102184 and WO 2007/004221).

SUMMARY OF THE INVENTION

There is therefore provided a balloon catheter, the catheter includes an outer conduit and an inner conduit, suitable for passage over a guide wire. The inner conduit is disposed within the lumen of the outer conduit such that the longitudinal axes of the inner and outer conduits are substantially parallel. The inner and outer conduit are positioned such that the distal tip of the inner conduit extends beyond the distal tip of the outer conduit. The inner conduit is capable of being moved along its longitudinal axis in relation to the outer conduit. The catheter also includes an inflatable balloon having a proximal margin attached to the outer surface of the distal tip of the outer conduit and a distal margin attached to the outer surface of the portion of the inner conduit that extends beyond the distal tip of the outer conduit. The inflatable balloon has at least one corrugated portion. The distal end portion of the balloon is capable of intussuscepting upon proximal movement of the inner conduit in relation to the outer conduit. The catheter also includes a fluid port for introducing an inflation fluid into the space formed between the inner surface of the outer conduit and the outer surface of the inner conduit and into the lumen of the balloon, and for removing the inflation fluid from the space and from the lumen.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the balloon catheter also includes a pressure adjusting mechanism for preventing substantial pressure changes within the space formed between the inner surface of the outer conduit and the outer surface of the inner conduit and within the lumen of the balloon upon axial movement of the inner conduit in relation to the outer conduit.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the pressure adjusting mechanism is selected from, a pressure adjusting mechanism including a syringe-like structure disposed at the proximal end of the balloon catheter, the syringe-like structure includes a barrel and a plunger disposed within said barrel. The plunger co-axially surrounds the proximal end of the inner conduit, and is affixed thereto, an over-pressure outlet in fluidic communication with the lumen of the inflatable balloon and having an opening and a compliant member sealingly attached to the opening for at least partially relieving over-pressure in the lumen, an over-pressure valve outlet in fluidic communication with the lumen of the inflatable balloon and an over-pressure valve disposed within the over-pressure outlet to allow discharging of fluid from the lumen when over-pressure conditions develop in the lumen, and an expandable or inflatable portion of the outer conduit, capable of being inflated when over-pressure conditions occur in the lumen of the balloon to at least partially relieve the over-pressure in said lumen.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the inflatable balloon includes a substantially cylindrical middle portion flanked by a distally extending portion and a proximally extending portion, wherein the diameter of the distally extending portion diminishes in the distal direction and the diameter of the proximally extending portion diminishes in the proximal direction.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the balloon is selected from a balloon wherein at least part of the middle portion is corrugated, a balloon wherein at least part of the distal portion is corrugated, and a balloon wherein at least part of the middle portion and at least part of the distal portion is corrugated.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, at least part of the distal portion of the balloon is corrugated such that the force required for causing collapse of the distal portion of the balloon is substantially smaller than the force required to cause collapse of the proximal portion of the balloon.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, at least part of the distal portion and at least the distal part of the middle portion are corrugated such that the force required for causing collapse of the distal portion of the balloon is substantially smaller than the force required to cause collapse of the proximal portion of the balloon. Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the wall thickness of the balloon is non-uniform along the length of the balloon.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the wall thickness of the proximal part of the balloon is greater than the wall thickness of the distal part of the balloon.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the corrugations of the corrugated portion(s) of the balloon have a cross-sectional shape selected from the group consisting of symmetrical triangular corrugations, non-symmetrical triangular corrugations, curved corrugations, sawtooth like corrugations, symmetrical rounded corrugations, non-symmetrical partly rounded corrugations, and any combinations thereof.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the corrugations of thee corrugated portion(s) of said balloon are arranged intermittently such that corrugated and non-corrugated portions alternate along the corrugated portion(s).

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the inflatable balloon has a distal portion selected from a domelike portion, a truncated dome-like portion, a conical portion, a frusto-conical portion, a corrugated dome-like portion, a corrugated conical portion, a corrugated frusto-conical portion and a truncated dome-like portion.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the corrugated portion(s) of the inflatable balloon increase the surface area of the balloon for improving retention of debris or particulate material trapped within the balloon after intussuscepting of said balloon.

Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the corrugated portion(s) of the inflatable balloon increase the probability of collapse of the distal portion of the balloon upon proximal moving of the inner conduit as compared to the probability of collapse of the distal portion of a similarly shaped balloon having no corrugated portion(s). Furthermore, in accordance with another embodiment of the balloon catheter of the present application, the at least one corrugated portion of the inflatable balloon is configured to be internally disposed within the space formed in the intussuscepted balloon after the intussuscepting of the balloon is completed, such that no corrugated portion is presented on the external surface of the fully intussuscepted balloon.

There is also provided, in accordance with the methods of the present application, a method of manufacturing an intussusceptible corrugated balloon catheter. The method includes the steps of: providing a catheter having an outer conduit and an inner conduit, suitable for passage over a guide wire, the inner conduit is disposed within the lumen of the outer conduit such that the longitudinal axes of the inner and outer conduits are substantially parallel. The inner conduit is positioned such that the distal tip thereof extends beyond the distal tip of the outer conduit. The inner conduit is capable of being moved along its longitudinal axis in relation to the outer conduit. The catheter has an inflation fluid port in fluidic communication with the space formed between the inner surface of the outer conduit and the outer surface of the inner conduit; providing an inflatable corrugated balloon having at least one corrugated portion, said corrugated balloon has a proximal margin and a distal margin; and sealingly attaching said proximal margin of said balloon to the outer surface of the distal end of said outer conduit and sealingly attaching said distal margin of said balloon to the outer surface of the portion of the inner conduit that extends beyond the distal end of said outer conduit such that the lumen of said corrugated balloon is in fluidic communication with said space formed between said inner surface of said outer conduit and said outer surface of said inner conduit, said attaching is performed such that the distal end portion of said corrugated balloon is capable of intussuscepting upon proximal movement of said inner conduit in relation to said outer conduit.

There is also provided, in accordance with an embodiment of the methods of the present application, a method for collecting debris from an internal passage of a mammalian subject. The method includes the steps of: inserting a corrugated balloon catheter including a balloon having at least one corrugated portion into the internal passage and advancing the catheter until the distal tip thereof has reached the site, at which it is desired to collect debris, inflating the corrugated balloon with expansion fluid, pulling the inner conduit of the corrugated balloon catheter in a proximal direction, such that the distal end of the corrugated balloon intussuscepts forming a cavity into which debris is collected and entrapped, deflating the intussuscepted corrugated balloon, and removing the deflated corrugated balloon catheter from the internal passage of the subject together with the entrapped debris.

Furthermore, in accordance with an embodiment of the method, the internal passage is a blood vessel.

Furthermore, in accordance with an embodiment of the method, the step of pulling includes pulling the inner conduit of the corrugated balloon catheter in a proximal direction to form the cavity, such that all of the corrugated portions of the balloon are disposed within the cavity to enhance retention of the debris.

Furthermore, in accordance with an embodiment of the method, the catheter includes a mechanism for preventing substantial pressure changes when the inner conduit is moved proximally within the outer conduit while the balloon is inflated and the fluid port is closed and wherein the step of pulling includes pulling the inner conduit of the corrugated balloon catheter in a proximal direction for collapsing the distal end of the corrugated balloon to form a cavity within the balloon into which cavity debris is collected and entrapped without inducing substantial pressure changes within the lumen of the balloon during the intussuscepting.

There is also provided a corrugated element for use in constructing a catheter, the corrugated element includes a sleeve-like element including a first side portion having a first open end with a first diameter, a second side portion having a second open end with a second diameter smaller than the first diameter and a middle portion disposed between the first side portion and the second side portion, at least part of the sleeve-like element is corrugated.

Furthermore, in accordance with an embodiment of the sleeve-like element of the present application, at least part of the second side portion is corrugated.

Furthermore, in accordance with an embodiment of the sleeve-like element of the present application, at least part of the second side portion is corrugated and at least part of the middle portion is corrugated. Furthermore, in accordance with an embodiment of the sleeve-like element of the present application, the wall thickness of the sleeve-like element is non-uniform along a longitudinal axis of the element.

Furthermore, in accordance with an embodiment of the sleeve-like element of the present application, the wall thickness of the first side portion is greater than the wall thickness of the second side portion of the sleeve-like element.

Furthermore, in accordance with an embodiment of the sleeve-like element of the present application, the corrugations of the corrugated part of the sleeve-like element have a cross-sectional shape selected from the group consisting of symmetrical triangular corrugations, non-symmetrical triangular corrugations, curved corrugations, sawtooth like corrugations, symmetrical rounded corrugations, non-symmetrical partly rounded corrugations, and any combinations thereof.

Furthermore, in accordance with an embodiment of the sleeve-like element of the present application, the corrugations of the corrugated part of the sleeve-like element are arranged intermittently such that corrugated and non-corrugated portions alternate along the corrugated part of said sleeve-like element.

Finally, in accordance with an embodiment of the sleeve-like element of the present application, the shape of the second side portion of the sleeve-like element is selected from a dome-like shape, a truncated dome-like shape, a conical shape, a frusto- conical shape, a corrugated dome-like shape, a corrugated conical shape, corrugated frusto-conical shape and a corrugated truncated dome-like shape.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is herein described, by way of example only, with reference to the accompanying drawings, in which like components are designated by like reference numerals, wherein:

Fig. 1 is a schematic side view diagram illustrating a corrugated inflatable sleeve-like usable as an intussusceptible balloon in a balloon catheter in accordance with an embodiment of the balloons of the present application;

Fig. 2 is a schematic cross section of the corrugated balloon of Fig. 1, taken along the lines II-II;

Fig. 3 is a schematic cross-sectional diagram illustrating a catheter system including the corrugated intussusceptible inflatable balloon of Fig. 1 in accordance with an embodiment of the catheter systems of the present application;

Figs. 4-8 are a schematic cross-sectional diagrams illustrating different steps of a method of using a catheter system including the corrugated intussusceptible inflatable balloon of Fig. 1, in accordance with an embodiment of the method of the present application;

Figs. 9-12 are schematic side view diagrams illustrating different types of corrugated inflatable intussusceptible balloons, in accordance with additional embodiments of the balloon of the present application;

Figs. 13-15 are schematic cross-sectional diagrams illustrating different types of corrugated inflatable intussusceptible balloons having different types of corrugations, in accordance with further additional embodiments of the balloon of the present application; Figs. 16-19 are schematic cross-sectional diagrams illustrating additional different types of corrugated inflatable intussusceptible balloons having different types of corrugated balloon regions and/or different balloon wall thickness at different portions of the balloon, and/or multiple different types of folds on the same balloon, in accordance with yet further additional embodiments of the balloon of the present application; Figs. 20-21 are schematic cross-sectional diagrams illustrating parts of catheters with different types of corrugated inflatable intussusceptible balloons having partially corrugated middle balloon portions and/or corrugated side portions, in accordance with yet additional embodiments of the corrugated balloon of the present application; Figs. 22-25 are schematic cross-sectional diagrams illustrating parts of corrugated balloons having different additional types of folds or corrugation shapes and/or having multiple corrugated portions interspersed with non-corrugated portions, in accordance with additional embodiments of corrugated balloons of the present application;

Fig. 26 is a schematic cross sectional diagram illustrating part of the wall of a corrugated balloon having alternating types of differently shaped corrugations, in accordance with an embodiment of the corrugated balloons of the present application; and

Fig. 27 is a schematic cross-sectional diagram illustrating a catheter system including the corrugated intussusceptible inflatable balloon of Fig. 1 having a compliant member usable as a pressure adjusting mechanism in accordance with another embodiment of the catheter systems of the present application.

DETAILED DESCRIPTION OF THE INVENTION

It is noted that the terras "corrugated balloon" and "concertina-like balloon" (in the single as well as the plural forms) are interchangeably used herein to indicate a balloon or an inflatable element having multiple folds or corrugations formed at least in a part or a portion thereof. The folds or corrugations may be symmetrical or non-symmetrical and may be of any desired shape such as but not limited to folds having triangular, or rounded, or curved, or sawtooth like cross-sectional shape or any other suitable cross- sectional shape.

It is also noted that in the following description and in the claims of the present application, the terms "distal" and "proximal" are defined as follows: the catheter side or end which is inserted into the body first is referred to as the distal side or distal end and the trailing side or end of the catheters part of which remains outside the body after insertion of the catheter is referred to as the proximal side. For example, in the balloon catheter 30 of Fig. 3, the graduated scale 19 is disposed on the proximal side of the catheter 30 and the terminal cylindrical portion 10J is disposed near the distal side or distal end of the catheter 30.

Similarly, when referring to sides, parts or portions of the corrugated balloons (or sleeve-like elements) of the catheters of the present application, the term distal refers to a part, end or portion of the balloon (or sleeve-like element) which is inserted first into the body when the balloon catheter is operated. For example, the corrugated balloon 10 of Figs. 1-2 has a middle portion 1OA, a proximal side portion 1OB and a distal side portion 1OC.

Reference is now made to Figs. 1 and 2. Fig. 1 is a schematic side view diagram illustrating a corrugated inflatable balloon usable as an intussusceptible balloon in a balloon catheter in accordance with an embodiment of the balloons of the present application. Fig. 2 is a schematic cross section of the corrugated balloon of Fig. 1, taken along the lines H-II.

It is noted that while for the sake of clarity of illustration Figs. 1-2 and 9-19 illustrate only the sleeve-like elements 10, 34, 35, 36, 37, 40, 45, 47, 50, 60, 70 and 80 usable for implementing the balloon catheters having corrugated inflatable intussuscepting balloons of the present application, all the sleeve-like elements 10, 34, 35, 36, 37, 40, 45, 47, 50, 60, 70 and 80 may be assembled into such catheters in the same way(s) in which the balloon 10 of Figs. 1-2 is assembled into the balloon catheter 30 of Fig. 3. It is further noted that in view of the above, all the sleeve-like elements illustrated in Figs. 1-2 and 9- 19 are also referred to in the application as balloons and the terms "balloon" and "sleeve- like element" in their singular and plural forms are interchangeably used throughout the specification.

The balloon 10 has a middle portion 1OA and two side portions 1OB and 1OC. The side portion 1OB is also referred to as the proximal side portion 1OB and the side portion 1OC is referred to as the distal side portion 1OC. A portion 1OD of the wall of the middle portion 1OA is corrugated or folded in a concertina-like or accordion-like structure. The shape of the corrugations of the portion 1OD may be generally triangular and symmetrical as may be seen in the cross-sectional view of Fig. 2. The middle portion 1OA is the portion that has the largest diameter of the portions HA, 1OB and 1OC. The middle portion also includes a curving portion 1OE. The proximal side portion 1OB includes a cylindrical portion 1OF, a frusto-conical portion 1OG and a terminal cylindrical portion 1OH. The cylindrical portion 1OH is the proximal margin of the balloon 10. The distal side portion 1OC includes a truncated dome-like portion 101 and a terminal cylindrical portion 10J. The cylindrical portion 10J is the distal margin of the balloon 10. The diameter of the terminal cylindrical portion 1OH is larger than the diameter of the terminal cylindrical portion 10J.

Preferably the balloon 10 is made from Nylon® or another suitable biocompatible material, as is known in the art, such as, but not limited to, PET, PAl 2 (for example Grilamid^® L25, L55 and the like), PAI l, Polyether block amides (PEBA, such as for example, PEBAX^® 7233, 7033, 6333), various types of Grilflex^® (such as, for example, ELG 6260), and the like. However, any other suitable biocompatible material known in the art and suitable for fabrication of catheter balloons may be used in implementing the balloons of the present application.

The balloon 10 may be suitably attached to a catheter system 20 as disclosed in detail hereinbelow. Reference is now made to Fig. 3 which is a schematic cross-sectional diagram illustrating a catheter system including the corrugated intussusceptible inflatable balloon of Fig. 1, in accordance with an embodiment of the catheter systems of the present application.

In the following description, the terms "conduit" and "tube" are used interchangeably. As shown in Fig. 3 the balloon catheter 30 comprises an inner tube 17 slidably positioned inside an outer tube 18. The proximal (i.e., trailing) end of inner tube 17 comprises an entry port 12, which extends outwardly through orifice 29 provided at the proximal end of the outer tube 18. Orifice 29 tightly fits around the outer surface of inner tube 17 without gripping it, thereby allowing proximal and distal movements of inner tube 17 while sealing the inner lumen of outer tube 18. The outer tube 18 may (optionally but not obligatorily) include an over-pressure valve outlet 15 or other suitable pressure adjusting mechanisms constructed and operable to relieve over-pressure as is disclosed in detail hereinafter. However, it is noted that the presence of such pressure adjusting mechanisms is not obligatory to practicing the invention, and that other embodiments may be constructed and operated without such a pressure adjusting mechanisms by suitable designing the balloon 10 and other catheter components to withstand over-pressure. Therefore, In accordance with an additional embodiment (not shown in Fig.3) of the catheter, the outer conduit 18 of the catheter 30 does not include the over-pressure valve outlet 15 or any other type of pressure adjusting mechanism. It is noted that a graduated scale 19 may optionally be provided on the outer surface of inner tube 17 as illustrated and described in detail in the above referenced international patent application published as WO 2007/7004221 and as explained hereinafter with reference to Fig. 3 of the present application.

The proximal end of outer tube 18 further comprises a fluid port 11 for injecting/removing inflation fluids to/from the inner lumen of outer tube 18, an overpressure valve outlet 15 for discharging inflation fluids whenever over-pressure conditions develop in the inner lumen of outer tube 18, and an inner tube safety lock 14 adapted for gripping the outer surface of inner tube 17, thereby preventing proximal- distal movements thereof relative to outer tube 18. The precise structure and operation of the safety lock 14 is as disclosed in detail in WO 2007/7004221. When the balloon 10 is inflated and the fluid port 11 is closed, an over-pressure may develop within the balloon 10 when the inner conduit 17 is pulled proximally within the outer conduit 18 for intussuscepting the balloon 10.

In certain embodiments of the catheters of the present application (not shown in Fig. 3), there is no the over-pressure adjusting mechanism and the over-pressure may be resolved by slight expansion of some parts of the catheter (such as but not limited to, the outer conduit 18) if these parts are made of sufficiently compliant material. While in some embodiments of the catheters of the present application, the pressure inside the lumen of the balloon 10 may increase during the intussuscepting of the balloon, such pressure increase may be safely accommodated by using a balloon 10 capable of safely withstanding the over-pressure resulting from the intussuscepting of the balloon 10. For example, the wall thickness of the balloon 10 may be made sufficiently thick to safely withstand the over-pressure or the balloon 10 may be made from a material having sufficient strength to effectively withstand the over-pressure resulting from the intussuscepting of the balloon 10.

However, preferably, in accordance with additional embodiments of the balloon catheter of the present invention, a pressure adjusting mechanism may be used in the catheter 30 of Fig. 3. In accordance with one embodiment of the catheter 30 of the present application, the pressure adjusting mechanism includes an over-pressure valve outlet 15 and an over-pressure valve 16 disposed therein. The over-pressure valve outlet 15 may include an over-pressure valve 16 for sealing the opening of over-pressure valve outlet 15 and for discharging portions of inflating fluids therethrough whenever overpressure conditions are reached in inner lumen of outer tube 18. The over-pressure valve outlet 15 is in fluidic communication with the lumen of the inflatable balloon 10 through the space formed between the inner surface of the outer tube 18 and the outer surface of the inner tube 17, and the over-pressure valve 16 disposed within the over-pressure outlet 15 may allow discharging of fluid from the lumen of the balloon 10 when over-pressure conditions develop in the lumen of the balloon 10 during the intussuscepting of the balloon 10. It should be realized however that such over-pressure conditions may be resolved by other means. For example, an inflatable member may be attached to the opening of over-pressure valve outlet 15, and in such an implementation over-pressure valve 16 may be eliminated. Reference is now made to Fig. 27 which is a schematic cross-sectional diagram illustrating a catheter system including the corrugated intussuscepting inflatable balloon of Fig. 1 and having an additional compliant member usable as a pressure adjusting mechanism in accordance with another embodiment of the catheter systems of the present application. The catheter 39 is similar in construction and operation to the catheter 30 of Fig. 3, except that the over-pressure valve 16 of Fig. 3 is replaced by a compliant member 9 such as (but not limited to) an inflatable and expandable balloon made from latex or from any other suitable expandable material. The compliant member 9 is sealingly attached to the outlet 15 to seal the outlet 15. In this embodiment, the outlet 15 is in fluidic communication with the lumen of the inflatable balloon 10. When the balloon 10 of the catheter 39 is intussuscepted while it is in the inflated state (by pulling the inner tube 17 proximally), the compliant member 9 may expand to accommodate some of the inflating fluid thus relieving some of the over-pressure in the lumen of the balloon 10.

Moreover, in accordance with yet another embodiment of the catheters of the present application, the outer tube 18, or portions thereof, may be made inflatable or expandable or compliant, such that over-pressure conditions may be at least partially resolved by the expansion of the tube 18 or of a compliant portion thereof. The inner tube safety lock 14 contacts the outer surface of inner tube 17 via a tight orifice provided on the outer surface at the proximal end of outer tube 18. It is noted that the details of construction and operation of the safety lock 14 are fully explained and illustrated in Figs IA and IB of the above referenced International Patent Application published as WO 2007/7004221, and are therefore not disclosed in detail hereinafter. As seen in Fig. 3, the distal (leading) end (distal tip) of the inner tube 17 extends outwardly through the distal opening of outer tube 18. The corrugated balloon 10 (of Figs. 1-2), is attached to the distal ends of outer tube 18 and the inner tube 17. The portion 1OH of the corrugated balloon 10 is attached at a circumferential attachment region 7 to the outer surface near the distal tip of outer tube 18. The portion 10J of the corrugated balloon 10 is attached at circumferential attachment region 6 to the outer surface near the distal tip of inner tube 17, such that it seals the distal opening of the outer tube 18. The attachment of the balloon 10 to the tips of the inner tube 17 and the outer tube 18 may be implemented using any suitable sealing attachment method known in the art, including but not limited to heat bonding, welding, ultrasonic welding, gluing, or any other method known in the art and capable of producing a sealed attachment capable of withstanding the pressures required for operating the inflatable expandable balloon(s) of the present application.

In accordance with another embodiment of the catheter systems of the present application, the catheter may include a pressure adjusting mechanism comprising a syringe-like structure. The syringe-like structure is disposed at the proximal end of the balloon catheter. The syringe-like structure may include a barrel and a plunger disposed within the barrel. The plunger co-axially surrounds the proximal end of the inner conduit 17, and is affixed thereto. This embodiment is fully disclosed in detail in the above referenced International Patent Application published as WO 2007/7004221 incorporated herein by reference in its entirety (in Fig 1C thereof), and is therefore not described in detail hereinafter. Briefly, the syringe- like structure of Fig. 1C of WO 2007/7004221 is positioned at the proximal end of the catheter system, wherein the barrel portion 26 (of Fig. 1C of WO 2007/7004221) of the syringe-like structure is formed by an expanded portion of the outer conduit 18, and wherein the plunger 17a (of Fig. 1C of WO 2007/7004221) of the syringe- like structure co-axially surrounds the proximal end of the inner conduit 17. However, the barrel portion 26 may also be implemented as a separate member suitably sealingly attached to the outer conduit 18.

Reference is now made to Figs. 4-8 which are a schematic cross-sectional diagrams illustrating different steps of a method of using a catheter system including the corrugated intussusceptible inflatable balloon of Fig. 1, in accordance with an embodiment of the method of the present application. Figs. 4-8 illustrate the insertion of the balloon catheter 30 to a treatment site, for example a blood vessel 20. It is noted that while the illustrations of the application use the blood vessel 20 as an example of the treated site, this is done by way of exemplary demonstration only, and other body passages may also be treated by the catheters, and catheter systems of the present application. Turning to Fig. 4, an exemplary interventional procedure using the corrugated balloon catheter 30 of the present application starts as the balloon catheter 30 is guided to the treatment site within the blood vessel 20 (e.g., over the wire). Fig. 4 illustrates over-the- wire insertion, wherein the insertion of the balloon catheter 30 is performed over a guide wire 13. It should be clear, however, that the invention is not limited to one specific insertion method and that other appropriate and practicable catheter insertion methods known in the art (such as, but not limited to, using a guiding catheter) may also be used. The catheter is advanced over the guide wire 13 until the (non-inflated) middle portion 5A is positioned within an atheromatous plaque 23 attached to the inner surface 21 of the blood vessel 20.

Turning to Fig. 5, the operator inflates the corrugated balloon 10 by injecting inflation fluids via fluid port 11 (see Fig. 3) and the inner lumen of outer tube 18. When carrying out procedures in blood vessel 20 as demonstrated in the Figs. 4-8, inflation fluids are preferably injected into the corrugated balloon 10 such that the circumferential corrugated sides of the portion 1OA of the corrugated balloon 10 are expanded and pressed against the inner surface 21 of blood vessel 20 and against the plaque 23, as illustrated in Fig. 5. The pressure inside the corrugated balloon 10 in such conditions may be in general about 1-25 Atmospheres, preferably about 6 Atmospheres.

It is noted that while in the embodiment of the treatment method illustrated in Figs. A- 8 the middle portion 1OA of the corrugated balloon 10 is placed within the region of the plaque 23 and is used to treat the plaque 23 by pushing the plaque 23 towards the walls of the blood vessel 20 to open a larger passage within the atheromatous portion of the blood vessel 20, other different treatment methods are also possible, in which the portion 1OA is not used as a plaque treating or plaque pushing means, but is used as an anchoring portion of the corrugated balloon 10 enabling firm anchoring of the catheter 30 to the walls of the blood vessel 20 which in turn allows other different plaque treating devices (not shown in Fig. 4-8) to be inserted into the lumen of the inner tube 17 (after withdrawal of the guide wire 13) for treating the plaque, hi such alternative treatment methods, the portion 1OA of the balloon is typically positioned within the blood vessel 20 at a site proximal to the position of the plaque 23, and plaque treatment is performed by an additional treating device (such as, but not limited to, a rotablator burr, a mechanical cutting device, a laser device such as an excimer laser or other laser for performing ELCA or other types of laser based atherectomies, Radiofrequency angioplasty device, an ultrasonic ablator device, and the like) inserted into the lumen of the inner tube 17.

In the state in which the balloon catheter 30 is anchored, the inner lumen of the inner tube 17 may now be utilized for operating in the treated site with different interventional tools (not shown in Figs 4-8), as may be required. However, some procedures (for example angioplasty) may be completed, or may be near completion, once balloon 10 reaches its fully inflated state.

Irrespective of which particular method of plaque treatment is used, after plaque treatment is achieved, a sample of liquid or solid matter, for example fluids, secretions, and/or debris 25 (resulting from plaque breakup due to treatment steps) may be collected and removed from the treatment site by causing the balloon 10 to intussuscept. The inner tube safety lock 14 (see Fig. 3) is pulled out, thereby releasing its grip from inner tube 17. The inner tube 17 is then retracted outwardly (proximally) by the operator as shown by arrow 28 of Fig. 6. During retraction of inner tube 17 the distal portion of balloon 10 collapses and the outer surface portions of the balloon 10 are folded inwardly over the distal tip of inner tube 17 and thereafter over itself as further portions of the balloon collapse, as illustrated in Figs. 6-7.

It is noted that the corrugated form of the balloon 10 advantageously assists the proper folding of the balloon 10 because the corrugated shape results in reducing the force required for initiating the internal folding of the distal end of the balloon.

The proximal retraction of the inner tube 17 and the resulting inward folding of balloon 10 shortens the overall length of inflated balloon 10 which actually reduces the volume of inflated balloon 10. Consequently, the pressure exerted by the inflating fluids increases, resulting in a considerable pressure increase in the balloon 10 and inner lumen of outer tube 18. Whenever the pressure in the balloon 10 and the inner lumen of outer tube 18 reaches a certain set-point (e.g., 5-20 atmospheres) inflation fluids flow towards the proximal side of the balloon 10 and are discharged via over-pressure valve outlet 15, such that the pressure in the balloon 10 and the inner lumen of outer tube 18 remains within a predetermined pressure range (e.g., 5-20 atmospheres). Optionally, in catheters including the graduated scale 19 (see Fig. 3), the operator can determine by monitoring the graduated scale 19, the amount of length of the inner tube 17 that has been retracted and in this way the operator may determine when to stop the retraction and restore immobilization (locking) of the inner tube 17 by pushing down the inner tube safety lock 14 (of Fig. 3), as explained in the catheter systems disclosed in detail in WO 2007/7004221.

It is noted, however, that in embodiments of the catheters having no over-pressure valve outlet 15 and no over-pressure valve 16 and no other pressure adjusting mechanism, the balloon 10 may have a substantially increase in the pressure during the period in which it is intussuscepted while the fluid port 11 is sealed. Turning to Fig. 6, during the retraction of the inner tube 17 in the proximal direction indicated by the arrow 27, the dome-like portion 101 of the balloon 10 inverts starting the intussuscepting of the balloon 10.

Turning to Fig. 7, during the retraction of during the retraction of the inner tube 17 in the proximal direction indicated by the arrow 27, the additional portions of the balloon 10 continue to intussuscept as illustrated, such that portion 101, and part of the portion 1OD form an internal cavity 41. As the inner tube 17 continues to be pulled in the proximal direction indicated by the arrow 27, the internal cavity 41 increases in length and its volume increases until the retraction of the inner tube 17 is stopped and the operator restores immobilization (locking) of the inner tube 17 by pushing down the inner tube safety lock 14 (of Fig. 3), as explained in the catheter systems disclosed in detail in WO 2007/7004221. At this locked state (not shown) the fluids contained within the walls of the intussuscepted balloon 10 and may be withdrawn through the open annular passage 33 formed between the inner tube 17 and the outer tube 18.

Some of the debris 25 resulting from the compaction and breakup of the plaque 23 during the full inflation of the balloon 10, (as illustrated in Fig. 5), adheres to the extended surface area of the corrugated portion 1OD and is carried by the intussuscepted part of the portion 1OD into the cavity 41 being formed within the intussuscepting balloon 10. It is noted that the corrugation of the portion 1OD advantageously assists the intussuscepting of the balloon 10 by reducing the puling force required for the internal folding of the balloon, as compared to the force required for the internal folding of a non-corrugated balloon (having substantially similar dimensions but including no corrugations), such as the balloons disclosed in WO 2007/7004221.

It will be appreciated by those skilled in the mechanical art that the corrugated portion(s) of the corrugated inflatable balloons disclosed in the present application increase the probability of collapse of the distal portion of the balloon upon proximal moving of the inner conduit 17 as compared to the probability of collapse of a distal portion of a similarly shaped balloon having no corrugated portion(s).

Furthermore, the corrugations of the portion 10D, increase the surface area of the part of the balloon 10 which is in contact with the wall of the blood vessel 20 when the balloon 10 is in the inflated state, and thus advantageously increases the surface area onto which the debris 25 and other particular matter released from the compacted and/or disrupted plaque 23 may adhere and may result in advantageously increasing the amount of debris 25 and/or plaque particulate material that is carried into and trapped within the cavity 41 internally formed within the balloon 10 after the intussuscepting of the balloon 10.

Turning to Fig. 8, after the intussuscepting of the balloon 10 has been completed, the balloon 10 is deflated by retracting inflation fluids through the fluid port 11 (of Fig. 3) as explained in detail in WO 2007/7004221. In result, the pressure inside the balloon 10 and in the inner lumen of outer tube 18 is substantially decreased, and the intussuscepted balloon 10 is deflated. After the balloon intussuscepting and deflation, the operator may retract (withdraw) the balloon catheter 30 proximally in the direction of the arrow 31 such that the portion of fluid/secretion and the debris 25 confined within the cavity 41 are withdrawn with the balloon catheter 30 outside of the treated body (not shown in the figures). The debris 25, or objects or samples may be easily collected when the entire length of balloon catheter 30 is withdrawn from the body of the treated subject, by pushing the inner tube 17 distally and unfolding the folded portions of balloon 5, thus restoring the deflated state of balloon 10 (shown in Fig. 3).

It is noted that as may be seen in Fig. 8, after the intussuscepting of the balloon 10, the coiTugated portion 1OD of the balloon 10 is completely internally disposed within the cavity 41 formed in the intussuscepted balloon 10 such that no corrugated portion or surface is presented on the external surface of the fully intussuscepted balloon 10. This may be advantageous, as such a configuration may assist the withdrawal of the deflated balloon 10 and catheter 30 from within the blood vessel 20 (or from any other bodily cavity in which it was inserted), by ensuring that no corrugations are presented on the outside surface of the deflated intussuscepted balloon 10. However, while this feature of the balloon 10 is preferred, this feature is not obligatory and in some embodiments of the catheters of the present invention, the entire surface of the balloon may be corrugated ( as described in detail hereinafter) or a substantial part of the length of the balloon may be corrugated, such that at least part of the corrugated surface is present on the outer surface of the intussuscepted balloon facing the internal blood vessel 20 after intussuscepting of the balloon and after deflating the balloon.

In view of the axially-directed stretching and buckling forces exerted on the inner and outer tubes during elongation and shortening of the balloon, said tubes need to be constructed such that they are able to withstand axially-directed forces in the range of between 2 and 20 Newton without undergoing deformation. In order to achieve this aim, the conduits may be constructed of a braided material or of materials having a defined molecular orientation. The approximate maximum forces that the inner and outer tubes need to withstand (for two difference size ranges of balloon inflated diameter, when the inflated diameter is defined as the diameter of the balloon midsection at the balloon's nominal pressure) are as follows: I) 2.5-4 mm diameter balloons: the tubing should withstand forces of up to 500 gram; polymer tubing made of Nylon or Pebax^® (a thermoplastic polyether block amide polymer) reinforced during the manufacturing process can be used. II) 4-8 mm diameter (or larger) balloons: the tubing should withstand forces up to 2 kilogram. In this case it may be necessary to use a braided tube (polymer tube with metal mesh reinforcement).

Exemplary results for a representative study of the forces generated during balloon folding are presented in Example 2, of WO 2007/7004221 incorporated herein by reference in its entirety.

The outer tube 18 is preferably made from a biocompatible polymer type of material, such as polyurethane or nylon or PET, and may be manufactured using conventional methods, such as extrusion. The diameter of the inner lumen of outer tube 18 is generally in the range of 0.5-2.0 mm (millimeters), preferably about 0.7 mm, and the diameter of the fluid port 11 is generally in the range of 2-6 mm, preferably about 4 mm. The diameter of the over-pressure valve outlet 15 is generally in the range of 1-6 mm, preferably about 4 mm, and the entire length of the outer tube 18 is generally in the range of 100-2000 mm, preferably about 1400 mm.

The inner tube 17 is preferably made from a biocompatible polymer type of material, such as polyurethane or Nylon or PET, and it may be manufactured using conventional methods, such as extrusion. The diameter of the inner lumen of inner tube 17 is generally in the range of 0.2-2.0 mm, preferably about 0.5 mm, and its entire length is generally in the range of 100-2000 mm, preferably about 1500 mm.

However, it will be appreciated by those skilled in the art that all values and dimensions of the various parts of the catheters and the values of the forces acting on the various parts as disclosed herein, are given by way of practical examples only and it may be possible to implement the catheters and balloons of the present invention by using other different values and/or value ranges of dimensions of the various parts of the catheters and/or forces to be withstood by such parts and/or different structural materials for constructing and implementing the catheters disclosed herein and any of their parts and/or components.

While the diameter of the orifice 29 provided at the proximal tip of the outer tube 18 should be adapted to provide appropriate sealing of inner lumen of the outer tube 18 it should also close over the outer surface of the inner tube 17 such that inner tube 17 may be displaced therethrough with relatively low frictional forces. For example, if the diameter of the inner tube 17 is 0.7 mm, then the diameter of the orifice 29 should be 1.0 mm. The balloon 10 is preferably a non-compliant or semi-compliant balloon such as manufactured by Advanced Polymers (Salem, USA) and by Interface Associates (CA). The balloon 10 may be manufactured using conventional methods known in the balloon catheter industry (such as, for example, pressure induced thermoforming - by forming the balloon shape using a suitably corrugated mold and a cylindrical tube made from a thermoplastic material which is shaped within the heated mold by suitable application of pressure). The balloon 10 may be made from a non-compliance type of material such as Pebax^® or Nylon (preferably Nylon 12), but any other suitable material known in the art may also be used. The length of the balloon 10 is generally in the range of 10-60 mm, preferably about 20 mm, but other different lengths may also be used. The diameter of the corrugated portion 1OD of the balloon 10 may vary between 2.0 mm to 5 mm for coronary artery applications, but may be significantly larger for use in larger blood vessels. Preferably (but not obligatorily), the balloon 10 should have a burst pressure within the range of 12-20 atmospheres. The proximal and distal edges of the balloon 10 such as the cylindrical portions 1OH and 10J, respectively, of the balloon 10, are preferably sealingly attached to the outer surfaces of outer tube 18 and of the inner tube 17 respectively, at circumferential attachment points 7 and 6 respectively, by using, heat bonding, or a UV or thermo bonding type of adhesive such as commonly used in the art.

Thus, the advantages of the corrugated balloons described herein are providing facilitated balloon folding and intussuscepting by reducing the force required for folding of the corrugated portion of the balloon and the providing of an increased surface area (relative to a non-corrugated balloon) of the corrugated portion which may substantially assist the adherence and inclusion of debris particles within the intussuscepted corrugated balloon.

It is noted that while the corrugated balloon 10 and the catheter 30 including it are shown by way of example, they are not intended to limiting by any way. Rather, many other different types of corrugated balloons may be advantageously implemented in the catheters of the present application.

Reference is now made to Figs. 9-12 which are schematic side view diagrams illustrating different types of corrugated inflatable intussusceptible balloons usable in the catheters and systems of the present application, in accordance with additional embodiments of the balloon of the present application.

Turning to Fig. 9, the corrugated balloon 34 includes contiguous portions 34H, 34G, 34F, 34E, 34D, 341 and 34J. The cylindrical portion 34H is shorter than the cylindrical portion 1OH (of Fig. 2). The frusto-conical portion 34G is longitudinally shorter than the frusto-conical portion 1OG (of Fig. 2) and therefore has a steeper cone angle. The cylindrical portion 34F is longer than the cylindrical portion 1OF (of Fig. 2). The portions 34D, 341 and 34J are similar in shape to the corresponding portions 10D, 101 and 1OJ, respectively, of Fig. 2. As seen in the inset of Fig. 9, the corrugations 34N have a symmetrical triangular shape, in accordance with an embodiment of the balloons of the present application.

Turning to Fig. 10, the corrugated balloon 35 includes contiguous portions 35H, 35G, 35E, 35D, 351 and 35J. The cylindrical portion 35H is similar in length to the cylindrical portion 1OH (of Fig. 2). The frusto-conical portion 35G is similar to the frusto-conical portion 1OG (of Fig. 2) However, it is noted that the frusto-conical portion 35G is contiguous with the portion 35E (without a cylindrical portion between them as in the balloon 10 of Fig. 2). The portions 35D, 351 and 35J are similar in shape to the corresponding portions 10D, 101 and 10J, respectively, of Fig. 2. As seen in the inset of Fig. 10, the corrugations 35N have a symmetrical rounded shape, in accordance with another embodiment of the balloons of the present application.

Turning to Fig. 11 the corrugated balloon 36 includes contiguous portions 36H, 36G, 36F, 36E, 36D, 361 and 36J. The cylindrical portion 36H is shorter than the cylindrical portion 1OH (of Fig. 2). The portion 36G is shaped like a truncated dome (having a convex shape) and is longitudinally shorter than the frusto-conical portion 1OG (of Fig. 2). The cylindrical portion 36F is shorter than the cylindrical portion 1OF (of Fig. 2). The portions 36D, 361 and 36J are similar in shape to the corresponding portions 34D, 341 and 34J respectively, of Fig. 9. Turning to Fig. 12 the corrugated balloon 37 includes contiguous portions 37H, 37G,

37F, 37E, 37D, 371 and 37J. The cylindrical portion 37H is shorter than the cylindrical portion 1OH (of Fig. 2). The portion 36G has a tapered shape (having a concave shape) and is longitudinally shorter than the frusto-conical portion 1OG (of Fig. 2). The cylindrical portion 37F is shorter than the cylindrical portion 1OF (of Fig. 2). The portions 37D, 371 and 37J are similar in shape to the corresponding portions 34D, 341 and 34J respectively, of Fig. 9.

It may thus be seen that the dimensions and shapes of the different portions of the balloons of the present application may be varied, including the shape and number of the corrugations included in the corrugated portion of the balloon. Such variations may depend on and may be used in different applications of the catheters (including the use for treatment of different blood vessels and/or other types of body-passage of varying sizes and dimensions.

Reference is now made to Figs. 13-15 which are schematic cross-sectional diagrams illustrating different types of corrugated inflatable intussusceptible balloons having different types of corrugations, in accordance with further additional embodiments of the balloon of the present application.

Turning to Fig. 13, the corrugated balloon 40 includes contiguous portions 4OH, 4OG, 4OF, 4OD, 401 and 4OJ. The portions 4OH, 4OG, 4OF, 401 and 4OJ are similar the corresponding portions 1OH, 1OG, 1OF, 101 and 10 J (of Fig. 2), respectively. However, the number and shape of the corrugations 4ON of the portion 4OD are different then those of the corresponding portion 1OD (of Fig. T). Each of the corrugations 4ON is wider than the corrugations ION (i.e, the length L2 of each of the corrugations 4ON is longer than the length Ll of the corrugations ION of Fig. 2)

Turning to Fig. 14, the corrugated balloon 45 includes contiguous portions 45H, 45G, 45F, 45D, 451 and 45 J. The portions 45H, 45G, 45F, 451 and 45 J are similar the corresponding portions 1OH, 1OG, 1OF, 101 and 10J (of Fig. T), respectively. However, the shape (and possibly the number) of the corrugations 45N of the portion 45D are different then those of the corresponding portion 1OD (of Fig. 2). Each of the corrugations 4ON is formed such that it has a sawtooth-like cross-sectional shape with the direction of the sawtooth shape arranged as illustrated in Fig. 14.

Turning to Fig. 15, the corrugated balloon 47 includes contiguous portions 47H, 47G, 47F, 47D, 471 and 47 J. The portions 47H, 47G, 47F, 471 and 47J are similar the corresponding portions 1OH, 1OG, 1OF, 101 and 10J (of Fig. 2), respectively. However, the shape (and possibly the number) of the corrugations 47N of the portion 47D are different then those of the corresponding portion 1OD (of Fig. 2). Each of the corrugations 4ON is formed such that it has a sawtooth-like cross-sectional shape with the direction of the sawtooth shape reversed in comparison to the direction of the sawtooth shapes formed on the portion 45D of the balloon 45(of Fig. 14), as illustrated in Fig. 15. Reference is now made to Fig. 16-19 which are schematic cross-sectional diagrams illustrating additional different types of folded or corrugated inflatable intususseptable balloons having different types of corrugated balloon regions and/or different balloon wall thickness at different portions of the balloon, and/or multiple different types of folds on the same balloon, in accordance with yet further additional embodiments of the balloon of the present application. Turning to Fig. 16, the corrugated balloon 50 includes a middle potion 5OA, a proximal side portion 5OB and a distal side portion 5OC. The proximal side portion 5OB comprises contiguous portions 5OH, 5OG and 5OF. The middle portion 5OA comprises contiguous portions 5OM and 5OD. The portion 5OM is not corrugated and the portion 5OD is coiTugated as disclosed hereinabove. The distal side portion 5OC comprises a corrugated curved portion 501 which is contiguous with the corrugated portion 50D, and a non-corrugated cylindrical portion 50 J.

The portions 5OH, 5OG, 5OF, and 5OJ are similar the corresponding portions 4OH, 4OG, 4OF, and 4OJ of the balloon 40 (of Fig. 13), respectively. However, while the truncated dome-like portion 401 of Fig. 13 is not corrugated, the portion 5OT has a corrugated dome like shape. This corrugated truncated conical structure may further facilitate the folding and intussuscepting of the balloon 50. The shape and dimensions of the corrugations 5OK of the potion 501 may be similar to the shape and dimensions of the corrugations 5ON of the portion 5OD. However, this is not obligatory and the shape and dimensions of the corrugations 5OK of the potion 501 may be different than the shape and dimensions of the corrugations 5ON of the portion 5OD (such as, but not limited to, the corrugations 5OK of the potion 501 being smaller than and/or having a different shape then the corrugations 5ON of the portion 50D).

Turning to Fig. 17, the corrugated balloon 60 includes a middle potion 6OA, a proximal side portion 6OB and a distal side portion 6OC. The corrugated balloon 60 has a non-uniform wall thickness along it's length. The proximal side portion 6OB comprises contiguous portions 6OH, 6OG and 6OF. The middle portion 6OA comprises contiguous portions 6OM and 6OD. The portion 6OM is not corrugated and the portion 6OD is corrugated, as disclosed hereinabove. The distal side portion 6OC comprises a truncated dome-like portion 601 which is contiguous with the corrugated portion 6OD, and a non-corrugated cylindrical portion 6OJ. The portions 6OD, 601 and 6OJ are similar in shape and dimensions the corresponding portions 10D, 101 and 10J of the balloon 10 (of Figs. 1-2), respectively. However, the portions 6OH, 6OG, 6OF and 6OM have walls which are thicker than the walls of the corresponding portions 1OH, 1OG, 1OF and 1OE of the balloon 10 (of Fig.2). The extra thickness of the walls of the balloon portions 6OH, 6OG, 6OF and 6OM of the balloon 60 mechanically reinforce the proximal side portion 6OB and the portion 6OM and advantageously prevents (or reduces the probability of) the folding of the proximal side of the balloon 60 and ensures that when the balloon is attached to a catheter similar to the catheter 30 of Fig. 3) and a pulling force is applies to the distal side of the balloon 60 by moving the inner tube 17 (see Fig. 3) of the catheter in the proximal direction, as disclosed hereinabove, the distal side of the balloon 60 will fold (by collapsing) preferentially at a lower force than the force required to cause folding of the balloon at the thicker walled region of the proximal side portion 6OB and the portion 6OM.

Turning to Fig. 18, the corrugated balloon 70 includes a middle potion 7OA, a proximal side portion 7OB and a distal side portion 7OC. The proximal side portion 7OB comprises contiguous portions 7OH, 7OG and 7OF. The middle portion 7OA comprises contiguous portions 7OM and 7OD. The portion 7OM is not corrugated and the portion 7OD is corrugated as disclosed hereinabove. The distal side portion 7OC comprises a corrugated truncated conical portion 701 which is contiguous with the corrugated portion 7OD, and a non-corrugated cylindrical portion 70 J.

The portions 7OH, 7OG, 7OF, and 7OJ are similar the corresponding portions 4OH, 4OG, 4OF, and 4OJ of the balloon 40 (of Fig. 13), respectively. However, while the portion 401 of Fig. 13 has a non-corrugated truncated dome-like shape, the portion 701 has a corrugated truncated conical shape. As explained hereinabove with regard to the corrugated dome-like portion 501 of the balloon 50, the corrugated structure of the portion 701 may similarly facilitate the folding and intussuscepting of the balloon 70. The shape and dimensions of the corrugations 7OK of the potion 701 may be similar to the shape and dimensions of the corrugations 7ON of the portion 7OD. However, this is not obligatory and the shape and dimensions of the corrugations 7OK of the potion 701 may be different than the shape and dimensions of the corrugations 7ON of the portion 7OD (such as, but not limited to, the corrugations 7OK of the potion 501 being smaller than and/or having a different shape then the corrugations 5ON of the portion 50D).

Turning to Fig. 19, the corrugated balloon 80 includes a middle potion 8OA, a proximal side portion 8OB and a distal side portion 8OC. The proximal side portion 8OB is identical to the proximal portion 1OB (of Fig. 2) and comprises contiguous portions 8OH, 8OG and 8OF. The distal side portion 8OC is identical to the distal portion 1OC (of Fig. 2) and includes the portions 801 and 8OJ. However, the middle portion 8OA comprises portion 8OM which is identical to the portion 1OE of Fig. 2, and two contiguous corrugated portions 8OD and 8OP. The corrugations of the portion 8OD are similar in shape to the symmetrical triangular corrugations 5ON of Fig. 16. In contrast, the corrugations of the portion 8OP are symmetrical rounded or curved corrugations similar to the corrugations 35N (illustrated in the inset of Fig.10).

It is noted that other embodiments with other mixed types of corrugations are also possible in the balloons (and sleeve-like elements) of the present application. For example, in accordance with an embodiment of the balloons of the present application the middle portion of the balloon may include three contiguous portions (not shown), a first portion with rounded corrugations, a second portion with symmetrical triangular corrugations and a third portion with sawtooth-like corrugations. Thus, many other combinations and sub-combinations of multiple corrugated portions (either contiguous or non-contiguous) with multiple different types of corrugations may be implemented in the balloons and balloon catheters of the present application.

It is noted that while in the embodiments of the balloons (and sleeve-like elements) disclosed hereinabove, the corrugated portion(s) occupied most of the longitudinal dimension of the balloon's middle portion (the portion having the largest diameter of all the balloon portions), this is by no means obligatory. Rather, only a part of the middle portion may be corrugated resulting in a partially corrugated middle portion. Similarly, embodiments are possible in which the middle portion of the balloon is completely non- corrugated while the distal portion of the balloon or a part thereof is corrugated. Reference is now made to Fig. 20-21 which are schematic cross-sectional diagrams illustrating parts of catheters with different types of corrugated inflatable intussusceptible balloons having partially corrugated middle balloon portions and/or corrugated side portions, in accordance with yet additional embodiments of the corrugated balloon of the present application.

Turning to Fig. 20, the corrugated balloon 140 includes a middle potion 140A, a proximal side portion 140B and a distal side portion 140C. The proximal side portion 140B is identical to the proximal portion 4OB (of Fig. 13) and comprises contiguous portions 140H, 140G and 1400F. The distal side portion 140C is identical to the distal portion 1OC (of Fig. 2) and includes the portions 1401 and 140J. However, the middle portion 140A comprises a non-corrugated portion 140D and a contiguous corrugated portion 141D. In the specific non-limiting embodiment illustrated in Fig. 20, the non- corrugated portion 140D occupies approximately two thirds of the length of the middle portion 140A, and the corrugated portion 141D occupies approximately a third of the length of the of the middle portion 140A. However, this is not obligatory and other different length relationship between the corrugated portion and the non-corrugated portion of the middle portion 140A are also possible.

Turning to Fig. 20, the corrugated balloon 140 includes a middle potion 140A, a proximal side portion 140B and a distal side portion 140C. The proximal side portion 140B is identical to the proximal portion 4OB (of Fig. 13) and comprises contiguous portions 140H, 140G and 140F. The distal side portion 140C is identical to the distal portion 1OC (of Fig. 2) and includes the portions 1401 and 140J. However, the middle portion 140A comprises a non-corrugated portion 140D and a contiguous corrugated portion 141D. In the specific non-limiting embodiment illustrated in Fig. 20, the non- corrugated portion 140D occupies approximately two thirds of the length of the middle portion 140A, and the corrugated portion 141D occupies approximately a third of the length of the of the middle portion 140A. However, this is not obligatory and other different length relationship between the corrugated portion and the non-corrugated portion of the middle portion 140A are also possible.

Turning to Fig. 21, the corrugated balloon 150 includes a middle potion 150A, a proximal side portion 150B and a distal side portion 150C. The proximal side portion 150B is identical to the proximal portion 4OB (of Fig. 13) and comprises contiguous portions 150H, 150G and 150F. The distal side portion 150C is identical to the distal portion 5OC (of Fig. 16) and includes a corrugated dome-like portion 1501 and a non- corrugated cylindrical portion 150J similar to the portions 501 and 5OJ, respectively, of Fig. 16. However, the middle portion 140A comprises a single non-corrugated portion. Thus, while the middle portion 150A does not have an extended surface area as do other corrugated middle portions described herein, the balloon 150 has the advantage of facilitated folding of the distal portion 150C of the balloon 150 during the intussuscepting of the balloon 150 because the corrugations of the portion 1501.

Thus, it is noted that in balloon catheters in which at least part of the distal portion is corrugated, the force required for causing collapse of the distal portion of the balloon is substantially smaller than the force required to cause collapse of the proximal portion of the balloon. Similarly for the same mechanical reasons, in balloon catheters in which at least part of the distal portion and at least the distal part of the middle portion are corrugated, the force required for causing collapse of the distal portion of the balloon is substantially smaller than the force required to cause collapse of the proximal portion of the balloon. Such balloons have the advantage of increasing the probability of collapse of the distal part or portion of the corrugated balloon upon pulling the inner tube 17 proximally within the outer tube 17 (see Fig. 3).

It is also noted that while preferably, the proximal portion of the balloons described herein and illustrated in the drawings are not corrugated (in order to minimize the probability of initial collapse of the proximal portion of the balloon when the inner tube 17 is pulled proximally), it is possible to construct and use embodiments of balloon catheters having balloons having a corrugated proximal part and balloon catheters having the entire balloon being corrugated (continuously or altematingly as shown in the example of Fig. 25 hereinbelow). For example, in accordance with other embodiments of the balloon catheters of the present application, if the balloon is made to have a corrugated proximal part or to be corrugated along the entire balloon length, the probability of the proximal collapse of the balloon when the inner tube 17 is pulled proximally may be substantially reduced by making the walls of the proximal part of the balloon thicker than the walls of the middle and/or distal parts of the same balloon. This will enable the use of such balloons safely and effectively while allowing a greater part of the balloon to be corrugated. It is further noted that typically (but not obligatorily), the balloon catheters of the present application may have a substantially cylindrical middle portion flanked by a distally extending portion and a proximally extending portion. The diameter of the distally extending portion typically diminishes in the distal direction and the diameter of the proximally extending portion typically diminishes in the proximal direction. The change of the diameter of the distal and/or proximal balloon portions may be gradual ( as in a conical shape or dome shape but may also be non-gradual or at least partially non- gradual by diminishing abruptly ( as in the form of a step or a step or an abrupt transition between a first cone angle to a steeper cone angle). Additionally the balloons of the present application maybe non-linearly tapered in their proximal and/or distal portions by having outwardly or inwardly curving cross sectional shapes of the proximal and/or distal portions.

Reference is now made to Figs. 22-25 which are schematic cross-sectional diagrams illustrating parts of corrugated balloons having different additional types of folds or corrugation shapes and/or having multiple corrugated portions interspersed with non- corrugated portions, in accordance with additional embodiments of corrugated balloons of the present application.

It is noted that in all of the drawings of Figs. 22-25, the reference numeral P schematically represents the proximal side and the reference numeral D schematically represents the distal side of the balloon.

Turning to Fig. 22, the corrugated portion of the balloon 160 (only part of which is illustrated in Fig. 22) includes multiple corrugations 160N. Each one of the multiple corrugations 160N has a straight part 160Q facing towards the proximal side of the balloon 160 and a curved part 160R facing the distal side of the balloon 160. Turning to Fig. 23, the corrugated portion of the balloon 170 (only part of which is illustrated in Fig. 23) includes multiple corrugations 170N. Each one of the multiple corrugations 170N has a straight part 170Q facing towards the distal side of the balloon 170 and a curved part 170R facing the proximal side of the balloon 170.

Turning to Fig. 24, the corrugated portion of the balloon 180 (only part of which is illustrated in Fig. 24) includes multiple symmetrical corrugations 180N. Each one of the multiple corrugations 180N has a first curved part 180Q facing towards the proximal side of the balloon 180 and a second curved part 180R facing the distal side of the balloon 180.

Turning to Fig. 25, the balloon 190 (only part of which is illustrated in Fig. 25) includes three corrugated portions 190A, 190B and 190C and non-corrugated portions 190D, 190E and 190F. It is noted that in accordance with embodiments of the corrugated balloons disclosed herein, the balloons may include any practical number of corrugated portions interspersed by non-corrugated portions. Furthermore, while the type, shape and dimensions of the corrugations in the portions 190A, 190B and 190C in the non-limiting example illustrated in Fig. 25 are identical, this is by no means obligatory and in different embodiments of balloons with multiple corrugated portions, each portion may have a different type of corrugation in which one or more parameters of the corrugation's shape, dimensions, may be varied at will.

Moreover, different types and/or sizes and/or shapes of corrugations may be mixed and matched within each corrugated portion of the balloons of the present application. Turning now to Fig. 26 which is a schematic cross sectional diagram illustrating part of the wall of a corrugated balloon having alternating types of differently shaped corrugations, the wall of the balloon 200 (only part of which is shown in Fig. 26) includes triangular shaped corrugations 200N interspersed with curved corrugations 200R. Generally, in the mixed corrugation type balloons of the present application, any types and sizes of corrugations may be used mixed and matched as desired. For example, the balloon 200 of Fig. 26 may be modified to have repeated sequences of corrugations having a single triangular corrugation 200N followed by two curved corrugations 200R and this sequence may be repeated along the entire length of the corrugated portion. Furthermore, any desired type of repeating or non-repeating combinations and sequences of two or more different corrugation types may be used in the corrugated balloons of the present application.

It is further noted that the cylindrical portions 10J, 34J, 35J, 36J, 37J, 4OJ, 45J, 47J, 5OJ, 6OJ, 7OJ, 8OJ, 140J, and 150J are also referred to as the "distal margins" of the balloons 10, 34, 35, 36, 37, 40, 45, 47, 50, 60, 70, 80, 140, and 150, respectively, throughout the specification and the claims of the present application. Similarly, it is also noted that the cylindrical portions 1OH, 34H, 35H, 36H, 37H,

4OH, 45H, 47H, 5OH, 6OH, 7OH, 8OH, 140H, and 150H and are also referred to as the

"proximal margins" of the balloons 10, 34, 35, 36, 37, 40, 45, 47, 50, 60, 70, 80, 140, and 150, respectively, throughout the specification and the claims of the present application.

It is noted that the side portion(s) of the corrugated balloons of the present application may have cylindrical and/or conical and/or frusto-conical, and/or rounded truncated dome-like and/or tapering shape(s). The side portion(s) may also have a shape which is a combination of one or more of cylindrical, conical, frusto-conical, dome-like and tapering shapes. These shapes are not intended to be limiting, and other different types of portion shapes may also be used in implementing the corrugated balloons of the present application.

The corrugated balloon catheters of the present application may use sleeve like elements having various different dimensions. Typically (but not obligatorily), the inflated diameter of the corrugated balloon may be in the range of 1.5 - 35 millimeter and the length of the corrugated balloons may be in the range of 5- 300 millimeter, with all possible combinations of balloon length and balloon diameters within these ranges may be used. In accordance with some typical non-limiting examples, a balloon with a length of 15 millimeter may have an inflated diameter of 3 millimeters and a balloon with a length of 250 millimeters may have an inflated diameter of 12 millimeter. The typical (but non-limiting) range of balloon wall thickness is 0.022 - 0.030 millimeter depending, inter alia, on the balloon dimensions and on the application. It will be appreciated by those skilled in the art that the above dimension ranges and ratios of balloon diameter to balloon length are not obligatory and that other different dimensions and ratios extending beyond the above indicated ranges may be used in implementing the catheters, depending, inter alia, on the particular application.

While it is possible for the corrugations to span the entire inflatable length of the balloons, as disclosed herein, typically, in some preferred embodiments only the distal portion of the balloon is corrugated and in some other preferred embodiments, both the distal balloon portion and part of the balloon middle portion are corrugated. Typically, in these embodiments between a fifth (1/5) and a third (1/3) of the total length of the balloon are corrugated. However, shorter or longer portions of the balloon length may be corrugated, depending, inter alia, on the balloon structure and shape, the balloon's wall thickness (and/or on the balloon's wall thickness gradient in balloons with a non-uniform wall thickness), and on the particular application. Returning to Fig. 2, with respect to the dimensions of the corrugations, the corrugations span a "peak to valley" amplitude L (defined as the difference between the maximal radial distance of the corrugation and the minimal radial distance of the corrugation as measured from the longitudinal axis of the inflated balloon, irrespective of the precise corrugation shape). Typically, the corrugation amplitude L depends on the diameter of the balloon. Preferably, the corrugation amplitude L is in the range of 2.5%

- 20% of the inflated balloon diameter. However, other values of the corrugation amplitude L may also be used which are larger or smaller than this range depending, inter alia, on the balloon wall thickness and on the particular shape of the corrugations.

The corrugation pitch P is defined as the distance between adjacent peaks of the corrugations (see Fig. 2 for an indication of P in the particular case of symmetrical triangularly shaped corrugations of the balloon 10), and may depend, inter alia, on the outer diameter of the inflated balloon and on the type and shape of the corrugations.

In accordance with one typical non-limiting example, in a balloon having a length of 15 millimeter and an inflated outer diameter of 3 millimeter, the corrugation pitch P may preferably (but not obligatorily) be in the range of 0.025-1.8 millimeter. In accordance with another typical non-limiting example, in a balloon having a length of 250 millimeter and an inflated outer diameter of 12 millimeter, the corrugation pitch P may preferably (but not obligatorily) be in the range of 0.1 - 7.2 millimeter. It will be appreciated by those skilled in the art that the above two examples are given by way of example only and are not intended to be limiting, and that other values of the corrugation pitch P which are higher or lower than the corrugation pitch ranges of the above given examples may be used depending, inter alia, on the particular values of the balloon length, balloon diameter, balloon wall thickness, corrugation shape and other design and manufacturing considerations. Finally, it is noted that while the particular exemplary catheter illustrated in Fig. 3 discloses use of the corrugated balloons of the present application in an "over the wire" catheter configuration, the corrugated balloons described herein may also be used in conjunction with other different types of catheters, as is known in the art. For example, the corrugated balloons described herein may also be used in the rapid exchange catheters disclosed in Published International Patent applications, Publication Number WO 2007/042935, or in other catheter systems having intussuscepting balloons, such as the catheters disclosed in Published International Patent applications, Publication Numbers. WO2005/102184, WO2007/004221, WO2008/004238 and WO2008/004239.

Claims

1. A balloon catheter comprising: an outer conduit; an inner conduit, suitable for passage over a guide wire, disposed within the lumen of said outer conduit such that the longitudinal axes of said inner and outer conduits are substantially parallel, and positioned such that the distal tip of said inner conduit extends beyond the distal tip of said outer conduit, said inner conduit is capable of being moved along its longitudinal axis in relation to said outer conduit; an inflatable balloon having a proximal margin attached to the outer surface of the distal tip of said outer conduit, and a distal margin attached to the outer surface of the portion of the inner conduit that extends beyond the distal tip of said outer conduit, said inflatable balloon has at least one corrugated portion, and wherein the distal end portion of said balloon is capable of intussuscepting upon proximal movement of said inner conduit in relation to said outer conduit; a fluid port for introducing an inflation fluid into the space formed between the inner surface of said outer conduit and the outer surface of said inner conduit and into the lumen of said balloon, and for removing said fluid from said space and from said lumen.

2. The balloon catheter according to claim 1, wherein said balloon catheter also includes a pressure adjusting mechanism for preventing substantial pressure changes within said space and the lumen of said balloon upon axial movement of said inner conduit in relation to said outer conduit.

3. The balloon catheter according to claim 2, wherein said pressure adjusting mechanism is selected from, a pressure adjusting mechanism comprising a syringe-like structure disposed at the proximal end of said balloon catheter, said syringe-like structure includes a barrel and a plunger disposed within said barrel, said plunger co-axially surrounds the proximal end of the inner conduit, and is affixed thereto, an outlet in fluidic communication with the lumen of said inflatable balloon and having an opening and a compliant member sealingly attached to said opening for at least partially relieving over-pressure in said lumen, an over-pressure valve outlet in fluidic communication with the lumen of said inflatable balloon and an over-pressure valve disposed within said over-pressure outlet to allow discharging of fluid from said lumen when over-pressure conditions develop in said lumen, and an expandable or inflatable portion of said outer conduit, capable of being inflated when over-pressure conditions occur in the lumen of said balloon to at least partially relieve the over-pressure in said lumen.

4. The balloon catheter according to any of claims 1 to 2 wherein said inflatable balloon comprises a substantially cylindrical middle portion flanked by a distally extending portion and a proximally extending portion, wherein the diameter of said distally extending portion diminishes in the distal direction and the diameter of said proximally extending portion diminishes in the proximal direction.

5. The balloon catheter according to any of claims 1 to 2, wherein said balloon is selected from, a balloon wherein at least part of said middle portion is corrugated, a balloon wherein at least part of said distal portion is corrugated, and a balloon wherein at least part of said middle portion and at least part of said distal portion is corrugated.

6. The balloon catheter according to claim 5, wherein at least part of said distal portion is corrugated such that the force required for causing collapse of the distal portion of said balloon is substantially smaller than the force required to cause collapse of the proximal portion of said balloon.

7. The balloon catheter according to claim 5, wherein at least part of said distal portion and at least the distal part of said middle portion are corrugated such that the force required for causing collapse of the distal portion of said balloon is substantially smaller than the force required to cause collapse of the proximal portion of said balloon.

8. The balloon catheter according to claim 1, wherein the wall thickness of said balloon is non-uniform along the length of the balloon.

9. The balloon catheter according to claim 1 wherein the wall thickness of the proximal part of said balloon is greater than the wall thickness of the distal part of said balloon.

10. The balloon catheter according to claim 1, wherein the corrugations of said at least one corrugated portion of said balloon have a cross-sectional shape selected from the group consisting of symmetrical triangular corrugations, non-symmetrical triangular corrugations, curved corrugations, sawtooth like corrugations, symmetrical rounded corrugations, non-symmetrical partly rounded corrugations, and any combinations thereof.

11. The balloon catheter according to claim 1 , wherein the corrugations of said at least one corrugated portion of said balloon are arranged intermittently such that corrugated and non-corrugated portions alternate along said at least one corrugated portion.

12. The balloon catheter according to claim 1, wherein said inflatable balloon has a distal portion selected from a dome-like portion, a truncated dome -like portion, a conical portion, a frusto-conical portion, a corrugated dome-like portion, a corrugated conical portion, a corrugated frusto-conical portion, and a corrugated truncated dome- like portion.

13. The balloon catheter according to claim 1, wherein said at least one corrugated portion of said inflatable balloon increases the surface area of said balloon for improving retention of debris or particulate material trapped within said balloon after intussuscepting of said balloon.

14. The balloon catheter according to claim 1, wherein said at least one corrugated portion of said inflatable balloon increases the probability of collapse of the distal portion of said balloon upon proximal moving of said inner conduit as compared to the probability of collapse of a distal portion of a similarly shaped balloon having no corrugated portion.

15. The balloon catheter according to claim 1, wherein said at least one corrugated portion of said inflatable balloon is configured to be internally disposed within the space formed in the intussuscepted balloon, after the intussuscepting of said balloon is completed, such that no corrugated portion is presented on the external surface of the fully intussuscepted balloon.

16. A method of constructing an intussusceptible corrugated balloon catheter, the method comprising the steps of: providing a catheter having an outer conduit and an inner conduit, suitable for passage over a guide wire said inner conduit is disposed within the lumen of said outer conduit such that the longitudinal axes of said inner and outer conduits are substantially parallel, said inner conduit is positioned such that the distal tip thereof extends beyond

5 the distal tip of said outer conduit, said inner conduit is capable of being moved along its longitudinal axis in relation to said outer conduit, said catheter has an inflation fluid port in fluidic communication with the space formed between the inner surface of said outer conduit and the outer surface of said inner conduit; providing an inflatable corrugated balloon having at least one corrugated portion, o said corrugated balloon has a proximal margin and a distal margin; and sealingly attaching said proximal margin of said balloon to the outer surface of the distal end of said outer conduit and sealingly attaching said distal margin of said balloon to the outer surface of the portion of the inner conduit that extends beyond the distal end of said outer conduit such that the lumen of said corrugated balloon is in fluidic5 communication with said space formed between said inner surface of said outer conduit and said outer surface of said inner conduit, said attaching is performed such that the distal end portion of said corrugated balloon is capable of intussuscepting upon proximal movement of said inner conduit in relation to said outer conduit.

17. A method for collecting debris from an internal passage of a mammalian subject0 comprising the steps of: inserting a corrugated balloon catheter comprising a balloon having at least one corrugated portion as defined in any one of claims 1 to 15 into said internal passage, and advancing said catheter until the distal tip thereof has reached the site, at which it is desired to collect debris; 5 inflating said corrugated balloon with expansion fluid; pulling the inner conduit of said corrugated balloon catheter in a proximal direction, for collapsing the distal end of said corrugated balloon to form a cavity within said balloon into which debris is collected and entrapped; deflating the intussuscepted corrugated balloon; and 0 removing the deflated corrugated balloon catheter from the internal passage of the subject, together with the entrapped debris.

18. The method according to claim 17, wherein the internal passage is a blood vessel.

19. The method according to claim 17, wherein said step of pulling comprises pulling the inner conduit of said corrugated balloon catheter in a proximal direction to form said cavity, such that all of the corrugated portions of said balloon are disposed within said cavity to enhance retention of said debris.

20. The method according to claim 17, wherein said catheter includes a mechanism for preventing substantial pressure changes when said inner conduit is moved proximally within said outer conduit while said balloon is inflated and said fluid port is closed, and wherein said step of pulling comprises pulling said inner conduit of said corrugated balloon catheter in a proximal direction, for collapsing the distal end of said corrugated balloon to form a cavity within said balloon into which debris is collected and entrapped without inducing substantial pressure changes within the lumen of said balloon during the intussuscepting.

21. A corrugated element for use in constructing a catheter, the corrugated element comprises: a sleeve-like element comprising a first side portion having a first open end with a first diameter, a second side portion having a second open end with a second diameter smaller than said first diameter and a middle portion disposed between said first side portion and said second side portion, at least part of said sleeve-like element is corrugated.

22. The corrugated element according to claim 21, wherein at least part of said second side portion is corrugated.

23. The corrugated element according to claim 21, wherein at least part of said second side portion is corrugated and at least part of said middle portion is corrugated.

24. The corrugated element according to claim 21, wherein the wall thickness of said sleeve-like element is non-uniform along a longitudinal axis of said element.

25. The corrugated element according to claim 21, wherein the wall thickness of the first side portion of said element is greater than the wall thickness of said second side portion of said sleeve-like element.

26. The corrugated element according to claim 21, wherein the corrugations of the corrugated part of said sleeve-like element have a cross-sectional shape selected from the group consisting of symmetrical triangular corrugations, non-symmetrical triangular corrugations, curved corrugations, sawtooth like corrugations, symmetrical rounded corrugations, non-symmetrical partly rounded corrugations, and any combinations thereof.

27. The corrugated element according to claim 21, wherein the corrugations of the corrugated part of said sleeve-like element are arranged intermittently such that corrugated and non-corrugated portions alternate along the corrugated part of said sleeve-like element.

28. The corrugated element according to claim 21, wherein the shape of said second side portion of said sleeve-like element is selected from a dome-like shape, a truncated dome-like shape, a conical shape, a frusto-conical shape, a corrugated dome-like shape, a corrugated conical shape and a corrugated frusto-conical shape, and a corrugated truncated dome-like shape.