WO2010060888A1

WO2010060888A1 - Medical balloon catheter with hollow wire cable rope guidewire duct

Info

Publication number: WO2010060888A1
Application number: PCT/EP2009/065689
Authority: WO
Inventors: Ronald Adrianus Maria Horvers
Original assignee: Blue Medical Devices Bv
Priority date: 2008-11-26
Filing date: 2009-11-24
Publication date: 2010-06-03

Abstract

The application concerns an intraluminal balloon catheter (100) comprising an elongated flexible shaft (5) having a proximal end (20), a distal end (10), a longitudinal inflation lumen (21) disposed within the shaft (5), and at least one inflatable balloon (4) towards the distal end (10) in fluid communication with the inflation lumen (21), the inflation lumen (21) provided with a longitudinal guidewire duct (7), disposed with a longitudinal guidewire lumen (6) extending therein, in fluid connection with a distal guidewire port (30) located in a region at the distal end (10) of the shaft (5), and a proximal guidewire port (32) located at the proximal end (20) of the longitudinal guidewire duct (7), the guidewire duct (7) comprising a hollow rope duct (8) formed from a plurality of longitudinal wire cables (40, 40') cylindrically stranded to form the hollow rope duct (8), the hollow rope duct (8) optionally having a region of transitional flexibility between the proximal (20) and distal ends (10).

Description

MEDICAL BALLOON CATHETER WITH HOLLOW WIRE CABLE ROPE GUIDEWIRE

DUCT

FIELD OF THE INVENTION This invention relates to dilatation and stent catheters for dilating structures or for stent delivery and deployment in the human body. More particularly, the invention relates to an over the wire balloon catheter comprising a flexible hollow guidewire rope duct formed from a plurality of longitudinal wire cables cylindrically stranded to form the flexible duct that improves the passage of the guidewire through the catheter.

BACKGROUND TO THE INVENTION

The use of balloon catheters to treat structures, stenoses, or narrowings in various parts of the human body is well known in the prior art. Examples of such catheters are shown in Bonzel U.S. Pat. No. 4,762,129, Yock U.S. Pat. No. 5,040,548, Kanesaka U.S. Pat. No. 5,330,499, Solar U.S. Pat. No. 5,413,557, Lentz US 2008/0287786, EP 1 902 745, Keith et al. US 2004/01331158 and Tsukashima ef a/. U.S. Pat. No. 5,458,639.

An illustrative procedure involving balloon catheters is known as percutaneous translumenal coronary angioplasty, which may be used to reduce arterial build-up of cholesterol fats or atherosclerotic plaque. This procedure involves passing a balloon catheter over a guide wire to a stenosis. Once positioned appropriately (e.g., under fluoroscopic guidance), the balloon is inflated, which breaks the plaque of the stenosis and causes the arterial cross section to increase. Then the balloon is deflated and withdrawn over the guide wire.

In many cases, a stent must be implanted to provide permanent support for the artery. When a stent is to be implanted, the usual practice is to first dilate the stenosis with a first balloon catheter that does not carry a stent. Then the first catheter is withdrawn over the guide wire and a second catheter which carries a stent on its balloon is inserted via the guide wire. When the balloon of the second catheter is at the location of the stenosis, that balloon is inflated to circumferentially expand and thereby implant the stent. Thereafter, the balloon of the second catheter is deflated and the second catheter and the guide wire are withdrawn from the patient.

After a first catheter has been placed in the patient on the guide wire, the physician may wish to remove that catheter and replace it with another catheter having a larger dilatation balloon or an implantable stent as described above. The guide wire is left substantially in place during these catheter removal and replacement steps.

Over the wire catheters employ a long guidewire lumen from the distal end to the top. As known in the art, the guidewire lumen of an over the wire catheter may be a duct at least partly reinforced with a hypotube as described in US 7,166,1 10 B2. The proximal portion of the catheter reinforced by the hypotube may have much greater column strength, which will tend to enhance the pushability of the balloon catheter. The distal end also reinforced by hypotube disposed with a smaller distal pitch provides increased flexibility compared with the proximal end, which assists with advances through curves and crossing junctions.

The skilled practitioner understands that a catheter will have an optimum combination of performance characteristics, which may be selected among: flexibility, pushability, catheter trackability, guidewire trackability, low profile, torque transfer and others. Flexibility may relate to bending stiffness of a balloon catheter and/or stent, in a particular region or over its entire length. Pushability may relate to the column strength of a device or system along a selected path. Catheter trackability may refer to a capability of a catheter to successfully follow a desired path in a vessel, for example without prolapse. Guidewire trackability may refer to the ability of the catheter to advance along the guidewire, offering minimal resistance. Profile may refer to a maximum transverse dimension of the balloon catheter, at any point along its length. Torque transfer refers to the ability of a catheter to transfer a rotational force from the proximal (handling) end to the distal end.

A disadvantage of some catheters in the art is their guidewire trackability that is reduced by the use of hypotubing. Said tubing creating a series of transverse circular ridges within the guidewire lumen that frictionally engage with the guidewire and prevent its advancement. Guidewire passage is particularly hindered when the catheter is bent so exposing gaps between the hypotube spiral into which a guidewire tip can enter and lodge. The guidewire then needs to be withdrawn and an attempt made to re-advance it through the guidewire lumen.

A further disadvantage of catheters in the art is their low torque transfer. During catheter advancement through a tortuous vasculature, a rotation of the catheter at the proximal end can be effective in opening vessels directing the tip of the catheter in a different direction. The presence of hypotubing prevents efficient transfer of rotations originating from the proximal end. A still further disadvantage of catheters of the art is their difficulty of manufacture. When a hypotubing requires rendering watertight by way of a jacket, the jacket must be manually applied over the hypotubing which, owing to the presence of near-transverse spiral cuts, can lead to the leading end of the jacket becoming engaged in the spiral cuts, thereby preventing its smooth passage over the hypotubing.

Conventional over the wire balloon catheters of the art, in which the shaft is formed from polymeric material, may also suffer from a wide profile. The diameter of the shaft is ideally wide to allow the passage of medium during inflation and deflation, to accommodate the guidewire and to provide sufficient strength (wall thickness). A common problem, however, is that wide lumen catheters can kink or buckle easily, which kinking damages the catheter wall and prevents smooth passage of the guidewire through the guidewire lumen. As a consequence, a surgeon will be weary of applying too much push using conventional catheters.

In view of the foregoing, it is an object of this invention to provide improved catheters for use with guide wires and stents. In particular, the present invention aims to provide a medical balloon catheter having differential flexibility at the distal and proximal ends, excellent guidewire trackability and torque transfer, while still maintaining good pushability, low profile and catheter trackability. These and various other objects, advantages and features of the present invention will become apparent from the following description and claims, when considered in conjunction with the appended drawings.

SUMMARY OF THE INVENTION

One embodiment of the present invention concerns an intraluminal balloon catheter (100) comprising an elongated flexible shaft (5) having a proximal end (20), a distal end (10), a longitudinal inflation lumen (21 ) disposed within the shaft (5), and at least one inflatable balloon (4) towards the distal end (10) in fluid communication with the inflation lumen (21 ), the inflation lumen (21 ) provided with a longitudinal guidewire duct (7), disposed with a longitudinal guidewire lumen (6) extending therein, in fluid connection with a distal guidewire port (30) located in a region at the distal end (10) of the shaft (5), and a proximal guidewire port (32) located at the proximal end (20) of the longitudinal guidewire duct (7), the guidewire duct (7) comprising a hollow rope duct (8) formed from a plurality of longitudinal wire cables (40, 40') cylindrically stranded to form the hollow rope duct (8), the hollow rope duct (8) optionally having a region of transitional flexibility between the proximal (20) and distal ends (10). Another embodiment of the present invention is a catheter as described above, wherein the hollow rope duct (8) has a region of transitional flexibility, and the outer diameter of the hollow rope duct (8) gradually decreases in a direction from the proximal end (20) to the distal end (10) in the region of transitional flexibility.

Another embodiment of the present invention is a catheter as described above, wherein the hollow rope duct (8) is provided with a medium impermeable coating or outer jacket.

Another embodiment of the present invention is a catheter as described above, wherein the hollow rope duct (8) has a region of transitional flexibility, and the thickness of the coating or outer jacket gradually decreases in a direction from the proximal end (20) to the distal end (10) in the region of transitional flexibility.

Another embodiment of the present invention is a catheter as described above, further comprising a hub at the terminus of the proximal end (20) for connection of the inflation lumen (21 ) to a source of pressurized inflation fluid and for access to the guidewire lumen (6).

Another embodiment of the present invention is a catheter as described above, further comprising a stent in the unexpanded condition.

Another embodiment of the present invention is a catheter as described above, further comprising one or more radiopaque markers configured to indicate the position of the balloon in a subject during placement.

Another embodiment of the present invention is a catheter as described above, wherein the guidewire duct (7) is formed by cylindrically stranding a group of stainless steel wire cables (40, 40') along a predetermined circle line to provide the duct (7) of the invention.

Another embodiment of the present invention is a catheter as described above, wherein the interior surface (25) of the duct (7) may comprise of high and/or low density polyethylene, polyamides, poly(ethylene terephthalate) (PET) or polyesters and copolymers thereof, teflon or any such material that comprises a hydrophilic character.

Another embodiment of the present invention is a catheter as described above, wherein the exterior surface of the elongated shaft may comprise of high and/or low density polyethylene, polyamides, poly(ethylene terephthalate) (PET) or polyesters and copolymers thereof, teflon or any such material that comprises a hydrophilic character.

Another embodiment of the present invention is a catheter as described above, wherein the guidewire duct (7) further comprises a flexible polymeric tubing (1 1 ) joined to the distal end of the hollow rope duct (8), to which the distal end (10) of the distal-most balloon (4) is circumferentially sealed.

Another embodiment of the present invention is a catheter as described above, wherein the distance, D2, between the proximal end (20) of the polymeric tubing (1 1 ) and the proximal end (20) of the proximal most balloon (4), is between 0 cm and 5 cm.

Another embodiment of the present invention is a catheter as described above, wherein the length, D1 , of the polymeric tubing (11 ) is between 0 cm and 30cm.

Another embodiment of the present invention is a catheter as described above, wherein the guidewire duct (7) further comprises a distal tip (9) joined to the distal end, to which the distal end (10) of the distal-most balloon (4) is circumferentially sealed.

Another embodiment of the present invention is a catheter as described above, wherein the distal tip (9) is joined to the distal end of the hollow rope duct (8) or to the distal end of the polymeric tubing (1 1 ) where present.

DETAILED DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic illustration of a medical balloon catheter of the invention

FIG. 2 is a schematic illustration of a medical balloon catheter of the invention, with S-, T- and F- regions of the hollow rope guidewire duct indicated.

FIG. 3 is a schematic illustration of a medical balloon catheter of the invention disposed with a softened tip, with S-, T- and F- regions of the hollow rope duct indicated.

FIG. 4 is a schematic illustration of a medical balloon catheter of the invention, wherein the guidewire duct comprises of the hollow rope duct extended distally by a polymeric tube.

FIG. 4A is a schematic illustration of a medical balloon catheter as depicted in FIG. 4 further disposed with a distal tip. FIG. 5 is a schematic illustration of a medical balloon catheter of the invention, as shown in FIG. 4, wherein the polymeric tube is joined to the hollow rope duct proximal of the balloon.

FIG. 5A is a schematic illustration of a medical balloon catheter as depicted in FIG. 5 further disposed with a distal tip.

FIG. 6A is a transverse (A-A) cross-section through the S-region of a catheter as shown in

FIGs. 2 to 5, whereby the cables of the guidewire duct have a circular profile, and the duct is devoid of coating or jacket.

FIG. 6B is a transverse (B-B) cross-section through the T-region of a catheter as shown in FIGs. 2 to 5, whereby the cables of the guidewire duct have a part-circular profile, and the duct is devoid of coating or jacket.

FIG. 6C is a transverse (C-C) cross-section through the F-region of a catheter as shown in

FIGs. 2 to 5, whereby the cables of the guidewire duct have a semi-circular profile, the catheter is devoid of coating or jacket. FIG. 7A is a transverse (A-A) cross-section through the S-region of a catheter as shown in

FIGs. 2 to 5, whereby the cables of the guidewire duct have a circular profile, and the duct has a coating of constant thickness.

FIG. 7B is a transverse (B-B) cross-section through the T-region of a catheter as shown in

FIGs. 2 to 5, whereby the cables of the guidewire duct have a part-circular profile, and the duct has a coating of constant thickness.

FIG. 7C is a transverse (C-C) cross-section through the F-region of a catheter as shown in

FIGs. 2 to 5, whereby the cables of the guidewire duct have a semi-circular profile, and the duct has a coating of constant thickness.

FIG. 8A is a transverse (A-A) cross-section through the S-region of a catheter as shown in FIGs. 2 to 5, whereby the cables of the guidewire duct have a circular profile, and the duct has a coating that is thickest in the S-region.

FIG. 8B is a transverse (B-B) cross-section through the T-region of a catheter as shown in

FIGs.2 to 5, whereby the cables of the guidewire duct have a circular profile, and the duct has a coating that is intermediate thickness in the T-region. FIG. 8C is a transverse (C-C) cross-section through the F-region of a catheter as shown in

FIGs. 2 to 5, whereby the cables of the guidewire duct have a circular profile, and the duct has a coating that is thinnest in the F-region.

FIG. 9 is a transverse cross-section through a catheter as shown in FIGs. 2 to 5 (e.g. across A-A, B-B, or C-C), indicating the dimensions of the catheter shaft and duct. FIG. 10 is an illustration of the apparatus used to prepare a hollow cable rope duct of the present invention. DETAILED DESCRIPTION OF THE INVENTION

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art. All publications referenced herein are incorporated by reference thereto. All United States patents and patent applications referenced herein are incorporated by reference herein in their entirety including the drawings.

The articles "a" and "an" are used herein to refer to one or to more than one, i.e. to at least one of the grammatical object of the article. The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1 , 2, 3, 4 when referring to, for example, a number of articles, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of end points also includes the end point values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0).

The present invention concerns a medical balloon catheter having a proximal end and distal end, comprising a longitudinal shaft with an inflation lumen extending therewithin and at least one inflatable balloon towards the distal end in fluid communication with the shaft inflation lumen. The distal end of the inflation lumen opens into the balloon inflation chamber, while the proximal end is open and may be configured for coupling to a fitting that connects to a source of pressurised inflation medium (e.g. gaseous or fluid). Disposed within the inflation lumen and along the length of the catheter is a guidewire duct, provided with a guidewire lumen along the length of the guidewire duct. The catheter thus effectively has two lumens co-axially arranged.

The guidewire duct comprises a hollow rope duct formed from a plurality of longitudinal wire cables cylindrically stranded to form the flexible duct. The flexibility of the hollow rope duct may be uniform from its proximal to distal end, which may be achieved with a uniform duct diameter or wall thickness. Alternatively, the distal end may be more flexible than the proximal end, and a region of transitional flexibility may be used to connect the differentially flexible ends. Advantageously, the hollow rope duct so formed facilitates the ease of passage of the guidewire, since the cables forming the hollow rope duct lumen run in a longitudinal direction. As mentioned elsewhere, advancement of a catheter of the art over a guidewire, can be difficult due to the guidewire frictionally engaging with a spiral cuts of the guidewire lumen. It is exacerbated in the case when the guidewire tip lodges in the gap of a bent hypotube spiral. Because the guidewire lumen is provided with a plurality of essentially longitudinal grooves in the present invention, the proximal end of the guidewire is actively guided in the longitudinal direction. Moreover, the cylindrical cables presents a plurality of convex surfaces which direct the guidewire away from the inner wall, compared with a concave surface of traditional catheters which contribute to passage of a guidewire into the inner wall, particularly at bends. In additional, the duct so formed exhibits excellent torque transfer in both rotational (clockwise and anti-clockwise) directions. The flexibility of the hollow rope duct of the guidewire lumen may gradually change from the proximal end to the distal end, typically being more stiff at the proximal end so as to provide better pushability. The more flexible distal end facilitates advancement of the catheter tip through the tortuous route of the vasculature. The longitudinal disposition of the cables also facilitates covering with a jacket, which can be pulled over the hollow rope duct with ease. Optionally extending the distal end of the hollow rope duct with a flexible polymeric tubing provides additional flexibility at the distal end, useful for passage through severely convoluted routes. The length of the flexible polymeric tubing can be determined by requirements of the procedure according to the intervention.

Reference is made in the description below to the drawings which exemplify particular embodiments of the invention; they are not at all intended to be limiting. The skilled person may adapt the device and substitute components and features according to the common practices of the person skilled in the art.

With reference to FIG. 1 , one embodiment of the present invention concerns an intraluminal balloon catheter 100 comprising an elongated flexible shaft 5 having a proximal end 20, a distal end 10, a longitudinal inflation lumen 21 disposed within the shaft 5, and at least one inflatable balloon 4 towards the distal end 10 in fluid communication with the inflation lumen 21 , the inflation lumen 21 being open at the proximal end 20, the inflation lumen 21 provided with a longitudinal guidewire duct 7, disposed with a longitudinal guidewire lumen 6 extending therein, in fluid connection with a distal guidewire port 30 located in a region at the distal end 10 of the shaft 5, and a proximal guidewire port 32 located at the proximal end 20 of the longitudinal guidewire duct 32, the guidewire duct 7 being formed at least partially from a hollow rope duct 8 comprising a plurality of longitudinal wire cables 40, 40' (FIG. 6A) cylindrically stranded to form the hollow rope duct 8 having a region of transitional flexibility between the proximal 20 and distal ends 10.

The terms "distal", "distal end", "proximal" and "proximal end" are used through the specification, and are terms generally understood in the field to mean towards (proximal) or away (distal) from the surgeon side of the apparatus. Thus, "proximal (end)" means towards the surgeon side and, therefore, away from the patient side. Conversely, "distal (end)" means towards the patient side and, therefore, away from the surgeon side.

The medical balloon catheter 100 comprises an elongated shaft 5 (also referred to as a shaft herein) having a proximal end 20 and a distal end 10, and an inflation lumen 21 therein which extends the longitudinal length of the shaft 5. The proximal 20 terminal end of the inflation lumen 21 is open (not sealed) for the passage of inflation medium. The guidewire duct 7 may pass through and protrude from the proximal 20 terminal end of the elongated shaft 5 as shown in FIGs. 1 and 2. The distal end 10 of the inflation lumen 21 is in fluid connection with an inflatable balloon 4. The distal end 10, of the catheter provides a distal guidewire port 30 which allows access to the guidewire lumen 6 of the guidewire duct 7. The elongated shaft 5 is typically cylindrical. It will be appreciated that the elongated shaft 5 and guidewire duct 7 utilize an essentially co-axial assembly.

In fluid connection with the inflation lumen 21 is at least one inflatable balloon 4 located towards the distal end 10 of the elongated shaft 5.

The balloon 4 is normally disposed in coaxial alignment with the shaft 5. The elongated shaft 5 may terminate where it joins the proximal end 20 of the proximal most balloon 4. In which case the distal end 10 of the distal most balloon 4 is preferably sealed against the guidewire duct 7, thereby sealing the inflation lumen 21 at the distal 10 end. This configuration is shown, for instance, in FIGs. 1 , and 3 to 5. Alternatively, the inflation lumen 21 may be in fluid connection with the at least one inflatable balloon 4 via a plurality of apertures 17 in the wall of the elongated shaft 5 (FIG. 2). An application of inflation medium such as saline and/or contrast media fluid through the inflation lumen 21 causes the at least one inflatable balloon 4 to open, expanding in a radial direction allowing deployment of the stent or dilatation of the vessel wall.

The elongated shaft 5 is formed from suitable biocompatible materials that are conventionally used for catheter shafts, and which include silicone rubber, polypropylene, polyethylene, polyurethanes, polyamide, poly(ethylene terephthalate) (PET) or polyesters and copolymers thereof.

The diameter of elongated shaft 5 is sufficiently narrow to introduce through the subject vasculature. The diameter of the inflation lumen 21 of the elongated shaft 5 should be sufficiently larger than the outer diameter of the guidewire duct 6 to provide passage for inflation medium to and from the balloon(s) 4. Generally the inner diameter of inflation lumen 21 will be 1 %, 2 %, 3 %, 4 %, 5 %, 6 %, 7 %, 8 %, 9 %, 10 %, 1 1 %, 12 %, 13 %, 14 %, 15 %, 16 %, 17 %, 18 %, 19 %, 20 %, 25 %, 30 %, 35 %, 40 %, 45 %, or 50% greater than the outer diameter (DOD, FIG. 9) of the guidewire duct 7.

According to one aspect of the invention, the inner diameter (SID, FIG. 9) of the inflation lumen 21 is 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.80 mm, 0.85 mm, 0.90 mm or a value in the range between any two of the aforementioned values, preferably between 0.65 mm and 0.8 mm, more preferably 0.5 mm and 0.8 mm.

According to one aspect of the invention, the wall of the elongated shaft 5 has a thickness of 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.10 mm or a value between any two of the aforementioned values, preferably between 0.05 mm and 0.09 mm.

According to one aspect of the invention, the external diameter (SOD, FIG. 9) of the elongated shaft 5 is 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, 0.95 mm, 1.0 mm, 1.1 mm, or a value in the range between any two of the aforementioned values, preferably between 0.85 mm and 0.95 mm, more preferably between 7 mm and 0.95 mm.

The overall length of the medical balloon catheter 100 is typically about 90 to about 150 cm.

According to one aspect of the invention, the elongated shaft 5 is formed from a single piece of tubing from the proximal end 20 to the proximal-most balloon 4. According to another aspect of the invention, the elongated shaft 5 is formed from a single piece of tubing from the proximal end 20 to the proximal end of the distal-most balloon 4. The distal 10 terminal end of the elongated shaft 5 may be extended with a softened tip to facilitate passage of the catheter 100 through the patient vessel. The tip is provided with a lumen for access to the guidewire lumen 6. The exterior surface of the elongated shaft may comprise of high and/or low density polyethylene, polyamides, poly(ethylene terephthalate) (PET) or polyesters and copolymers thereof, teflon or any such material that comprises a hydrophilic character .

The medical balloon catheter 100 comprises an elongated guidewire duct 7 having a proximal end 20 and a distal end 10, and comprising a guidewire lumen 6 therein extending the longitudinal length of the duct 7. The distal 10 end of the guidewire duct 7 terminates with a distal guidewire port 30, and the proximal end of the guidewire duct 7 terminates with a proximal guidewire port 32. The guidewire duct 7 extends within the longitudinal length inflation lumen 21. The guidewire duct 7 is typically cylindrical. The guidewire duct 7 has an inherent medium-impermeable property, however, it may rendered medium-impermeable at higher pressures, for instance up to 30 bar by a medium-impermeable coating or jacket. The proximal 32 and distal ports 30 of the guidewire duct 7 provide access to the guidewire lumen 6 through which the guidewire may pass. It will be appreciated that the elongated shaft 5 and guidewire duct 7 utilize an essentially co-axial assembly.

The guidewire duct 7 is at least partly formed form a hollow wire-cable rope that forms a hollow rope duct 8. It is made by cylindrically stranding a group of stainless steel wires along a predetermined circle line to provide a hollow rope duct 8 of the invention. An inner surface 25 of the hollow rope duct 8 forms a plurality of concave structures represented by the stainless steel wires 40, 40' that are circular in cross-section. Such tubing is known in the art, for example, the Actone cable tube as manufactured by Asahi Intecc, and described, for instance, in US 2004/0249277. An outer surface 27 of the hollow rope duct 8 may be rendered partially smooth in regions of increased flexibility giving rise to wires 40, 40' that are part or semi-circular, while the inner surface forms a guidewire lumen 6 in which the convex-concave structure resides.

The hollow rope tube 72 may have 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23 or 24 metallic wires 40, 40', or a number in the range between any two of the aforementioned values, preferably between 2 and 24.

The maximum outer diameter (DOD, FIG. 9) of the hollow rope duct 8 including any coating or jacket for use in a dilatation or stent catheter may be equal to or no greater than 0.50 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.70 mm, 0.80 mm, 0.90 mm, 1.0 mm, 1.2 mm, or a value in the range between any two of the aforementioned values, preferably between 0.5 mm and 0.7 mm. The maximum inner diameter (DID, FIG. 9) of the hollow rope duct 8 for use in a dilatation or stent catheter may be equal to or no greater than 0.30 mm, 0.35 mm, 0.40 mm, 0.45 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, or a value in the range between any two of the aforementioned values, preferably between 0.3 mm and 0.5 mm.

The hollow rope duct 8 may be manufactured according to a scheme as shown in FIG. 10. Namely, a wire rope R is provided by stranding the metallic wires 40, 40' around an elongated core (not shown). One end of the wire rope R is secured to a rotational chuck

60 of a twisting device 70. The other end of the wire rope R is secured to a slidable chuck 62 from which a weight 66 is attached applying a longitudinal force. The wire rope R is twisted under the tensile force applied by the weight 66. A current generating device 68 provides electric currents to the chucks 60 and 62 through an electric wire 64 so that the wire rope R is heated by its electric resistance to remove the residual stress appeared on the wire rope R during the twisting process. Once the rope has formed, the outer surface of the hollow rope duct 8 may be smoothly ground to provide the requisite flexibility as necessary so that the metallic wires 40, 40' have a semi- or part-circular cross-section in the flexible regions. The elongated core is withdrawn from the wire rope R to provide a hollow tube structure that is the hollow rope duct 8.

The hollow rope duct 8 formed from the plurality of wire cables may be provided with a jacket or coating 50, 52, 54, 56 (FIGs. 7A to 7C; FIGs. 8A to 8C) made from a substance typically used to form lumens in corresponding catheters of the art. For example, the jacket or coating may comprise materials such as polyethylene, polyamide, polyurethanes, poly(ethylene terephthalate) (PET) or polyesters and copolymers thereof. The jacket or coating may comprise of high and/or low density polyethylene, polyamides, poly(ethylene terephthalate) (PET) or polyesters and copolymers thereof, teflon or any such material that comprises a hydrophilic character. The coating or jacket improves the medium- impermeable property of the hollow rope duct 8. In the case of a coating, it can be applied by spraying or dipping a liquid form of the polymer over the surface of the duct. In the case of a jacket, it may be slid over or in the hollow rope duct 8; advantageously, the longitudinal disposition of the cables facilitates sliding of the jacket. It is within the scope of the invention, that the coating is applied on the outside and/or the inside surface(s) of the duct. The interior surface 25 of the guidewire duct 7 may may be coated with or comprise a tubing of high and/or low density polyethylene, polyamides, poly(ethylene terephthalate) (PET) or polyesters and copolymers thereof, teflon or any such material that comprises a hydrophilic character.

The flexible hollow rope duct 8 of the invention may have a region of transitional flexibility between its proximal 20 and distal ends 10. The region provides a gradually changing flexibility from a stiffer proximal end to a less stiff (more flexible) distal end, thereby imparting differential flexibility on the guidewire duct. Differential flexibility of the hollow rope duct 8 is transferred to the catheter as a whole. The outer diameter (DOD) of the hollow rope duct 8 may gradually decrease in a direction from the proximal end 20 to the distal end 10 in the region of transitional flexibility. Proximal 20 to the region of transitional flexibility, the outer diameter of the hollow rope duct 8 may be essentially constant and essentially equal to the largest diameter present in the region of transitional flexibility. Distal 10 to the region of transitional flexibility, the outer diameter of the hollow rope duct 8 may be essentially constant and essentially equal to the smallest diameter present in the region of transitional flexibility. The inner diameter (DID) of the hollow rope duct 8 remains constant along the length of the hollow rope duct 8.

The distal end 10 of the hollow rope duct 8 may have a section in the lengthwise direction known herein as a flexible (F) region, depicted in FIGs. 2 to 5. The proximal end 20 of the hollow rope duct 8 may have a section in the lengthwise direction that belongs to the stiff (S) region as known herein. The hollow rope duct 8 in the F-region exhibits greater flexibility compared with the hollow rope duct 8 in the S-region. A lengthwise portion, the transition (T) region, between the F-region and S-region serves as a region of transitional flexibility between the F-region and S-region. The S-region provides the requisite pushability to advance the catheter from the proximal end 20 without kinking the catheter, while the F-region being more flexible, can bend and flex around the tortuous route of a vasculature. The T-region effectively buffers the movements between the F-region and S- region.

The flexibility of the hollow rope duct 8 in the F-region may be increased compared with that in the S-region by a diametric reduction of the hollow rope duct 8. A lengthwise portion, the T-region, between the F-region and S-region diametrically increases progressively from distal 10 to the proximal 20 end to serve as a region of transitional flexibility between the F-region and S-region. As shown in FIGS. 6A, 6B and 6C the outer diameter of the duct, DOD, is maximal in the S-region (FIG. 6A), minimal in the F-region (FIG. 6C) and is transitional in the T-region (FIG. 6B). It will be appreciated that the cross- sections in the T-region progressive increase in diameter from the distal to proximal end. The smaller outer diameter, DOD, combined with a constant internal diameter, DID, provide a thinner wall in the F-region exhibiting increased flexibility compared with the thicker walled hollow rope duct 8 in the S-region. The outer diameter of the hollow rope duct 8 may be modified by chemical treating or deforming or grinding the outside surface, for instance the metallic wires 40, 40' have a circular form in cross section with its outer surface not ground in the S-region (FIG. 6A), compared with in the F-region where the ground wires adopt a semi-circular profile (FIG. 6C). The maximum outer diameter (DOD) of the hollow rope duct 8 in the F-region, when the catheter is for use in a dilatation or stent catheter may be 100%, 98 %, 96 %, 95 %, 90 %, 85 %, 80 %, 75 %, 70 % of that of the maximum outer diameter (DOD) of the hollow rope tube 72 in the S-region. The maximum outer diameter (DOD) of the hollow rope duct 8 in the S-region, when the catheter is for use in a dilatation or stent catheter may be equal to or no greater than 0.50 mm, 0.55 mm, 0.60 mm, 0.65 mm, 0.70 mm, 0.80 mm, 0.90 mm, 1.0 mm, 1.2 mm, or a value in the range between any two of the aforementioned values, preferably between 0.5 mm and 0.7 mm.

According to an aspect of the invention, the hollow rope duct 8 may be provided with a polymeric coating or jacket. The purpose of the jacket may be to provide or enhance medium impermeability. Where the differently flexible regions are provided by diametric changes in the hollow rope duct 8, the thickness of the jacket or coating may be constant as shown in FIGs. 7A, 7B and 7C, where the minimum coating 50 thickness is the same in the S-region (FIG. 7A), T-region (FIG. 7B) and F-region (FIG. 7C). In such cases, the jacket or coating thickness does not contribute to differential flexibility.

According to another aspect of the invention, the hollow rope duct 8 may be provided with a polymeric coating or jacket which thickness varies according to the desired flexibility. The purpose of the jacket may be to add medium impermeability, but also to control flexibility. In such cases, the diameter of the hollow rope duct 8 may be constant, and differential flexibility is achieved by virtue of the coating or jacket only.

The thickness of the coating or jacket only may gradually decrease in a direction from the proximal end 20 to the distal end 10 in the region of transitional flexibility. Proximal 20 to the region of transitional flexibility, the thickness of the coating or jacket may be essentially constant and essentially equal to the largest thickness present in the region of transitional flexibility. Distal 10 to the region of transitional flexibility, the thickness of the coating or jacket may be essentially constant and essentially equal to the smallest thickness present in the region of transitional flexibility. The inner diameter (DID) of the hollow rope duct 8 remains constant along the length of the hollow rope duct 8; and outer diameter (DOD) preferably remains constant, or may vary to further enhance differential flexibility.

Depicted in FIG. 8A to 8C is the instance where the hollow rope duct 8 has a constant diameter, the thickness of the coating 52 in the S-region (FIG. 8A) is greater compared with in the F-region (FIG. 8C) and the section is accordingly stiffen T-region exhibits a transition thickness at the section indicated (FIG. 8B). According to one aspect of the invention, differential flexibility may be enhanced by combining both diametric changes in hollow rope duct 8 with variable coating or jacket thicknesses.

The maximum thickness of the coating or jacket in the F-region, when the catheter is for use in a dilatation or stent catheter may be equal to or no greater than 0.01 mm, 0.10 mm, 0.3 mm, or a value in the range between any two of the aforementioned values, preferably between 0.01 mm and 0.1 mm. The maximum thickness of the coating or jacket in the S- region, when the catheter is for use in a dilatation or stent catheter may be equal to or no greater than 0.01 mm, 0.2 mm, 0.3 mm, 0.4 mm, or a value in the range between any two of the aforementioned values, preferably between 0.01 mm and 0.2 mm.

Other ways to achieve a variation in flexibility includes differentially tempering the metal during formation of the rope, changing the weight applied during the stranding process, changing the diameter of the elongated cored used during stranding, changing the type of metal used during stranding.

The length of the F-region, may be 0 %, 2 %, 5 %, 10 %, 20 %, 30 %, or 40 % of the length of the catheter or a value in the range between any two of the aforementioned values, preferably between 2 and 30 %.

The length of the T-region, may be 0 %, 2 %, 5 %, 10 %, 15%, or 20 %, of the length of the catheter or a value in the range between any two of the aforementioned values, preferably between 2 and 20%.

The length of the S-region, may be 40 %, 55 %, 60 %, 65 %, 70 %, 80%, 85%, 90%, 95% or 100% of the length of the catheter or a value in the range between any two of the aforementioned values, preferably between 70 and 95%.

According to one aspect of the invention, the guidewire duct 7 is formed from a single piece of hollow rope duct 8 from the distal guidewire port 30 to the proximal guidewire port 32 as shown for instance in FIGs. 1 and 2. According to another aspect of the invention, the guidewire duct 7 is formed from a piece of hollow rope duct 8 and a piece of flexible polymeric tubing 11 attached at the distal end of hollow rope duct 8 as shown, for instance, in FIGs. 4 and 5. The distal guidewire port 30 is disposed on the polymeric tubing 11 while the proximal guidewire port 32 is disposed on the hollow rope duct 8. The distal end of the distal-most balloon (4) is circumferentially sealed against the cylindrical outer wall of the polymeric tubing 11. The polymeric tubing 11 is disposed with a lumen extending the length of the polymeric tubing 11 ; the lumen of the hollow rope duct 8 and the lumen of the polymeric tubing 11 are in fluid communication and their longitudinal axis are preferably aligned coaxially.

The polymeric tubing 11 may be attached to the hollow rope duct 8 using any suitable attachment means in the art, for instance, by way of a frictional joint e.g. a portion of the proximal end 20 of the tubing being disposed over a portion of the distal end of the hollow rope duct 8 as depicted, for instance in FIGs. 4 and 5. Other means include the use of adhesive, or an inline adaptor (e.g. portion of bridging tubing) that mates one end of the hollow rope duct 8 with one end of the polymeric tubing 11. Other means include the use of heat bonding.

The maximum outer diameter of the polymeric tubing 11 , when the catheter is for use in a dilatation or stent catheter may be equal to or no greater than that of the hollow rope duct

8 or the hollow rope duct 8 in the F-region where present. According to one aspect of the invention, the maximum outer diameter of the polymeric tubing 11 is 0 %, 1 %, 5%, 10%,

15%, 20% less than that of the hollow rope duct 8 or the hollow rope duct 8 in the F-region where present. According to another aspect of the invention, the maximum outer diameter of the polymeric tubing 11 is 0.45 mm, 0.50 mm 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm or 0.8 mm, or a value in the range between any two of the aforementioned values, preferably between 0.5 mm and 0.6 mm.

The maximum diameter of the lumen of the polymeric tubing 11 for use in a dilatation or stent catheter can be smaller than, equal to or greater than that of the hollow rope duct 8 in the F-region. According to one aspect of the invention it is equal to or no greater than 0.30 mm, 0.35 mm, 0.40 mm, 0.45 mm, 0.5 mm, or a value in the range between any two of the aforementioned values, preferably between 0.4 mm and 0.5 mm.

The length of polymeric tubing 11 , D1 (FIGs. 4 and 5), will depend on the requisite flexibility at the distal end 10. Generally a longer length of D1 is more suitable for tortuous routes or providing improved crossability though narrow channels, while a shorter length is better suited for advancement through and widening of blocked vessels, providing better pushability. The length, D1 may be determined by the skilled practitioner, and as a general guidance, may be 0 cm, 0.5 cm, 1 cm, 2 cm, 4 cm, 5 cm, 6 cm, 8 cm, 10 cm, 12 cm, 14 cm, 16 cm, 18 cm, 20 cm, 22 cm, 24 cm, 26 cm, 28 cm, 30 cm, 32 cm, 34 cm, 36 cm, 38 cm, 40 cm, or a value in the range between any two of the aforementioned values, preferably between 0 and 30 cm.

As a general rule, the polymeric tubing 11 passes through the balloon 4 from the balloon's proximal end 20 to its distal end. It may join the hollow rope duct 8 at the proximal end 20 of the proximal-most balloon 4 as shown in FIG. 4; alternatively, the polymeric tubing 11 may extend from the proximal end 20 of the proximal-most balloon 4 and join the hollow rope duct 8 proximal to the proximal-most balloon 4 as shown in FIG. 5. The distance between the proximal end 20 of the polymeric tubing 11 and the proximal end 20 of the proximal most balloon 4, D2 (FIG. 5), may be 0 cm, 0.5 cm, 1 cm, 2 cm, 4 cm, 5 cm, 6 cm, 8 cm, 10 cm, 12 cm, 15 cm, 20 cm, 25 cm, 30 cm, 35 cm or a value in the range between any two of the aforementioned value, preferably between 0 cm and 5 cm or between 2 cm and 5 cm.

The polymeric tubing may be made from suitable biocompatible materials that are conventionally used for catheter shafts, and which include nylon polymer, polyamide, silicone rubber, polypropylene, polyethylene, polyurethanes, poly(ethylene terephthalate) (PET), polyesters and copolymers thereof.

According to another aspect of the invention, the guidewire duct 7 comprises a distal tip 9 at its distal end 10 as shown, for instance, in FIGs. 3, 4A and 5A. The distal tip 9 provides a non-abrasive surface that avoids or reduces injury to a vessel as the distal end of the catheter 100 is advanced. The guidewire lumen 6 extends into the distal tip 9. In other words, the distal tip 9 is disposed with a lumen extending the length of the distal tip 9; the lumen of the guidewire duct 7 and the lumen of the distal tip 9 are in fluid communication and their longitudinal axis are preferably aligned coaxially. The distal guidewire port 30 is disposed at the distal terminal end of the distal tip 9.

The distal tip 9 is attached to the distal end 10 of the guidewire duct 7. According to one aspect of the invention, the distal tip 9 is attached to the distal end 10 of the hollow rope duct 8 as shown, for instance in FIG. 3. According to another aspect of the invention, the distal tip 9 is attached to the distal end 10 of the polymeric tubing 11 as shown, for instance in FIGs. 4A and 5A.

The distal tip 9 may be attached to the distal end of the guidewire duct 7 (i.e. to the hollow rope duct 8 or to the polymeric tubing 11 ) using any suitable attachment means in the art, for instance, by way a frictional joint e.g. a portion of the proximal end 20 of the softened distal tip 9 being disposed over a portion of the distal end of the guidewire duct 7. Other means include the use of adhesive, or an inline adaptor (e.g. portion of bridging tubing) that mates one end of the guidewire duct 7 with one end of the distal tip 9. Other means include the use of heat bonding.

The maximum outer diameter of the distal tip 9, when the catheter is for use in a dilatation or stent catheter may be equal to or no greater than that of the hollow rope duct 8, or of the hollow rope duct 8 in the F region where present. According to one aspect of the invention, the maximum outer diameter of the distal tip 9 is 0 %, 1 %, 5%, 10%, 15%, 20% less than that of the hollow rope duct 8, or of the hollow rope duct 8 in the F region where present. According to another aspect of the invention, the maximum outer diameter of the distal tip 9 is 0.35 mm, 0.40 mm, 0.45 mm, 0.50 mm, 0.55 mm, 0.6 mm, 0.65 mm, or 0.7 mm, or a value in the range between any two of the aforementioned values, preferably between 0.4 mm and 0.7 mm.

The maximum diameter of the lumen of the distal tip 9 for use in a dilatation or stent catheter can be smaller than, equal to or no greater than that of the hollow rope duct 8, or of the hollow rope duct 8 in the F region. According to one aspect of the invention it is equal to or no greater than 0.30 mm, 0.35 mm, 0.40 mm, 0.45 mm, 0.5 mm, or a value in the range between any two of the aforementioned values, preferably between 0.4 mm and 0.5 mm.

The length of distal tip 9, will depend on the requisite flexibility at the distal end 10. The length, as a general guidance, may be 0 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm or 10 mm, or a value in the range between any two of the aforementioned values, preferably between 1 and 5 mm.

As a general rule, the distal tip 9, joins the guidewire duct 7 at the distal end 10 of the distal-most balloon 4 as shown in FIGs. 3, 4A and 5A, and extends from the distal end 10 of the distal-most balloon 4.

The distal tip 9 is general made from a softened polymer material; it may be made from any suitable biocompatible material that is conventionally used for softened catheter distal tips, and which include materials such as polyethylene, polyamide, polyurethanes, poly(ethylene terephthalate) (PET) or polyesters and copolymers thereof As mentioned elsewhere, the medical balloon catheter of the invention effectively comprises two lumens co-axially arranged, one 21 for the selectively inflating and deflating the balloon 4 and the other 6 for passage of the guidewire. A hub may be connected at the proximal 20 terminal end of the catheter 100 to provide ports for separate access to the lumens. The inflation ports may have a coupling or Luer-lock fitting for connecting the inflation lumen 21 to a source of pressurized inflation fluid in the conventional manner. Typically the hub is a Y-shaped adapter.

The balloon catheter 100 may be provided with one or more radiopaque markers for determining the position of the balloon in a subject during placement. The radiopaque markers are preferably placed in the balloon 4. They may be present on the guidewire duct 7.

The medical balloon catheter 100 is provided with one or more balloons (e.g. 2, 3, 4, 5, 6, 7, 8) 4, in fluid communication with the inflation lumen 21 of the elongated catheter tube 5.

The one or more balloons 4 (referred to "the balloon" herein, unless otherwise indicated) is an inflatable member that expands radially to contact the wall of vessel or tissue being treated. Such balloons are well known in the art. Its function is to expand so as to fill the vasculature, and apply pressure to the vessel walls thereby increasing the volume of the restricted region, or to open out a stent and secure its position in the vasculature wall.

According to one aspect of the invention, the balloon catheter is provided without a stent. According to another aspect of the invention, the balloon catheter is provided with a stent, disposed at least partly on the balloon part 4. In addition to the stent, an annular elastic sleeve structure may be placed around the balloon.

The balloon 4 in the uninflated state may be provided as a plurality of radially and axially extending "wings" spaced from one another in the circumferential direction around the central longitudinal axis of the balloon. The wings may be wrapped or folded laterally in the manner desired. An elastic sleeve may be disposed around the folded balloon. The balloon 4 is configured to inflate essentially radially, to an extent that the inner walls of the esophagus are contacted. The balloon 4 may be configured to refold with a relatively compact cross section after it has been inflated and deflated. This feature facilitates withdrawal of the deflated catheter from the patient.

According to one aspect of the invention, the external diameter of the balloon 4 in the uninflated state is equal to or no greater than 0.5 mm, 0.7 mm, 1 mm, 1.5 mm, 2 mm or a value between any two of the aforementioned values, preferably between 0.5 mm and 1 mm.

According to one aspect of the invention, the external diameter of the balloon 4 in the inflated state is equal to or no greater than 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm or a value between any two of the aforementioned values, preferably between 1 mm and 4.5 mm.

The balloon 4 is made from an elastic material such as polyethylene, nylon, polyurethane, silicone, latex, poly(ethylene terephthalate) (PET) or polyamide. Conventional balloon materials used in dilatation catheters would be suitable for use with the catheter. Variations can be made in the composition of the materials to vary properties.

According to one embodiment of the invention, the elongated shaft 5 terminates proximal 20 to the proximal-most balloon 4 as depicted, for instance, in FIGs. 1, and 3 to 5, and the distal end 10 of the inflation lumen 21 opens out into the inflation chamber of the balloon 4, thereby fluidicly connecting the former with the latter. In such case, the balloon 4 may be attached to and sealed against the outer wall of the elongated shaft 5 at its proximal 20 end, and attached to and sealed against the outer wall of the elongated guidewire duct 7 at its distal end 10. According to another embodiment of the invention, the elongated shaft 5 passes through the balloon 4 as depicted, for instance, in FIG. 2, and one or more apertures 17 in the elongated shaft 5 fluidicly connect the inflation lumen 21 with the interior of the balloon 4. In such case, the balloon 4 may be attached to, and sealed against the outer wall of the elongated shaft 5 at both its distal 10 and proximal 20 ends. The attachment to and sealing of the balloon may be achieved using any known technique of the art. For example, techniques commonly used are those which use a short piece of tubing to bind the balloon over the elongated shaft 5 or guidewire duct 7. One instance is a heat shrinking tubing which binds the balloon over the elongated shaft 5 or guidewire duct 7. Another is melting the tubing over the elongated shaft 5 or guidewire duct 7, or gluing the tubing over the elongated shaft 5 or elongated guidewire duct 7 or welding the tubing over the elongated shaft 5 or guidewire duct 7. The elongated shaft 5 or guidewire duct 7 is commonly prepared to receive either technique of attaching a tubing by roughening or modifying the elongated shaft 5 or guidewire duct 7 bonding surface with either sandblasting or laser carvings. Radiopaque markers may be provided under the balloon 4. They may be provided at predetermined locations near the balloon (e.g. mid balloon adjacent or under each axial end of a balloon) to facilitate positioning the balloons at the desired location in the body.

The medical balloon catheter 100 may be provided with a pusher or stiffening wire (not shown), which extends from a point proximal 20 of the balloon 4 to maximally a point distal 10 of the balloon 4. The distal end 10 of the pusher wire is preferably securely attached to the catheter e.g. to the tip of the balloon. The stiffening wire may reside inside or outside the balloon. A preferred material for the pusher wire is stainless steel or nitinol (nickel- titanium) because of its very high flexibility and elasticity, which will help prevent kinking of any portion of the catheter through which it passes. Radiopaque markers, mentioned above, may be provided on the pusher wire. Where the catheter carries a stent, they may be provided at predetermined locations near the stent (e.g. adjacent each axial end of the stent) to facilitate positioning the stent at the desired location in the body.

In use, catheter 100 is fed into a patient along guide wire by threading the proximal end of the guidewire through the distal guidewire port, and advancing the catheter along the guidewire. The proximal end of the guidewire exits through the proximal end of the guidewire duct where it can be grasped and can facilitate advancement of the catheter 100. Then the catheter is fed into the patient along the guide wire. An initial portion of the entry of the guide wire and catheter 100 into the patient may be made via a conventional guide catheter.

When balloon is at the location in the patient's tubular body structure that is to receive dilatation treat (which may be determined with the aid of radiopaque markers), pressurized balloon inflation fluid is supplied to balloon via inflation lumen. This causes balloon to unfold and inflate. Inflation of balloon circumferentially expands the vessel.

After balloon has been inflated and the vessel expanded as described above, balloon is deflated by draining the inflation fluid from it, via lumen. This allows the balloon to collapse and preferably refold. Catheter can then be withdrawn from the patient by pulling it out along guide wire.

In use, catheter 100 is fed into a patient along guide wire, which is already in place in the patient. For example, guide wire may have already been used with another balloon catheter for the purpose of preliminarily dilating a body structure that is to receive the stent from catheter as described above. Guide wire will then have been left in the patient when the other catheter is withdrawn from the patient along the wire. Catheter may be placed on guide wire by threading the proximal end of the guidewire through the distal guidewire port, and advancing the catheter along the guidewire. The proximal end of the guidewire exits through the proximal end of the guidewire duct where it can be grasped and can facilitate advancement of the catheter 100. Then the catheter is fed into the patient along the guide wire. An initial portion of the entry of the guide wire and catheter 100 into the patient may be made via a conventional guide catheter.

When balloon is at the location in the patient's tubular body structure that is to receive stent (which may be determined with the aid of radiopaque markers), pressurized balloon inflation fluid is supplied to balloon via inflation lumen. This causes balloon to unfold and inflate. Inflation of balloon circumferentially expands stent structure. Circumferential expansion of stent structure permanently implants the stent structure in the patient's tubular body structure.

After balloon has been inflated and stent structure thereby implanted as described above, balloon is deflated by draining the inflation fluid from it via lumen. This allows the balloon to collapse and preferably refold. Catheter can then be withdrawn from the patient by pulling it out along guide wire. If there is no further need for guide wire, the guide wire can also be withdrawn from the patient.

Those skilled in the art will recognize that other modifications and improvements can be made to the invention without departing from the scope thereof.

Claims

1. An intraluminal balloon catheter (100) comprising an elongated flexible shaft (5) having a proximal end (20), a distal end (10), a longitudinal inflation lumen (21 ) disposed within the shaft (5), and at least one inflatable balloon (4) towards the distal end (10) in fluid communication with the inflation lumen (21 ), the inflation lumen (21 ) provided with a longitudinal guidewire duct (7), disposed with a longitudinal guidewire lumen (6) extending therein, in fluid connection with a distal guidewire port (30) located in a region at the distal end (10) of the shaft (5), and a proximal guidewire port (32) located at the proximal end (20) of the longitudinal guidewire duct (7), the guidewire duct (7) comprising a hollow rope duct (8) formed from a plurality of longitudinal wire cables (40, 40') cylindrically stranded to form the hollow rope duct (8), the hollow rope duct (8) optionally having a region of transitional flexibility between the proximal (20) and distal ends (10).

2. Catheter according to claim 1 , wherein the hollow rope duct (8) has a region of transitional flexibility, and the outer diameter of the hollow rope duct (8) gradually decreases in a direction from the proximal end (20) to the distal end (10) in the region of transitional flexibility.

3. Catheter according to claims 1 or 2, wherein the hollow rope duct (8) is provided with a medium impermeable coating or outer jacket.

4. Catheter according to claim 3, wherein the hollow rope duct (8) has a region of transitional flexibility, and the thickness of the coating or outer jacket gradually decreases in a direction from the proximal end (20) to the distal end (10) in the region of transitional flexibility.

5. Catheter according to any of the preceding claims, further comprising a hub at the terminus of the proximal end (20) for connection of the inflation lumen (21 ) to a source of pressurized inflation fluid and for access to the guidewire lumen (6).

6. Catheter according to any of the preceding claims, further comprising a stent in the unexpanded condition.

7. Catheter according to any of the preceding claims, further comprising one or more radiopaque markers configured to indicate the position of the balloon in a subject during placement.

8. Catheter according to any of the preceding claims, wherein the guidewire duct (7) is formed by cylindrically stranding a group of stainless steel wire cables (40, 40') along a predetermined circle line to provide the duct (7) of the invention.

9. Catheter according to any of the preceding claims, wherein the interior surface (25) of the duct (7) may comprise of high and/or low density polyethylene, polyamides, poly(ethylene terephthalate) (PET) or polyesters and copolymers thereof, teflon or any such material that comprises a hydrophilic character.

10. Catheter according to any of the preceding claims, wherein the exterior surface of the elongated shaft may comprise of high and/or low density polyethylene, polyamides, poly(ethylene terephthalate) (PET) or polyesters and copolymers thereof, teflon or any such material that comprises a hydrophilic character.

1 1. Catheter according to any of the preceding claims, wherein the guidewire duct (7) further comprises a flexible polymeric tubing (1 1 ) joined to the distal end of the hollow rope duct (8), to which the distal end (10) of the distal-most balloon (4) is circumferentially sealed.

12. Catheter according to claim 11 , wherein the distance, D2, between the proximal end (20) of the polymeric tubing (11 ) and the proximal end (20) of the proximal most balloon (4), is between 0 cm and 5 cm.

13. Catheter according to claim 11 or 12, wherein the length, D1 , of the polymeric tubing (1 1 ) is between 0 cm and 30cm.

14. Catheter according to any of the preceding claims, wherein the guidewire duct (7) further comprises a distal tip (9) joined to the distal end, to which the distal end (10) of the distal-most balloon (4) is circumferentially sealed.

15. Catheter according to claim 14, wherein the distal tip (9) is joined to the distal end of the hollow rope duct (8) or to the distal end of the polymeric tubing (1 1 ) where present.