AU2815299A - System for rapid exchange of an intravascular device - Google Patents

Description

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AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT

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Applicant(s): Address for Service: Invention Title: The following statement is a full performing it known to me:- Cordis Corporation 14201 N.W. 60th Avenue Miami Lakes Florida 33014 UNITED STATES OF AMERICA DAVIES COLLISON CAVE Patent Trade Mark Attorneys Level 10, 10 Barrack Street SYDNEY NSW 2000 System for rapid exchange of an intravascular device description of this invention, including the best method of 5020 P:\WPDOCS\DYS\SPECIE\621442.DIV- 12/5/99 -1- SYSTEM FOR RAPID EXCHANGE OF AN INTRAVASCULAR DEVICE This invention relates to a system for rapid exchange of an intravascular device. In one preferred aspect, this invention relates to a rapid exchange catheter system comprising one or more balloon dilatation catheters and an exchange facilitator consisting of an elongated exchange member and a rigid shaft.

In the utilization of catheters to diagnose and treat various medical disorders, it is very often required that more than one device be used during the procedure. Because positioning of the catheter at the desired location may be difficult, time consuming, or critical or pose a high risk, techniques have been developed that facilitate exchange of catheter devices.

The most common technique for catheter exchange employs a very long guidewire called an exchange wire. In this technique the exchange wire is placed within a central lumen of a catheter that has been previously positioned within the body. To maintain the desired position, the exchange wire is advanced while the catheter is simultaneously withdrawn. Once the catheter is completely out of the body, it is removed from the exchange wire.

A second catheter is then positioned over the exchange wire, and, once the catheter is completely on the exchange wire, it is then advanced to the desired site in the body. This over-the-wire technique for catheter exchange is considerably time consuming, and it requires at least two operators to effect the exchange.

In addition, the very long exchange wire extends beyond the sterile field, which adds to the risk of contamination during the procedure.

U.S. Patent No. 4,762,129 to Bonzel and U.S. Patent No.

5,040,548 to Yock describe balloon angioplasty catheters that can be exchanged over a standard length guidewire. These catheters are called monorail catheters, and they are designed such that only a relatively short segment of the distal end of the catheter is advanced over the guidewire, the catheter has a lumen to receive the guidewire that extends from the distal tip of the catheter to a location proximal to the balloon. Since the length of the guidewire used is only about half that of an exchange wire, the catheter exchange can be done more quickly, and a single operator may do the exchange. However, since a much shorter segment of the catheter is concentric to the guidewire, the monorail-type catheters have diminished axial support for tracking the guidewire (trackability) and transmission of axial or longitudinal forces (pushability).

In additign to the drawbacks cited above, both of the catheter exchange techniques described above have two additional shortcomings increased diameter of the catheters to accommodate the guidewire, and risk of vessel trauma resulting from repeated catheter passages. In a number of applications, over-the-wire catheters are too large to be placed at the desired location. In these applications, smaller catheters, whose diameters have been reduced by eliminating the guidewire lumen, have been required.

Exchange with these prior art systems consisted essentially of starting over after the first catheter was removed. This is Soften time consuming, and there is an increased risk of complications resulting from vessel trauma. U.S. Patent Nos.

4,944,740 and 4,976,689 addressed the trauma issue by providing an outer tubular sheath concentric to an inner catheter.

I; However, this system would have very limited application in small blood vessels, as the system itself would occlude the blood vessel and cause ischemic complications. Moreover, the outer tubular sheath must be used as a system with its inner catheter; S if another catheter or guidewire was used initially, this system could not make the exchange.

P:\WPDOCS\DYS\SPECIE\621442.DIV 12/5/99 -4- According to one aspect of the present invention there is provided a system for rapid exchange of an intravascular device along a path from an access point on a patient's body to a desired site, comprising: an exchange member defining a lumen and having open proximal and distal ends, wherein the terms proximal and distal refer to relative positions along the path; a longitudinally rigid pushing wire having proximal and distal ends, the distal end of the pushing wire being affixed to the proximal end of the exchange member, and an intravascular device which is capable of being positioned within the lumen 10 defined by the exchange member, .o S such that said pushing wire is configured to advance the exchange member distally to a desired site, wherein the exchange member is positioned concentrically surrounding the S. intravascular device.

0o In one preferred form, the pushing wire has a flexible, collapsible sheath having 0 proximal and distal ends and being arranged thereon, the collapsible sheath being expandable to allow infusion of fluid or insertion of an intravascular device, and being collapsible when fluid flow ceases or the device is withdrawn.

The exchange member may be in the form of a coil. The pushing wire and exchange i member may each be comprised of a medically acceptable metal or polymer.

Preferably, the pushing wire extends to at least the distal end of the exchange member.

In one form, the pushing wire may be a guidewire. In another form, the pushing wire may be a catheter.

In one form, the proximal end of the collapsible sheath may be attached to a hemostatic manifold or hub in fluid connection with the collapsible sheath. Preferably, hemostatic manifold or hub has an infusion port in fluid communication with the sheath.

P:\WPDOCS\DYS\SPECIE\621442.DIV 12/5/99 4a- In a preferred form, the distal end of the collapsible sheath extends to the proximal end of the exchange member. Preferably, the collapsible sheath is capable of delivering at least one fluid selected from the group consisting of blood, saline solution, pharmaceuticals, and the like to a site of vascular disease.

In another arrangement, distal end of the collapsible sheath may extend into or through the exchange member.

The collapsible sheath may be arranged so as to be capable of delivering at least one fluid selected from the group consisting of blood, saline solution, pharmaceuticals, and the like to a site of vascular disease.

0 The intravascular device may be selected from the group consisting of catheters, balloon dilation catheters, guidewires, stents, perfusion catheters, infusion catheters, and atherectomy catheters.

In one form, at least two exchangeable members may be provided.

Preferred embodiments of the invention will be hereinbefore described with reference to the accompanying drawings.

Figs. 1 and 2 each represent lateral, longitudinal views of respective embodiments of the invention; Fig. 3 represents a cross-sectional view of the embodiment of Fig. 1; Figs. 4, 5, and 6 represent additional cross-sectional views of embodiments of the invention; Fig. 7 represents an additional embodiment of the invention with the sheath collapsed; Fig. 8 represents the embodiment of Fig. 7 with the sheath expanded; and Figs. 9 and 10 represent cross-sectional views of a further embodiment of the invention.

Detailed Descriotion of the Invention The rapid exchange catheter system (RECS) of this invention provides a very rapid, atraumatic means of exchanging one balloon dilatation catheter or other device for another balloon dilatation catheter or other device. The RECS is comprised of a distal exchange member, preferably radiopaque, and a rigid shaft or wire attached to the exchange member. Optionally the RECS may also comprise a membrane sheath, which is folded around and attached along the length of the rigid shaft, and (4) a hemostatic manifold in fluid connection with the membrane sheath.

The RECS is used by, first, placing the exchange member over the proximal portion of the shaft of a catheter, a balloon dilatation (PTCA) catheter, or a guidewire or other device, that is to be withdrawn from a patient. Then, the exchange member is advanced distally along the shaft until the exchange member is positioned at the target site, adjacent to or across a stenosis, by pushing the rigid wire. The catheter, guidewire, or other device is withdrawn, and then, if a membrane sheath is present, the sheath is unfolded by flushing through the hemostatic manifold.

Now, subsequent PTCA catheters, guidewires, or other devices, for example, atherectomy catheters, laser catheters, stents, angioscopic or ultrasound imaging catheters, infusion

S.

S catheters, perfusion catheters, or the like, may be passed through the sheath to thetarget site.

Additional exchanges can be made as desired through the sheath. Since such additional exchanges are made within the sheath, the subsequent catheters and other devices that are introduced do not rub against the intima of the arteries, as happens with both over-the-wire and monorail exchange techniques.

The exchanges with the RECS are rapid and atraumatic, with the possibility of endothelial denudation, plaque, and intimal dissection minimized.

In addition to providing a rapid and atraumatic means for exchanging catheters and other devices, the RECS of the invention can also be used for suselective infusion and perfusion.

Subselective infusion of various pharmacological agents directly to a lesion, especially during a procedure, may reduce complications, minimize systemic side-effects, and improve the

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long-term outcome of the procedure. In the event of an abrupt closure during an angioplasty, the RECS can be rapidly deployed to provide coronary perfusion. With the sheath in the collapsed, folded position, the distal exchange member can act as a temporary stent, providing passive perfusion. If necessary, blood or an oxygen-bearing fluid could be pumped through the sheath for active perfusion.

With the ability to perfuse, the RECS can provide lifesaving capability not presently available in known exchange systems. Patients can be stabilized, and the requirement of surgical standby for PTCA could be reduced or eliminated. In addition to significantly reducing the cost of a PTCA procedure, the reduction or elimination of the surgical standby requirement would facilitate increasing the number of PTCA procedures performed each year.

The invention can perhaps be better understood by making reference to the drawings. The embodiment of the invention 1 shown in Fig. 1 comprises an exchange member 2 and a rigid shaft, or corewire, 3 for advancing and/or retracting the exchange member 2 to and/or from the target area in the vasculature (not shown). The shaft 3 is preferably a wire. Exchange member 2 comprises a tubular member here; however, exchange member 2 can be comprised of any structure that defines a lumen suitable for exchange purposes.

Another embodiment of the invention 4 can be seen in Fig. 2, wherein the exchange member is comprised of coil 5. Coil which is preferably helically wound, is either continuous with shaft 6, that is, formed from the same wire, or is another wire attached to shaft 6, preferably by solder, glue, a weld, or similar affixation. In an alternate embodiment, coil 5 is butt joined to shaft 3.

Fig% 3 represents a cross-sectional view of exchange member S 2, wherein it can be seen that shaft 3 is affixed to the interior surface 7 of exchange member 2. The distal portion of shaft 3 within exchange member 2 preferably extends at least about 25% of S the length of exchange member 2, more preferably about 50 to 100% of the-length of exchange member 2. It is within the scope of the invention that shaft 3 may extend distally of exchange member 2 and have, preferably, a flexible and/or otherwise atraumatic tip (not shown).

Shaft 3 may optionally, as shown in Fig. 4, be affixed to the outer surface 8 of exchange member 2, in the same manner as discussed for affixation to interior surface 7. It is also within the scope of this invention that shaft 3 could reside within the wall of exchange member 2.

As shown in Frig. 5, exchange member 2 may have a longitudinal slit 10 of sufficient width to enable the exchange member 2 to "snap" over a PTCA catheter, guidewire or other device.

Preferably the width of slit 10 would be from about 1 to 5 mm.

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Also, as shown in Fig. 6, exchange member 2 may be discontinuous to the extent that wall members 11, 12 overlap to provide an opening of the same function as slit In a typical application of the invention described above, a PTCA catheter is in position across or adjacent to a stenosis.

The exchange member 2 is positioned over the proximal end of the PTCA catheter outside the body, and the exchange member 2 is advanced over the PTCA catheter shaft to the stenosis. Then, the PTCA catheter is withdrawn, leaving the exchange member 2 across the stenosis, where it can function as a temporary stent to permit perfusion while additional therapy, for example, PTCA, atherectomy, insertion of a permanent stent, CABG, or the like, is planned. Optionally such an exchange can be done after the.

catheter/manifold hub of the PTCA catheter has been removed.

A secondary device, for example, a second PTCA catheter, is advanced adjacent to shaft 3, to the lesion. Then, the shaft 3 is moved proximally to cause exchange member 2 to move proximally, either adjacent to the target site or entirely from the body.

Rigid shaft 1 may be a conventional guidewire, preferably a spring guidewire, as is well known. Typical guidewires are shown in U.S. Patents Nos. 4,757,827, 4,815,478, 4,813,434, 4,619,274, 4,554,929, 4,545,390, 4,538,622, 3,906,938, 3,973,556, and 4,719,924, all-of which are incorporated herein by reference. In addition, shaft 3 could be solid or hollow, such as a hypotube, with an open distal end, to facilitate drug infusion. The proximal end of the shaft would then preferably have a Luer hub.

The shaft and exchange member of the invention may each optionally have a lubricous coating or covering, such as any of the known polysiloxane or TEFLON* materials. Also, either, or both, of the shaft and exchange member could be made of lubricous material.

The exchange member is, in general, made of medically So. acceptabIe metal, for example, stainless steel, or rigid polymer, such as a polyester selected from the group consisting of poly- S urethanes, polyethyleneterephthalate, polyethyleneterephthalate glycol,- and copolymers thereof, an olefin such as polyethylene or a copolymer thereof, polyvinylchloride, or the like. The S* exchange member could also be component of a material having properties shape, size, or flexibility), that change due to hydration, temperature, or another factor. For example, a shape memory alloy such as Nitinol may be used.

It is within the scope of the invention that the exchange member may be detachable from the shaft, to leave the exchange member permanently in place. Such detachability could either be immediate or "on demand", where the shaft and exchange member would be joined in such a way, or with such a mechanism, thLat the operator could manipulate the proximal end of the shaft to cause the shaft and exchange member to separate. In the alternative, the shaft and exchange member may be affixed by appropriate glue, for example, whose adhesive properties would lessen with time, hydration, or temperature, such that after 24 to 48 hours the shaft could be detached and withdrawn. For example, the adhesive bonding properties of a hydrogel adhesive would diminish with hydration.

In the embodiment of the invention shown in Figs. 7 and 8, the RECS 20 comprises a coil 21, preferably a radiopaque coil, and a rigid shaft or pushing wire 22. Positioned eccentrically or concentrically, preferably eccentrically, around shaft 22 is a S flexible, collapsible sheath 23, shown collapsed in Fig. 7 and expanded in Fig. 8. At the proximal end of sheath 23 is a hemostatic manifold 24, including a valved infusion port 25 in fluid communication with the interior of sheath 23.

In the alternate embodiment shown in cross-section in Figs.

9 and 10, sheath 32 is bonded or formed with shaft 30, which defines lumen 31. Pushing wire 33 extends longitudinally within lumen 31.

Sheath 23 or 32 extends distally to at least the distal end of pushing wire 22 or 33. Where exchange member 21 is instead a cylindrical tubular member, such as exchange member 2, the sheath 23 or 32 can extend into and/or through said exchange member.

Sheath 23 or 32 facilitates the passage of a second PTCA catheter, guiewire, or other exchangeable device after the first device is removed, and provides for atraumatic passage of these other devices since the sheath 23 or 32 prevents contact of the catheter or other device with the lining of the artery. Also, the sheath can provide a means for subselective catheterization for purposes such as active perfusion of blood or oxygenbearing fluid; distal/selective dye injection; or (3) selective infusion of medications directly to the lesion site.

The flexible sheath 23 or 32 is preferably bonded by suitablemeans, such as heat-shrinking or adhesive, to the S pushing wire 22 or 33, respectively, either continuously or at discrete points longitudinally along the pushing wire 22 or 33.

The proximal end of the sheath 23 or 32 is bonded by suitable eans, such as heat-shrinking or adhesive, to a manifold or hub, and the pushing wire 22 or 33 may terminate at the manifold or hub or extend proximally therethrough. Flexible sheath 23 or 32 and/or shaft 30 may each be single or multiple, such as double or triple, lumen.

The preceding specific embodiments are illustrative of the Spractice of the invention. It is to be understood, however, that other expedients known to those skilled in the art or disclosed herein, may be employed without departing from the spirit of the invention or the scope of the appended claims.

P:\WPDOCS\DYS\SPECIE\621442.DIV 12/5/99 12a Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" or comprising" will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

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Claims (3)

13- THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS 1. A system for rapid exchange of an intravascular device along a path from an access point on a patient's body to a desired site, comprising: an exchange member defining a lumen and having open proximal and distal ends, wherein the terms proximal and distal refer to relative positions along the path; a longitudinally rigid pushing wire having proximal and distal ends, the distal end of the pushing wire being affixed to the proximal end of the exchange member, and 10 an intravascular device which is capable of being positioned within the lumen defined by the exchange member, such that said pushing wire is configured to advance the exchange member distally to a desired site, wherein the exchange member is positioned concentrically surrounding the intravascular device. 2. A system according to claim 1 wherein the pushing wire has a flexible, collapsible sheath having proximal and distal ends and being arranged thereon, the collapsible sheath being expandable to allow infusion of fluid or insertion of an intravascular device, and being collapsible when fluid flow ceases or the device is withdrawn. 3. The system of claim 1 or claim 2, wherein the exchange member is a coil. 4. The system of claim 1, 2 or 3, wherein the pushing wire and exchange member are each comprised of a medically acceptable metal or polymer. The system of any preceding claim, wherein the pushing wire extends to at least the distal end of the exchange member. 6. The system of any preceding claim, wherein the pushing wire is a guidewire. P:\WPDOCS\DYS\SPECIE\621442. DIV 12/5/99 -14- 7. The system of claims 1 to 4, wherein the pushing wire is a catheter. 8. The system of claim 2 wherein the proximal end of the collapsible sheath is attached to a hemostatic manifold or hub in fluid connection with the collapsible sheath. 9. The system of claim 8, wherein the hemostatic manifold or hub has an infusion port in fluid communication with the sheath. The system of claim 2, wherein said distal end of the collapsible sheath extends to the 10 proximal end of the exchange member. 11. The system of claim 10, wherein the collapsible sheath is capable of delivering at least :o *one fluid selected from the group consisting of blood, saline solution, pharmaceuticals, and the like to a site of vascular disease. 12. The system of claim 2, wherein said distal end of the collapsible sheath extends into or through the exchange member. 13. The system of claim 12, wherein the collapsible sheath is capable of delivering at least 20 one fluid selected from the group consisting of blood, saline solution, pharmaceuticals, and •the like to a site of vascular disease.

14. The system of claim 1 or claim 2, wherein the intravascular device is selected from the group consisting of catheters, balloon dilation catheters, guidewires, stents, perfusion catheters, infusion catheters, and atherectomy catheters. The system of claim 1 or 2, which comprises at least two intravascular devices. P:\WPDOCS\DYS\SPECIE\621442. DIV 12/5/99 15

16. The system substantially as heremrbefore described with reference to the accompanying drawings. Dated this 30th day of April, 1999 CORDIS CORPORATION By Its Patent Attorneys DAVIES COLLISON CAVE