AU2815399A - Method of positioning a stent - Google Patents

Description

Our Ref: 729701 P/00/011 Regulation 3:2

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Applicant(s): Address for Service: Invention Title: 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 Method of positioning a stent The following statement is a full description of this invention, including the best method of performing it known to me:- 5020 P:\WPDOCS\DYS\SPECIE\62142.DV2 13/5/99 -1-METHOD OF POSITIONING A STENT METHOD OF POSITIONING A STENT This invention relates to a method of positioning a stent in a corporeal channel of a patient's body.

According to one aspect of the present invention there is provided a method of positioning a stent in a corporeal channel of patient's body, which comprises the steps of: advancing into a patients body through a corporeal channel an intravascular device having proximal and distal portions to the extent that the distal portion of said device is at a desired site inside the patient's body; -outside the patient's body positioning an exchange system comprising an exchange member having proximal and distal ends and defining a lumen; P:\WPDOCS\DYS\SPECIE\62"2.DV2 1215199 -2and a rigid pushing wire having proximal and distal ends, the distal end of the pushing wire being integral with and non-detachable from the proximal end of the exchange member, such that said pushing wire is configured to advance the exchange member distally to a desired location, so that said exchange member is concentric to the proximal portion of said device and advancing said exchange member distally through said corporeal channel to the desired site; and withdrawing said device proximally through said exchange member and removing said device through said corporeal channel from the body, whereby the exchange member functions as a removable stent in the corporeal channel.

According to another aspect of the present invention there is provided a method of positioning a stent in a corporeal channel of a patient's body, which comprises the steps of: advancing into a patients body through a corporeal channel an intravascular device having proximal and distal portions to the extent that the distal portion of said device is at a desired site inside the patient's body; -outside the patient's body positioning a rapid exchange intravascular device system comprising

I

P:\WPDOCS\DYS\SPECIE\621442. DV2 12/5/99 -3an exchange member having proximal and distal ends and defining a lumen; and a rigid pushing wire having proximal and distal ends, the distal end of the pushing wire being integral with and non-detachable from the proximal end of the exchange member, such that said pushing wire is configured to advance the exchange member distally to a desired location, wherein the pushing wire has a flexible, collapsible sheath having proximal and distal ends and being arranged thereon, such that as the collapsible sheath is expanded by infusion of fluid or insertion of a catheter, guidewire, or other device, the sheath's diameter increases, and when fluid flow ceases or the catheter, guidewire, or other device is withdrawn, the sheath's diameter decreases, so that the exchange member is concentric to the proximal portion of said device and advancing said exchange member distally through said corporeal channel to the desired site; and withdrawing said device proximally through said exchange member and removing said device through said corporeal channel from the body, whereby the exchange member functions as a removable stent in the corporeal channel.

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

P:\WPDOCS\DYS\SPECIE\621442.DV2 12/5/99 -4- 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 Description of the Invention The rapid exchange catheter system (RECS) for use in 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 a hemostatic P:\WPDOCS\DYS\SPECIE\621442.DV2 12/5/99 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 catheters, perfusion catheters, or the like, may be passed through the sheath to the target 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 subselective 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 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 ee wherein the exchane member is s e e n in Fig. 5 Which is preferably helically wound, is e e coi Col shaft 6, that is, formed from the smewre, or is ano t us with attached to shaft 6, referabl by Solder glue, or is another Wire similar affixation. I y solder, glue, a weld, or In an alternate coil 5 is butt joined to shaft 3. tembodiment coil 5 is butt Fi 3 represents a cro sectionl vi 2, wherei n it can be seen s- ional v i e ofmember s. X e i shaft 3 is afe s^ surface 7 ofexchane memberthat shaft 3 is affixed to the interior isthin exchange member 2 The dital portion of shat 3 ithi e length e memer 2 Preferably extends at least about 25% of f thelength of exchane member 2, ore Preferably about 50 to 100% the inventionhae member 2. It is within the scope of 2 t nvention that shaft 3f may extend distally of exchange member 2ti (not shown flexible and/or otherwise atraumatic Shaft 3 may optionally, he ter surface 8 of o w n i n ig. 4, be affixed to the outer surface 8 o exchange member 2, in the same manner as discussed for affixation to interior surfae s as whLn the scope of this Is also "thin the Scope of this invention that shaft 3 could reside ithin the wall of exchange member 2ld reside As shown in Pig inl shn n Fig. 5, exchange member 2 may have a longitudto snapt 1 O u ciet W h to enable the exchange member 2 Preferabl the w h of ter dew or Other device.

Preferably the idth of slit uld be from about 1 to 5 mm.

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 acceptable metal, for example, stainless steel, or rigid polymer, such as a polyester selected from the group consisting of polyurethanes, polyethyleneterephthalate, polyethyleneterephthalate glycol, and copolymers thereof, an olefin such as polyethylene or a copolymer thereof, polyvinylchloride, or the like. The 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, that 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 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, guidewire, 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 suitable means, such as heat-shrinking or adhesive, to the 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 means, 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 practice 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.

I

P:\WPDOCS\DYS\SPECIE\621442.DV2 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.

Claims (3)

1. A method of positioning a stent in a corporeal channel of patient's body, which comprises the steps of: advancing into a patients body through a corporeal channel an intravascular device having proximal and distal portions to the extent that the distal portion of said device is at a desired site inside the patient's body; outside the patient's body positioning an exchange system comprising an exchange member having proximal and distal ends and defining a lumen; and a rigid pushing wire having proximal and distal ends, the distal end of the pushing wire being integral with and non-detachable from the proximal end of the exchange member, such that said pushing wire is configured to advance the exchange member distally to a desired location, so that said exchange member is concentric to the proximal portion of said device and advancing said exchange member distally through said corporeal channel to the desired site; and withdrawing said device proximally through said exchange member and removing said device through said corporeal channel from the body, whereby the exchange member functions as a removable stent in the corporeal channel.

2. A method of positioning a stent in a corporeal channel of a patient's body, which comprises the steps of: advancing into a patients body through a corporeal channel an intravascular device having proximal and distal portions to the extent that the distal portion of said device is at a desired site inside the patient's body; outside the patient's body positioning a rapid exchange intravascular device system comprising an exchange member having proximal and distal ends and defining a lumen; and a rigid pushing wire having proximal and distal ends, the distal end of the PAWPD0CS\DYS\SPECIE\621442.DV2 12/5/99 -14- pushing wire being integral with and non-detachable from the proximal end of the exchange member, such that said pushing wire is configured to advance the exchange member distally to a desired location, wherein the pushing wire has a flexible, collapsible sheath having proximal and distal ends and being arranged thereon, such that as the collapsible sheath is expanded by infusion of fluid or insertion of a catheter, guidewire, or other device, the sheath's diameter increases, and when fluid flow ceases or the catheter, guidewire, or other device is withdrawn, the sheath's diameter decreases, so that the exchange member is concentric to the proximal portion of said device and advancing said exchange member distally through said corporeal channel to the desired site; and withdrawing said device proximally through said exchange member and removing said device through said corporeal channel from the body, whereby the exchange member functions as a removable stent in the corporeal channel.

3. A method of positioning a stent substantially as hereinbefore described with reference to the accompanying drawings. Dated this 30th day of April, 1999 CORDIS CORPORATION By Its Patent Attorneys DAVIES COLLISON CAVE