Apparatus for delivering endoluminal prostheses and methods of making and using them

Abstract

An apparatus for delivering a stent into a blood vessel includes a sheath having a rounded bullet-shaped distal portion including a plurality of flexible leaflets integrally molded thereto. The stent is disposed in its contracted condition within a lumen of the sheath proximate the distal portion. A bumper is slidably disposed within the lumen that includes a helical compression coil, a bumper element attached to the helical coil including a blunt distal edge for abutting the stent, and an extension element extending distally from the bumper element through the stent and between the leaflets to facilitate introducing the apparatus over a guidewire. The sheath is formed by inserting a bullet into a blunt-ended tube, and inserting the tube into a bullet-shaped bore in a heated die until the tube material is softened and deforms into a rounded bullet shape. Slits are then cut into the distal portion to create the leaflets.

Description

[0001] This application is a continuation of application Ser. No. 09 / 664,970, filed Sep. 18, 2000, the disclosures of which is expressly incorporated herein by reference.FIELD OF THE INVENTION [0002] The present invention relates generally to apparatus and methods for delivering endoluminal prostheses within body lumens of a patient, and more particularly to apparatus for delivering tubular prostheses or “stents” within a patient's vasculature for treating stenoses or other lesions, for example, within the coronary and carotid arteries, and to methods of making and using such apparatus. BACKGROUND [0003] In recent years, a number of minimally invasive technologies have been developed for treating diseases, such as atherosclerosis, that result in narrowing of blood vessels, for example, within the coronary or carotid arteries. Tubular prostheses or “stents” have been developed for maintaining the patency of a blood vessel, for example, following angioplasty or other procedures used t...

AI Technical Summary

Benefits of technology

[0015] In a preferred embodiment, a tubular prosthesis is disposed within the lumen proximate the distal portion. An elongate bumper member having a proximal end and a distal end is also provided, the bumper member being slidably disposed within the lumen of the sheath. The distal end of the bumper member has a blunt edge disposed adjacent to the proximal end of the prosthesis for preventing axial displacement of the prosthesis upon retraction of the tubular member with respect to the bumper member and / or the prosthesis.

[0017] In accordance with another aspect of the present invention, an apparatus for delivering a prosthesis into a blood vessel of a patient is provided that includes an elongate tubular member, such as that described above, having a proximal end, a distal end, and a lumen extending between the proximal and distal ends, the distal end having a size for endoluminal insertion into a blood vessel. A tubular prosthesis is disposed within the lumen proximate the distal end. An elongate bumper member is also provided that includes a helical coil having a proximal end and a distal end, the bumper member being slidably disposed within the lumen of the sheath. The distal end of the bumper member has a blunt distal edge disposed adjacent a proximal end of the prosthesis for preventing axial displacement of the prosthesis upon retraction of the tubular member with respect to the bumper member.

Problems solved by technology

One of the problems associated with these devices is that they may have substantially blunt distal ends that may scrape along the wall of a vessel during advancement therethrough, possibly damaging the wall and / or dislodging embolic material from the wall.

The nosepiece may facilitate advancement of the device through a narrow region of a blood vessel, although it may also risk catching on the wall of the vessel and / or dislodging embolic material, e.g., between the distal edge of the sheath and the nosepiece.

If the nosepiece is withdrawn directly, the proximal edge of the nosepiece may catch on the stent struts, resulting in the potential for trauma and embolic debris release.

Introduction of saline or other liquids into a patient's vasculature, however, may be undesirable, but is necessary in order to soften the sections on the distal end of the sheath and allow the stent to be deployed from the sheath.

Another problem associated with such delivery systems is that the sheaths and / or catheters may buckle during insertion, because of the distal force applied from the proximal end to advance them through the patient's vasculature.

In addition, because of their tubular nature, they may kink when advanced through tortuous anatomy, possibly damaging the device or an element within the device.

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