This invention relates generally to luminal stents, and more particularly to a method and apparatus for providing a secure connection between components of a modular stent.
Modular stents are used to treat luminal defects in a human body. For example, a modular stent comprising an aortic bifurcate component and an iliac limb component may be used to bypass an abdominal aortic aneurysm (AAA). In this exemplary modular stent, the aortic bifurcate component is a bifurcated female covered stent or stent-graft (sometimes referred to as a long leg-short leg) configured for placement in the aorta proximate the aortic bifurcation with a long leg extending into one of the iliac arteries and a short leg or stump extending into the other iliac artery. The iliac limb component is a male covered stent configured for placement in the iliac artery in which the short leg extends with its proximal end deployed within the short leg or stump. The stent in such combinations typically comprises an open framework or mesh of structural elements such as wires or thin metallic members, which may cross or intersect one another in various ways. In one such stent graft configuration, a braided stent is provided where opposing helical stent members overlap one another to form crossing intersections. Exemplary braided stents 10 are disclosed, for example, in U.S. Pat. No. 4,655,771 to Hans I. Wallsten, incorporated herein by reference. The braided stent is designed to be contracted radially for endoluminal placement into a patient and to self-expand radially into a configuration in which it urges the graft or covering against the wall of the body lumen in which it is disposed providing an open lumen. Using shape memory material for the braided stent members may provide this self-expansion. The graft in a stent-graft may be a covering or liner, disposed inside or outside of the stent and covering the stent to define a fluid passageway through the lumen of the stent.
It is important for the components of a modular stent to form a secure connection with each other to prevent relative movement of the components with respect to each other due to force exerted by blood flow, morphology of the lumen in which the modular stent is placed, or other factors. Also, with covered stents, if the connection is not sufficiently secure, these factors may cause leakage of bodily fluid between the modular components.
In accordance with an exemplary embodiment of the present invention, a modular stent system is connected by an eversible extension on the male component of the modular stent system. An eversible extension is formed on the male component by continued braiding of stent members used to form a self-expanding stent in the male component. The eversible extension is eversed or folded back over the self-expanding stent and radially restrained in the eversed position. The eversible extension and self-expanding stent are at least partially introduced into a lumen of a female component of the modular stent with the eversible extension radially constrained in an eversed position. The eversible extension and self-expanding stent are released or allowed to self-expand against the inner surface of the female component, locking the modular components together.
While the applicant will describe the invention in connection with preferred and alternative embodiments, it should be understand that the invention is not limited to those embodiments. Furthermore, one should understand that the drawings are not necessarily to scale. In certain instances, the applicant may have omitted details that are not necessary for an understanding of the present invention.
The invention will next be described with reference to the figures wherein similar numbers indicate the same elements in all figures. Such figures are intended to be illustrative rather than limiting and are included herewith to facilitate the explanation of the apparatus of the present invention.
When used herein the following terms shall be understood to have the following meanings. The term proximal shall indicate a direction closer to a patient's heart, and the term distal shall indicate a direction farther from a patient's heart. The term stent shall indicate a generally tubular structural component for placement within a body lumen. The terms graft and covering shall indicate a flexible tubular member providing a passageway therethrough. The term stent-graft shall indicate a stent having a graft or covering attached thereto. Everse shall mean to roll or pivot a tubular member inside out.
Each self-expanding stent preferably comprises intersecting stent members, which are preferably helical braided to form a tubular stent. An exemplary braided stent comprises a first set of stent members wound in a first helical direction and a second set of stent members wound in a second, opposite helical direction, forming a plurality of intersections. The first and second sets of stent members may be continuous stent members with reversing axial direction at the ends of male and female components. These stent members may be wire, such as nitinol or stainless steel, or may comprise polymer or any other stent material known in the art. Shape memory material such as nitinol, however, is preferred.
An eversible stent extension 21 extends from the stent in the male component 20. Eversible stent extension 21 is preferably formed by continuation of the braided stent members forming the self-expanding stent of male component 20. Eversible stent extension 21 is configured to be eversed or pivoted back over the self-expanding stent, and held in this eversed position by a delivery sheath 25 (
Eversible stent extension 21 is pivoted outwardly and back over the male component 20, as shown in
As shown in
Referring now to
Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.
This application is a Divisional of U.S. patent application Ser. No. 11/446,687, filed Jun. 5, 2006, which is a Divisional of U.S. patent application Ser. No. 10/435,190, filed on May 9, 2003, now Abandoned, both of which are herein incorporated by reference.
Number | Date | Country | |
---|---|---|---|
Parent | 11446687 | Jun 2006 | US |
Child | 13722986 | US | |
Parent | 10435190 | May 2003 | US |
Child | 11446687 | US |