Method of preventing the dislodgment of a stent-graft
Endoluminal stent-grafts include several features which restrict dilation subsequent to installation but which allow the stent-grafts to be installed in the same manner as a conventional stent-graft. According to one embodiment, sutures are attached to an expanded stent-graft. The suture material is preferably braided PET or polypropylene and sutures are interwoven into the stent at substantially regular intervals. A second embodiment utilizes a band material in lieu of suture material. A third embodiment utilizes a warp knit tubular sheath with inlay yarn. The warp knit tubular sheath with inlay yarn may also act as the graft material. The invention includes a method of using these stent-grafts to prevent the dislodgment of an endoluminal stent-graft after deployment. The method includes the step of determining the maximum stent-graft diameter and related size of dilation restriction means to prevent excessive stent-graft shortening after initial deployment.
1. A method of treating an aneurysm with a stent-graft comprising the steps of:
(a) determining the length of the aneurysm;
(b) determining the diameter of the vessel into which a stent-graft will be placed;
(c) providing a stent-graft having dilation restriction means for restricting dilation of said stent-graft beyond a maximum diameter which maximum diameter is greater than the vessel diameter of step (b);
(d) trimming the stent-graft to a length that is greater than the length of the aneurysm when the stent-graft is dilated to its maximum diameter.
2. The method of claim 1 wherein the dilation restriction means of the stent-graft provided in step (c) is comprised of suture material.
3. The method of claim 2 wherein said suture material is flexible and substantially inelastic.
4. The method of claim 1 wherein said stent-graft is made of woven wires and a suture material is woven through said wires.
5. The method of claim 1 wherein the dilation restriction means of the stent-graft provided in step (c) is comprised of a plurality of sutures spaced along said stent-graft.
6. The method of claim 1 wherein the dilation restriction means of the stent-graft provided in step (c) is comprised of a plurality of sutures located in a plurality of substantially parallel planes which are substantially perpendicular to a longitudinal axis of said stent-graft.