Metallic implantable grafts and method of making same
View Patent ↗Implantable medical grafts fabricated of metallic or pseudometallic films of biocompatible materials having a plurality of microperforations passing through the film in a pattern that imparts fabric-like qualities to the graft or permits the geometric deformation of the graft. The implantable graft is preferably fabricated by vacuum deposition of metallic and/or pseudometallic materials into either single or multi-layered structures with the plurality of microperforations either being formed during deposition or after deposition by selective removal of sections of the deposited film. The implantable medical grafts are suitable for use as endoluminal or surgical grafts and may be used as vascular grafts, stent-grafts, skin grafts, shunts, bone grafts, surgical patches, non-vascular conduits, valvular leaflets, filters, occlusion membranes, artificial sphincters, tendons and ligaments.
1. A method of making an implantable medical graft comprising the steps of:
a. Providing a generally tubular implantable medical graft having a continuous cross section, the generally tubular implantable medical graft comprising a graft-forming material selected from the group consisting of biocompatible metals and pseudometals, the graft forming material including circumferential corrugations defined by a radially undulating pattern of longitudinally alternating radially extending peaks and valleys in an abluminal wall surface of the graft-forming material and a radially undulating longitudinally alternating pattern of radially extending peaks and valleys in a luminal wall surface of the graft-forming material, wherein each peak in the luminal surface is longitudinally coincident with each peak in the abluminal surface and each valley in the luminal surface is longitudinally coincident with each valley in the abluminal surface, wherein the peaks and valleys are disposed along at least a portion of the longitudinal axis of the graft-forming material and at least one of a plurality of non-undulated circumferential regions is positioned at the end regions of the graft-forming material; and
b. forming a plurality of microperforations disposed through the corrugations defined by coincident peaks and the coincident valleys wherein the plurality of microperforations in combination with the corrugations provide recoverable compliance to the graft.
2. The method of claim 1 , wherein forming the plurality of microperforations comprises:
a. Masking regions that are to remain; and
b. Removing material from the unmasked regions.
3. The method of claim 2 , wherein removing material comprises etching.
4. The method of claim 3 , wherein the etching method is selected from the group comprising wet chemical etching processing or dry chemical etching processing.
5. The method of claim 2 , wherein removing material comprises machining.
6. The method of claim 5 , wherein the machining method is selected from the group comprising laser ablation, electrical discharge machining, electrochemical machining, cutting, or grinding.
7. The method according to claim 1 , further comprising the step of forming at least one of a plurality of openings with suture retention strength through the wall thickness of at least one non-undulating region of the graft-forming material.