Impra, Inc.,

Endomed, Inc.

Joseph B Sinnott

William M Colone

Barbara L Teeter

Kevin G Farl

William L Creer

Rajagopal R Kowligi

Robert C Farnan

Linda V Della Corna

Ramon Berguer

A method is disclosed for making vascular prostheses from ePTFE said prostheses having a diameter which is larger, and a wall thickness which is smaller than previously achievable using ram extrusion techniques. The method consists of extruding a PTFE tube, finish processing the tube into an ePTFE tube, laterally dilating it by expansion in incremental steps, calendering the tube after each dilating step, while the tube is being maintained at an elevated temperature. Once the tube is dilated it can be sintered with another tube to form a laminate. Alternatively, a wire stent may be joined with one or more tubes, thereby biasing the laminate to a cylindrical configuration.

Method of making large diameter vascular prostheses and vascular prosthesis made by said method

Expandable vascular prosthesis

An intraluminal device such as a stent graft is formed of a conformable ePTFE tube and preferably a compressed self-expanding stent affixed to the tube. The conformable tube is made by a special process which insures that the tube is radially deformable up to a predetermined diameter without exceeding the plastic deformation limit of the tube. The stent has a relaxed diameter larger than the diameter of the expanded tube after insertion so that the tube is biased to a cylindrical shape. The process for making the tube involves progressively dilating a small diameter extruded tube until a desired diameter is achieved. The tube is then contracted on a small diameter mandrel by heating.

Balloon-assisted intraluminal stent graft

Method of making large diameter vascular prosteheses and a vascular prosthesis made by said method

A porous graft is provided with a non-porous coating or sheath which does not adhere to the graft. After the graft is implanted into the patient, circulation is restored through the graft. The sheath is left in place temporarily while blood works its way through the wall of the porous graft to the non-porous sheath, where it is prevented from leaking. Clots form in the graft, sealing it. After a few minutes, the sheath is removed. The graft or the inside surface of the sheath can be pre-treated with a coagulant to accelerate clotting. The sheath is applied to the graft as a coating, e.g. by dipping or spraying, or as a separate sleeve, e.g. heat-shrinkable tubing. The sheath can be removed by cutting. Preferably, the sheath incorporates a string, strip, or ribbon of material which is attached to the sheath. For removal, the string is pulled, tearing the sheath which is removed with the string.

Vascular graft with removable sheath

A non-porous coated PTFE graft includes a PTFE tube having a conventional porous inner cylindrical wall and a non-porous elastomeric coating applied over at least a portion of the outer cylindrical wall of the PTFE tube to render such portion of the outer cylindrical wall non-porous. The elastomeric coating is made of polyurethane or another biocompatible non-porous elastomer and precludes tissue ingrowth into the outer cylindrical wall, minimizes suture hole bleeding, and increases suture retention strength, while reducing the incidence of serous weepage. The elastomeric coating is preferably applied by mounting the PTFE tube upon a mandrel of like diameter and either dip coating or spray coating all, or selected portions, of the PTFE tube with liquified polyurethane. After the polyurethane coating is completely dried, the non-porous vascular graft is removed form the mandrel and is ready for use.

Non-porous coated PTFE graft

A vascular patch for closing an incision in a blood vessel includes a base layer of expanded polytetrafluoroethylene (PTFE) having an outer coating of an elastomeric, biocompatible material such as polyurethane to minimize suture hole bleeding. Suture guidelines are formed upon the ablumenal side of the PTFE base layer prior to application of the elastomeric coating to facilitate proper and consistent placement of sutures. A colorant is added to the elastomeric coating to identify the ablumenal side of the vascular patch. The vascular patch is made by mounting an expanded PTFE tube upon a mandrel and applying a water based PTFE ink as a helical stripe about the outer surface of the PTFE tube to form the suture guidelines. The striped PTFE tube is then dip-coated or spray-coated with the elastomeric coating to which the colorant has been added. The PTFE tube is slit to form a flat sheet from which vascular patches are cut.

Blood vessel patch

A vascular patch for closing an incision in a blood vessel includes a base layer of expanded polytetrafluoroethylene (PTFE) having an outer coating of an elastomeric, biocompatible material such as polyurethane to minimize suture hole bleeding. Suture guidelines are formed upon the ablumenal side of the PFTE base layer prior to application of the elastomeric coating to facilitate proper and consistent placement of sutures. A colorant is added to the elastomeric coating to identify the ablumenal side of the vascular patch. The vascular patch is made by mounting an expanded PTFE tube upon a mandrel and applying a water based PFTE ink as a helical stripe about the outer surface of the PTFE tube to form the suture guidelines. The striped PTFE tube is then dip-coated or spray-coated with the elastomeric coating to which the colorant has been added. The PTFE tube is slit to form a flat sheet from which vascular patches are cut.

Growing community of inventors

Tempe, AZ, United States of America

Joseph B Sinnott