Interior liner for tubes, pipes, and blood conduits

Abstract

A tube which circumferentially distends from its initial circumference upon the application of a circumferentially distending force such as applied by an internal pressure, and which exhibits minimal recoil following the removal of the circumferentially distending force. The tube preferably has a second circumference larger than the initial circumference which remains substantially unchanged by further increasing force once it has been achieved. Because of the distensible circumference and minimal recoil of the tube, the tube is useful as a liner for pipes and vessels and particularly for pipes and vessels having irregular internal surfaces to which the tube can smoothly conform. The tube is preferably made from porous PTFE with thin walls, in which form it is particularly useful as a liner for both living and prosthetic blood vessels and to line anastomoses between living and prosthetic blood vessels.

1 . A diametrically expandable tube comprising a wrapped film tube of one or more layers of porous polytetrafluoroethylene film, wherein the film tube is manufactured by wrapping one or more layers of porous polytetrafluoroethylene film around a mandrel having a circumference thereby resulting in the film tube having the circumference of the mandrel, removing the film tube from the mandrel and then reducing the circumference of the film tube to a smaller, first circumference, wherein, in use, the circumference of said film tube increases in response to the application of internal pressure from the first circumference up to a second circumference that is at least 100% larger than said first circumference, thereafter the second circumference remaining substantially unchanged with further increasing internal pressure if used within a designed range of operating pressures. 
     
     
         2 . The diametrically expandable tube of  claim 1  wherein the wrapped film tube of one or more layers of porous polytetrafluoroethylene film comprises a helical wrap. 
     
     
         3 . The diametrically expandable tube of  claim 2  wherein the wrapped film tube of one or more layers of porous polytetrafluoroethylene film is applied over a substrate tube of polytetrafluoroethylene. 
     
     
         4 . The diametrically expandable tube of  claim 3  wherein said polytetrafluoroethylene tube has a microstructure of nodes and fibrils. 
     
     
         5 . The diametrically expandable tube of  claim 4  wherein the diametrically expandable tube is adapted for use as a vascular graft. 
     
     
         6 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube is adapted for use as a vascular graft. 
     
     
         7 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube is adapted for use as a blood conduit liner. 
     
     
         8 . The diametrically expandable tube of  claim 1  wherein the wrapped film tube of one or more layers of porous polytetrafluoroethylene film is applied over a substrate tube of polytetrafluoroethylene during the reduction in circumference of the film tube. 
     
     
         9 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube further comprises a stent. 
     
     
         10 . The diametrically expandable tube of  claim 2  wherein the diametrically expandable tube further comprises a stent. 
     
     
         11 . The diametrically expandable tube of  claim 3  wherein the diametrically expandable tube further comprises a stent. 
     
     
         12 . The diametrically expandable tube of  claim 7  wherein the diametrically expandable tube further comprises a stent. 
     
     
         13 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube has a wall thickness of less than or equal to about 0.25 mm. 
     
     
         14 . The diametrically expandable tube of  claim 13  wherein the diametrically expandable tube has a wall thickness of less than or equal to about 0.10 mm. 
     
     
         15 . The diametrically expandable tube of  claim 2  wherein the diametrically expandable tube has a wall thickness of less than or equal to about 0.25 mm. 
     
     
         16 . The diametrically expandable tube of  claim 15  wherein the diametrically expandable tube has a wall thickness of less than or equal to about 0.10 mm. 
     
     
         17 . The diametrically expandable tube of  claim 3  wherein the diametrically expandable tube has a wall thickness of less than or equal to about 0.25 mm. 
     
     
         18 . The diametrically expandable tube of  claim 17  wherein the diametrically expandable tube has a wall thickness of less than or equal to about 0.25 mm. 
     
     
         19 . The diametrically expandable tube of  claim 4  wherein the diametrically expandable tube has a wall thickness of less than or equal to about 0.25 mm. 
     
     
         20 . The diametrically expandable tube of  claim 19  wherein the diametrically expandable tube has a wall thickness of less than or equal to about 0.10 mm. 
     
     
         21 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube is adapted for use as an intraluminal graft wherein the graft is secured to a blood conduit by sutures. 
     
     
         22 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube is adapted for use as an intraluminal graft wherein the graft is secured to a blood conduit by a stent. 
     
     
         23 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube is adapted for use as an intraluminal graft wherein the circumference is increased by inflating a balloon. 
     
     
         24 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube is adapted for use as an intraluminal graft wherein the circumference is increased by blood pressure. 
     
     
         25 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube exhibits circumferential recoil of 14 percent or less following a substantial reduction in pressure. 
     
     
         26 . The diametrically expandable tube of  claim 2  wherein the diametrically expandable tube exhibits circumferential recoil of 14 percent or less following a substantial reduction in pressure. 
     
     
         27 . The diametrically expandable tube of  claim 3  wherein the diametrically expandable tube exhibits circumferential recoil of 14 percent or less following a substantial reduction in pressure. 
     
     
         28 . The diametrically expandable tube of  claim 28  wherein the diametrically expandable tube exhibits circumferential recoil of 10 percent or less following a substantial reduction in pressure. 
     
     
         29 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube has first and second opposing ends wherein the second circumference at the first opposing end is larger than the second circumference at the second opposing end whereby the tube is tapered is tapered between the first and second opposing ends. 
     
     
         30 . The diametrically expandable tube of  claim 1  wherein the diametrically expandable tube is branched and has three ends.