Medical balloon devices and methods

Abstract

A balloon or balloon cover comprising a composite material having a least one expanded fluoropolymer material and an elastomer is provided. The expanded fluoropolymer material can contain serpentine fibrils. In exemplary embodiments, the fluoropolymer is polytetrafluoroethylene. The composite material may be axially, helically, and/or circumferentially wrapped to form a balloon or balloon cover. The balloon or balloon cover exhibits a sharp increase in stiffness at a predetermined diameter. The balloon or balloon cover can be designed to have a stop point in either a radial or axial direction.

1 - 70 . (canceled) 
     
     
         71 . A medical balloon cover configured for use with an underlying balloon, the medical balloon cover comprising:
 a composite material comprising at least one expanded fluoropolymer material comprising serpentine fibrils and an elastomer,   wherein the balloon cover has a delivery diameter before the balloon is inflated and a nominal diameter at least 3 times greater than the delivery diameter after the balloon is inflated.   
     
     
         72 . The medical balloon cover of  claim 71 , wherein the nominal diameter is at least 4 times greater than the delivery diameter. 
     
     
         73 . The medical balloon cover of  claim 71 , wherein the nominal diameter is at least 6 times greater than the delivery diameter. 
     
     
         74 . The medical balloon cover of  claim 71 , wherein the nominal diameter is at least 8 times greater than the delivery diameter. 
     
     
         75 . The medical balloon cover of  claim 71 , wherein the nominal diameter is at least 10 times greater than the delivery diameter. 
     
     
         76 . The medical balloon cover of  claim 71 , further comprising an expandable stent covering at least a portion of the balloon cover. 
     
     
         77 . The medical balloon cover of  claim 76 , wherein the portion of the balloon cover covered by the stent is more resistant to inflation of the balloon relative to the portion of the balloon cover not covered by the stent. 
     
     
         78 . The medical balloon cover of  claim 71 , wherein the elastomer is selected from the group consisting of perfluoromethylvinyl ether-tetrafluoroethylene copolymers, perfluoro (alkyl vinyl ether)-tetrafluoroetylene copolymers, silicones, polyurethanes, or other high strain elastomers. 
     
     
         79 . The medical balloon cover of  claim 71 , wherein the fluoropolymer material comprises polytetrafluoroethylene. 
     
     
         80 . The medical balloon cover of  claim 71 , wherein the composite material exhibits a sharp increase in stiffness at a predetermined diameter. 
     
     
         81 . A medical balloon cover configured for use with an underlying balloon, the balloon cover comprising:
 a composite material comprising at least one expanded fluoropolymer material comprising serpentine fibrils and an elastomer,   wherein the composite material exhibits greater stiffness at a nominal diameter relative to the stiffness of the composite material at a delivery diameter less than the nominal diameter.   
     
     
         82 . The medical balloon cover of  claim 81 , wherein the balloon cover has the delivery diameter before the balloon is inflated and the nominal diameter at least 3 times greater than the delivery diameter after the balloon is inflated. 
     
     
         83 . The medical balloon of  claim 81 , wherein the fluoropolymer material comprises a microstructure of substantially only serpentine fibrils. 
     
     
         84 . The medical balloon cover of  claim 81 , wherein each of the serpentine fibrils has a width of about 1.0 micron or less. 
     
     
         85 . The medical balloon cover of  claim 85 , wherein each of the serpentine fibrils has a width of 0.5 micron or less. 
     
     
         86 . The medical balloon cover of  claim 81 , wherein the composite material comprises at least a first portion having a first nominal diameter and at least a second portion having a second nominal diameter different from the first nominal diameter. 
     
     
         87 . The medical balloon cover of  claim 86 , wherein:
 the at least one expanded fluoropolymer material includes a plurality of pores; and   the elastomer is present in all or substantially all of the pores.   
     
     
         88 . A medical device, comprising:
 a balloon cover including a composite material comprising at least one expanded fluoropolymer material comprising serpentine fibrils and an elastomer, the composite material exhibiting greater stiffness at a nominal diameter relative to the stiffness of the composite material at a delivery diameter, wherein the nominal diameter is at least 3 times greater than the delivery diameter, and   a balloon underlying the balloon cover, wherein the balloon cover has the delivery diameter before the balloon is inflated and the nominal diameter after the balloon is inflated.   
     
     
         89 . The medical balloon cover of  claim 88 , the balloon cover having a first portion and a second portion, wherein a stent covers the first portion. 
     
     
         90 . The medical balloon cover of  claim 89 , wherein the balloon cover comprises multiple layers on the second portion.