Tapered implantable device and methods for making such devices
A tapered implantable device includes an ePTFE tubular member having a tapered length portion. The tapered length portion provides rapid recovery properties. The tapered length portion can feature a microstructure that includes a multiplicity of bent fibrils.
1 . An implantable article comprising:
a polymeric tube comprising a first length portion having a first diameter and a second length portion having a second diameter, the first length portion having a first rapid recovery property defined by a difference between an extended length of the first length portion and a recovered length of the first length portion; and
a tapered length portion extending between the first length portion and the second length portion, the tapered length portion having a tapered length portion rapid recovery property that is defined by a difference between an extended length of the tapered length portion and a recovered length of the tapered length portion, wherein the first rapid recovery property differs from the tapered length portion rapid recovery property at a compression ratio between 30% and 95%.
2 . The implantable article of claim 1 , wherein the tapered length portion rapid recovery property is greater than the first rapid recovery property.
3 . The implantable article of claim 1 , wherein the polymeric tube is formed of expanded polytetrafluoroethylene.
4 . The implantable article of claim 1 , wherein the tapered length portion defines a non-uniform shape.
5 . The implantable article of claim 1 , wherein the tapered portion defines a uniform, frustoconical shape.
6 . The implantable article of claim 1 , wherein the first diameter is smaller than the second diameter.
7 . The implantable article of claim 1 , wherein the tapered length portion has an expanded polymeric microstructure.
8 . The implantable article of claim 7 , wherein the tapered length portion includes a multiplicity of fibrils, the majority of which are bent fibrils.
9 . The implantable article of claim 1 , wherein the compression ratio is between about 50% to 75%.
10 . An implantable article comprising:
a polymeric tube comprising a first portion having a first diameter and a second portion having a second diameter, the first diameter being less than the second diameter, and the first portion having a first rapid recovery property defined by a difference between an extended length of the first portion and a recovered length of the first portion; and
a tapered portion extending between the first portion and the second portion, the tapered portion having a tapered portion rapid recovery property that is defined by a difference between an extended length of the tapered portion and a recovered length of the tapered portion, wherein the tapered portion rapid recovery property defines a compression ratio of between 30% and 95%.
11 . The implantable article of claim 10 , wherein the tapered portion rapid recovery property is greater than the first rapid recovery property.
12 . The implantable article of claim 10 , wherein the polymeric tube is formed of expanded polytetrafluoroethylene.
13 . The implantable article of claim 10 , wherein the tapered portion defines a non-uniform shape.
14 . The implantable article of claim 10 , wherein the tapered portion defines a uniform, frustoconical shape.