PTFE layers and methods of manufacturing
AssigneeTriVascular, Inc.
InventorsJoseph Humphrey, Jeffry Skiba
Life of this patent
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Abstract
Single, continuous PTFE layers having lateral zones of varied characteristics are described. Some of the lateral zone embodiments may include PTFE material having little or no nodal and fibril microstructure. Methods of manufacturing PTFE layers allow for controllable permeability and porosity of the layers, in addition to other characteristics. The characteristics may vary from one lateral zone of a PTFE layer to a second lateral zone of a PTFE layer. In some embodiments, the PTFE layers may act as a barrier layer in an endovascular graft or other medical device.
Claims34
A method of processing PTFE, comprising:
- providing a layer of PTFE;
- selectively applying a stretching agent to at least one lateral zone of the layer of PTFE in a predetermined pattern;
- and
- stretching the layer of PTFE.
A method of processing PTFE, comprising:
- providing a layer of PTFE having a stretching agent content level;
- selectively removing stretching agent from at least one lateral zone of the portion of the layer of PTFE in a predetermined pattern;
- and
- stretching the layer of PTFE.
A method of processing PTFE, comprising:
- providing a layer of PTFE;
- applying a stretching agent to at least one lateral zone of a surface of the layer in a predetermined pattern until the lateral zone is saturated with the stretching agent;
- and
- stretching the layer of PTFE while lateral zone of the layer of PTFE is saturated with the stretching agent.
A PTFE layer comprising a layer made by
- providing a layer of PTFE;
- selectively applying a stretching agent to at least one lateral zone of the layer of PTFE in a predetermined pattern;
- and
- stretching the layer of PTFE.
A PTFE layer comprising a layer made by
- providing a layer of PTFE having a stretching agent content level;
- selectively removing stretching agent from at least one lateral zone of the portion of the layer of PTFE in a predetermined pattern;
- and
- stretching the layer of PTFE.
A PTFE layer comprising a layer made by
- providing a layer of PTFE;
- applying a stretching agent to at least one lateral zone of a surface of the layer in a predetermined pattern until the lateral zone is saturated with the stretching agent;
- and
- stretching the layer of PTFE while lateral zone of the layer of PTFE is saturated with the stretching agent.
A multi-layered vascular graft comprising:
- a first tubular body having an outer surface and an inner surface that defines an inner lumen of the vascular graft;
- and
- a second tubular body having an outer surface and an inner surface coupled to the outer surface of the first tubular body,
- wherein at least one of the first tubular body and the second tubular body comprises a PTFE layer having a first lateral zone with a substantially low porosity, a low fluid permeability and no discernable node and fibril microstructure, and a second lateral zone which is fluid-permeable and has substantial node and fibril microstructure.
A tubular structure comprising a layer of PTFE having a first lateral zone which is fluid-permeable and which has substantial node and fibril microstructure and a second lateral zone with a closed cell microstructure having high density regions whose grain boundaries are directly interconnected to grain boundaries of adjacent high density regions and having no discernable node and fibril microstructure.
An endovascular graft comprising a PTFE layer having a first lateral zone with a liquid-permeable, expanded PTFE layer adjacent a second lateral zone having (a) a closed cell microstructure having high density regions whose grain boundaries are directly interconnected to grain boundaries of adjacent high density regions and (b) substantially no node and fibril microstructure.
A thin, continuous PTFE layer, comprising:
- a first lateral zone with a substantially low porosity, a low fluid permeability, no discernable node and fibril structure, and a high degree of limpness and suppleness to allow mechanical manipulation or strain of the PTFE layer without significant recoil or spring back;
- and
- a second lateral zone which is fluid-permeable and has a substantial node and fibril microstructure.
A method of processing a layer of PTFE, comprising:
- providing a layer of PTFE;
- stretching the layer of PTFE;
- and
- applying a stretching agent to the PTFE layer during the stretching process.
Dependencies are inferred from the claim text.