Method of insitu bypass to hold open venous valves
US5843171A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 24, 1997 |
| Grant date | Dec 1, 1998 |
| Priority date | — |
| Expiry date | Jan 24, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1397
- WIPO fieldMedical technology
- WIPO sectorInstruments
Abstract
A tube of porous PTFE having at least two first and at least two second regions wherein the at least two first regions have a greater density than the at least two second regions. For tubes of porous expanded PTFE having a microstructure of nodes interconnected by fibrils, the at least two first regions have a mean fibril length that is less than that of the at least two second regions. Preferably the regions are arranged in the form of ring-shaped segments of the tube wherein denser segments alternate along the length of the tube with less dense segments. Other arrangements between the different regions are possible; for example, the regions may be oriented in a spiral relationship with each other along the length of the tube. The porous PTFE tubes of the present invention have excellent radial compression resistance without requiring additional exterior reinforcing members due to the presence of the denser regions that are provided with a circumferential orientation. Tubes of this type are anticipated to be useful as vascular grafts and particularly as intraluminal vascular grafts. When provided as an intraluminal graft, the tube may also optionally be manufactured to be circumfe…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.