| 摘要 |
<p>An asymmetrical form of porous PTFE having substantially different dimensions at different points along the length of the form. If the form is, for example, a tubular form, the different dimensions may be thickness or diameter or both. The form is preferably a tubular form which is preferably tapered having opposing ends with large and small inside diameters respectively wherein the wall thickness of the large diameter end is greater than or equal to the wall thickness of the small diameter end. Tapered PTFE tubes of this type are particularly useful as implantable vascular grafts. A method of producing these asymmetrical porous PTFE forms is also described.</p> |
