PTFE, Collars, and Patches

Abstract

The results of PTFE grafts to crural vessels have been sufficiently poor for some surgeons to consider primary amputation for critical ischemia in the absence of suitable lengths of autologous vein from arm or leg.¹ However, the results of two anastomotic techniques using a short segment of interposed vein^2,3 are encouraging. We have attained 1-year patency rates of 74% (n=72) using PTFE with the Taylor patch technique (personal communication) and 47% (n=27) using PTFE with Miller collar anastomoses to distal crural vessels.⁴ To investigate the hemodynamic benefit of these techniques, they have been tested (using a pulsatile flow model⁵ incorporating standard pressure, viscosity, graft and vessel length, and anastomotic angle) against a standard end-to-side PTFE anastomosis to cadaver internal mammary artery. There was no significant difference in flow between the anastomotic methods. Downstream resistance was dictated by the diameter of the recipient vessel providing a vein interposition technique was used (r >. 80), but this relationship was lost if a direct PTFE-arterial anastomosis was performed (r =. 06), suggesting additional anastomotic resistance in the latter. This constitutes experimental evidence to suggest that direct PTFE-arterial anastomosis risks hemodynamically important technical errors, which are avoidable by the use of either the Miller collar or Taylor patch.

Key Words:

• PTFE
• graft patency
• vein collar
• Miller collar
• vein patch
• Taylor patch