Haemodynamics of the interposition vein cuff.

It has been suggested that the use of an interposition vein cuff for anastomosing PTFE grafts to small calibre arteries confers a haemodynamic advantage. Pulsatile blood flow through a standard anastomosis was compared, in vitro, to that incorporating a vein cuff. 6 mm PTFE was anastomosed end-to-side to 10 pairs of cadaver internal mammary arteries matched for length and internal diameter (median 1.8 mm, range 1.6-2.4). Blood flow was significantly higher through the vein cuff anastomosis than the standard anastomosis (comparison of regression analysis, P less than 0.001) when the arterial diameter was less than 2.0 mm (five pairs). These results suggest that the vein cuff does confer a significant haemodynamic advantage when PTFE is anastomosed to arteries less than 2.0 mm diameter and this may be because the compliant vein cuff allows more distension of the anastomosis thus reducing anastomotic resistance.