Suture technique and para-anastomotic compliance.

We previously described a para-anastomotic hypercompliant zone (PHZ), located 3 to 4 mm from end-to-end continuous anastomoses in canine femoral arteries, in which arterial compliance first increases approximately 50% above adjacent reference values before falling to a minimum at the anastomosis. To determine if PHZ is affected by suture technique, 16 interrupted and 21 continuous end-to-end anastomoses were studied. Pulsed ultrasound was used to obtain detailed longitudinal profiles of compliance and diameter vs. distance, at 1 mm intervals within a 2 cm region centered at the anastomoses. Both compliance and diameter at the anastomosis were lower in continuous compared with interrupted anastomoses (p less than 0.003). The PHZ was present in 86% of continuous but in only 50% of interrupted anastomoses (p less than 0.03). The site of peak compliance averaged 3.8 +/- 1.2 mm from the anastomosis and was independent of suture technique. The increase in peak compliance at the PHZ, when normalized to adjacent references values, was the same in continuous and interrupted anastomoses. PHZ augments any preexisting compliance mismatch between artery and graft, which may contribute to the development of para-anastomotic subintimal hyperplasia. Interrupted anastomoses, which create a smaller compliance mismatch than do continuous and have a lower incidence of PHZ, may be preferred in certain settings.