The effect of redundancy and tension on microvascular vein grafts.

Variation in length and tension occurs with microvascular vein grafts in clinical practice. The length and tension of a vein-grafted segment was varied in 50 Sprague-Dawley rats. This enabled a full range of redundancy and tension across the 1 mm diameter vein grafts. The initial patency rate was 100%. Wounds were reexplored 2 weeks after operation. A linear increase in microaneurysm formation was found with increasing tension. There was a mild but not statistically significant observed effect on patency. Increasing tension in rat vein graft anastomosis has an adverse effect with an increased incidence of microaneurysm formation and should be avoided.