Influence of flap factors on partial necrosis of reverse sural artery flap

Partial necrosis is a main complication of reverse sural artery flap. The purpose of this article is to evaluate effect of flap factors on partial necrosis in the flap.We retrospectively reviewed data of 175 patients with 179 flaps used to reconstruct soft tissue defects in the distal lower leg, heel, and foot between April 2001 and April 2010. Posterior aspect of the lower leg was equally divided into nine zones. The flap factors were compared between the survival flaps and the partial-necrosis flaps.There were 141 flaps surviving completely; distal de-epithelialization and wound dehiscence developed in 12 flaps and 6 flaps, respectively; partial necrosis occurred in 20 (11.2%) flaps. Partial-necrosis rate was significantly higher in the flaps with top-edge locating in the upper 1/9 of the calf (32.3%, 10 of 31), in the flaps with length-width ratio (LWR) ≥5:1 (17.8%, 13 of 73), or in the flaps with width of skin island (width) ≥8 cm (15.2%, 16 of 105); it was significantly lower in the flaps with top-edge locating in the lower 7/9 of the calf (3.8%, 3 of 80). Seventeen (80.9%) of 21 flaps with LWR ≥6:1 survived, and the maximal LWR of completely survival flap was 7.00:1.Probability of partial necrosis occurring in reverse sural artery flap significantly increase when top-edge of the flap locates in the upper 1/9 of the calf, when LWR of the flap is 5:1 or more, or when width is 8 cm or more. The flap with top-edge locating lower 7/9 of the calf is safe and reliable.