Arteriovenous vascular loops in free flap reconstruction of the extremities.

BACKGROUND: High-energy trauma or peripheral arteriopathy may render recipient vessels unsuitable for free tissue transfer. Vein grafts can be used to lengthen the vascular pedicles to reach healthy distant vessels but with an increased complication rate.
METHODS: From 1995 to 2006, 56 arteriovenous loops were constructed in the extremities of 55 patients as recipient vessels for 50 free flaps and two ectopic replantations. There were 40 lower extremity reconstructions, seven reconstructions of traumatic penile amputations, three upper extremity reconstructions, and two ectopic replantations of the forearm and the thigh. In 37 cases, the flap (or replant) was transferred directly in a single stage, and in 19 cases the loop was constructed 2 to 13 days (mean, 6 days) before the flap transfer. The flaps used were latissimus dorsi (23 cases), fibular (11 cases), radial osteocutaneous (six cases), rectus abdominis (three cases), iliac crest bone, vastus lateralis, and ectopic replantations (two cases each), and gracilis muscle, scapular bone, and omental (one case each).
RESULTS: One patient died after the first stage as a result of cardiac arrest. Three two-stage arteriovenous loops thrombosed. In one case, the loop was redone and the flap was transferred immediately. Two flaps were revised for arterial compromise and salvaged in the one-stage group. All 50 flaps and both ectopic replants survived. There were two delayed bleedings resulting from graft rupture. The occlusion rate was 3 percent for one-stage loops and 16 percent for the two-stage loops (all before flap transfer).
CONCLUSIONS: In complex injuries, the arteriovenous loop is a safe and reliable adjunctive for free flap transfer. Delaying flap transfer may be reasonable in some circumstances.