Late patency of clinical microvascular anastomoses to free composite tissue transplants. II. Hemodynamical aspects

In a series of 37 free composite tissue transplantations performed to the lower extremity in 34 patients, skin islands were included in 35 cases, as a cutaneous island flap (3), as a musculocutaneous island flap (19), and as an osteocutaneous island flap (13). In a follow-up study which included 26 patients with 29 flaps 6-48 months postoperatively an estimate was made of the importance of the blood supply through the vascular pedicle relative to the collateral blood supply through the recipient bed. Using transcutaneous oxygen tension measurements a significant reduction in calculated relative skin blood flow averaging 70% (p much less than 0.01) was seen after digital occlusion of the vascular stalk, suggesting that patent microvascular anastomoses are important for the vascularity of the transplanted tissues, not only for immediate postoperative survival, but also on the longer view.