Free-Flap Reconstruction for Diabetic Lower Extremity Limb Salvage

Background: Microsurgical free tissue transfer is an important treatment option for nonhealing lower extremity diabetic wounds. The purpose of this study was to identify factors that affect flap survival and wound complications. Methods: A retrospective review was conducted of 806 lower extremity free-flap reconstructions performed from 1979 to 2016. A total of 33 free flaps were used for coverage of nonhealing lower-extremity diabetic ulcers. Primary outcome measures were perioperative complications and long-term wound breakdown. Results: The average age was 54 ± 12.3 y. 15.2% of patients were smokers, 12.1% had coronary artery disease and 12.1% had end-stage renal disease. Muscle flaps predominated (75.8%) compared to fasciocutaneous flaps (24.2%). There were 7 patients (21.2%) that underwent a revascularization procedure before (71.4%) or at the same time (28.6%) as the free flap. Immediate complications occurred in 7 flaps (21.2%) with 4 partial losses (12.1%) and 3 total flap failures (9.1%). Major wound complications occurred in 18.2% of patients. An end-to-side (E-S) anastomosis for the artery was used in 63.6% (n = 22) of flaps compared with an end-to-end (E-E) anastomosis. E-S anastomosis was associated with a significantly lower risk of wound complications compared with an arterial E-E anastomosis (0% versus 45.5%, P = 0.001). Conclusions: The use of microvascular free flaps can be used successfully to cover lower-extremity diabetic wounds. E-E arterial anastomosis should be avoided if possible as it is associated with higher rates of wound breakdown, likely by impairing perfusion to a distal limb with an already compromised vasculature. Level of evidence: Level III.