“Go Deep or Go Home: Evaluating Venous Drainage Systems in Microvascular Lower Extremity Reconstruction”

Background: No consensus exists regarding the utilization of the lower extremity superficial venous system compared to the deep veins in free flap procedures for limb salvage. This study analyzed the risks of venous complications associated with superficial and deep venous anastomoses for lower extremity reconstruction. Methods: A retrospective review was performed on patients who required free flap reconstruction of the lower extremity between 2016 and 2024. The recipient veins were characterized as deep (venae comitantes) or superficial (saphenous veins). Flaps with two venous anastomoses were further classified as deep, superficial, or combined venous drainage. The primary study outcome was composite venous complications, which included venous congestion, flap hematoma, and partial and total flap necrosis during index hospitalization. Results: A total of 333 patients underwent free flap reconstruction of the lower extremity. Of these patients, 31 (9.3%) experienced the primary outcome. Free flaps with superficial-only drainage had a significantly higher rate of venous complications (27.8%) than those with deep (8.6%) or combined (4.3%) drainage systems. Multivariate analysis showed that flaps anastomosed to superficial veins had significantly higher odds of venous complications (OR = 4.11, CI: 1.24-11.9, p = 0.049) than those utilizing a deep drainage system. Conclusions: This study showed higher rates of venous complications with the use of superficial venous drainage in lower-extremity free flaps. Although efforts should be made to incorporate a deep venous recipient, superficial veins may be used as an adjunct in certain situations with good reconstructive outcomes.