Comparison of Complications According to the Number of Venous Anastomoses in Lower Extremity Reconstruction

BACKGROUND: Venous congestion remains a leading cause of early free flap failure in lower extremity reconstruction. Although double venous anastomosis has been proposed to enhance venous outflow, its benefit over single venous anastomosis remains controversial. This study aimed to compare complication rates between single and double venous anastomoses in lower extremity free flap reconstruction across different etiologies. METHODS: A retrospective review was conducted of 134 patients who underwent lower extremity soft tissue reconstruction with free flaps between 2015 and 2023. Patients were divided into single venous anastomosis (Group 1, n = 81) and double venous anastomosis (Group 2, n = 53) groups. Group 2 was further subdivided according to venous drainage configuration (double superficial, double deep, and dual-system). Demographics, comorbidities, flap characteristics, and complication rates were analyzed. Major complications included total flap loss and return to the operating room (OR); minor complications included wound-related problems not requiring additional flap coverage. RESULTS: Overall, 26 major complications and 9 total flap losses occurred. Group 1 demonstrated significantly higher overall, major, and minor complication rates compared with Group 2 (p < 0.05). Total flap loss rates were comparable between groups. No significant differences were found among double venous anastomosis subgroups with respect to complication rates. CONCLUSIONS: Double venous anastomosis in lower extremity free flap reconstruction is associated with a significant reduction in overall and perioperative complications, although total flap survival remains similar. These findings support consideration of dual venous outflow, particularly in high-risk lower extremity reconstructions, while emphasizing the importance of individualized recipient vein selection.