Single Versus Double Venous Anastomosis Microvascular Free Flaps for Head and Neck Reconstruction.

Venous congestion accounts for most microvascular free tissue flaps failures. Given the lack of consensus on the use of single versus dual venous outflow, the authors present our institutional experience with 1 versus 2 vein anastomoses in microvascular free flap for head and neck reconstruction. A retrospective chart review was performed on all patients undergoing free flaps for head and neck reconstruction at our institution between 2008 and 2020. The authors included patients who underwent anterolateral thigh, radial forearm free flap, or fibula free flaps. The authors classified patients based on the number of venous anastomoses used and compared complication rates. A total of 279 patients with a mean age of 55.11 years (standard deviation 19.31) were included. One hundred sixty-eight patients (60.2%) underwent fibula free flaps, 59 (21.1%) anterolateral thigh, and 52 (18.6%) radial forearm free flap. The majority of patients were American Society of Anesthesiologists classification III or higher (N = 158, 56.6%) and had history of radiation (N = 156, 55.9%). Most flaps were performed using a single venous anastomosis (83.8%). Univariate analysis of postoperative outcomes demonstrated no significant differences in overall complications (P = 0.788), flap failure (P = 1.0), return to the Operating Room (OR) (P = 1.0), hematoma (P = 0.225), length of hospital stay (P = 0.725), or venous congestion (P = 0.479). In our cohort, the rate of venous congestion was not statistically different between flaps with 1 and 2 venous anastomoses. Decision to perform a second venous anastomoses should be guided by anatomical location, vessel lie, flap size, and intraoperative visual assessment.