Superficial versus deep system single venous anastomosis in the radial forearm free flap: a meta-analysis

The selection of the superficial or deep drainage system for use with the radial forearm free flap (RFFF) remains controversial. The aim of this study was to identify the optimal drainage system for single venous anastomosis. A systematic review and cumulative meta-analysis was performed to assess superficial and deep system single venous anastomosis for use with the RFFF in postoperative reconstruction of the head and neck. This study included 1073 flaps (495 superficial system-based flaps, 578 deep system-based flaps) reported in six studies. The outcomes assessed in the studies selected for this meta-analysis included venous compromise, flap failure, and the salvage success rate. Venous compromise was more common in the superficial system group (odds ratio (OR) 2.29, 95% confidence interval (CI) 1.36-3.86, P=0.002). The rate of successful salvage was higher with the superficial system (OR 8.19, 95% CI 1.75-38.3, P=0.008). The rate of flap failure was lower in the superficial system group (OR 0.30, 95% CI 0.04-2.48, P=0.27). Although the deep system showed a lower risk of venous compromise, the evidence provided by the meta-analysis was insufficient to determine which type of drainage system is more suitable for single venous anastomosis in RFFF. All included studies were cohort studies; therefore, findings must be interpreted with caution.