Mechanical versus Hand-Sewn Venous Anastomoses in Free Flap Reconstruction: A Systematic Review and Meta-Analysis.

Background: Venous complications are the primary reason for flap loss in massive defect reconstructions; therefore, the quality and reliability of microvascular anastomoses are significant. The aim of this systematic review was to evaluate venous anastomotic time, the venous complication rate, and the flap failure rate with the mechanical anastomotic coupling device versus the hand-sewn technique in venous anastomoses of microvascular free flap operations.

Methods: Chinese and English databases were searched for eligible articles published between their inception and July of 2017. The pooled relative risk was calculated for dichotomous variables, and the weighted mean difference was calculated for continuous data. Whether to use the fixed effects or random effects model depended on the heterogeneity evaluation among the studies.

Results: Twelve studies were selected, including 3788 flaps (mechanical anastomotic coupling device, n = 1667; hand-sewn, n = 2121). Using the mechanical anastomotic coupling device significantly decreased venous anastomotic time (weighted mean difference, -13.50; 95 percent CI, -17.09 to -9.91; p < 0.01) and the incidence of venous complications (relative risk, 0.40; 95 percent CI, 0.25 to 0.65; p < 0.01). There was a significant difference in terms of flap failure between the groups (relative risk, 0.56; 95 percent CI, 0.32 to 0.97; p = 0.04); thus, flap survival improved with the assistance of the mechanical anastomotic coupling device. No publication bias was detected in those analyses.

Conclusion: This meta-analysis suggests that the mechanical anastomotic coupling device contributes to reduced operative time, decreased probability of surgical reexploration, and mitigation of flap loss.