Efficiency and outcomes in microvascular anastomosis: A meta-analysis of mechanical versus manual techniques

Microvascular anastomosis plays a critical role in free flap transfers, aiming to reduce ischemia time, minimize vessel trauma, and optimize ease of use. This meta-analysis compares coupler devices and hand-sewn techniques for venous anastomosis across all types of free flaps, with a subgroup analysis focused on head and neck reconstruction. A comprehensive literature search following PRISMA guidelines was conducted across multiple databases up to November 6, 2024. Eighteen retrospective comparative studies met the inclusion criteria from an initial pool of 3184 articles. The overall flap loss rate was 1.53 % for coupler devices and 2.32 % for hand-sewn techniques. Thrombosis occurred in 2.91 % of coupler cases versus 3.17 % for hand-sewn. Anastomosis time was notably shorter with coupler devices (7.5 min) compared to hand-sewn methods (32.2 min). In head and neck reconstruction, the coupler group showed even more favorable outcomes: flap loss was 0.66 % versus 3.08 %, thrombosis rates were 1.7 % versus 3.88 %, and anastomosis times were 7.5 versus 17 min. These findings suggest that coupler devices are a safe and time-efficient alternative to traditional hand-sewn techniques in free flap surgery, particularly in head and neck reconstruction.