Enhancing microvascular anastomoses with the Synovis Coupler device: A retrospective analysis of management of vascular diameter discrepancies.

Background and Introduction: Microvascular surgery enables complex tissue repairs with free flaps. The Synovis Coupler has streamlined venous anastomoses, improving speed and precision. However, size discrepancies between donor and recipient vessels continue to cause postoperative complications. This study presents our experience in managing caliber discrepancies, optimizing venous flow, reducing thrombosis risk, and improving free flap survival. Material and Methods: This retrospective observational study analyzed data from patients undergoing free flap reconstruction between January 2018 and January 2024. A total of 84 microvascular free tissue transfers and 86 venous anastomoses were performed using a mechanical coupler system. Results: Eighty-six venous anastomoses were completed, averaging 3.25 min each, with an average coupler size of 2.34 mm. No postoperative returns to the operating room or anastomosis revisions were required. Complications included one infection and one hematoma, both resulting in flap necrosis. The average follow-up was 1.7 years, with no cases of venous ischemia. Discussion and Conclusion: Our experience suggests that adapting the vessel lumen may represent a practical option for managing diameter discrepancies when using couplers. The approach appeared to reduce the need for grafts and allowed efficient anastomosis. However, the retrospective design, limited sample size, and lack of a comparative group constrain the strength of these findings. Further prospective studies are warranted to confirm whether this method offers a consistent advantage over established techniques.