Outcomes of anastomotic venous flow couplers in head and neck free flap reconstruction - five-year experience in a single centre.

Flow couplers for venous anastomosis, which enable the invasive monitoring of free flaps during the postoperative period with a continuous venous signal audible immediately after completion of the anastomosis, have been reported to be reliable, sensitive, and specific as anastomotic flap monitoring adjuncts. The purpose of this study was to evaluate the reliability, sensitivity, specificity, and outcomes of surgical exploration, and the impact on free-flap survival of the venous anastomotic flow coupler for microvascular head and neck reconstruction in a consecutive series of patients. This is a retrospective review of consecutive patients treated in the department of oral and maxillofacial surgery who underwent reconstruction of a head and neck defect using venous anastomosis with a flow coupler-vascularised free flap between October 2015 and December 2020. A total of 189 patients had free-flap reconstruction of head and neck defects. We compared the venous flow coupler group (n = 72) with patients who had free flaps with hand-sewn anastomoses over the same period (n = 117). There were no false positive/negatives associated with the flow coupler as an implantable flap monitor. The flow coupler cohort had a significantly higher flap salvage rate compared with free flaps that were monitored clinically (p = 0.04). The venous flow coupler has been shown to be a reliable microvascular anastomotic and invasive flap monitor that enables accurate and timely detection of flap compromise and prompt, successful free-flap salvage.