Postoperative Monitoring of Free Flaps in Autologous Breast Reconstruction: A Multicenter Comparison of 398 Flaps Using Clinical Monitoring, Microdialysis, and the Implantable Doppler Probe

TLDR

Many flap‑monitoring techniques have been described, yet evidence that they improve flap salvage over standard clinical monitoring is lacking, underscoring the need for objective comparison. We sought to compare three established monitoring techniques across three experienced microsurgical centers in a comparable cohort of patients. A retrospective matched cohort of 398 free flaps in 347 patients across three centers over three years compared clinical monitoring, the Cook‑Swartz implantable Doppler probe, and microdialysis, evaluating both objective and subjective efficacy. The study found no technique superior to clinical monitoring alone, with similar flap‑salvage and false‑negative rates, but microdialysis and Doppler probes produced significantly more false‑positive alarms and unnecessary reoperations.

Abstract

Many techniques for flap monitoring following free tissue transfer have been described; however, there is little evidence that any of these techniques allow for greater rates of flap salvage over clinical monitoring alone. We sought to compare three established monitoring techniques across three experienced microsurgical centers in a comparable cohort of patients. A retrospective, matched cohort study of 398 consecutive free flaps in 347 patients undergoing autologous breast reconstruction was undertaken across three institutions during the same 3-year period, with a single form of postoperative monitoring used at each institution: clinical monitoring alone, the Cook-Swartz implantable Doppler probe, or microdialysis. Both objective and subjective measures of efficacy were assessed. Clinical monitoring alone, the implantable Doppler probe, and microdialysis showed statistically similar rates of flap salvage. False-negative rates were also statistically similar (only seen in the clinically monitored group). However, there was a statistically significant increase in false-positive alarms causing needless take-backs to theater in the microdialysis and implantable Doppler arms, p < 0.001. This study did not find any technique superior to clinical monitoring alone. New monitoring technologies should be compared objectively with clinical monitoring as the current standard in postoperative flap monitoring.