A comparison of the Cook-Swartz Doppler with conventional clinical methods for free flap monitoring: A systematic review and a meta-analysis

Introduction: Currently there is no consensus on what is the optimal method for monitoring free flaps. Our meta-analysis compared the free flap success and salvage rates of Cook-Swartz Implantable Doppler monitoring with clinical monitoring to gain insight into the relative benefit of these systems. Methods: Medline, Cochrane, EMBASE, and Google Scholar databases were searched until January 16, 2016. Search terms included free flap surgery, free flap microsurgery and implantable Doppler. Studies were included if they involved the comparison of Cook-Swartz Doppler and clinical assessment for monitoring free flap function. Studies using free flap monitoring as an outcome measure for drug treatment were also excluded. Sensitivity analysis using the leave-one-out approach was used to assay the reliability of the findings. Results: Initial search identified 14 studies, of which five studies were included in the meta-analysis. Cook-Swartz Doppler had significantly better rate of free flap success and salvage than clinical monitoring methods (P values <= 0.006). Data did not markedly changed when each study was removed in turn, showing reliability of the findings. Discussion: The Cook-Swartz Doppler as a monitoring method may result in a higher rate of free flap success and salvaging but also a greater frequency of false positives than conventional methods. Our analysis is limited by designs of included studies and by heterogeneity of clinical monitoring techniques. Conclusions: More studies are needed to evaluate if Cook-Swartz Doppler can be used alone, or to be better used as an adjunctive technique to complement the clinical method of monitoring. (C) 2016 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.