Advancements in Free Flap Monitoring in the Last Decade: A Critical Review

Abstract
The authors conducted a review of the recent literature on the monitoring of free flaps to create an overview of the current monitoring devices and their potential as an ideal monitoring method. A literature-based study was conducted using the PubMed and Cochrane databases. The following search terms were used: "flap" and "monitoring." All monitoring methods found between January of 1999 and January of 2009 were evaluated. Monitoring methods that were described in five or more clinical reports were further investigated. The advantages and disadvantages of conventional monitoring methods, the implantable Doppler system, color duplex sonography, near-infrared spectroscopy, microdialysis, and laser Doppler flowmetry are presented. Furthermore, an overview is given of their potential as ideal monitoring method. The implantable Doppler system, near-infrared spectroscopy, and laser Doppler flowmetry appear to be the best monitoring devices currently available. As most of the publications on monitoring have focused on the reliability of the systems, future research should also address their cost efficiency.