Free flap monitoring: a review of the recent literature

Purpose of reviewFree flap surgery has revolutionized our ability to perform composite reconstructions following ablative surgery. Although flap failure is rare (approximate to 5%), it results in high patient morbidity if not recognized and corrected early. There are numerous means to assess flap viability. We review the recent literature on flap monitoring, and discuss the difference between techniques in regard to overall flap survival, cost, and ease of use.Recent findingsThe current literature on implantable Doppler, microdialysis, video-based application (Eulerian), fluorescence angiography, spectroscopy, contrast-enhanced duplex, and activated clotting time is reviewed. Of these methods, implantable Doppler and spectroscopy have the most recent and largest series of data describing efficacy with implantable Doppler, demonstrating comparable flap survival rates to clinical monitoring. Arterial implantable Doppler has the additional benefit of less false-positives than venous Doppler. Spectroscopy demonstrates promise with commensurate flap survival rates and improved salvage rates over clinical monitoring.SummaryClinical monitoring alone has proven to be so effective that it is difficult to demonstrate better outcomes with alternative methods. That said, a minimally invasive, reliable method that does not require physician assessment on a frequent basis would prove ideal in many small centers and academic centers limited by resident hours. Venous and, more recently, arterial monitoring have been successfully implemented at many programs. Spectroscopy appears promising, but the data are still limited.