Preoperative Assessment and Monitoring of Free Flaps

Abstract

Microvascular free-tissue transfer for reconstruction of head and neck defects has become routine. Failure rates are low, particularly in high volume centres. While this is reassuring at a population level, free-flap failure and its sequelae can be devastating to the individual patient who is affected and arguably the stakes are highest in the head and neck region due to the cosmetic and functional implications. The risk of flap failure is also a significant stressor for the surgeon and their team. When required, salvage surgery will often occur out of hours or displace other elective work. In order to reduce the risks of failure, assessment of flap suitability preoperatively, perfusion intra-operatively and then reliable monitoring post-operatively is crucial. Most flap failures are due to vascular compromise in the first 24–48 h post-surgery, and the chance of successful salvage is highly time critical. The ideal flap monitoring method should be accurate, continuous, harmless to both the patient and the flap, inexpensive, instantaneous, non-invasive, objective, recordable, reliable, reproducible, sensitive and simple to interpret [1].