Postoperative monitoring of microsurgical free-tissue transfers for head and neck reconstruction: a systematic review of current techniques--part II. Invasive techniques.

A systematic review of the literature relating to methods of monitoring viability of microvascular free-tissue transfers in the head and neck region was conducted. The aim of this review is to identify the best method of monitoring that would allow timely salvage of potentially failing free flaps. An analysis and description of the various studied techniques is also given. In this second part, invasive modalities are covered.