A Novel Method of Noninvasive Monitoring of Free Flaps With Near-Infrared Spectroscopy.

Objective: Thrombosis of a site of anastomosis in microsurgical free tissue transfer can result in tissue necrosis. To salvage potentially failing free flap, various methods of monitoring the viability of tissue have been described. We report a novel method of monitoring free flaps using near-infrared spectroscopy. Methods: After microsurgical operation, we monitored the regional oxygen saturation of the flap with using the In-Vivo Optical Spectroscopy. A total of 57 patients participated in this study. Results: Of 57 cases, arterial insufficiency was detected in 1 case and venous insufficiency was detected in 3 cases. Regional oxygen saturation decreased before the flap color changed to a pale or congestive color. We could salvage these 4 patients by re-exploration. Conclusions: The postoperative monitoring with the In-Vivo Optical Spectroscopy is noninvasive, continuous, reliable, and reproducible. This technique could be one of the best methods for monitoring microsurgical free tissue transfers.