Use of a monitor muscle flap in buried free forearm flap transfer.

The free forearm flap is a reliable and versatile tool in head and neck reconstruction. However, the patency of the microvascular anastomosis is difficult to monitor when the flap is buried in the reconstruction of the esophagus or orbital floor. We used a portion of forearm muscle on a branch of the radial artery and vein as a monitor flap. After the free forearm flap transfer, the monitor muscle flap was placed externally through a small skin incision. Flap viability was assessed by observing the color of the bleeding elicited from the muscle flap. Monitor muscle flaps are raised easily during elevation of the forearm flap. This technique was used successfully in 5 patients. This monitoring method provides a simple and reliable assessment of viability when direct monitoring of the forearm flap is not possible.