Monitoring of intraoral free flaps with microdialysis.

Because of the confined nature of their position, monitoring intraoral free flaps is a challenge, but it is essential to detect vascular complications in time to ensure the possibility of salvaging the flap. Microdialysis has been the standard technique of choice at the Department of Plastic Surgery, Aarhus University Hospital, since September 1998. In this study we present our experience of monitoring 78 intraoral free flaps. It is a retrospective evaluation of patients' casenotes from November 1998 to March 2008. Sixty-five of the 78 flaps healed without complications. Sixty-one of these showed no sign of ischaemia in the microdialysis values; in 4 cases the microdialysis system caused technical problems. Thirteen patients were reoperated on based on the results of microdialysis analysis, and in all but 2 cases critical ischaemia was found. Ten of the 11 critically ischaemic flaps were saved. The overall loss rate of flaps was 1.3%. The 2 flaps that were reoperated on but no critical ischaemia found were 2 fibular flaps during the time that we were learning how to monitor with microdialysis (1999 and 2000). Since then we have developed a decision algorithm for standard monitoring, and since 2000 we have had no false positive results. We have never lost a flap from neglected ischaemia. Our results show that microdialysis is a safe and reliable technique for postoperative monitoring of intraoral free flaps.