[Microdialysis: experience in postoperative monitoring of 30 free flaps]

Free flaps have become a usual practice in maxillofacial surgery. A postoperative follow-up is crucial to detect any thrombotic events. Microdialysis is a technique of monitoring for free flaps, which has been proposed recently. It is being assessed, but stay confidential in the clinical practice. We report our experience of microdialysis.

This prospective series includes 30 free flaps performed in our unit during the last 30 months. The critical values used as warning indicators were glucose lesser than 1 mmol/L and lactate more than 10 mmol/L. These values were assessed during the first five days of the post-operative period.

Twenty-six monitoring were effective versus four incidents. Seven thrombosis occurred, and one flap had an extrinsic compression of the pedicle. All of these events were detected early by microdialysis. There were no false positive and no false negative. Four flaps were lost. For the 19 flaps without complication, the mean values were for glucose 6.8 mmol/L, lactate 4.4 mmol/L, pyruvate 235 micromol/L and 20 for the ratio lactate/pyruvate (L/P).

The authors' experience in this mode of recent surveillance is reported. Problems and answers are discussed. Microdialysis is a reliable technique for postoperative surveillance of free flaps but a practice on few cases is needed to master this technique.