Thermographic mapping of perforators and skin blood flow in the free transverse rectus abdominis musculocutaneous flap

Abstract

There is no ideal method for preoperative or intraoperative mapping of cutaneous perforators or for postoperative monitoring of blood flow in cutaneous flaps. To study the suitability of thermography for the mapping and monitoring of free transverse rectus abdominis musculocutaneous (TRAM) flaps for breast reconstruction, we performed thermography pre-, intra-, and postoperatively (eight patients). The temperature of the TRAM flap increased during the induction of anesthesia and was still higher than normal on the first and second postoperative days (p < 0.05). During the operation, the flap cooled, reaching its minimum temperature (3.62 +/- 0.6 degrees C below phase 2, p < 0.05) after ligation of both pedicles of the flap. When blood flow had been re-established, all parts of the flap warmed rapidly. The locations of perforators ("hot spots") could be seen before, during, and after the operation. However, induction and cutting of both pedicles made the flap isothermic, and the perforators disappeared temporarily. Thermography is a potential method of mapping cutaneous perforators pre-, intra-, and postoperatively and of monitoring the flaps at bedside. The method is easy to use and the outcome can be seen immediately. Our results also showed that the temperature (blood flow) in free TRAM flaps is higher than in the tissue in its original position.