Perforator Detection by Thermographic Imaging Augmented With Tourniquet-Reperfusion: A Modified Approach and Preliminary Report in Distal Lower Leg Reconstruction

Background: Dynamic infrared thermography provides a new imaging method of perforator detection. This study introduces an augmented technique to improve its accuracy by tourniquet-reperfusion and reports its preliminary use in the distal lower leg reconstruction.

Methods: A tourniquet (450 mm Hg) was applied for 3 minutes on proximal thighs. After the tourniquet release, the rewarming rate and pattern of hotspots were observed by thermography to delineate the location and quality of perforators. The results were compared with those detected by computed tomographic angiography. Clinically, the local transferred posterior tibial artery or peroneal artery propeller perforator flap was performed in 9 patients for the distal lower leg reconstruction.

Results: There was a 20- to 140-second "perforator observing window" after the tourniquet release. Tourniquet-reperfusion augmented thermal imaging method (TRATIM) had a sensitivity of 90.3% and a positive predictive value of 93.3%. The TRATIM and computed tomographic angiography had an excellent concordance with a kappa index value of 0.839 (P < 0.001). Based on the TRATIM, 9 propeller perforator flaps were successfully designed and raised for the distal lower leg resurfacing. All flaps survived entirely, except one with size of 1.0 cm × 2.0 cm that had terminal necrosis.

Conclusions: The TRATIM is a quick, easy, cheap, and reliable approach for perforator detection in the lower leg. With the aid of TRATIM, a customized propeller perforator flap could be raised efficiently for the distal lower leg reconstruction.