Using dynamic infrared thermography to optimize color Doppler ultrasound mapping of cutaneous perforators

Abstract

Aims: The high technical demands associated with perforator flaps demand a precise preoperative identification and evaluation of perforator vessels. Color Doppler Ultrasonography (CDU) and Dynamic Infrared Thermography (DIRT) are currently used for preoperative perforator mapping. Each individual technique has advantages and disadvantages. The purpose of this paper is to analyze the value of combining the two methods in order to optimize the process of preoperative perforator mapping.

Material and methods: CDU and DIRT were used for preoperative perforator mapping in 10 pigs. The results were compared to intraoperative findings. Total number of perforators, localization, and identification of the dominant perforator was analyzed for each method. The examination time was recorded for each procedure.

Results: Both methods had a high sensitivity in determining the number and localization of perforators when compared to those identified during surgery. DIRT produced a higher number of false positive results. CDU accurately identified the emergence of the perforators in the fascia in all cases. Both methods correctly identified the dominant perforator. The sensitivity, positive predictive value, and accuracy of CDU were 93.56%, 97%, and 91.30% respectively and for DIRT 95.05%, 80.67%, and 77.41% respectively. The average examination was 39.76 minutes for CDU and 10.24 minutes for DIRT. The average time taken into account for the analysis of a single perforator in order to confirm DIRT findings was 1.83 minutes.

Conclusions: Preoperative perforator mapping has become a compulsory step in nearly all reconstructive procedures. In our study, both CDU and DIRT correctly identified the dominant perforator in all cases. By combining the two examinations overall mapping time can be reduced significantly. A reduced examination time translates into increased patient compliance and a lower procedure cost. The combined mapping technique facilitates the selection of the ideal perforator in all cases. Correctly identifying the dominant perforator preoperatively reduces operative time, lowers complication rates and ensures an overall better result.