Combination of Smartphone Thermography with Color-Doppler Ultrasonography—an Easy Method for Preoperative Planning of ALT Flaps for Novice Microsurgeons

Abstract

Background

The design and preoperative planning of microsurgical free flaps are crucial for successful outcomes. Studies have shown that preoperative vascular mapping significantly shortens operative time, reduces complication rates, and lowers overall costs. Various methods of perforator detection have been introduced; however, none is ideal. Some surgeons propose that combining two or even three different methods could better meet clinical expectations. Therefore, this study sought to determine the effect of augmenting color Doppler ultrasound (CDUS) preoperative perforator detection with smartphone-based dynamic infrared thermography (DIRT) on concordance with intraoperative findings.

Methods

The study included 46 patients scheduled for anterolateral thigh flap (ALTF) reconstruction. Patients were divided into two groups according to the method of perforator mapping: Group 1 underwent CDUS alone, while Group 2 underwent DIRT followed by CDUS. Assessments were performed by novice surgeons with limited ultrasound experience.

Results

The time required for perforator mapping was significantly shorter in Group 2 (9 min vs. 16 min, p < 0.0001). The mean number of detected perforators in the evaluated area was 2.5 in Group 1 and 2.96 in Group 2 (p = 0.046). Combining CDUS with DIRT significantly reduced the number of overlooked vessels (p < 0.01).

Conclusion

DIRT plays an important role in perforator flap planning by identifying likely perforator locations before CDUS. In turn, CDUS provides detailed information on the perforator's course and hemodynamic properties. The combination of these two techniques offers a rapid, easily interpretable method for preoperative flap planning that can be used by any microsurgeon.

Keywords

free flap - perforator - ultrasound - color Doppler sonography - thermal imaging - anterolateral thigh flap

Publication History

Received: 09 April 2025

Accepted: 21 September 2025

Accepted Manuscript online:
10 October 2025

Article published online:
11 November 2025

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