Abstract
Background The anterolateral thigh (ALT) flap is commonly utilized in reconstructive surgery.
Preoperative perforator mapping facilitates dissection. Dynamic infrared thermography
can be applied to identify ALT perforators. However, its accuracy has not been evaluated
in detail before. Therefore, this study aimed to assess the precision of dynamic infrared
thermography in ALT perforator localization.
Methods The survey site was defined as a 25 × 8 cm rectangle on the anterolateral thigh and
a coordinate system was established. The area was examined consecutively by dynamic
infrared thermography with a FLIR ONE camera after 2-minute fan precooling. Two surgeons
then independently performed color duplex ultrasound on the basis of the identified
hotpots.
Results Twenty-four healthy subjects were examined. About 74.8% of perforators were musculocutaneous
or musculoseptocutaneous. The mean distance between study area center and perforator
or hotspot center was 51.8 ± 27.3 and 46.5 ± 26.2 mm, respectively. The mean distance
from hotspot center to sonographic perforator fascia passage was 15.9 ± 9.9 mm with
a maximum of 48.4 mm. The positive predictive value of thermographic ALT perforator
identification was 93%.
Conclusion Thermographic hotspot and perforator location diverge widely in ALT flaps. Dynamic
infrared thermography can therefore not be used as standalone technique for preoperative
ALT perforator identification. However, the application before color duplex ultrasound
examination is a reasonable upgrade and can visualize angiosomes and facilitate the
examination.
Keywords
ALT flap - perforator - thermography - color duplex ultrasound - DIRT
