Abstract
Background Due to the variable vascular anatomy preoperative perforator mapping facilitates
anterolateral thigh (ALT) free flap harvesting. Dynamic infrared perforator imaging
can assist preoperative planning by displaying hot spots that represent angiosomes.
This study aims to compare previously described precooling methods to develop a standardized
simplified protocol for ALT perforator planning.
Methods Fifty thighs were examined with a FLIR ONE thermal camera. Four different cold challenges,
including alcoholic disinfection, wet laparotomy sponge cooling, fan cooling, and
cold pack application, were compared. Hot spot locations within a 250 mm × 80 mm area
were compared double-blinded to perforator locations determined by Doppler ultrasonography
considered as gold standard.
Results The matching rate of thermographic hot spots and sonographically identified perforators
was 34.9 ± 22.2%. An increased matching rate of 62.2 ± 42.2% was noted taking only
favored perforators (septocutaneous course, diameter >1 mm, distance <3 cm to the
center, and visible concomitant veins) into account. Precooling with a fan followed
by alcoholic disinfection provided clearest thermograms and fastest results.
Conclusion Thermographic imaging is a reliable method for perforator imaging. Its supplemental
use to ultrasound may reduce examination time and yield additional information. Precooling
by air flow or alcoholic disinfection can be easily implemented and provide the best
thermograms. The matching rate of thermographic hot spots and perforators increases
when taking only clinically relevant perforators into account. Thermal perforator
mapping therefore reduces distraction by negligible perforators.
Keywords
thermography - FLIR - perforator mapping
