True and "Choke" Anastomoses between Perforator Angiosomes: Part II. Dynamic Thermographic Identification

Background: Cadaveric studies have revealed that cutaneous perforators are linked by either reduced-caliber "choke" arteries, or by vessels without change in caliber, the true anastomoses. These true anastomotic vessels are often found in parallel with the cutaneous nerves and accompanying veins, and are associated both experimentally and clinically with larger areas of flap survival. The Doppler probe and computed tomographic angiography are already used preoperatively to determine perforator locations but currently cannot reveal the type of anastomotic connections. Methods: Thermal images were taken in a previously described fashion and compared with both computed tomographic angiographic studies where available and with cadaveric angiographic studies previously performed by the authors' laboratory. Results: Perforators larger than 1 mm were accurately localized by thermography when compared with computed tomographic angiography. Perforator angiosome rewarming closely approximated a log-based line of best fit. Interperforator zones were variable in their rewarming and correlated with known anatomical patterns of true and choke anastomoses between perforator angiosomes. Conclusions: Thermography now offers a new modality with which to bridge the gap not only by identifying the perforator "hot spots" but also by the robustness of their interconnections. The pattern of these interconnections seen on thermographic imaging has in turn been found to match those seen in the authors' cadaveric studies.