Vasculature Characterization of a Multiterritory Perforator Flap: An Experimental Study

Background Tip necrosis in the perforator flap is a significant problem in clinical practice. This study aimed to characterize the vasculature of a multiterritory perforator flap using a rat model and to investigate the impact of the vasculature on flap survival. Methods In total, 105 Sprague Dawley rats were divided into seven groups, including the control, 3 hours postoperative (PO), 12 hours PO, 1 day PO, 3 days PO, 5 days PO, and 7 days PO. A perforator flap with three territories based on the deep iliac circumflex artery was performed. Flaps with only skin incisions and vessel exposure were performed in the control group. The first choke zone (FCZ) was located between the anatomical and dynamic territories, and the second choke zone (SCZ) was located between the dynamic and potential territories. Sodium fluorescein and lead oxide-gelatin angiography and histological examination were performed in each group. Results Sodium fluorescein angiography revealed delayed staining in the perforator flap PO, particularly in the FCZ and SCZ. The delay phenomenon disappeared after 12 hours PO in the FCZ and after 1 day PO in the SCZ. Nonfluorescein-stained areas were found distal to the potential territory. In the FCZ PO, the choke vessels were dilated, while the number of microvessels was increased in the SCZ without choke vessel dilation. Conclusions The remodeling of choke vessels and increase in microvessel number represent arteriogenesis and angiogenesis, respectively. This neovascularization was responsible for flap survival in the entire dynamic territory and part of the potential territory.