Arteriogenesis Mechanism in Remodeling of Choke Vessels Within Choke Zone 2 of Delayed Multiterritory Perforator Flap

Background The aim of this study is to validate that both morphological and hemodynamic changes in the choke vessels remodeling within the choke zone 2 of delayed multiterritory perforator flap (MPF) in rats are consistent with revascularization through the arteriogenesis mechanism. Methods Two hundred seventy-two Sprague-Dawley (SD) rats were randomly divided into 4 groups: group A (classical group with harvested MPF), group B (delay group with ligated perforator in the potential region), group C (delay group with ligated perforator in the dynamic region), and group D (delay group with double fasciocutanoeus pedicles). The morphological changes in the choke vessels were evaluated using integument radiography and H&E staining, while the hemodynamic alterations within the choke zones were assessed utilizing a laser Doppler blood flow imager. Results In choke zone 2, the true anastomosis emerged on 5 days postoperatively, and 3, 3, and 5 days after the delay surgery in group A, B, C, and D, respectively. The microvessel densities on each time points postoperatively were lower than those before operation in the 4 groups ( P > 0.05). The arteriolar diameters on 5 days after the delay surgery were significantly larger than those before operation in group B, group C, and group D ( P < 0.05). In the group B, C, and D, the blood perfusion at 1 day after the delay surgery was significantly higher than that at 6 hours after the delay surgery ( P < 0.05). Conclusions The arteriogenesis mechanism plays an important role in the remodeling of the choke vessels in the choke zone 2 within the MPF after 3 types of delay procedures.