High-pressure infusion improves multi-territory perforator flap viability via choke artery dilation: A preliminary study in a rat model

Abstract

Multi-territory perforator flaps have become the preferred option for the repair and reconstruction of large soft tissue defects. Although methods (e.g., pharmacological agents, mechanical stimulation, and thermal stimulation) were developed to open choke vessels to improve flap survival, the flap necrosis rate is still as high as 28.8%. The authors hypothesized that high-pressure infusion might enhance flap viability by dilating choke arteries intraoperatively in a rat model of multi-territory perforator flap. Two-month-old male Sprague-Dawley rats were randomized into two groups (n=32 each). During the multi-territory perforator flap elevation based on the right superficial epigastric angiosome, one group received continuous high-pressure infusion (mean pressure, 250mmHg; duration, 1min) of an isotonic heparin sodium solution (12,500U/L) via the artery in the pedicle, whereas the other group received no infusion. At 7 days postoperatively, arteriography was performed; endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor (VEGF) expression and microvascular density were evaluated by western blot and histology, respectively; and flap survival was compared. Moreover, intraluminal diameters were examined at 1day and 7 days postoperatively using hematoxylin and eosin staining, and coagulation function was assessed immediately postoperatively. High-pressure infusion significantly promoted the dilation of choke arteries at 1day and 7 days postoperatively. It also increased eNOS and VEGF expression, flap survival, and microvascular density. The coagulation function remained unaffected. High-pressure infusion allowed intraoperative and postoperative dilation of the choke arteries that enhanced the viability of multi-territory perforator flaps in rats.