Novel Noninvasive Hybrid Flap Preconditioning Surpasses Surgical Delay in the Murine Model

Abstract

Background: Ischemic necrosis in the distal portion of the flap is a challenging complication in plastic surgery. We hypothesize a novel hybrid flap preconditioning (HFP) device combining foam-mediated external suction and non-surgical delay can promote skin flap survival better than surgical delay. Method: Twenty-eight mouse were divided into four groups. Control group: a 4*1.5 dorsal flap was made with no preconditioning. Surgical delay (SD) group: surgical delay was made 7 days before flap elevation. Foam-mediated external suction (FMES) group: foam-mediated external suction at -100mmHg was employed 5 hours per day for 6 days, and the flap was elevated on the seventh day. Hybrid Flap Preconditioning (HFP) group: silicone strips was applied along the contour of the foam interface. Same negative pressure protocol was used as the FMES group. Seven days after flap elevation, macroscopic, histologic, and Western blot analyses were performed. Results: The flap survival rate was 46.25% (8.12%) in the control group, 68.72% (7.00%) in the SD group, 57.03% (8.17%) in the FMES group and 80.66% (3.27%) in the HFP group. Immunohistologic analysis of CD 31+ cell in distal end of viable tissue procured seven days after flap elevation showed a significantly higher angiogenesis in SD group and HFP group. Western Blot results showed an increased expression of VEGF in SD group and HFP group. Conclusion: We have developed and fabricated a novel hybrid flap precondition (HFP) device combining foam-mediated external suction and non-surgical delay. The concept of HFP is proved to promote flap survival better than surgical delay.