Preconditioning with Foam-mediated External Suction on Flap Microvasculature and Perfusion in a Rodent Model

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

BACKGROUND

Ischemic necrosis in the distal portion of a flap is a challenging complication in plastic surgery. The authors hypothesized that a novel hybrid flap preconditioning (HFP) device combining foam-mediated external suction and nonsurgical delay can promote skin flap survival better than surgical delay.

METHOD

Twenty-eight mice were divided into 4 groups: a control group, in which a 4 × 1.5-cm dorsal flap was made with no preconditioning; a surgical delay group, in which surgical delay occurred 7 days before flap elevation; a foam-mediated external suction (FMES) group, in which foam-mediated external suction at -100 mm Hg was used 5 hours a day for 6 days, and the flap was elevated on the seventh day; and a hybrid flap preconditioning (HFP) group, in which silicone strips were applied along the contour of the foam interface. The same negative-pressure protocol was used as in 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 surgical delay group, 57.03% (8.17%) in the FMES group, and 80.66% (3.27%) in the HFP group. Immunohistologic analysis of CD31 + cells in the distal end of viable tissue procured 7 days after flap elevation showed significantly higher angiogenesis in the surgical delay and HFP groups. Western blot results showed an increased expression of vascular endothelial growth factor in the surgical delay and HFP groups.

CONCLUSIONS

The authors developed and fabricated a novel HFP device combining foam-mediated external suction and nonsurgical delay. The concept of HFP has proved to promote flap survival better than surgical delay.

CLINICAL RELEVANCE STATEMENT

This study presented an innovative noninvasive method of flap preconditioning, which has been demonstrated to be superior to surgical delay in a murine model and holds promise for potential application in clinical settings.

Negative-Pressure Wound Therapy: What We Know and What We Need to Know

Negative-pressure wound therapy (NPWT) promotes wound healing by applying negative pressure to the wound surface. A quarter of a century after its introduction, NPWT has been used in various clinical conditions, although molecular biological evidence is insufficient due to delay in basic research. Here, we have summarized the history of NPWT, its mechanism of action, what is currently known about it, and what is expected to be known in the future. Particularly, attention has shifted from the four main mechanisms of NPWT to the accompanying secondary effects, such as effects on various cells, bacteria, and surgical wounds. This chapter will help the reader to understand the current status and shortcomings of NPWT-related research, which could aid in the development of basic research and, eventually, clinical use with stronger scientific evidence.

Early Experience with External Negative Pressure Delay in Free Anterolateral Thigh Perforator Flap Reconstruction

Negative pressure therapy has been utilized in the treatment of open and closed wounds to increase blood flow and improve wound healing. More recently, external negative pressure has been shown to induce a noninvasive delay phenomenon in animal models by increasing vessel size and density within a planned flap, leading to improvement in flap survival. Although successful in animal models, this new method of delay has not been demonstrated in clinical practice. We present our initial experience with preoperative external negative pressure delay of free anterolateral thigh flaps in upper extremity reconstruction to detail the technique and safety profile of this innovative new technique. External negative pressure delay has the potential to provide results similar to those of traditional surgical delay, while being cost effective, safer, and more convenient for patients. More research is needed to investigate the clinical benefit and cost effectiveness of external negative pressure delay.