Use of perfusion device for free flap salvage after ischemia in swine

Abstract

In free flap reconstruction, improving flap tolerance to warm ischemia (WI) is fundamental. WI is the result of a venous or arterial thrombosis, which can only be addressed through surgical revision. No additional treatments have shown superior efficacy at salvaging free flaps after or during WI. Custom perfusion machines (PM), used to reduce the intensity of lesions of the flap stored in cold ischemia, have not been evaluated for WI flap salvage. This proof-of-concept study assessed whether the Lifeport® perfusion machine could improve the salvage procedure's success rates after one hour of venous WI. Five different groups were evaluated with four porcine latissimus dorsi free flaps included in each group. Depending on the group, the flaps were subjected to one hour of WI followed by revascularization, static hypothermic submersion, or dynamic Lifeport® perfusion. Additionally, two flap perfusion liquids were evaluated: KPS-1® and IGL-1®. Biopsies were performed before in vivo warm ischemia of the flap, after in vivo warm ischemia of the flap, and after one and two hours of preservation. Interstitial edema, muscular cell size and muscular diffuse necrosis were quantified by histological assessment. Static submersion did not demonstrate any efficacy for venous flap salvage. Dynamic perfusion on Lifeport® machine showed a significant improvement in tissue parameters. Thrombi and fibrine, present during the WI period, were no longer visible inside vessels and the perfusion machine flow evacuated the inflammatory cells and their substrates from the flap. The flap weights did not increase during perfusion time, confirming the benefits of the Lifeport® perfusion machine. Evaluating Lifeport® advantages on human free flap salvage is necessary to confirm the benefits for the tissue and to increase post-operative results after congestive free flap revision surgery.