Towards Optimizing Sub-Normothermic Machine Perfusion in Fasciocutaneous Flaps: A Large Animal Study

Abstract

Machine perfusion has developed rapidly since its first use in solid organ transplantation. Likewise, reconstructive surgery has kept pace, and ex vivo perfusion appears as a new trend in vascularized composite allotransplants preservation. In autologous reconstruction, fasciocutaneous flaps are now the gold standard due to their low morbidity (muscle sparing) and favorable functional and cosmetic results. However, failures still occasionally arise due to difficulties encountered with the vessels during free flap transfer. The development of machine perfusion procedures would make it possible to temporarily substitute or even avoid microsurgical anastomoses in certain complex cases. We performed oxygenated acellular sub-normothermic perfusions of fasciocutaneous flaps for 24 and 48 h in a porcine model and compared continuous and intermittent perfusion regimens. The monitored metrics included vascular resistance, edema, arteriovenous oxygen gas differentials, and metabolic parameters. A final histological assessment was performed. Porcine flaps which underwent successful oxygenated perfusion showed minimal or no signs of cell necrosis at the end of the perfusion. Intermittent perfusion allowed overall better results to be obtained at 24 h and extended perfusion duration. This work provides a strong foundation for further research and could lead to new and reliable reconstructive techniques.

Machine Perfusion Enables 24-h Preservation of Vascularized Composite Allografts in a Swine Model of Allotransplantation

“…In contrast, the use of subnormothermic “room” temperatures (20°C–25°C) in machine perfusion offers several advantages. First, it simplifies the perfusion device setup, eliminating the need for a heating or cooling system [ 29 , 38 ]. Second, it allows clinicians to reach a balance between oxygen needs and subdued tissue metabolism resulting in perfusate simplifications [ 28 ].…”

VCA supercooling in a swine partial hindlimb model

“…The variety of tissues composing VCAs brings a substantial challenge when translating solid organ preservation protocols. Kruit et al and later our team described the first machine perfusion protocols applied to large animal VCA 27 , 28 , 36 , 39 , 44 – 46 . Nonetheless, current dynamic hypothermic and SNMP techniques are limited to preservation periods of 24 to 36 h due to factors such as edema and vascular resistance 34 , 47 – 49 .…”

The Autonomization Principle in Vascularized Flaps: An Alternative Strategy for Composite Tissue Scaffold In Vivo Revascularization

“…These multi-step procedures could benefit from simplification resulting from a reduction in the necessary delay. Another benefit that may result from these data is the improvement in the reliability of extracorporeal machine-perfused flap reconstruction techniques [117,118], as initially described by Wolff [102]. Their pioneering work requires optimization to decrease the observed complication rate, yet the total perfusion time (4 to 6 days) deserves attention.…”