Allograft procurement in the first successful combined face and bilateral hand transplant: Timing and sequence

2 SAGE Open Medicine with the 50% perfusate exchange at 12 h. Potassium concentration plateaued at 5 mmol/L and remained below 5.8 mmol/L in both groups after 24 h of perfusion. Mean weight gain at the end of perfusion was higher in the continuous flow group (35%) compared with the pulsatile flow group (19%). Conclusion: Pulsatile flow offers similar outcomes to continuous flow in vascularized composite allografts viability after 24 h of perfusion and demonstrates a trend in the reduction edema after subnormothermic preservation. We hypothesize that pulsatile flow is essential to preserve an optimal endothelial function, thus limiting edema after 24 h of vascularized composite allografts ex vivo perfusion. Machine perfusion of vascularized composite allografts in small animal model Dor Yoeli1, Yong Wang1, Bing Li1, Joy L Huang1, Swati Jain1, Zhaohui Wang1, Niyati Nakra1, Jerry Yang1, Kelsey Rampalski2, An-Jey Su1, David W Mathes1, Kia M Washington1, Evan Farkash2, Alkesh Jani1 and Christene A Huang1 1University of Colorado Anschutz Medical Campus, Aurora, CO, USA 2University of Michigan School of Medicine, Ann Arbor, MI, USA Introduction: Machine perfusion may improve vascular composite allograft transplantation outcomes by mitigating ischemia reperfusion injury. The aim of this study was to evaluate the capability of preserving a small animal hind limb graft for 24 h with hypothermic machine perfusion in comparison with static cold storage preservation. Methods: Six male Brown Norway rats (14–18 weeks old) were used as hind limb donors, with one limb subjected to 24 h of hypothermic machine perfusion (flow rate of 0.2 mL/ min with heparinized KPS-1® solution) and the contralateral limb subjected to 24 h of static cold storage. Continuous variables are presented as mean (±standard deviation) and compared using two-sample or paired Student’s t test. Edema scores were compared using the Wilcoxon matched-pairs signed-rank test. Results: On average, hypothermic machine perfusion limbs gained 1.58 (±0.98) g and static cold storage limbs gained 0.15 (±0.77) g after 24 h, representing a statistically (p = 0.02) but not clinically significant change. There was no significant difference in the skin or muscle histological edema score between treatment groups (p = 0.5 and 0.2, respectively). In total, 50% of the hypothermic machine perfusion limbs demonstrated moderate or severe nerve edema in comparison to only 17% in the static cold storage group (p = 0.03) (Figure 1). Among the hypothermic machine perfusion limbs, there was no significant change in vascular resistance from baseline (181.43 ± 46.59 mm Hg*min/mL) and 24 h (249.18 ± 257.62 mm Hg*min/mL) (p = 0.5). Discussion and Conclusion: Rodent hind limb vascular composite allografts can be preserved up to 24 h with Figure 1. Perfusion parameters.