There is no financial information to disclose. Currently vascularized composite allografts (VCA) are cold preserved (4°C) until transplantation.1Hartzell T.L. Benhaim P. Imbriglia J.E. Shores J.T. Goitz R.J. Balk M. et al.Surgical and technical aspects of hand transplantation: is it just another replant?.Hand Clin. 2011; 27: 521-530Abstract Full Text Full Text PDF PubMed Scopus (34) Google Scholar This process is time limited, as the tissue has to be revascularized within 4-6 hours to minimize ischemia reperfusion (IR) injury. Normothermic perfusion was proposed as an alternative method of preservation in solid organ transplantation.2Rojas-Pena A. Reoma J.L. Krause E. Boothman E.L. Padiyar N.P. Cook K.E. et al.Extracorporeal support: improves donor renal graft function after cardiac death.Am J Transpl. 2010; 10: 1365e-1374eCrossref PubMed Scopus (33) Google Scholar This method helps to avoid complications associated with cold preservation and maintains tissue viability without inducing IR injury.3Murata S. Miniati D.N. Kown M.H. Koransky M.L. Lijkwan M.A. Balsam L.B. et al.Superoxide dismutase mimetic m40401 reduces ischemia-reperfusion injury and graft coronary artery disease in rodent cardiac allografts.Transplantation. 2004; 78: 1166-1171Crossref PubMed Scopus (27) Google Scholar Using this method, previous investigators demonstrated its potential to prolong swine forelimb allograft survival up to 24 hours.4Ozer K. Rojas-Pena A. Mendias C.L. Bryner B. Toomasian C. Bartlett R.H. Ex-situ limb perfusion system to extend vascularized composite tissue allograft survival.Transplantation. 2015; 99: 2095-2101Crossref PubMed Scopus (37) Google Scholar, 5Ozer K. Rojas-Pena A. Mendias C.L. Bryner B. Toomasian C. Bartlett R.H. The effect of ex situ perfusion in a swine limb vascularized composite tissue allograft on survival up to 24 hours.J Hand Surg Am. 2016; 41: 3-12Abstract Full Text Full Text PDF Scopus (45) Google Scholar In this study, we aimed to test this system on human limb allografts. Four human forearms were procured from brain-dead adult donors under tourniquet control. Following elbow disarticulation, the brachial artery was cannulated. The limb was flushed with heparinized saline and connected to a temperature controlled (30-33°C) ex situ perfusion system (Figure) for 24 hours. The perfusate consisted of plasma and red blood cells with a target hemoglobin (Hb) concentration of 4-6 g/dL. Muscle biopsies (flexor carpi radialis) were obtained at 0, 12, and 24 hours. Average warm ischemia time was 76 minutes. Average arterial systolic pressure was 98±2 mmHg, perfusion flow 319±18 mL/min (∼6-8% of the donor’s estimated cardiac output), and vascular resistance 158±18 mmHg/mL/min. Perfusate had an average pH of 7.43±0.04, pCO2 32±1 mmHg, pO2 317±18 mmHg, and Hb 4.8±0.4 g/dL. Electrolytes (sodium, potassium, chloride) remained within a physiologic range. Lactate started to increase steadily throughout the experiment; however, neuromuscular electrical stimulation revealed ongoing contraction throughout the experiment and H& E staining showed mild to moderate fatty infiltration on some myocytes at 24 hours. •All limbs appeared viable after 24 hours of near-normothermic ex situ perfusion as evidenced by ongoing neuromuscular stimulation.•While no conclusions can be drawn about the long-term function of the extremity, this approach could help extend VCA transplantation to a wider geographic area.•It also has the potential to circumvent complications associated with cold preservation.