48 hour ex-vivo perfusion and two hour simulated reperfusion after a traumatic major amputation of the upper extremity

Background: Extremity replantation as well as allotransplantation aim to restore form and function of the amputated limb. Both approaches, however, are clearly limited by the ischemic time. Ex-vivo perfusion (EVP), already well established in the field of solid organ transplantation, represents a promising tool to overcome this restriction. Methods: We have currently established the technical requirements to provide ex-vivo perfusion (EVP) to severed limbs in a clinical hospital setting and hereby report of a 48-hour hypothermic EVP (EVP48) of an upper extremity amputated at the level of the proximal humerus, followed by a 2-hour simulated reperfusion (2SR) with donor blood. Results: Muscle biopsies revealed histopathologically well preserved, vital muscle tissue after EVP24, and partially grouped muscle fiber necrosis with predominantly vital muscle tissue after EVP48 and 2SR. Analyses of perfusate samples showed a marked decline of biochemical muscle damage markers during EVP48. Cytokine analysis disclosed an isolated increase of the pro-inflammatory cytokines interleukine-6, monocyte chemotactic protein-1 and interferon-γ during EVP and 2SR. Magnetic resonance imaging, performed after EVP48, indicated partial muscle necrosis of the intrinsic hand muscles only, whilst no signs for infection or inflammation were present. Conclusion: Our single case experience shows the general feasibility of an amputated limb ex-vivo salvage perfusion setting to allow for delayed replantation up to 24 hours. Nevertheless, an accurate prior planning, is crucial to ensure successful implementation of EVP in the acute clinical setting.