LAUSR

To the Editor: We would like to thank Dr. Eberlin for his insightful remarks regarding our recent report on 2 cases of extracorporeal perfusion in the situation of major traumatic limb amputations. We certainly agree that based on these 2 cases, our limb-saving strategy cannot be considered a standard procedure in every clinical scenario of major amputations. Indeed, our limb perfusion strategy should be restricted to centres with an expertise in extracorporeal perfusion, especially since worst case scenarios of a delayed replantation of a major amputate can potentially cause a life-threatening ischemia-reperfusion syndrome. There are a couple of points in the comment from Dr. Eberlin that we would like to respond to. First, although the neurological regenerations in such proximal amputations remain unclear, even when incomplete limb recovery results, critical tissue is saved in the process that allows reconstruction of at least the pelvis in case of hemipelvectomies; in fact, the first patient in our report is able to sit in a stable position without prosthetic devices because of such a pelvic reconstruction. Second, we want to comment on whether the complexity of an extracorporeal perfusion setup limits widespread use of this technique. We have reduced the extracorporeal perfusion setup in the laboratory to a simple unidirectional infusion method that has been demonstrated in a clinical case. Moreover, we would like to point out that this simple technique was applied in the initial phase of the 2 reported amputations until the time that ECMO units were available. Notably, the initial unidirectional perfusion comes at the cost of needing relatively large amounts of perfusion solution, but is simple and feasible in the short term, for example, to bridge the time in the battle field or by first responders until a microsurgical center is reached. Finally, we would like to emphasize 1 last point. Given certain restrictions of our reported techniques, it is important to highlight that the perfusions we have been testing use readily available ‘‘acellular’’ extracorporeal solutions. Therefore, our simplified approach is already clinically feasible on a broader scale to perform by centers experienced with extracorporeal perfusion, especially if the need for specialized cell-cell-based oxygen carriers can be avoided.