The reconstruction of severe tissue defects with autologus tissue can in fact be paralleled by a detrimental spectrum of IRI related problems. Especially the replantation of ischemic limbs can not only cause severe IRI related complications in the affected organ, but can accordingly lead to severe damage in distant organs due to acidosis, hyperkalemia, myoglubinuria and disseminated intravascular coagulation. As expected there is a strong correlation between acute renal failure due to arterial occlusion and limb revascularization surgery. Furthermore, replantation surgery can cause severe dysfunction of the respiratory system, since reactive oxygen species and cytokines, which are released upon reperfusion, can cause a severe capillary leakage within the microvasculature of the lung leading to pulmonary edema. It has been shown that these effects can be so profound that replanted limbs had to be removed in an effort to overcome these problems.
In free flap surgery, IRI always occurs when a graft is transplanted from one area to another. This so-called primary ischemia can be succeeded by any circulation-compromising event (e.g. failure of the anastomosis resulting in thrombosis, external mechanical compression due to haematoma or tight wound closure or compression), which is then referred to as secondary ischemia. Animal studies have confirmed that skin flaps are indeed less tolerant to secondary than to primary ischemia. However, since secondary ischemia cannot be prevented except for training the surgeons microsurgical skills, efforts are mainly aimed at reducing (primary) IRI. Ischemia and Reperfusion Injury in Reconstructive Transplantation: Barbara Kern and Robert Sucher
Last date updated on July, 2014