Reperfuusiota

Reperfuusiota, or reperfusion, is the restoration of blood flow to tissue that has experienced ischemia. It is a central concept in cardiology, neurology, and transplant medicine. Reperfusion is essential to salvage endangered tissue, but the reintroduction of blood can also cause injury, known as reperfusion injury, driven by oxidative stress, calcium overload, endothelial dysfunction, and an inflammatory response.

Common settings include myocardial infarction, ischemic stroke, and donated organ transplantation. In acute myocardial infarction, timely reperfusion through percutaneous coronary intervention or thrombolysis limits infarct size and improves outcomes; in ischemic stroke, reperfusion through thrombolysis or mechanical thrombectomy can restore function but carries risks such as hemorrhagic transformation. In organ transplantation, controlled reperfusion and optimized preservation aim to reduce primary graft dysfunction.

Mechanistically, reperfusion introduces oxygen that forms reactive oxygen species and activates inflammatory cascades, while mitochondrial permeability transition can trigger cell death. Reperfusion can also disrupt the microvasculature, aggravating tissue injury even after blood flow is restored.

Clinical management emphasizes rapid reperfusion while mitigating injury. Strategies include gentle or staged reperfusion, ischemic conditioning, and pharmacologic approaches studied to limit oxidative stress and inflammation. Advances in preservation technologies, such as machine perfusion for organs and targeted therapies, continue to reduce reperfusion injury. Research areas include mitochondrial protection, anti-inflammatory trials, and conditioning protocols. While reperfusion is indispensable for tissue survival, its optimization remains a balance between restoring circulation promptly and limiting injury.