Thrombolytic Salvage of Threatened Frostbitten Extremities and Digits: A Systematic Review

Frostbite is a cold injury that results in soft tissue loss and can lead to amputation. Vascular thrombosis following injury causes ischemic tissue damage. Despite understanding the pathology, its treatment has remained largely unchanged for over 30 years. Threatened extremities may be salvaged with thrombolytics to restore perfusion. The authors performed a systematic review to determine whether thrombolytic therapy is effective and to identify patients who may benefit from this treatment. The Pubmed, EBSCO, and Google Scholar databases were queried using the key words "thrombolytics," "frostbite," "fibrinolytics," and "tPA." Studies written after 1990 in English met inclusion criteria. Exclusion criteria were failure to delineate anatomic parts injured, failure to report number of limbs salvaged, animal studies, and non-English language publications. Thrombolytic therapy was defined as administration of tPA, alteplase, urokinase, or streptokinase. Forty-two studies were identified and 17 included. Included were 1 randomized trial, 10 retrospective studies, 2 case series, and 4 case reports. One thousand eight hundred and forty-four limbs and digits in 325 patients were studied and 216 patients treated with thrombolytics and 346 amputations performed. The most common means of thrombolysis was intra-arterial tPA. The most common duration of therapy was 48 hours. Limb salvage rates ranged from 0% to 100% with a weighted average of 78.7%. Thrombolytics are a safe and effective treatment of severe frostbite. They represent the first significant advancement in frostbite treatment by preventing otherwise inevitable amputations warranting both greater utilization and further research to clarify the ideal thrombolytic protocol.