World survey on the complications of hepatic and prostate cryotherapy

Cryotherapy is used as a treatment for nonresectable liver tumors and adenocarcinoma of the prostate. Morbidity and mortality following cryotherapy are generally considered to be infrequent, but a syndrome of multiorgan failure, severe coagulopathy, and disseminated intravascular coagulation following hepatic cryotherapy has been described and referred to as the cryoshock phenomenon. In this study we aimed to assess and describe the incidence and clinical features of the cryoshock phenomenon following cryosurgery from the surveyed experience of a large number of clinical centers and to relate the data to the overall mortality and morbidity of this treatment. A questionnaire was sent to all cryotherapy users (n = 299) of whom we were aware. We requested information on the number of patients treated, the occurrence, and the clinical features of cryoshock and mortality and morbidity following cryotherapy of the prostate or liver. Altogether 134 completed questionnaires were returned (44.8%). Seventy-two centers had experience with hepatic cryotherapy and 62 with prostate cryotherapy. Following hepatic cryotherapy, the phenomenon of cryoshock was observed in 21 of 2173 patients (1%) and was responsible for 6 of 33 perioperative deaths (18.2%). Cryoshock was rare following prostate cryotherapy (2 of 5432 patients, 0.04%) and did not contribute to the overall mortality of 0.06%. Hepatic and prostate cryotherapy are safe. Cryoshock is rare after prostate cryotherapy but occurs in 1% of patients following hepatic cryotherapy. Cryoshock is associated with a high risk of death, being responsible for 18.2% of deaths in this survey. Research regarding the mechanism and possible avoidance of cryoshock is required.