The treatment of primary and metastatic hepatic neoplasms using percutaneous cryotherapy

Cryotherapy has been used clinically in the treatment of metastatic liver malignancies since the 1980s. Rapid freezing to sub-zero temperatures promotes ice formation in the extracellular space and the exit of intracellular water. Cellular death is the result of dehydration, protein denaturation, and microcirculatory failure. Cryotherapy probes use nitrogen or argon gas as a coolant and the development of the ice ball can be monitored using ultrasound, computed tomography, or magnetic resonance imaging. Traditionally, cryotherapy has been performed during laparoscopy or laparotomy, using intraoperative ultrasound for image guidance. A decrease in cryoprobe size (from ~24 Fr to ~15 gauge) in conjunction with experience gained in open cryosurgical treatment has allowed the development of minimally invasive percutaneous approaches. In this review, we describe the use of cryotherapy for treatment of primary or secondary liver neoplasms using a percutaneous approach.