Hepatic cryosurgery.

Cryoablation of liver metastases from colorectal and neuroendocrine tumors was accomplished in 20 patients using liquid nitrogen delivered through insulated probes. Intra-operative ultrasound was used to detect liver metastases and to monitor freezing and thawing. Tumor response was evaluated by histologic examination, CT, and serum tumor markers. This study established the safety and technical feasibility of hepatic cryosurgery and provided guidelines for treating liver tumors of diverse origins.