Cryosurgical ablation of hepatic neoplasms

Cryosurgical ablation involves the in situ freezing and resultant devitalization of neoplastic lesions. It offers a number of potential advantages over surgical resection that make it particularly appealing for the treatment of hepatic neoplasms. Recent improvements in imaging modalities used to monitor cryosurgery, particularly ultrasonography, have made it a reasonable procedure in select patients. Colorectal carcinoma accounts for the second highest cancer-related mortality in the United States with nearly 70,000 annual deaths from this disease. Approximately 150,000 new cases are diagnosed each year. The liver represents the sole site of metastatic spread in approximately 20% of cases, reflective of the preferential spread of colorectal cancer to the liver via the portal venous system. Unfortunately, fewer than 25% of these patients (i.e., 4000 to 5000 patients) are candidates for surgical resection secondary to bilobar involvement, proximity to major vessels, poor liver reserve, or co-morbid disease states. Currently, systemic chemotherapy offers no significant impact on survival in patients with colorectal liver metastases with response rates in the range of 20% to 30%.