A pproximately 20 percent of the nearly 160,000 Americans diagnosed with colorectal cancer each year will have liver metastases at presentation. An additional 20 percent to 30 percent will develop liver metastases subsequent to treatment of their primary cancer. The inability to achieve a complete response with regional chemotherapy alone, even with prolonged treatment, is part of the problem.
Regional chemotherapy is limited by liver toxicity and biliary sclerosis during long-term use.
Cryoprobe tip is placed into tumor using ultrasound guidance Cryosurgery has been available for many years but only recently has been applied to the ablation of liver tumors in situ. This is primarily due to improvements in cryotechnology as well as the availability of high-resolution intraoperative ultrasound. The technique involves operative placement of a metal probe into the center of a tumor. Liquid nitrogen or argon gas flows through this freezing probe and initiates the creation of an ice ball starting in the tumor's center and gradually expanding outward. The formation of the spherical ice ball is monitored by intraoperative ultrasonography and is complete when the ice ball is 1 centimeter beyond the tumor.