Cryosurgical ablation and radiofrequency ablation for unresectable hepaticmalignant neoplasms - A proposed algorithm

Background: Thermal ablation of unresectable hepatic tumors can be achieved by cryosurgical ablation (CSA) or radiofrequency ablation (RFA). The relat ive advantages and disadvantages of each technique have not yet been determ ined. Hypothesis: Radiofrequency ablation of malignant hepatic neoplasms can be p erformed safely, but is currently limited by size. Cryosurgical ablation, w hile associated with higher morbidity, is more effective for larger unresec table hepatic malignant neoplasms. Design: Retrospective analysis of prospective patient database. Patients rind Methods: Between July 1992 and September 1999, 308 patients w ith liver tumors not amenable to curative surgical resection were treated w ith CSA and/or RFA (percutaneous, laparoscopic, celiotomy). No patient had preoperative evidence of extrahepatic disease. All patients underwent lapar oscopy with intraoperative ultrasound if technically possible. Both RFA and CSA were performed under ultrasound guidance. Resection, as an adjunctive procedure, was combined with ablation in certain patients. Results: Laparoscopy identified extrahepatic disease in 12% of patients, an d intraoperative hepatic ultrasound identified additional lesions in 33% of patients, despite extensive preoperative imaging. Radiofrequency ablation alone or combined with resection or CSA resulted in reduced blood loss (P<. 05), thrombocytopenia (P<.05), and shorter hospital stay compared with CSA alone (P<.05). Median ablation times for lesions greater than 3 cm were 60 minutes with RFA and 15 minutes with CSA (P<.001). Local recurrence rates f or lesions greater than 3 cm were also greater with RFA (38% vs 17%). Conclusions: Laparoscopy and intraoperative ultrasound are essential in sta ging patients with hepatic malignant neoplasms. Radiofrequency ablation whe n combined with CSA reduces the morbidity of multiple freezes. Although RFA is safer than CSA and can be performed via different approaches (percutane ously, laparoscopically, or at celiotomy), it is limited by tumor size (<3 cm). Percutaneous RFA should be considered in highrisk patients or those wi th small local recurrences.