Background: For unresectable liver tumors, cryosurgery has opened a new therapeutic approach.
Objective: To determine the applicability of cryogenic surgery in treating liver metastases (LM) with respect to intraoperative tumor reduction and survival rate.
Material and Method: 87 patients were treated by cryogenic surgery. The other 81 patients used conventional surgical techniques only and excluded all cryotechnology. Hepatic cryodestruction was performed by means of probes of roughly disk design 5-mm, 10-mm, 15-mm, 20-mm, 35-mm, 45-mm, and 55-mm. The probes were refrigerated by liquid nitrogen. The source of liquid nitrogen was driven by a cryosurgical system, Cryoelectronic-2 and Cryoelectronic-4. A temperature from - 180°C to -190°C was used. The thawing of freeze-thaw cycle took automatically approximately I to 3 minutes. Results: The tumor was reduced significantly (>90% <97%) in all patients with nonresectable LM treated by cryodestruction. The follow-up period in patients with LM ranged from 5 months to 12 years, and in control subjects, from 3.5 months to 10 years. The 3-year survival rate was higher after cryosurgery (63%) than in control group (46%).
The 5-year survival rate was 48% after cryosurgical procedure and 32% after conventional surgery. Fourteen patients and two patients survived 10 years after cryosurgical vs. conventional surgery. All patients of both groups received systemic chemotherapy.
Conclusion: Our results suggest that hepatic cryogenic techniques with liquid nitrogen can be used safely and essentially bloodlessly by patients with initially unresectable liver tumors. However, hepatic cryosurgery can be performed in combination with several neo-adjuvant conservative treatments (and its possible improvement in survival time clearly requires future investigations).