Cryoablation induces greater inflammatory and coagulative responses than radiofrequency ablation or laser induced thermotherapy in a rat liver model

Background. Cryoablation (CA), radiofrequency ablation (RFA), and laser induced thermotherapy (LITT) are alternative therapies for patients with unresectable liver tumors. We investigated whether there are different inflammatory and coagulative responses between these techniques. Methods. Livers of 48 rats were subjected to either CA, RFA, LITT, or sham operation (n = 12 in each group). Blood was withdrawn before, and 1, 3, 6, and 24 h after ablation. Liver enzymes as well as inflammatory and coagulation parameters were determined. Whole liver sections from the coagulated liver lobe were stained for quantification of necrosis and morphologic examination. Results. Histologic examination showed similar volume of complete destruction of liver parenchyma after CA, RFA, or LITT. Transaminase levels as well as the inflammatory response upon CA, as reflected by white blood cell count and cytokine levels, were significantly higher than following RFA or LITT. The systemic intravascular procoagulative state in rats that underwent CA, as reflected by platelets, and levels of sensitive markers for activation of coagulation and fibrinolyis, was also significantly higher. Conclusion. CA of liver in rats induces greater inflammatory and coagulative responses than RFA or LITT. The combined activation of inflammation and coagulation may importantly contribute to the higher morbidity after CA. (Surgery 2009;j:j-j.)