Lactate levels in open interstitial thermal ablation for liver tumors

Intraoperative radio frequency interstitial thermal ablation (RITA) may result in a reduction of the functional hepatic reserve. To assess this further, we evaluated perioperative lactate levels as a measure of hepatic dysfunction. Sixteen patients scheduled for open RITA (O-RITA) were enrolled in the study. Arterial lactate levels (mmol/L) were measured prior to tumor needle insertion (TO), after O-RITA completion (T-1), after wound closure (T 2) and 24 hrs after surgery (T-3). Correlation between hemodynamic parameters including MAP, and CVP, at T-0. T-1, T-2, T-3 and the perioperative rate of lactate production were also analyzed. Total bilirubin, transaminases and international normalized ratio for prothrombin activity (INR) were measured preoperatively and postoperative at day 1, 2, 3 and 7. Data are expressed as mean +/-SD and analyzed with ANOVA. Additionally, the Duncan post hoe test was used for multiple comparisons of the differences in mean values. A p-value <0.05 was considered significant. Lactate levels did not increase significantly at time points specified above (P = NS). Similarly, hemodynamic parameters analyzed did not show any significant change at the different time points (P = NS). Total bilirubin and INR did not demonstrate statistically significant changes at the aforementioned time points. Serum transaminases peaked during the immediate postoperative period and normalized to preoperative values by one-week post surgery. Those results demonstrate that O-RITA does not induce hyperlactatemia and does not reduce the functional residual liver parenchyma.