Changes in interleukin-1β and 6 after hepatic microwave tissue ablation compared with radiofrequency, cryotherapy and surgical resections.

BACKGROUND: Cytokine changes after microwave tissue ablation (MTA) were compared with hepatic resection, eryotherapy (CRYO), and radiofrequency ablation (RFA). Cytokine production was measured at various ablation volumes for each modality and correlated with the transitional inflammatory zone produced by the ablation techniques. METHODS: Live rats underwent MTA, surgical resection, CRY() or RFA of 15%, 33%, or 66% of the total hepatic volume. Serum samples were collected preoperatively and at 1, 3, 6, 24, and 48 hours after surgery and analyzed for pro-inflammatory cytokines interleukin (IL)-1 beta and IL-6. RESULTS: Significantly higher levels of both cytokines were present after CRY and RFA compared with MTA, hepatic resection, or controls (P < .001). All animals survived except those undergoing RFA or CRYO of 66% of the hepatic volume, which died within 6 hours. Transitional zones produced after RFA were larger than those after CRYO or MTA, but no correlation was present with the amount of cytokines. CONCLUSIONS: Large-volume MTA is associated with a significant decreased cytokine response and is well tolerated compared with RFA and CRYO. (C) 2010 Elsevier Inc. All rights reserved.