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Background: Radiofrequency ablation (RFA) and electrochemical treatment (ECT) are two methods of local liver tumour ablation. The objective of this study was to compare these methods when applied in proximity to vessels in vivo., Methods: In a total of ten laparotomised pigs, we used ECT (Group A, four animals) and RFA (Group B, four animals) to create four areas of ablation per animal under ultrasound guidance within 10 mm of a vessel. Group C consisted of two control animals. Chemical laboratory tests were performed immediately before and after each procedure and on days 1, 3 and 7 after surgery. Following the last tests, the livers were harvested for morphological evaluation., Results: The mean duration of surgery was 5 h 40 min in Group A (ECT), 2 h 47 min in Group B (RFA), and 2 h 30 min in Group C (control animals). After ECT, the harvested livers showed a mean volume of necrosis of 1.84 cm(3) ± 0.88 at the anode and 2.59 cm(3) ± 1.06 at the cathode. The presence of vessels did not influence the formation of necrotic zones. Ablation time was 67 min when a charge of 200 coulombs was delivered. We measured pH values of 1.2 (range: 0.9-1.7) at the anode and 11.7 (range: 11.0-12.1) at the cathode. In one of the 16 RFA ablations (6%), the target temperature was not reached and the procedure was discontinued. After 14 of 16 RFA procedures (88%), morphological analysis showed incomplete ablation in perivascular sites. Both ECT and RFA were associated with a reversible increase in monocyte, C-reactive protein (CRP) and aspartate aminotransferase (AST) levels. There was no significant increase in interleukin-1β (IL-1β), tumour necrosis factor-α (TNF-α) and IL-6., Conclusion: In the majority of cases, intrahepatic RFA in vivo leads to incomplete necrosis in proximity to vessels and the presence of histologically intact perivascular cells. Without a reduction in liver perfusion, the central application of RFA should be considered problematic. ECT is a safe alternative. It is not associated with a heat sink effect but has the disadvantage of long treatment times., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Background: Radiofrequency ablation (RFA) and electrochemical treatment (ECT) are two methods of local liver tumor ablation. A reproducible perfusion model allowed us to compare these methods when applied in proximity to vascular structures., Material and Methods: In a porcine liver perfusion model, we used RFA (group A) and ECT (group B) to perform ablations under ultrasound guidance within 10 mm of a vessel and examined the induced necrosis macroscopically and histologically., Results: We created 83 lesions (RFA: 59, ECT: 24) in 27 livers. In group A (mean liver weight: 2046 g), perfusion was macroscopically found to limit necrosis in 52.5% of the procedures. Histology demonstrated the destruction of only 30.4% of the vessel walls within the ablation areas. In group B (mean liver weight: 1885 g), we detected reproducible and sharply demarcated ablation areas both macroscopically and histologically. Necrosis was unaffected by nearby vessels. No viable cells were found perivascularly. Histology showed destruction of the vascular endothelium without any discontinuities. We measured pH values of 0.9 (range: 0.6-1.8) at the anode and 12.2 (range: 11.4-12.6) at the cathode. Treatment time was 100 min when a charge of 300 coulombs was delivered., Conclusions: Electrochemical treatment is a method of ablation that creates reproducible and predictable volumes of necrosis. It produces sharply demarcated areas of complete necrosis also in perivascular sites. ECT, however, requires much longer treatment times than RFA. In our model, the effects of RFA were considerably limited by perfusion, which caused incomplete areas of necrosis in proximity to vessels., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background/Aim: Ablative techniques such as radiofrequency ablation or non-thermal electrochemical treatment (ECT) are used to manage unresectable liver metastases. Although ECT is not affected by the cooling effect from adjacent vessels, there is a paucity of data available on ECT. Materials and Methods: We used porcine livers to establish an organ model with portal venous and hepatic arterial blood flow for a standardized analysis of the relationship between dose (electric charge) and response (volume of necrosis). Results: This model allowed us to study pressure-controlled perfusion of portal venous and hepatic arterial circulation in the absence of a capillary leak. A specially designed guiding template helped us place platinum electrodes at reproducible locations. With two electrodes, there was a linear relationship between charges of no more than 200 C and necrosis. The relationship was logarithmic at charges of 400-600 C. Larger electrode spacing led to a significant increase in necrosis. We measured pH values of 0.9 (range: 0.6-1.3) at the anode and 12.6 (range: 11.6-13.4) at the cathode. Conclusions: Using a perfusion model, we established an experimental design that allowed us to study ECT in the liver of large animals without experiments on living animals. An electrode template helped us improve the standardized analysis of dose-response relationships. ECT created reproducible and sharply demarcated areas of necrosis, the size of which depended on the charge delivered as well as on the number and spacing of electrodes. Doses higher than 600 C require longer treatment times but do not increase the area of necrosis (logarithmic dose-response relationship). [ABSTRACT FROM AUTHOR]