Irreversible electroporation of the liver: is there a safe limit to the ablation volume?

Abstract

Irreversible electroporation is a fast-growing liver ablation technique. Although safety has been well documented in small ablations, our aim is to assess its safety and feasibility when a large portion of liver is ablated. Eighty-seven mice were subjected to high voltage pulses directly delivered across parallel plate electrodes comprising around 40% of mouse liver. One group consisted in 55 athymic-nude, in which a tumor from the KM12C cell line was grown and the other thirty-two C57-Bl6 non-tumoral mice. Both groups were subsequently divided into subsets according to the delivered field strength (1000 V/cm, 2000 V/cm) and whether or not they received anti-hyperkalemia therapy. Early mortality (less than 24 hours post-IRE) in the 2000 V/cm group was observed and revealed considerably higher mean potassium levels. In contrast, the animals subjected to a 2000 V/cm field treated with the anti-hyperkalemia therapy had higher survival rates (OR = 0.1, 95%CI = 0.02–0.32, p < 0.001). Early mortality also depended on the electric field magnitude of the IRE protocol, as mice given 1000 V/cm survived longer than those given 2000 V/cm (OR = 4.7, 95%CI = 1.8–11.8, p = 0.001). Our findings suggest that ionic disturbances, mainly due to potassium alterations, should be warned and envisioned when large volume ablations are performed by IRE.

Percutaneous Irreversible Electroporation (IRE) of Hepatic Malignancy: A Bi-institutional Analysis of Safety and Outcomes

“…Cardiac arrhythmias rarely impair completion of an IRE procedure, as was the case in our three instances of atrial fibrillation which were all either self-limiting or medically managed [19]. Ablation of large tumour volumes (40% of liver) has been shown in an animal model to induce alterations in serum potassium levels due to ionic shifts with nanopore formation resulting in the potential for electrocardiogram arrhythmias, but this mechanism is not felt to be applicable in this study as lesional volume was considerably smaller [20].…”

Focused transhepatic electroporation mediated by hypersaline infusion through the portal vein in rat model. Preliminary results on differential conductivity

“… 28 , 29 , 30 For instance, our previous IRE protocol with plate electrodes lasted for 100 seconds (90-100 pulses at a frequency of 1 Hz). 16 , 31 Our protocol IRE lasted 100 seconds, without pauses. However, pauses can be reduced in case the TW values obtained in this preliminary study are set in this range of time, in future essays with bigger sample size.…”

“… 15 In this study we showed that even with high electrical fields (up to 2000 V/cm) complete eradication of the tumour was infrequent even when massive destruction of nearby healthy hepatic tissue was present (expressed by life-threating ionic imbalances). 16 …”

Allogenic Natural Killer Cell Immunotherapy Combined with Irreversible Electroporation for Stage IV Hepatocellular Carcinoma: Survival Outcome

“…IRE is practical and safe for ablation in hepatic adenocarcinoma [29]. In a prospective, nonrandomized study, Cheung et al [30].…”