Cardiac synchronization and arrhythmia during irreversible electroporation.

BACKGROUND AND OBJECTIVES: Irreversible electroporation (IRE) is a nonthermal electrical tumor ablative strategy for unresectable tumors. IRE is relatively safe around critical structures but may induce cardiac arrhythmia when its delivery is not synchronized to the cardiac cycle. We performed a systematic literature review to determine rates of arrhythmia when IRE was utilized with or without cardiac synchronization. METHODS: An online literature search was conducted with additional hand selection of articles. Data were extracted and pooled analyses were performed. RESULTS: Twelve articles were included in analysis. IRE was performed for 481 patients; 46% hepatic tumors (n = 223), 36% pancreatic lesions (n = 168), and multiple other locations including prostate. Synchronization was performed on 422 patients. Arrhythmias were noted in 3.7% of cases (n = 18/481); cardiac synchronization: 1.2% (n = 5/422) vs unsynchronized: 22.0% (n = 13/59), P < .0001. These events occurred in every organ except the prostate. CONCLUSIONS: IRE remains a potent technology for unresectable tumors, but arrhythmia is a clinical concern. This literature review confirms that cardiac gating should be used in all cases outside of prostate to prevent this potentially serious adverse event.

Health-related quality of life in dogs treated with electrochemotherapy and/or interleukin-12 gene electrotransfer.

The aim of this study was to evaluate the owners' perception of health-related quality of life (HRQoL) of dogs after treatment with electrochemotherapy (ECT) alone or combined with interleukin-12 gene electrotransfer (IL-12 GET) and/or surgery. The owners of 44 dogs with histologically different tumours were offered the ¼Cancer Treatment Form« at least one month after treatment. The owners assessed their dogs' quality of life (QoL) after treatment as good (mean 7.4) (from 1-very poor to 10-excellent) and the general health compared with the initial diagnosis of cancer as improving (mean 3.9) (from 1-worse to 5-better). The assessment of the current QoL was better within the group of dogs treated with non-invasive treatment (ECT and/or IL-12 GET only), compared with those that received invasive treatment, where, in addition to ECT and/or IL-12 GET, surgery was performed (p < .05). The owners of dogs that achieved an objective response (OR) to the treatment assessed the QoL as significantly better compared with those whose dogs did not respond to the treatment (p < .05). The majority of the owners (86.4%) would opt for the therapy again, regardless of the financial costs. In conclusion, the results of this study demonstrate that the majority of the owners of dogs assessed their dogs' QoL as good and felt that it improved after the treatment, especially in dogs, treated with non-invasive treatment and in those that responded to the treatment. This supports further use of ECT and IL-12 GET as suitable methods for the treatment of selected tumours in veterinary medicine.

Similar complication rates for irreversible electroporation and thermal ablation in patients with hepatocellular tumors.

Background To compare the frequency of adverse events of thermal microwave (MWA) and radiofrequency ablation (RFA) with non-thermal irreversible electroporation (IRE) in percutaneous ablation of hepatocellular carcinoma (HCC). Patients and methods We retrospectively analyzed 117 MWA/RFA and 47 IRE procedures (one tumor treated per procedure; 144 men and 20 women; median age, 66 years) regarding adverse events, duration of hospital and intensive care unit (ICU) stays and occurrence of a post-ablation syndrome. Complications were classified according to the Clavien & Dindo classification system. Results 70.1% of the RFA/MWA and 63.8% of the IRE procedures were performed without complications. Grade I and II complications (any deviation from the normal postinterventional course, e.g., analgesics) occurred in 26.5% (31/117) of MWA/RFA and 34.0% (16/47) of IRE procedures. Grade III and IV (major) complications occurred in 2.6% (3/117) of MWA/RFA and 2.1% (1/47) of IRE procedures. There was no significant difference in the frequency of complications (p = 0.864), duration of hospital and ICU stay and the occurrence of a post-ablation syndrome between the two groups. Conclusions Our results suggest that thermal (MWA and RFA) and non-thermal IRE ablation of malignant liver tumors have comparable complication rates despite the higher number of punctures and the lack of track cauterization in IRE.

Effect of Differing Parameters on Irreversible Electroporation in a Porcine Model.

INTRODUCTION AND OBJECTIVE: Irreversible electroporation (IRE) is a new ablative technology to treat small renal masses. We evaluated differed ablation settings on lesion size and temperature changes in a porcine model. MATERIALS AND METHODS: After Institutional Animal Care and Use Committee approval, 36 laparoscopy-guided and 16 open ablations were performed on 13 domestic female pigs. Ablation parameters studied were voltage (1000 V/cm, 1500 V/cm, or 2000 V/cm), probe exposure (1.0 or 1.5 cm), and lesion size over time (survival) (0-, 7-, or 14 day). Temperature changes were monitored during open ablations with differed settings. Gross lesion size was measured, and histologic analysis with hematoxylin and eosin and nicotinamide adenine dinucleotide staining was performed. RESULTS: The 1000 V/cm ablations had no gross or histologic lesions. A factorial analysis of variance demonstrated that day (p = 0.56), exposure (p = 0.33), and voltage (p = 0.06) did not demonstrate statistical significance for affecting lesion size. For 1.0 cm probe exposure, 2000 V/cm did more closely approximate expected lesion size (p = 0.02) compared with 1500 V/cm. While significance was not seen for 1.5 cm probe exposure, 2000 V/cm often exceeded expected lesion volume. Only 1 of 4 temperature sensors, located adjacent to one of the IRE probes, noted a significant increase with increased voltage. However, all maximum temperatures remained less than 70°C. CONCLUSIONS: Variation in lesion volume was seen with different ablation settings in this porcine model. Maximal energy and probe exposure settings should be utilized to ensure full coverage of target volume/mass, potentially without concern for thermal injury to renal collecting system or nearby structures.