Martina Distelmaier, Presenter: Nothing to Disclose

Alexandra Barabasch MD, Abstract Co-Author: Nothing to Disclose

Nils Andreas Kraemer, Abstract Co-Author: Nothing to Disclose

Christiane Katharina Kuhl MD, Abstract Co-Author: Nothing to Disclose

Philipp Bruners MD, Abstract Co-Author: Nothing to Disclose

IRE has been proposed as a non-thermal ablation procedure that offers specific advantages over thermal methods, notably absence of heat sink effect, and to help avoid thermal damage to vessels or bile ducts. Our aim was to verify this concept by investigating the local efficacy and complications of CT-guided percutaneous IRE for hepatic malignancies located immediately adjacent to major portal and hepatic veins and bile ducts.

24 metastes in 19 patients (mean age 62 ± 12 y) suffering from liver tumors (9 colorectal, 4 breast, 1 hepatocellular, 1 renal cell, 1 GIST, 1 mesothelioma, 1 oesophageal) with a mean size 17 ± 10.5 mm, range 7 – 44 mm, underwent percutaneous hepatic IRE. All lesions were located immediately adjacent to major hepatic veins (n = 12), portal vein branches (n = 6) or both (n = 6) and therefore not suitable for RF ablation. Between 3 and 5 IRE probes with an active tip length of 1.5 - 2.5 cm were placed strictly parallel under CT-guidance. IRE was performed with 70 pulses per probe pair, a pulse length of 75 µs and a maximum voltage of 3000 V. All patients undergo systematic follow-up CT and MR imaging; follow-up so far is up to 24 months.

Complete ablation of the target lesion was achieved in 22/24 (92%) cases with a safety margin of 5-10 mm as confirmed by CT and MRI. In 24/24 cases, the adjacent major portal or hepatic vein branches remained perfused at long term follow up. No major procedure-related complications were observed. In 4/22 cases (18%), local recurrence adjacent to the ablation zone was observed between 1 and 12 months after treatment. In one patient, a small, clinically asymptomatic arterio-portal fistula developed on f/u that did not require treatment. One patient, with a metastasis located on the portal bifurcation developed mild left-sided cholestasis, not requiring treatment.

In this small series, IRE for primary and secondary hepatic malignancies located adjacent to large portal or hepatic veins proved to be both, safe as well as efficient with regards to local control.

CT-guided IRE appears to be a useful for percutaneous ablation of primary and secondary liver tumors that are not amenable to RFA.

Distelmaier, M, Barabasch, A, Kraemer, N, Kuhl, C, Bruners, P, Irreversible Electroporation (IRE) of Malignant Liver Tumors Close to Major Portal or Hepatic Veins: Is It Safe and Effective?.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14017259.html