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Updated: Jun 21, 2026

Evaluation of the Feasibility, Safety, and Accuracy of an Intraoperative High-intensity Focused Ultrasound Device for Treating Liver Metastases
Published on: January 9, 2019
Radiofrequency ablation of large size liver tumours using novel plan-parallel expandable bipolar electrodes: initial
Martijn R Meijerink1, Petrousjka van den Tol, Aukje A J M van Tilborg
1Department of Radiology, VU University Medical Centre, Amsterdam, The Netherlands. mr.meijerink@vumc.nl
Purpose:
Although radiofrequency ablation (RFA) is a promising method for local treatment of liver malignancies, with conventional monopolar systems recurrence rates for large size tumours (≥3.5 cm) remain high. The objective of this study was to evaluate the safety, feasibility and local effectiveness of a novel bipolar plan-parallel expandable system for these larger tumours.
Methods And Materials:
Eight consecutive patients with either unresectable colorectal liver metastases (CRLM in 6 patients), carcinoid liver metastases (1 patient) and hepatocellular carcinoma (HCC in 1 patient) of ≥3.5 cm were treated with bipolar RFA during laparotomy with ultrasound guidance. Early and late, major and minor complications were recorded. Local success was determined on 3-8 month follow-up CT scans of the upper abdomen.
Results:
Nine CRLM, one carcinoid liver metastases and one HCC (3.5-6.6 cm) were ablated with bipolar RFA. Average ablation time was 16 min (range 6-29 min.). Two patients developed a liver abscess which required re-laparotomy. In both cases bowel surgery during the same session probably caused bacterial spill. There were no mortalities. The patients were released from hospital between 5 and 29 days after the procedure (median 12 days). The 6-12 month follow-up PET-CT scans showed signs for marginal RFA-site tumour recurrence in three patients with CRLM (3/11 lesions).
Conclusion:
Preliminary results suggest bipolar RFA to be a reasonably safe, fast and feasible technique which seems to improve local control for large size hepatic tumour ablations.

