Safety and feasibility of electrochemotherapy in patients with unresectable colorectal liver metastases: A pilot study.

•Electrochemotherapy is a novel ablation technique combining chemotherapeutic agents with reversible cell membrane electroporation.•Its application for deep-seated malignancies is under investigation.•We present the results of a prospective, pilot study to evaluate the feasibility, safety, and efficacy of intraoperative electrochemotherapy combined with open liver surgery for otherwise unresectable colorectal liver metastases.•A total of 9 colorectal liver metastases were treated in 5 patients with 20 electrode applications. No intraoperative complications were observed. At day 30, complete response was 55.5% and stable disease 45.5%. The 6-month overall and progression-free survival was 100% and 80%, respectively.•Larger studies and longer follow-ups are favored to better define its role in the treatment of secondary liver malignancies.