Irreversible Electroporation in Treating Colorectal Liver Metastases in Proximity to Critical Structures

To evaluate the safety, effectiveness, and oncological outcomes of irreversible electroporation (IRE) of unresectable colorectal liver metastases (CRLMs) close to critical structures.

This is a single-center, institutional review board (IRB)-approved, retrospective analysis of patients who underwent percutaneous computed tomography (CT)-guided IRE of CRLM. Between August 2018 and October 2023, 26 patients had 46 tumors treated with percutaneous IRE in 30 ablation sessions. Primary end points were tumor response and local progression-free survival analyzed using Kaplan-Meier survival curves. Secondary end points were overall survival (OS), distant progression-free survival (DPFS) analyzed using Kaplan-Meier survival curves, adverse events rated according to the Common Terminology Criteria for Adverse Events (CTCAE), and length of hospital stay.

All tumors were close to critical structures, including the portal and hepatic veins, inferior vena cava, bile ducts, and gallbladder. All patients received preprocedural systemic therapy (median 10 cycles). Median length of hospital stay was 1 night. Adverse events occurred in 7 (23%) of 30 procedures, with four Grade 1 and two Grade 2 adverse events, including pleural effusions (n = 2), ileus (n = 1), small hematoma (n = 1), and pneumothorax (n = 2) requiring chest tube placements. Following IRE, the 1- and 2-year local tumor progression-free survival rates were 55.0% and 51.3%. The median DPFS was 3.5 months, with 1- and 2-year DPFS rates of 23.3% and 9.7%. Six patients (23.1%) died during follow-up, with a median OS of 40.4 months. The 1- and 2-year OS rates were 90.9% and 83.9%.

IRE is a safe and viable option in the treatment of unresectable CRLMs in locations close to critical structures, but carries a risk of local recurrence.