RESUMEN

PURPOSE: To evaluate the safety, efficacy and oncological outcomes of irreversible electroporation (IRE) of unresectable colorectal liver metastases (CRLM) close to critical structures. MATERIALS AND METHODS: This is a single center, IRB approved, retrospective analysis of patients who underwent percutaneous, 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 endpoints were tumor response and local progression-free survival (LPFS) analyzed using Kaplan-Meier survival curves. Secondary endpoints were overall survival (OS), and distant progression-free survival (DPFS) using Kaplan-Meier survival curves, adverse events rated according to Common Terminology Criteria for Adverse Events, and length of hospital stay. RESULTS: All tumors were close to critical structures, including portal and hepatic veins, inferior vena cava, bile ducts and the gallbladder. All patients received preprocedural systemic therapy (median ten cycles). Median length of hospital stay was one night. Adverse events occurred in seven out of 30 (23%) 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, 1- and 2-year LTPFS was 55.0% and 51.3%. Median DPFS was 3.5 months, with 1- and 2-year DPFS of 23.3% and 9.7%. Six patients died during follow-up (23.1%), with a median OS of 40.4 months. The 1- and 2-year OS were 90.9% and 83.9%. CONCLUSION: IRE is a safe and viable option in the treatment of unresectable CRLM in locations close to critical structures.