Does portal vein embolization prior to liver resection influence the oncological outcomes – A propensity score matched comparison

Introduction There is an ongoing controversy surrounding portal vein embolization (PVE) regarding the short-term safety of PVE and long-term oncological benefit. This study aims to compare survival outcomes of patients subjected to major liver resection for colorectal liver metastases (CRLM) with or without PVE. Methods All consecutive patients who underwent major liver resection for CRLM in four high volume liver centres between January 2000 and December 2015 were included. Major liver resection was defined as resection of at least three Couinaud liver segments. To reduce selection bias, propensity score matching was performed for PVE and non-PVE patients with overall and disease-free survival as primary endpoints. For matching, all patients who underwent PVE followed by a major liver resection were selected. Patients were matched to patients who had undergone major liver resection without PVE. Results Of 745 patients undergoing major liver resection for CRLM, 53 patients (7%) underwent PVE before liver resection. In the overall cohorts, PVE patients had inferior DFS and a trend towards inferior OS. A total of 46 PVE patients were matched to 46 non-PVE patients to create comparable cohorts and between these two matched cohorts no differences in DFS (3-year DFS 16% vs 9%, p = 0.776) or OS (5-year OS 14% vs 14%, p = 0.866) were found. Conclusions This retrospective, matched analysis does not suggest a negative impact of PVE on long-term outcomes after liver resection in patients with CRLM.