Oncological Outcomes of Major Liver Resection Following Portal Vein Embolization: A Systematic Review and Meta-analysis

Background: Preoperative portal vein occlusion with either percutaneous portal vein embolization (PVE) or portal vein ligation is routinely used to induce liver hypertrophy prior to major liver resection in patients with hepatic malignancy. While this increases the future liver remnant, and hence the number of patients suitable for resection, recent evidence suggests that induction of liver hypertrophy preoperatively may promote tumor growth and increase recurrence rates. The aims of this current study were to evaluate the impact of PVE on hepatic recurrence rate and survival in patients with colorectal liver metastases (CRLM). Methods: The MEDLINE, EMBASE and Web of Science databases were searched to identify studies assessing the oncological outcomes of patients undergoing major liver resection for CRLM following PVE. Studies comparing patients undergoing one-stage liver resection with or without preoperative PVE were included. The primary outcome was postoperative hepatic recurrence (PHR), while secondary outcomes were 3- and 5-year overall survival (OS). Results: Of the 2131 studies identified, six non-randomized studies (n = 668) met the eligibility criteria, comparing outcomes of patients undergoing major liver resection with or without PVE (n = 182 and n = 486, respectively). No significant difference was observed in PHR (odds ratio [OR] 0.78; 95 % confidence interval [CI] 0.42–1.44), 3-year OS (OR 0.80; 95 % CI 0.56–1.14) or 5-year OS (OR 1.12; 95 % CI 0.40–3.11). Conclusions: PVE does not have any adverse effect on PHR or OS in patients undergoing major liver resection for CRLM. Further studies based on individual patient data are needed to provide definitive answers.