Controversies in the Use of Portal Vein Embolization

BACKGROUND/AIMS: Portal vein embolization (PVE) has reached worldwide acceptance to increase future remnant liver (FRL) volume before undertaking major liver resection. The aim of this overview is to point out and discuss current controversies in the application of PVE. METHODS: Review of literature pertaining to techniques of PVE, complications, tumor proliferation, timing of resection, and hypertrophy response after PVE. RESULTS: Procedure-related complications after PVE include hematoma, hemobilia, overflow of embolization material, and thrombosis of portal vein branch(es) of the non-embolized lobe. Persistence of the embolized, atrophic lobe is usually not harmful. Embolization of the portal branches to segment 4 in addition to embolization of the right portal trunk is controversial and is advised only in selected cases. It remains undecided whether embolization of the portal venous system is more effective in inducing hypertrophy of the FRL than ligation of the portal vein. Accelerated tumor growth after PVE is a major concern and requires consideration of post-PVE chemotherapy. A waiting time of 3 weeks between PVE and liver resection is advised. Post-hepatectomy regeneration is not hampered after preoperative PVE. CONCLUSION: PVE is a useful preoperative intervention to increase volume and function of the FRL. Further progress awaits clarification of the mechanisms of the hypertrophy response induced by PVE in conjunction with new embolization materials and protective chemotherapy.