title: Preoperative portal vein embolization for major liver resection: a meta-analysis.
abstract: BACKGROUND
  Preoperative portal vein embolization (PVE) is used clinically to prevent postoperative liver insufficiency. The current study examined the impact of portal vein embolization on liver resection.
  
  
  METHODS
  A comprehensive Medline search to identify all registered literature in the English language on portal vein embolization. Meta-analysis was performed to assess the result of PVE and its impact on major liver resection.
  
  
  RESULTS
  A total of 75 publications met the search criteria but only 37 provided data sufficiently enough for analysis involving 1088 patients. The overall morbidity rate for PVE was 2.2% without mortality. Four weeks following PVE, 85% patients underwent the planned hepatectomy (n = 930). Twenty-three patients had transient liver failure following resection after PVE (2.5%) but 7 patients developed acute liver failure and died (0.8%). The reason for nonresection following PVE (n = 158, 15%) included inadequate hypertrophy of remnant liver (n = 18), severe progression of liver metastasis (n = 43), extrahepatic spread (n = 35), refusal to surgery (n = 1), poor general condition (n = 1), altered treatment to transcatheter artery embolization or chemotherapy (n = 24), complete remission after treatment with 3 cycles of fluoracil and interferon alpha in a patient with hepatocellular carcinoma (n = 1), incomplete pre- or postembolization scanning (n = 8). Of those who underwent laparotomy without resection, (n = 27) reasons included intraoperative finding of peritoneal dissemination (n = 15), portal node metastasis (n = 2), severe invasion of the tumor to the hepatic artery and portal vein (n = 1), and gross tumoral extension precluding curative resection (n = 9). Two techniques were used for portal vein embolization: percutaneous transhepatic portal embolization, (PTPE) and transileocolic portal embolization, (TIPE). The increase in remnant liver volume was much greater in PTPE than TIPE group (11.9% vs. 9.7%; P = 0.00001). However, the proportion of patients who underwent resection following PVE was 97% in TIPE and 88% PTPE, respectively (P = <0.00001). Although there was no significant difference in patients who had major complications post-PVE, the rate for minor complications was significantly higher among patients who had PTPE (53.6% vs. 0%, P = <0.0001).
  
  
  CONCLUSIONS
  PVE is a safe and effective procedure in inducing liver hypertrophy to prevent postresection liver failure due to insufficient liver remnant.
authors.affiliation: HPB Surgery, Division of Surgery, Oncology, Reproductive Biology and Anaesthetics, Imperial College of Science, Technology and Medicine, Hammersmith Hospital Campus, Du Cane Road, London, England.
authors.forename: Adel
authors.initials: A
authors.lastname: Abulkhir
authors.forename: Paolo
authors.initials: P
authors.lastname: Limongelli
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Healey
authors.forename: Osama
authors.initials: O
authors.lastname: Damrah
authors.forename: Paul
authors.initials: P
authors.lastname: Tait
authors.forename: James
authors.initials: J
authors.lastname: Jackson
authors.forename: Nagy
authors.initials: N
authors.lastname: Habib
authors.forename: Long R
authors.initials: LR
authors.lastname: Jiao
mesh_terms: D016009:Chi-Square Distribution; D004621:Embolization, Therapeutic / Q000009:adverse effects / Q000379:methods*; D006498:Hepatectomy / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D008113:Liver Neoplasms / Q000601:surgery / Q000628:therapy*; D011169:Portal Vein; D011300:Preoperative Care