title: Systematic review and meta-analysis of feasibility, safety, and efficacy of a novel procedure: associating liver partition and portal vein ligation for staged hepatectomy.
abstract: BACKGROUND
  Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a novel strategy to resect liver tumors despite the small size of the liver remnant. It is an hepatectomy in two stages, with PVL and parenchymal transection during the first stage, which induces rapid growth of the remnant liver exceeding any other technique. Despite high postoperative morbidity and mortality in most reports, the technique was adopted by a number of surgeons.
  
  
  METHODS
  This systematic review explores current data regarding the feasibility, safety, and oncologic efficacy of ALPPS; the search strategy has been published online. A meta-analysis of hypertrophy, feasibility (ALPPS stage 2 performed), mortality, complications, and R0 (complete) resection was performed.
  
  
  RESULTS
  A literature search revealed a total of 13 publications that met the search criteria, reporting data from 295 patients. Evidence levels were low, with the highest Oxford evidence level being 2c. The most common indication was colorectal liver metastasis in 203 patients. Hypertrophy in the meta-analysis was 84 %, feasibility (ALPPS stage 2 performed) 97 % (CI 94-99 %), 90-day mortality 11 % (CI 8-16 %), and complications grade IIIa or higher occured in 44 % (CI 38-50 %) of patients. A standardized reporting format for complications is lacking despite the widespread use of the Clavien-Dindo classification. Oncological outcome is not well-documented. The most common topics in the selected studies published were technical feasibility and indications for the procedures. Publication bias due to case-series and single-center reports is common.
  
  
  CONCLUSIONS
  A systematic exploration of this novel operation with a rigid methodology, such as registry analyses and a randomized controlled trial, is highly advised.
authors.affiliation: Department of Surgery, Swiss HPB and Transplant Center, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Erik
authors.initials: E
authors.lastname: Schadde
authors.forename: Andreas A
authors.initials: AA
authors.lastname: Schnitzbauer
authors.forename: Christoph
authors.initials: C
authors.lastname: Tschuor
authors.forename: Dimitri A
authors.initials: DA
authors.lastname: Raptis
authors.forename: Wolf O
authors.initials: WO
authors.lastname: Bechstein
authors.forename: Pierre-Alain
authors.initials: PA
authors.lastname: Clavien
mesh_terms: D004621:Embolization, Therapeutic / Q000379:methods*; D005240:Feasibility Studies; D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D008099:Liver / Q000098:blood supply / Q000601:surgery*; D011169:Portal Vein / Q000601:surgery*; D011379:Prognosis; D012449:Safety