title: Clinical comparison of laparoscopic and open liver resection after propensity matching selection.
abstract: BACKGROUND
  This study aimed to compare the radicality for and clinical advantages of laparoscopic liver resection, which is increasingly used, and the corresponding open procedure by propensity score matching analysis.
  
  
  METHODS
  We analyzed 260 hepatocellular carcinoma patients who underwent initial liver resection at our department between January 2003 and June 2011, including 60 laparoscopic (the Lap group) and 200 open cases (the Open group). Propensity scores were calculated for each patient via the use of various clinicopathologic features as covariates, and patients' survival was compared.
  
  
  RESULTS
  The Lap group had more women and patients of advanced age (n = 60) than the Open group (n = 200). Tumor size (2.3 cm vs 3.5 cm median), multiple tumors (18.3% vs 41.0%), vascular invasion (15.0% vs 36.5%), poor differentiation status (11.2% vs 24.5%), intraoperative bleeding (110 mL vs 420 mL; median), and operative time (277 minutes vs 312 minutes; median) were significantly more favorable in the Lap group than in the Open group because of a selection bias of the patients (Lap vs Open). The postoperative recurrence-free and overall survival rates were greater in the Lap group than in the Open group; however, when 35 patients from each group were analyzed after propensity score matching of clinicopathologic characteristics of the patients, intraoperative bleeding was lesser in the Lap group. The recurrence-free survival rates at 1, 3, and 5 years were 75.0%, 43.8%, and 43.8%, respectively, in the Lap group and 73.6%, 49.3%, and 37.2%, respectively, in the Open group, which indicated no significant differences (P = .954). Similarly, the overall survival rates at 1, 3, and 5 years were 93.9%, 82.1%, and 82.1%, respectively, in the Lap group and 94.3%, 85.2%, and 61.8%, respectively, in the Open group, indicating no significant differences between the 2 groups (P = .672).
  
  
  CONCLUSIONS
  Our results indicate that laparoscopic liver resection is comparable with the corresponding open procedure in clinical safety and prognostic efficacy.
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan. Electronic address: meguro@sapmed.ac.jp.
authors.forename: Makoto
authors.initials: M
authors.lastname: Meguro
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Mizuguchi
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Kawamoto
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
authors.forename: Shigenori
authors.initials: S
authors.lastname: Ota
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ishii
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Nishidate
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Okita
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
authors.forename: Yasutoshi
authors.initials: Y
authors.lastname: Kimura
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Hokkaido, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Hirata
mesh_terms: D000368:Aged; D006528:Carcinoma, Hepatocellular / Q000401:mortality / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006498:Hepatectomy / Q000379:methods* / Q000401:mortality; D006801:Humans; D010535:Laparoscopy / Q000401:mortality; D008113:Liver Neoplasms / Q000401:mortality / Q000601:surgery*; D008297:Male; D016555:Matched-Pair Analysis; D008875:Middle Aged; D057216:Propensity Score; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome