title: Long-term and perioperative outcomes of laparoscopic versus open liver resection for colorectal liver metastases with propensity score matching: a multi-institutional Japanese study.
abstract: BACKGROUND
  The aim of the present study was to clarify the surgical outcome and long-term prognosis of laparoscopic liver resection (LLR) compared with conventional open liver resection (OLR) in patients with colorectal liver metastases (CRLM).
  
  
  METHODS
  A one-to-two propensity score matching (PSM) analysis was applied. Covariates (P < 0.2) used for PSM estimation included preoperative levels of CEA and CA19-9; primary tumor differentiation; primary pathological lymph node metastasis; number, size, location, and distribution of CRLM; existence of extrahepatic metastasis; extent of hepatic resection; total bilirubin and prothrombin activity levels; and preoperative chemotherapy. Perioperative data and long-term survival were compared.
  
  
  RESULTS
  From 2005 to 2010, 1,331 patients with hepatic resection for CRLM were enrolled. By PSM, 171 LLR and 342 OLR patients showed similar preoperative clinical characteristics. Median estimated blood loss (163 g vs 415 g, P < 0.001) and median postoperative hospital stay (12 days vs 14 days; P < 0.001) were significantly reduced in the LLR group. Morbidity and mortality were similar. Five-year rates of recurrence-free, overall, and disease-specific survival did not differ significantly. The R0 resection rate was similar.
  
  
  CONCLUSIONS
  In selected CRLM patients, LLR is strongly associated with lower blood loss and shorter hospital stay and has equivalent long-term survival comparable with OLR.
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Beppu
authors.affiliation: Department of Surgery, Iwate Medical University School of Medicine, Iwate, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Wakabayashi
authors.affiliation: Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hasegawa
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Gotohda
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Mizuguchi
authors.affiliation: Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Takahashi
authors.affiliation: Department of General and Gastroenterological Surgery, Osaka Medical College, Osaka, Japan.
authors.forename: Fumitoshi
authors.initials: F
authors.lastname: Hirokawa
authors.affiliation: Department of Gastrointestinal Hepato-Biliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Taniai
authors.affiliation: Department of Surgery, Toho University Ohashi Medical Center, Tokyo, Japan.
authors.forename: Manabu
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Katou
authors.affiliation: Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Nagano
authors.affiliation: Department of Surgery, Tokyo Metropolitan Cancer and Infectious Disease Center Komagome Hospital, Tokyo, Japan.
authors.forename: Goro
authors.initials: G
authors.lastname: Honda
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Baba
authors.affiliation: Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, Tokyo, Japan.
authors.forename: Norihiro
authors.initials: N
authors.lastname: Kokudo
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, National Cancer Center Hospital East, Kashiwa, Chiba, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Konishi
authors.affiliation: Department of Surgery, Surgical Oncology and Science, Sapporo Medical University School of Medicine, Sapporo, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Hirata
authors.affiliation: Department of Surgery, Institute of Gastroenterology, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yamamoto
authors.affiliation: Department of General and Gastroenterological Surgery, Osaka Medical College, Osaka, Japan.
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Uchiyama
authors.affiliation: Department of Gastrointestinal Hepato-Biliary-Pancreatic Surgery, Nippon Medical School, Tokyo, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Uchida
authors.affiliation: Department of Surgery, Toho University Ohashi Medical Center, Tokyo, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Kusachi
authors.affiliation: Department of Gastroenterological Surgery, Dokkyo Medical University, Tochigi, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Kubota
authors.affiliation: Department of Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Mori
authors.affiliation: Department of Surgery, Tokyo Metropolitan Cancer and Infectious Disease Center Komagome Hospital, Tokyo, Japan.
authors.forename: Keiichi
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: Medical Quality Management Center, Kumamoto University Hospital, Kumamoto, Japan.
authors.forename: Ken
authors.initials: K
authors.lastname: Kikuchi
authors.affiliation: Department of Healthcare Quality Assessment, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Miyata
authors.affiliation: Department of Surgery, Iwate Medical University School of Medicine, Iwate, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Takahara
authors.affiliation: Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Nakamura
authors.affiliation: Deparment of Surgery, Toho University Faculty of Medicine, Tokyo, Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Kaneko
authors.affiliation: Second Department of Surgery, Wakayama Medical University, School of Medicine, Wakayama, Japan.
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yamaue
authors.affiliation: Department of General Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Miyazaki
authors.affiliation: Japanese Society of Hepato-biliary-Pancreatic Surgery, Department of Surgery, Teikyo University School of Medicine, Tokyo, Japan.
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Takada
mesh_terms: D000368:Aged; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D018572:Disease-Free Survival; D005260:Female; D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D007564:Japan; D010535:Laparoscopy / Q000379:methods* / Q000401:mortality; D007813:Laparotomy / Q000379:methods* / Q000401:mortality; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology; D009367:Neoplasm Staging; D059035:Perioperative Period; D011379:Prognosis; D057216:Propensity Score; D012189:Retrospective Studies; D018570:Risk Assessment; D018709:Statistics, Nonparametric; D016019:Survival Analysis; D016896:Treatment Outcome
keywords: Colorectal liver metastases; Laparoscopic liver resection; Open liver resection; Propensity score matched analysis