title: Elevation of liver function tests after laparoscopic gastrectomy using a Nathanson liver retractor.
abstract: BACKGROUND
  Although pneumoperitoneum has been suspected as a possible cause of transient elevation of liver function tests (LFTs) after laparoscopic surgery, liver damage by direct retraction could also influence postoperative LFTs. The aim of this study was to clarify whether laparoscopic gastrectomy (LG) using a Nathanson retractor was associated with the postoperative elevation of LFTs compared with open gastrectomy (OG).
  
  
  METHODS
  A retrospective cohort study of 199 LG and 120 OG patients was conducted. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin were measured before operation and at postoperative days 1, 3, and 7. Abnormal elevation of LFTs was defined as a grade 2 or greater elevation in any parameter. To assess the possible effect of pneumoperitoneum, patients who underwent laparoscopic (n = 324) and open (n = 56) colectomy for colorectal cancer were also compared.
  
  
  RESULTS
  In both LG and OG groups, LFTs were significantly elevated postoperatively compared with baseline values. Mean ALT and total bilirubin levels on days 1, 3, and 7 were significantly higher in the LG than OG group. Abnormal elevation of LFTs was more frequent in the LG than OG group (50 vs. 12%). In multivariate analysis, LG was significantly associated with postoperative liver dysfunction (odds ratio [OR] = 7.99; 95% confidence interval [95% CI] = 3.69-18.85). No significant difference in the elevation of the LFTs was observed between laparoscopic and open colectomy (6% and 9%, respectively).
  
  
  CONCLUSIONS
  LG resulted in frequent elevation of LFTs. Care should be taken to minimize intraoperative liver damage when performing LG using a Nathanson retractor.
authors.affiliation: Department of Surgery, Graduate School of Medicine, Kyoto University, 54 Kawahara-cho, Shogoin, Sakyo-ku, Kyoto, 606-8507, Japan.
authors.forename: Yousuke
authors.initials: Y
authors.lastname: Kinjo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Okabe
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Obama
authors.forename: Shigeru
authors.initials: S
authors.lastname: Tsunoda
authors.forename: Eiji
authors.initials: E
authors.lastname: Tanaka
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Sakai
mesh_terms: D000368:Aged; D015331:Cohort Studies; D005260:Female; D005743:Gastrectomy / Q000009:adverse effects* / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D010535:Laparoscopy; D008107:Liver Diseases / Q000175:diagnosis / Q000453:epidemiology* / Q000209:etiology*; D008111:Liver Function Tests / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000601:surgery