title: Safety and efficacy of bariatric surgery in patients with advanced fibrosis.
abstract: Bariatric surgery is performed safely in non-alcoholic fatty liver disease (NAFLD) patients with minimal fibrosis (stage 1-2). However, the safety and potential benefits of bariatric surgery for NAFLD with advanced fibrosis (stage 3-4) remain unclear. This study was designed to compare the safety and efficacy of bariatric surgery in patients with biopsy proven advanced fibrosis to those with minimal fibrosis.
  
  
  
  All patients who underwent bariatric surgery between 2005 and 2014 and had evidence of NAFLD with fibrosis score 3-4 (advanced fibrosis) based on the staging system defined by Kleiner et al. on intraoperative liver biopsy were included and compared with patients who had fibrosis score 1-2 (minimal fibrosis). The groups were compared for length of hospital stay after bariatric surgery and incidence of postoperative complications over a follow-up period of 1 year. An improvement in hepatic function tests before and 1 year after surgery was used as a parameter to evaluate for NAFLD improvement.
  
  
  
  Ninety-nine patients with F3-4 (group 1) and 198 patients with F1-2 (group 2) were included. Mean age (51.9 vs 50.1 years) and body mass index (46.4 vs 46.5 kg m-2) were similar in the two groups. Median serum aspartate aminotransferase (43  vs 30 U l-1; normal 10-40 U l-1) and alanine aminotransferase (40.5 vs 34 U l-1; normal 10-50 U l-1) were significantly higher in group 1 and improved 1 year after surgery. Median length of hospital stay after surgery was higher in group 1 than that in group 2 (4 days vs 3 days; P-value=0.002). The proportion of patients developing postoperative complications over 1 year was similar in both groups (36.4% vs 32.8%; P-value=0.54).
  
  
  
  Advanced fibrosis does not increase the risk of developing postoperative complications in medically optimized patients undergoing bariatric surgery. Improvement in serum transaminase levels suggests a reduction in hepatic necroinflammatory activity following bariatric surgery.
authors.affiliation: Department of Internal Medicine, Cleveland Clinic, Cleveland, OH, USA.|Department of Gastroenterology, Cleveland Clinic and the Cleveland Clinic Lerner College of Medicine at Case Western Reserve University Cleveland, Cleveland, OH, USA.
authors.forename: T
authors.initials: T
authors.lastname: Singh
authors.affiliation: Department of Gastroenterology, Cleveland Clinic and the Cleveland Clinic Lerner College of Medicine at Case Western Reserve University Cleveland, Cleveland, OH, USA.
authors.forename: G S
authors.initials: GS
authors.lastname: Kochhar
authors.affiliation: Department of Gastroenterology, Cleveland Clinic and the Cleveland Clinic Lerner College of Medicine at Case Western Reserve University Cleveland, Cleveland, OH, USA.
authors.forename: G B
authors.initials: GB
authors.lastname: Goh
authors.affiliation: Department of Bariatric Surgery, Bariatric and Metabolic Institute, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: P
authors.initials: P
authors.lastname: Schauer
authors.affiliation: Department of Bariatric Surgery, Bariatric and Metabolic Institute, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: S
authors.initials: S
authors.lastname: Brethauer
authors.affiliation: Department of Bariatric Surgery, Bariatric and Metabolic Institute, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: M
authors.initials: M
authors.lastname: Kroh
authors.affiliation: Department of Bariatric Surgery, Bariatric and Metabolic Institute, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: A
authors.initials: A
authors.lastname: Aminian
authors.affiliation: Department of Quantitative Health Sciences, Cleveland Clinic, Cleveland, OH, USA.
authors.forename: R
authors.initials: R
authors.lastname: Lopez
authors.affiliation: Department of Gastroenterology, Cleveland Clinic and the Cleveland Clinic Lerner College of Medicine at Case Western Reserve University Cleveland, Cleveland, OH, USA.|Department of Pathobiology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH, USA.
authors.forename: S
authors.identifier: 0000-0003-1774-0104
authors.initials: S
authors.lastname: Dasarathy
authors.affiliation: Department of Gastroenterology, Cleveland Clinic and the Cleveland Clinic Lerner College of Medicine at Case Western Reserve University Cleveland, Cleveland, OH, USA.|Department of Pathobiology, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Cleveland, OH, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: McCullough
mesh_terms: D000410:Alanine Transaminase / Q000097:blood; D050110:Bariatric Surgery / Q000009:adverse effects / Q000379:methods; D015415:Biomarkers / Q000097:blood; D001706:Biopsy; D019317:Evidence-Based Medicine; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000453:epidemiology / Q000209:etiology / Q000473:pathology*; D007902:Length of Stay / Q000706:statistics & numerical data*; D008099:Liver / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D065626:Non-alcoholic Fatty Liver Disease / Q000150:complications / Q000473:pathology*; D009767:Obesity, Morbid / Q000150:complications / Q000473:pathology / Q000601:surgery*; D018579:Patient Selection; D011183:Postoperative Complications / Q000453:epidemiology / Q000473:pathology*; D012307:Risk Factors; D012720:Severity of Illness Index; D014481:United States
chemical_list: D015415:Biomarkers; D000410:Alanine Transaminase