title: Liver regeneration after major liver hepatectomy: Impact of body mass index.
abstract: Obese patients may present with metabolic abnormalities that impact liver regeneration. We sought to assess the impact of body mass index (BMI) on liver volume regeneration index (RI) and kinetic growth rate (KGR) among patients undergoing liver resection.
  
  
  
  The study included 102 patients undergoing major hepatectomy (≥3 segments) between July 2004 and April 2015 and stratified the patients by preoperative BMI, number of segments resected, and postoperative remnant liver volume (RLVp) to total liver volume ratio. Resected volume at operation was subtracted from total liver volume to calculate postoperative RLVp. RI was defined as the relative increase in RLV within 2 months [(RLV2m-RLVp)/RLVp] and 7 months [(RLV7m-RLVp)/RLVp] postoperatively; KGR was calculated as RI divided by time postoperatively (weeks).
  
  
  
  Median patient age was 59.6 years (interquartile range 48.1-68.7 years), and most patients were men (52.0%). Liver failure was associated with the KGR at 2 months (KGR2m) and was greater among patients with KGR2m <2.5% per week (KGR <2.5%, 18.5% vs KGR ≥ 2.5%, 4.6%; P = .04). Although RI and KGR within 2 and 7 months postoperatively were similar among all patients, after excluding patients with fibrosis, obese (0.42% per week) and overweight patients (0.29% per week) had lesser KGR2-7m compared with patients of normal BMI (0.82% per week; P < .05). Additionally, risk of a major complication was greatest among obese patients (normal weight, 8.1% vs overweight, 12.9% vs obese, 29.4%; P = .04).
  
  
  
  BMI did not impact liver regeneration during the first 2 months. In contrast, KGR per week between 2 and 7 months postoperatively was less among overweight and obese patients.
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Neda
authors.initials: N
authors.lastname: Amini
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Georgios A
authors.initials: GA
authors.lastname: Margonis
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Stefan
authors.initials: S
authors.lastname: Buttner
authors.affiliation: Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Sepideh
authors.initials: S
authors.lastname: Besharati
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Yuhree
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Faiz
authors.initials: F
authors.lastname: Gani
authors.affiliation: Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Sobhani
authors.affiliation: Department of Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Ihab R
authors.initials: IR
authors.lastname: Kamel
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD. Electronic address: tpawlik1@jhmi.edu.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Pawlik
mesh_terms: D000368:Aged; D015992:Body Mass Index; D015331:Cohort Studies; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000150:complications* / Q000473:pathology / Q000601:surgery*; D008115:Liver Regeneration; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000473:pathology; D009929:Organ Size; D013997:Time Factors; D016896:Treatment Outcome