title: National trends in the use of surgery for benign hepatic tumors in the United States.
abstract: BACKGROUND
  The widespread use of diagnostic imaging has led to an increase in the incidence and diagnosis of benign liver tumors. The objective of this study was to define the overall use and temporal trends of operative procedures for benign liver tumors using a nationally representative cohort.
  
  
  METHODS
  All patients who underwent liver surgery for benign liver tumors between 2000 and 2011 were identified from the Nationwide Inpatient Sample database. Trends in annual volume of liver procedures were analyzed using the average annual percent change (AAPC) assessed by joinpoint analysis.
  
  
  RESULTS
  There were 2,489 open (94.5%) and 144 (5.5%) minimally invasive surgical (MIS) procedures. Partial hepatectomy accounted for 43.8% of all cases (n = 1,153). Surgery for patients with benign liver tumors increased from 156 in 2000 to 272 in 2011 (AAPC, 5.8%; 95% CI, 3.2-8.6%). There was decline in the relative use of open operative procedures from 98.1% in 2000 to 92.3% in 2011 (AAPC, -0.4%; 95% CI, -0.7 to -0.1%). In contrast, the proportion of MIS procedures increased from 1.9% in 2000 to 7.7% in 2011 (AAPC, 7.4%; 95% CI, 1.9-13.3%). The median duration of stay among all patients was 5 days (interquartile range, 4-7; 5 days [open] vs 3 days [MIS]; P < .001). Inpatient mortality was 0.6% (n = 15 [open] vs n = 0 [MIS]; P = .43) and did not change during the study period (P > .05).
  
  
  CONCLUSIONS
  Overall volume of surgical management of benign liver tumors has increased substantially over the past decade. There has been a relative shift away from open procedures toward MIS procedures.
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: Neda
authors.initials: N
authors.lastname: Amini
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Jin
authors.initials: J
authors.lastname: He
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: Matthew
authors.initials: M
authors.lastname: Weiss
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Wolfgang
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Martin
authors.initials: M
authors.lastname: Makary
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirose
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD.
authors.forename: Gaya
authors.initials: G
authors.lastname: Spolverato
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: D000328:Adult; D001707:Biopsy, Needle; D016001:Confidence Intervals; D016208:Databases, Factual; D005260:Female; D005544:Forecasting; D006498:Hepatectomy / Q000706:statistics & numerical data / Q000639:trends*; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D010535:Laparoscopy / Q000706:statistics & numerical data / Q000639:trends*; D007813:Laparotomy / Q000706:statistics & numerical data / Q000639:trends*; D007902:Length of Stay / Q000639:trends; D008113:Liver Neoplasms / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D019060:Minimally Invasive Surgical Procedures / Q000379:methods / Q000639:trends; D012189:Retrospective Studies; D018570:Risk Assessment; D016896:Treatment Outcome; D014481:United States