title: National trends with a laparoscopic liver resection: results from a population-based analysis.
abstract: BACKGROUND
  Interest in laparoscopic liver resection (LLR) has grown since the International 'Louisville Statement' regarding laparoscopic liver surgery was published in 2009. However, limited population-based data on LLR utilization patterns and outcomes are available.
  
  
  METHODS
  LLR data from the Nationwide Inpatient Sample (NIS, 2000-2012) and the National Surgical Quality Improvement Project (NSQIP, 2005-2012) were compared before and after the Louisville Statement in 2009.
  
  
  RESULTS
  In total, 1131 and 642 LLR were identified from NIS and NSQIP, respectively. Three-quarters of patients underwent LLR for a malignant indication (NIS primary malignancy, 29.6% versus metastasis, 45.1%; NSQIP primary malignancy, 35.5% versus metastasis, 46.1%). The annual volume of LLR increased from 2000-2008 versus 2009-2012 (NIS: 63 versus 168, P < 0.001; NSQIP: 52 versus 127; both P = 0.001). The peri-operative mortality associated with LLR was 2.8% in NIS and 2.2% in NSQIP. The morbidity was 38.1% in NIS and 30.7% in NSQIP. Mortality and morbidity did not change over time (both P > 0.050). After 2009, LLR was associated with a shorter length of stay (LOS) (NIS: 5 versus 6 days, P = 0.007).
  
  
  CONCLUSIONS
  Since the Louisville Statement in 2009, utilization of LLR has increased. LLR is associated with a modest decrease in LOS and appears to be safe with mortality and morbidity similar to open surgery.
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Jin
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Neda
authors.initials: N
authors.lastname: Amini
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Gaya
authors.initials: G
authors.lastname: Spolverato
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirose
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Makary
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Wolfgang
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Weiss
authors.affiliation: Department of Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Pawlik
mesh_terms: D000368:Aged; D005260:Female; D005500:Follow-Up Studies; D006498:Hepatectomy / Q000379:methods / Q000706:statistics & numerical data*; D006801:Humans; D010535:Laparoscopy / Q000706:statistics & numerical data*; D008107:Liver Diseases / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009017:Morbidity / Q000639:trends; D011159:Population Surveillance; D011183:Postoperative Complications / Q000453:epidemiology*; D058996:Quality Improvement; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D014481:United States / Q000453:epidemiology