title: Refining the definition of perioperative mortality following hepatectomy using death within 90 days as the standard criterion.
abstract: OBJECTIVE
  Defining perioperative mortality as death that occurs within 30 days of surgery may underestimate 'true' mortality among patients undergoing hepatic resection. To better define perioperative mortality, trends in the risk for death during the first 90 days after hepatectomy were assessed.
  
  
  METHODS
  Surveillance, Epidemiology and End Results (SEER) Medicare data were used to identify 2597 patients who underwent hepatic resection during 1991-2006. Data on their clinicopathological characteristics, surgical management and perioperative mortality were collected and survival was assessed at 30, 60 and 90 days post-surgery.
  
  
  RESULTS
  Overall, 5.7% of patients died within the first 30 days. Postoperative mortality at 60 and 90 days were 8.3% and 10.1%. In-hospital mortality after hepatic resection was greater among patients with hepatocellular carcinoma (HCC) than among those with colorectal liver metastases (CRLM) (8.9% and 3.8%, respectively; P < 0.001). In CRLM patients, mortality increased from 4.3% at 30 days to 8.4% at 90 days, whereas mortality in HCC patients increased from 9.7% at 30 days to 15.0% at 90 days (both P < 0.05). Patients with HCC were twice as likely as CRLM patients to die within 30 days [odds ratio (OR) 2.03], 60 days (OR = 1.74) and 90 days (OR = 1.71) (all P < 0.001). Differences in 30- and 90-day mortality were greatest among HCC patients undergoing major hepatic resection (P < 0.05).
  
  
  CONCLUSIONS
  Reporting deaths that occur within a maximum of 30 days of surgery underestimates the mortality associated with hepatic resection. Traditional 30-day definitions of mortality are misleading and surgeons should report all perioperative outcomes that occur within 90 days of hepatic resection.
authors.affiliation: Department of Surgery, School of Medicine, School of Medicine, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: Skye C
authors.initials: SC
authors.lastname: Mayo
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Shore
authors.forename: Hari
authors.initials: H
authors.lastname: Nathan
authors.forename: Barish H
authors.initials: BH
authors.lastname: Edil
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirose
authors.forename: Robert A
authors.initials: RA
authors.lastname: Anders
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Wolfgang
authors.forename: Richard D
authors.initials: RD
authors.lastname: Schulick
authors.forename: Michael A
authors.initials: MA
authors.lastname: Choti
authors.forename: Timothy M
authors.initials: TM
authors.lastname: Pawlik
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006498:Hepatectomy / Q000009:adverse effects / Q000401:mortality*; D006801:Humans; D008113:Liver Neoplasms / Q000601:surgery*; D008297:Male; D059035:Perioperative Period / Q000401:mortality*; D018426:SEER Program; D013997:Time Factors; D014481:United States