title: Operative mortality for renal artery bypass in the United States: Results from the National Inpatient Sample.
abstract: BACKGROUND
  The mortality rate for renal artery bypass grafting (RABG) is reported to be 0% to 4% for patients with renovascular hypertension and 4% to 7% for patients with ischemic nephropathy. However, these data come from high-volume referral centers known for their expertise in treating these conditions. Because of the relative infrequency of these operations in most vascular surgery practices, the nationwide outcomes for RABG are not known. The purpose of this study was to define the operative mortality rate for RABG in the United States and to identify risk factors for perioperative mortality.
  
  
  METHODS
  The National Inpatient Sample was analyzed to identify patients undergoing RABG for the years 2000 to 2004. Categoric data were analyzed using chi(2) and the Cochran-Armitage trend tests. Multivariate logistic regression analyses were performed to identify risk factors for perioperative mortality after RABG.
  
  
  RESULTS
  During the study period, 6608 patients underwent RABG, representing a frequency of 3.51 operations per 100,000 discharges. More than two-thirds were performed at teaching hospitals (4564 vs 2,044; P < .0001). The frequency of RABG decreased by 30.7% between 2000 and 2004 (4.28 vs 2.96 RABGs per 100,000 discharges; P for trend < .0001). The in-hospital mortality for RABG was 10.0%. On univariate analysis, in-hospital mortality after RABG varied with increasing age, race, region of the country, and a preoperative history of chronic renal failure, congestive heart failure, or chronic lung disease. Logistic regression models identified advanced age (odds ratio [OR] 1.57; 95% confidence interval [CI], 1.44-1.72], female gender (OR, 1.20; 95% CI, 1.02-1.41), and a history of chronic renal failure (OR, 2.21; 95% CI, 1.75-2.78), congestive heart failure (OR, 1.94; 95% CI, 1.44-2.62), or chronic lung disease (OR, 1.40; 95% CI, 1.18-1.67) as independent markers of risk-adjusted, in-hospital mortality (P < .0001 for each of these five variables).
  
  
  CONCLUSIONS
  Nationwide in-hospital mortality after RABG is higher than predicted by prior reports from high-volume referral centers. Advanced age, female gender, and a history of chronic renal failure, congestive heart failure, or chronic lung disease were predictive of perioperative death. For the typical vascular practice, these data may provide a rationale for lower risk alternatives, such as renal artery stenting or referral to high-volume referral centers for RABG.
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Surgery, University of Texas Southwestern Medical Center, and Dallas Veterans Affairs Medical Center, Dallas, TX, USA. greg.modrall@utsouthwestern.edu
authors.forename: J Gregory
authors.initials: JG
authors.lastname: Modrall
authors.forename: Eric B
authors.initials: EB
authors.lastname: Rosero
authors.forename: Stephen T
authors.initials: ST
authors.lastname: Smith
authors.forename: Frank R
authors.initials: FR
authors.lastname: Arko
authors.forename: R James
authors.initials: RJ
authors.lastname: Valentine
authors.forename: G Patrick
authors.initials: GP
authors.lastname: Clagett
authors.forename: Carlos H
authors.initials: CH
authors.lastname: Timaran
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D017052:Hospital Mortality / Q000639:trends*; D006801:Humans; D006977:Hypertension, Renal / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D015994:Incidence; D007223:Infant; D007297:Inpatients; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000401:mortality; D011336:Probability; D012077:Renal Artery / Q000601:surgery*; D012078:Renal Artery Obstruction / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D018570:Risk Assessment; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology; D014656:Vascular Surgical Procedures / Q000379:methods / Q000401:mortality*