title: Epidemiology of surgically treated abdominal aortic aneurysms in the United States, 1988 to 2000.
abstract: Abdominal aortic aneurysm (AAA) repair is a complex procedure about which little information exists regarding trends in surgical practice in the United States. This study was undertaken to define benchmark data regarding performance and outcomes of conventional AAA repair that might be used in comparisons with endovascular AAA repair data. Patients undergoing repair of intact (n = 87,728) or ruptured (n = 16,295) AAAs in the Nationwide Inpatient Sample (NIS) for 1988 to 2000 were studied. The NIS represents a 20% stratified random sample of all discharges from US hospitals. Unadjusted and case mix-adjusted analyses of in-hospital mortality and length of stay were performed. The overall frequency of intact AAA repair remained relatively stable during the study period, ranging from 18.1 to 16.3 operations/100,000 adults between 1988 and 2000, respectively. The operative mortality rate for intact AAA repair decreased significantly (p < .001) from 6.5% in 1988 to 4.3% in 2000. Length of stay following intact AAA repair also declined significantly (p < .001) from a median of 11 days in 1988 (interquartile range [IQR] 9-15 days) to 7 days in 2000 (IQR 5-10 days). The incidence of ruptured AAA repair decreased significantly (p < .001) from 4.2 to 2.6 operations/100,000 adults between 1988 and 2000, respectively. Mortality for ruptured AAA repair, averaging 45.6%, did not decrease significantly during the study period. Intact AAA repair by conventional means has become increasingly safe, with decreased operative mortality and shorter hospital stays. Ruptured AAA repair by conventional means has not become safer but has decreased in incidence, suggesting possible reductions in risk factors contributing to rupture, coupled with more timely intact AAA repairs.
authors.affiliation: Department of Surgery, Section of Vascular Surgery, University of Michigan Medical Center, Ann Arbor, MI, USA.
authors.forename: Reid M
authors.initials: RM
authors.lastname: Wainess
authors.forename: Justin B
authors.initials: JB
authors.lastname: Dimick
authors.forename: John A
authors.initials: JA
authors.lastname: Cowan
authors.forename: Peter K
authors.initials: PK
authors.lastname: Henke
authors.forename: James C
authors.initials: JC
authors.lastname: Stanley
authors.forename: Gilbert R
authors.initials: GR
authors.lastname: Upchurch
mesh_terms: D000368:Aged; D017542:Aneurysm, Ruptured / Q000453:epidemiology / Q000401:mortality / Q000601:surgery; D017544:Aortic Aneurysm, Abdominal / Q000453:epidemiology* / Q000401:mortality / Q000601:surgery; D005260:Female; D006801:Humans; D015994:Incidence; D007902:Length of Stay / Q000639:trends; D008297:Male; D016896:Treatment Outcome; D014481:United States / Q000453:epidemiology