title: Rupture in small abdominal aortic aneurysms.
abstract: BACKGROUND
  The decision of whether to repair small abdominal aortic aneurysms (AAAs), which are those that are less than 5 cm in diameter, remains controversial.
  
  
  METHODS
  We describe 161 consecutive patients who were seen at a single urban hospital with ruptured AAAs (rAAAs) and in whom aneurysm size was measured with ultrasound scanning, or rarely computed tomography, en route to the operating room. Eleven patients (6.8%) had AAAs that measured less than 5.0 cm. This group was compared with 150 patients who had rAAAs that were more than 5 cm.
  
  
  RESULTS
  The mortality rates were similar in both of the groups 70% for small rAAAs versus 66% for large rAAAs. No significant differences were seen between the patients with small and large ruptured aneurysms with respect to the prevalence rates of hypertension (60% vs 50%) or of cardiac disease (20% vs 22%). However, the prevalence rate of obstructive lung disease was significantly different (64% vs 25%; P =.02) as was the rate of diabetes (28% vs 3%; P =.004). Five aneurysms were measured at exactly 5 cm. This suggests that approximately 10% of all aneurysms that rupture in this series do so at 5 cm or less.
  
  
  CONCLUSIONS
  In view of the safety of elective repair as compared with the prohibitive risk associated with aneurysm rupture, patients who are at good risk with small AAA (between 4 and 5 cm) should be considered for elective aneurysm resection. For unclear reasons, obstructive lung disease and diabetes are associated with a significantly greater risk for rupture of small AAA. Patients with these risk factors should be given special consideration.
authors.affiliation: Division of Vascular Surgery, Department of Surgery, Harborview Medical Center, University of Washington School of Medicine, Seattle, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Nicholls
authors.forename: J B
authors.initials: JB
authors.lastname: Gardner
authors.forename: M H
authors.initials: MH
authors.lastname: Meissner
authors.forename: H K
authors.initials: HK
authors.lastname: Johansen
mesh_terms: D000368:Aged; D017542:Aneurysm, Ruptured / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D017544:Aortic Aneurysm, Abdominal / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D048909:Diabetes Complications; D005260:Female; D006801:Humans; D008173:Lung Diseases, Obstructive / Q000150:complications; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D014463:Ultrasonography