title: Smoking increases the risk of de novo intracranial aneurysms.
abstract: OBJECTIVE
  Case series have identified that de novo intracranial aneurysms occur. However, the risk for this occurrence has not been established. We examined the risk for the de novo intracranial aneurysm detection in a consecutive surgical case series.
  
  
  METHODS
  A prospectively collected surgical database of intracranial aneurysms was retrospectively examined. Patients were analyzed if they were followed for more than 6 months postoperatively with angiography. Kaplan-Meier curve analysis of de novo aneurysms detection included the comparison of smoking vs. never smoked; those with and without a family history; single vs. multiple aneurysms at initial presentation; and original presentation with rupture vs. nonrupture.
  
  
  RESULTS
  Of the 1366 surgically treated patients (1942 aneurysms), 472 patients (702 aneurysms) were followed with angiography for more than 6 months (average, 54 months). Thirty-three patients (6.99%) were detected to have de novo aneurysms. Multivariate analysis found a smoking history significantly increases the likelihood of de novo aneurysm detection. Kaplan-Meier analysis found the 5- and 10-year de novo aneurysm detection rate to be 4.21% (95% confidence interval [CI] 3.86-12.8) and 15% (95% CI 10-16), respectively. A smoking history increases the 5- and 10-year detection rate to 5.81% and 17% (hazard ratio 2.58; 95% CI 1.13-5.90) respectively. No increased risk was present for an initial presentation that included multiple aneurysms, a family history, or rupture.
  
  
  CONCLUSIONS
  There is a 10-year de novo aneurysm detection rate of between 10% and 16% after surgery. Smoking increases the risk of de novo aneurysm detection. Consideration needs to be given to surveillance angiography after aneurysm treatment.
authors: Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia. Electronic address: drleonlai@gmail.com.
authors: Leon Tat
authors: LT
authors: Lai
authors: Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia.
authors: Michael Kerin
authors: MK
authors: Morgan
authors: Australian School of Advanced Medicine, Macquarie University, Sydney, New South Wales, Australia.
authors: Nirav J
authors: NJ
authors: Patel
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D002533:Cerebral Angiography; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D002532:Intracranial Aneurysm / Q000453:epidemiology*; D053208:Kaplan-Meier Estimate; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012907:Smoking / Q000009:adverse effects* / Q000453:epidemiology; D013345:Subarachnoid Hemorrhage / Q000453:epidemiology / Q000473:pathology; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D055815:Young Adult
keywords: De novo aneurysm; Intracranial aneurysm; Kaplan-Meier; New aneurysm; Risk; Smoking