This document discusses whether familial unruptured intracranial aneurysms are at greater risk of rupture than sporadic aneurysms. A literature search found 38 relevant articles. Retrospective data suggests familial aneurysms have a 2 to 5 times increased risk of rupture that occurs 5 years earlier and at a smaller size of 1-2mm. However, prospective data from one study showed a 17 times increased risk of rupture for familial aneurysms in patients who smoke or have hypertension. Therefore, the 34-year-old woman's unruptured aneurysm is likely at higher risk of rupture due to her brother's history of ruptured aneurysm, and treatment is recommended.

1. Unruptured Familial Intracranial Aneurysms:
Are these at greater risk of rupture?
Macquarie Neurosurgery
Evidence Based Surgery presentation
Date:23rd February 2012
Leon Lai
EBS presentation 1

2. Clinical case
34F; incidental paraclinoid aneurysm (5mm)
Non-smoker; No Hypertension
Brother died of ruptured aneurysm
Is this aneurysm at greater risk of rupture compared to
sporadic one?
(Treat or not treat?)

3. Searchable question (PICO format)
• P = Familial Unruptured Intracranial Aneurysms
• I = Observation
• C = Sporadic/Non-familial Unruptured Intracranial Aneurysms
• O = Rupture; SAH

4. Search strategy
P 1. exp Intracranial Aneurysm/ep, ge, pa [Epidemiology,
Genetics, Pathology] AND Familial.mp.
Or
5. exp Intracranial Aneurysm/ep, ge, pa [Epidemiology,
Genetics, Pathology] AND Family study.mp.
I NA
C NA
O exp Aneurysm, Ruptured/ep, ge, pa [Epidemiology, Genetics,
Pathology]
Or
exp Subarachnoid Hemorrhage/ep, ge, pa [Epidemiology,
Genetics, Pathology]

5. Medline Search results

6. Scopus Search results

7. Summary of search results
Year Results
Medline Search 1950-2012 55 articles
Scopus search 1960-2012 57 articles
Cochrane Review NA 0 articles
Duplicates References NA 26 articles
Subtotal 99 articles
Relevance (title/abstract) 32 articles
Bibliography/References 6 articles
TOTAL 38 articles

9. Retrospective FIA Series

10. Prevalence among aSAHs

11. Risk of rupture compared to non-FIA cases?

12. FIAs: Other features
Multiple aneurysms more common
De novo aneurysms more common
Rupture tend to occur within same decade of life as that of
sibling
Compared to sporadic aneurysms,
Rupture tends to be 5 years earlier
Rupture is at a smaller size (1-2mm)

13. Prospective FIA Series

14. (Stroke. 2009;40:1952-1957)
Prospective, 26 clinical centres in
North America, Australia, NZ.
2 or more affected family members
Smoker or Hypertension or both 17x increased risk of rupture
(ISUIA 0.069%)
2 ruptures 1.2% per year
(96% aneurysms<7mm)

15. FIA study: Ruptured IAs during prospective follow up

16. ISUIA Data
“Family history of SAH does not increase the risk of rupture
in this group”

17. SUAVA Data
(Prospective, 2000 to 2004; 12 clinical centres in Japan, aneurysms<5mm)

18. Conclusion
34F; incidental paraclinoid aneurysm (5mm)
Non-smoker; No Hypertension
Brother died of ruptured aneurysm
Is this aneurysm at greater risk of rupture compared to
sporadic one?
Retrospective data: 2 to 5x increased risk of rupture; rupture is 5 years
earlier and at a smaller size (1-2mm)
Prospective data (1 study) –17x increased risk of rupture

19. Conclusion
X = risk of rupture/year; Y = life expectancy (years)
ISUIA: X=0.069%; Y=40  Risk = 2.72% over next 40 years
SUAVE: X=0.34%; Y=40  Risk = 12.74% over next 40 years
FIA Study: X=1.2%; Y=40 Risk = 38.30% over next 40 years
TREAT!