Background:
The recent trend of the treatment of unruptured cerebral aneurysms(UIAs) is going to be conservative. Their natural history of rupture and growth is still unkown. We present the results of annual radiological follow-up study in UIAs.
Method:
In recent 12 years, we have found 121patients with 148 unruptured cerebral aneurysms were followed annually using 3D-CTA or MRA. Mean follow-up period was 5.5 year. Several factors influencing rupture or growth were statistically examined.
Results:
Among 121 patients, 9 ruptured and 11 showed growth of UIAs. Annual rupture rate was 1.3% per year and annual growth rate was 1.6% per year. Aneurysm size was the sole factor influencing rupture(P<0.001), whereas female sex and multiplicity were major factors influencing aneurysm growth(P<0.05). Under size 3mm, annual growth rate was 3.0% whereas annual rupture rate was 0.7%. In 4-6mm, growth rate was 1.6% and rupture rate was 1.6%. In 7-9mm, growth rate was 0 and rupture rate was 5.8%. In over 10mm, growth rate was 2.9% and rupture rate was 11.6%. Within 1 year, rupture occurred in 4 cases, and growth was found in 1 case.
Conclusions:
By annual radiological examination, growth of UIAs was noted more frequently than aneurysm rupture. Especially UIAs under 3mm, growth was 4 times higher than rupture, radiological follow up is effective for aneurysm rupture. Within 1 year, initially found UIAs should be carefully followed in a short interval.
