Application of endovascular
surgery for very small
aneurysms is controversial because of technical difficulties and high complication rates. The aim in the present study was to assess treatment results in a series of such
lesions at one institution. Since 1997, endovascular
surgery has been advocated for very small ruptured
aneurysms (< 3 mm in maximum diameter) that fulfill the criterion of a fundus/
neck ratio greater than 1.5. Twenty-one patients were treated, for whom the World Federation of
Neurosurgical Societies classification before treatment was Grade I in 10, Grade II in two, Grade III in two, Grade IV in five, and Grade V in two. The
aneurysm location was the
internal carotid artery in four, the
anterior communicating artery in 11, the
middle cerebral artery in one, and the
vertebrobasilar system in five. In all patients, endovascular
surgery was performed using Guglielmi detachable coils after induction of
general anesthesia. Initially, the presumed volume of the
lesions was calculated for each
aneurysm. Thereafter, the appropriate coil length was decided according to the volume
embolization ratio, as 30 to 40%. In all attempts to obliterate
aneurysms a single coil was used. All
aneurysms were completely obliterated as confirmed by postembolization
angiography, without procedure-related complications. During the follow-up period only one patient needed additional coil
embolization for a growing
aneurysm. Final outcomes were good recovery in 15 patients, moderate
disability in five, and severe
disability in one. Appropriate
selection of patients and coils, and use of sophisticated techniques allow a good outcome for patients with very small
aneurysms.
