Stent assisted coil embolization of unruptured middle cerebral artery aneurysms

Due to anatomic features, including wide necks and incorporation of important branches, endovascular coiling of middle cerebral artery (MCA) aneurysms has proved challenging. Stent assisted embolization may increase the likelihood of successful treatment.

Consecutive patients undergoing stent assisted coil embolization utilizing the Neuroform stent from 2004 to 2009 were identified by hospital billing records. Procedural and clinical information-including procedure related mortality and morbidity and long term outcomes-were then obtained by retrospective chart review.

Treatment was successful in 22/23 (96%) patients. Median age was 61 years and 16/22 (73%) were women. Aneurysm size was: <5 mm in 5/22 (23%); 5-9 mm in 14/22 (64%); and ≥10 mm in 3/22 (14%) patients. There were four periprocedural complications (including one stroke and one intraprocedural rupture), none associated with neurological dysfunction. Angiographic follow-up was available in 18/22 (82%) and clinical follow-up in 19/22 (86%) patients, both at a median of 1 year (mean 1.2 years) after coiling. Aneurysm occlusion was complete in 12/18 (67%), a neck remnant was present in 3/18 (17%) and persistent aneurysmal filling was present in 3/18 (17%) patients, requiring retreatment in 1/18 (6%) patient. In-stent stenosis of 50%, which was asymptomatic, occurred in 1/18 (6%) patient. No subarachnoid hemorrhages and no ischemic events related to the procedure were observed during follow-up.

In this small series, the technical success rate was 96%, there were no transient or permanent neurological complications and complete aneurysmal occlusion was achieved in two-thirds of treated aneurysms on follow-up angiography. These results suggest that in appropriately selected patients, stent assisted coil embolization of MCA aneurysms can be performed with a high degree of safety and acceptable durability.