Flow diversion for small caliber vessel aneurysms: efficacy, safety, and functional outcome.

Background: Flow-diverting stents had gained prominence among neurointerventionalists. Aneurysms originating from distal vessels, particularly dissecting or fusiform, pose more technical challenges. The aim of the following single center large series was to report the safety, efficacy, and functional outcome of flow diversion for aneurysms originating from small caliber vessel and compare to proximal vessels group.
Methods: A retrospective chart review of a prospectively maintained database for subjects treated with flow diversion from 2010-2019.
Results: A total of 598 aneurysms were treated during a period extending from 2010-2019 (87.8% large caliber group versus 12.20% small caliber group); 84.28% (N.=504) were females and the average age was 55.5 years. Ischemic stroke occurred at a rate of 2.99% with a non-significant difference between both groups. Delayed aneurysmal rupture and distal intraparenchymal bleed occurred at a rate of 3.70% with a non-significant difference between both groups. Complete aneurysms occlusion was seen at a rate of 75.3% with a non-significant difference between both groups. Morbidity rate occurred at a rate of 5.8% with non-significant difference between both groups. Multivariate logistic regression showed that small vessel was an independent predictor of aneurysm obliteration with a 2.6-fold-higher likelihood.
Conclusions: Flow-diverting stents are being used to treat diverse types of aneurysms and in various locations, in distal small caliber vessels where other treatment options pose a considerable risk. Small caliber group had similar complication and occlusion rates compared to proximal vessel group.