Endovascular treatment of intracranial 'blister' and dissecting aneurysms

Blister and dissecting aneurysms may have a different pathological background but they are commonly defined by instability of the vessel wall and bear a high risk of fatal rupture and rerupture. Lack of aneurysm sack makes treatment challenging.

The purpose of this study was to assess the safety and feasibility of endovascular treatment of intracranial blister and dissecting aneurysms.

We retrospectively analysed all patients with ruptured and unruptured blister and dissecting aneurysms treated endovascularly between 2004-2018. Procedural details, complications, morbidity/mortality, clinical favourable outcome (modified Rankin Scale ≤2) and aneurysm occlusion rates were assessed.

Thirty-four patients with endovascular treatment of 35 aneurysms (26 dissecting aneurysms and 9 blister aneurysms) were included. Five aneurysms were treated by parent vessel occlusion, and 30 aneurysms were treated by vessel reconstruction using stent monotherapy (n = 9), stent-assisted coiling (n = 7), flow diverting stents (n = 13) and coiling + Onyx embolization (n = 1). No aneurysm rebleeding and no procedure-related major complications or deaths occurred. There were five deaths in consequence of initial subarachnoid haemorrhage. Complete occlusion (79.2%) was detected in 19/24 aneurysms available for angiographic follow-up, and aneurysm recurrence in 2/24 (8.3%). The modified Rankin Scale ≤2 rate at mean follow-up of 15.1 months was 64.7%.

Treatment of blister and dissecting aneurysms developed from coil embolization to flow diversion with multiple stents to the usage of flow diverting stents. Results using modern flow diverting stents encourage us to effectively treat this aneurysm entity endovascularly by vessel reconstruction. Therefore, we recommend preference of vessel reconstructive techniques to parent vessel occlusion.