The Efficacy of Endovascular Stenting in the Treatment of Supraclinoid Internal Carotid Artery Blister Aneurysms Using a Stent-in-Stent Technique

BACKGROUND AND PURPOSE: Blister aneurysms of the supraclinoid ICA represent a rare but well-documented cause of subarachnoid hemorrhage. These aneurysms are difficult to detect, and their surgical treatment is challenging, with high morbidity and mortality rates. The reports currently in the literature that describe the surgical and endovascular treatment of these aneurysms offer no clear consensus on the optimal treatment. We describe a staged endovascular treatment entailing stenting using a stent-in-stent technique, as well as planned but delayed embolization as the aneurysm increases in size to allow the introduction of coils. MATERIALS AND METHODS: We performed a retrospective review of all cerebral angiograms performed at our institution over an 8-month period for evaluation of subarachnoid hemorrhage, identifying 6 ICA blister aneurysms. RESULTS: All 6 blister aneurysms were located in the supraclinoid ICA. The stent-in-stent technique was used for the initial treatment of all patients. Three patients had no residual or recurrent aneurysm following initial treatment. Three patients required retreatment with coils after continued growth of the aneurysm, identified on follow-up angiography. Five patients had good recovery (average mRS score of 1), and 1 patient had poor neurologic recovery (mRS score of 3) due to a large hemorrhagic infarction. CONCLUSIONS: Our case series suggests that staged endovascular treatment entailing the use of a stent-in-stent technique, augmented with subsequent coil embolization as necessary for progressive disease, is a viable endovascular option for treating ruptured supraclinoid blister aneurysms, allowing for parent artery preservation.