What is the effectiveness of endovascular flow-diverting stent treatment for blood blister aneurysms in the internal carotid artery (ICA) ophthalmic segment causing subarachnoid hemorrhage?

From the Guidelines

Endovascular flow diverting stent treatment is a highly effective and recommended approach for blood blister aneurysms in the ophthalmic segment of the internal carotid artery causing subarachnoid hemorrhage, as it offers high technical success rates and favorable clinical outcomes, with complete aneurysm occlusion rates ranging from 70-90% at 6 months. The use of flow diverters, such as Pipeline Embolization Device, SILK, and FRED stents, has become a preferred treatment option due to its ability to redirect blood flow away from the aneurysm, providing a scaffold for endothelial growth across the aneurysm neck, leading to gradual thrombosis and exclusion from circulation 1.

The procedure typically involves dual antiplatelet therapy, with loading doses of aspirin and clopidogrel before the procedure, followed by maintenance doses for 3-6 months, then aspirin alone indefinitely. Compared to traditional surgical clipping or coiling, flow diversion offers better outcomes for these challenging thin-walled aneurysms that have high rebleeding and rupture rates. Potential complications include thromboembolic events, in-stent stenosis, and delayed hemorrhage, necessitating close monitoring with follow-up angiography at 6 and 12 months post-procedure 1.

The American Heart Association/American Stroke Association guidelines support the use of flow diverters for ruptured fusiform/blister aneurysms, as it reduces mortality 1. The guidelines also emphasize the importance of early treatment, multidisciplinary discussion, and evaluation of the ruptured aneurysm by specialists with endovascular and surgical expertise to determine the relative risks and benefits of each treatment strategy 1.

Key points to consider:

• High technical success rate (over 90%) and favorable clinical outcomes
• Complete aneurysm occlusion rates range from 70-90% at 6 months
• Flow diverters offer better outcomes for challenging thin-walled aneurysms
• Potential complications include thromboembolic events, in-stent stenosis, and delayed hemorrhage
• Close monitoring with follow-up angiography at 6 and 12 months post-procedure is necessary
• Dual antiplatelet therapy is typically involved in the procedure
• The American Heart Association/American Stroke Association guidelines support the use of flow diverters for ruptured fusiform/blister aneurysms.

From the Research

Effectiveness of Endovascular Flow Diverting Stent Treatment

The effectiveness of endovascular flow diverting stent treatment in blood blister internal carotid artery ophthalmic segment aneurysmal subarachnoid hemorrhage can be evaluated based on the following points:

• Success Rate: Studies have shown that endovascular flow diverting stent treatment can be successful in treating blood blister-like aneurysms, with a high rate of complete occlusion of the aneurysm 2, 3, 4, 5.
• Morbidity and Mortality: The treatment has been shown to have a relatively low morbidity and mortality rate, with some studies reporting no acute complications or procedure-related deaths 2, 3, 6.
• Clinical Outcomes: Patients treated with endovascular flow diverting stents have been reported to have good clinical outcomes, with a high percentage of patients achieving a modified Rankin Scale score of 0-2 2, 3, 4, 5.
• Aneurysm Occlusion: The treatment has been shown to be effective in achieving complete occlusion of the aneurysm, with some studies reporting occlusion rates of up to 92.6% 5.
• Retreatment: Some studies have reported the need for retreatment in cases of persistent filling or regrowth of the aneurysm, highlighting the importance of careful angiographic follow-up 4.

Comparison of Treatment Strategies

Different treatment strategies have been compared in the studies, including:

• Flow Diverting Stents Alone: Some studies have reported the use of flow diverting stents alone for the treatment of blood blister-like aneurysms, with good clinical outcomes and high rates of aneurysm occlusion 2, 3.
• Stent-Assisted Coiling: Other studies have reported the use of stent-assisted coiling for the treatment of blood blister-like aneurysms, with good clinical outcomes and high rates of aneurysm occlusion 4, 5.
• Pipeline Flow Diversion: Some studies have reported the use of pipeline flow diversion for the treatment of blood blister-like aneurysms, with good clinical outcomes and high rates of aneurysm occlusion 5.

Key Findings

Key findings from the studies include:

• Acute Focal Dissection: Acute focal dissection of the supraclinoid segment of the internal carotid artery has been proposed as the underlying cause of blood blister-like aneurysm formation 5.
• Importance of Angiographic Follow-Up: Careful angiographic follow-up is necessary to monitor the aneurysm and detect any signs of persistent filling or regrowth 4.
• Need for Appropriate Preoperative Antiplatelet Administration: Appropriate preoperative antiplatelet administration and optimal timing of the treatment may reduce the risk of postoperative ischemic complication 4.