Introduction Blister aneurysms are unique and challenging to treat using both open cerebrovascular and endovascular techniques. These arise most commonly as sidewall aneurysms, in comparison to the branch-point location of saccular aneurysms and are exquisitely fragile with rapidly changing morphology. Pathologically, blister aneurysms are thought to form via hemodynamic stress, arterial dissection, or arteriosclerotic ulceration.¹ This creates an aneurysm prone to rupture that is not prone to conventional microsurgical clipping or endovascular coiling, leading these to commonly be treated with a flow diverting stent (FD). Yet in ruptured cases, flow diversion adds the need for dual antiplatelet therapy (DAPT), leading to additional concerns over safety in these patients. Given the rarity (approximately 1% of all aneurysms) and complexity of these cases, we aim to review the data on use of flow diversion in ruptured blister aneurysms.

Methods A literature search was performed in PubMed for ‘blister aneurysm flow diversion’ from 2013-2023 which were screened for inclusion (n=58). Case reports and studies where details specific to flow diversion cases were unavailable were not included.

Results Twelve studies published between 2013 and 2023 were identified that included necessary endpoints (table 1).^2-13 The Pipeline embolization device (PED) was the most used FD, and almost all patients were treated with first generation FDs. Pooled analysis of all patients demonstrates an overall mortality of 7/119 (5.9%), most commonly secondary to aneurysm re-rupture. Complete occlusion on follow up angiography occurred in 127/145 (87.6%) of patients. Data supporting the use of surface-modified FDs is currently limited, as only one study utilized these new devices in a limited number of patients.²

Conclusion Flow diversion has an adequate safety profile and is effective in the treatment of ruptured blister aneurysms. Currently, data primarily includes first-generation FDs. The implementation of surface-modified FDs limits the need for DAPT, which may provide an additional safety benefit in ruptured blister aneurysms and warrants further investigation.

References

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12. Linfante I, et al. DOI: 10.1136/neurintsurg-2016-012287

13. Chalouhi N, et al. DOI: 10.1227/NEU.0000000000000309

Disclosures S. Capone: None. B. Patel: None.