Pipeline embolization device with adjunctive coiling for ruptured blood blister-like aneurysms: a multicenter study focusing on Hunt-Hess grade I–III patients

Background Blood blister-like aneurysms (BBAs) of the internal carotid artery are rare and inherently unstable lesions that carry a high risk of rebleeding. Evidence regarding the outcomes of Pipeline embolization device (PED)-assisted coiling specifically in patients with mild-to-moderate neurological deficits (Hunt-Hess grade I-III) remains limited. Methods This multicenter retrospective study, conducted at three comprehensive stroke centers between January 2018 and December 2023, included 28 consecutive patients with ruptured ICA BBAs. We evaluated the safety and efficacy of PED combined with adjunctive coil embolization using a deliberate loose-scaffolding strategy. Results Technical success was achieved in 100% of cases. Immediate complete angiographic occlusion (modified Raymond-Roy class I) was observed in 67.9% (19/28), increasing to 75.0% (21/28) overall at 12 months and reaching 95.5% (21/22) among those with available imaging follow-up. Notably, all seven patients with residual neck filling on immediate postoperative angiography who completed follow-up subsequently achieved complete occlusion. Favorable clinical outcome (modified Rankin Scale 0-2) was recorded in 92.9% (26/28) at last follow-up. Perioperative complications occurred in 39.3% (11/28), predominantly neurological, including symptomatic vasospasm (21.4%, 6/28) and cerebral infarction (14.3%, 4/28); perioperative mortality was 3.6% (1/28). Conclusion PED-assisted coil embolization with a loose-scaffolding strategy is technically feasible and may yield favorable outcomes in selected patients with mild-to-moderate neurologic deficits. However, given the retrospective, single-arm design and modest sample size, these results are hypothesis-generating; prospective comparative studies are warranted.