Background: Stent-assisted coiling (SAC) is an established option for wide-neck intracranial aneurysms. However, ischemic complications such as in-stent thrombosis or stenosis remain, particularly when stents are deployed in small-caliber vessels. The Neuroform Atlas is generally recommended for parent vessels ≥2 mm, and data on its use in small-caliber arteries arising from the posterior cerebral artery (PCA), including the circumflex branch, are limited. Case Description: A 51-year-old woman with autosomal dominant polycystic kidney disease and prior renal transplantation presented with sudden severe headache and vomiting. Magnetic resonance imaging (MRI) showed no subarachnoid hemorrhage, while magnetic resonance angiography revealed a wide-neck basilar artery (BA) tip aneurysm suggestive of impending rupture. Emergent SAC was performed after dual antiplatelet therapy with aspirin and prasugrel. A microcatheter was advanced into a branch arising from the left PCA P1 segment, initially presumed to be the P2 segment. After coil placement revealed neck instability, a 3.0 × 15 mm Neuroform Atlas was deployed from the presumed P2 segment toward the BA. Cone-beam computed tomography demonstrated that approximately 5 mm of the distal stent had unintentionally extended into a PCA circumflex branch. Because antegrade flow was preserved, conservative management was chosen. Postprocedural MRI showed no infarction. One-year angiography demonstrated complete aneurysm occlusion and sustained circumflex branch patency. Conclusion: Long-term patency without ischemic complications was achieved despite unintentional stent deployment in a circumflex branch. This case underscores the importance of appropriate antithrombotic therapy and highlights the need for constant intraoperative awareness of the potential for unintended device deployment into perforating arteries during endovascular treatment.
Oka et al. (Fri,) studied this question.