Successful mechanical thrombectomy with an aspiration catheter for fenestrated basilar artery occlusion guided by preoperative basi-parallel anatomical scanning.

Basilar artery (BA) fenestration and its occlusion are relatively rare conditions. Mechanical thrombectomy for fenestrated BA occlusion has a high risk of complications. One limb occlusion or partial occlusion of fenestration mimics arterial stenosis or dissection. We present the case of a 75-year-old woman who presented with slight dysarthria, which subsequently worsened. Magnetic resonance imaging, magnetic resonance angiography, and basi-parallel anatomical scanning (BPAS) revealed BA fenestration and occlusion of the larger limb of the fenestrated BA, for which we performed thrombectomy with aspiration and achieved Thrombolysis in Cerebral Infarction Grade 3 flow restoration without procedure-related complications. If BA occlusion occurs at a site where a thrombus does not normally occur, confirming the anatomy of the BA before thrombectomy is desirable. As we obtained information on BA fenestration and occluded limb diameter using preoperative BPAS, we were able to safely achieve effective recanalization by guiding a relatively large-diameter aspiration catheter to the thrombus coaxially with a micro-guidewire and microcatheter.