Single-session bilateral vertebral artery occlusion for a ruptured fusiform distal basilar artery aneurysm in an 18-year-old with severe respiratory failure: a case report

Fusiform basilar artery aneurysms are challenging when major branches and perforators arise from the diseased segment. We report early complications and long-term hemodynamic course after bilateral vertebral artery occlusion for a ruptured fusiform distal basilar artery aneurysm. An 18-year-old Japanese man presented with Fisher group 3 subarachnoid hemorrhage and severe aspiration-related hypoxemic respiratory failure requiring mechanical ventilation. Imaging showed a 14 × 14 × 19 mm fusiform distal basilar artery aneurysm incorporating both superior cerebellar artery origins, without definite imaging evidence of dissection. On hospital day 3, after oxygenation had improved but while he remained intubated and deeply sedated, left vertebral artery coil occlusion was performed using a bidirectional approach without formal ischemic-tolerance testing. Right vertebral angiography then showed no appreciable reduction in aneurysmal filling, so the right vertebral artery was occluded during the same session. Four days later, diffusion-weighted magnetic resonance imaging showed pontine and midbrain infarctions, punctate cerebellar infarctions, bilateral medial frontal infarctions, a right occipital infarction, and a small left cerebral hemispheric infarction. On hospital day 18, recurrent basal cisternal and intraventricular hemorrhage with hydrocephalus was considered a presumed re-rupture. Subsequent imaging showed persistent retrograde aneurysmal filling through both posterior communicating arteries, followed by progressive thrombosis. Computed tomography angiography at approximately 11 months showed complete disappearance of aneurysmal contrast filling. Digital subtraction angiography at approximately 22 months showed recanalization of both vertebral arteries with restored antegrade basilar flow but no aneurysmal filling. The patient was transferred to rehabilitation on hospital day 111 with a modified Rankin scale score of 4 and improved to 0 by 3 years, with no residual neurological symptoms and return to university. Elimination of antegrade inflow did not ensure prompt aneurysm exclusion or prevent ischemic complications. The absence of aneurysmal filling after later bilateral vertebral artery recanalization documents a long-term hemodynamic course, but does not establish the safety, efficacy, or reproducibility of this strategy. Formal ischemic-tolerance assessment should be pursued whenever feasible.