Dissecting aneurysm of the basilar arterial trunk presenting with pontine infarction. Coil obliteration of the dissecting aneurysm including the diseased basilar arterial segment.

Dissecting basilar aneurysms have rarely been reported but are associated with high morbidity and mortality. Therefore, controversy exists as to the proper management of such lesions because their natural course is not well understood. We describe a 50-year-old man with a dissecting aneurysm involving the lower basilar trunk who presented with pontine infarction corresponding to the aneurysmal sac location. We obliterated the dissecting basilar aneurysm by coil embolization of the aneurysmal sac as well as the diseased segment of the basilar trunk after confirmation of collateral filling of the basilar artery through the posterior communicating artery. The patient recovered without any procedural complication. Eight month follow-up revealed complete disappearance of the aneurysm without symptom recurrence together with preservation of collateral flow in the distal basilar artery. Obliteration of the parent artery as well as the aneurysmal sac with coils could be considered in a lower basilar aneurysm of a dissecting nature.