Tandem balloon test occlusion for a large unruptured aneurysm associated with persistent primitive trigeminal artery: Technical note

Objective: We report a case of unruptured large aneurysm associated with persistent primitive trigeminal artery (PTA) treated by endovascular trapping after balloon test occlusion (BTO) with tandem balloons. Case presentation: A 37-year-old woman presented with diplopia and ptosis due to left oculomotor palsy. Cerebral angiography revealed a left PTA and unruptured large aneurysm at the junction of the PTA and the left internal carotid artery (ICA). The left carotid angiogram showed filling of the upper basilar artery via the PTA, and the left vertebral angiogram also showed filling of the basilar artery and entire posterior circulation. To evaluate the tolerance for the aneurysm trapping, we performed BTO with tandem balloons placed both proximal and distal to the aneurysm to isolate the left anterior circulation from both the ICA and PTA. As the mean stump pressure was below 60% of pre-BTO value, left superficial temporal artery-middle cerebral artery anastomosis was performed a week before endovascular trapping. Subsequently, the aneurysm, ICA, and PTA were successfully embolized with coils, leading to completion of trapping of the aneurysm, without causing any new neurological deficits. Conclusion: To evaluate the precise hemodynamics and collateral circulation, BTO using tandem balloons seems to be useful in cases of persistent PTA.