Technical Consideration for Coiling of Ruptured Proximal Posterior Inferior Cerebellar Artery Aneurysm

Stent-assisted coil embolization for an unruptured vertebral artery-posterior inferior cerebellar artery aneurysm with retrograde access via type 1 persistent primitive proatlantal artery: A case report

Vertebral artery (VA)-posterior inferior cerebellar artery (PICA) aneurysms are rare lesions that are difficult to treat with both endovascular and surgical techniques. Tight angulation of the PICA from VA may make access to the PICA difficult from ipsilateral VA if adjunctive techniques are needed. Recently, the safety and efficacy of retrograde access have been reported. We report a case of endovascular treatment for a VA-PICA aneurysm with a stent-assisted technique using retrograde access via contralateral persistent primitive proatlantal artery (PPA).The patient was a 76-year-old woman with an unruptured VA-PICA aneurysm on the dominant VA side. Coil embolization with a stent-assisted technique using retrograde access seemed appropriate. However, the origin of the left VA was not confirmed. Left common carotid artery angiography demonstrated that the PPA (type 1) branching from external carotid artery joined the VA V4 segment.Retrograde access via the PPA for stenting was performed. A microcatheter for stenting was retrogradely advanced to the right PICA at ease. After deploying the stent, coil insertion was completed from the right VA, and the final angiogram showed adequate occlusion of the aneurysm with preservation of the PICA.Thus, PPA may be an approach route in the treatment of VA-PICA aneurysms with unconfirmed contralateral VA orifice and apparent PPA on angiography, when retrograde access is needed.

Coil Embolization Results of the Ruptured Proximal Posteriori Inferior Cerebellar Artery Aneurysm: A Single-Center 10 Years' Experience

OBJECTIVE

To report a single-center experience with endovascular treatment of ruptured proximal posterior inferior cerebellar artery (PICA) aneurysms.

METHODS

Between January 2007 and December 2016, among 1403 patients with aneurysmal subarachnoid hemorrhage, 15 with ruptured proximal PICA aneurysms underwent endovascular embolization at our institution. Aneurysmal obliteration with a single microcatheter was performed in 9 patients. Additional microcatheter or stent-assisted coil embolization was performed in 4 patients and parent artery occlusion in 2 patients.

RESULTS

Immediate angiographic results showed 10 complete occlusions (66.7%, 10/15). Five patients showed incomplete occlusion (remnant neck in 4 patients, remnant aneurysm in 1). Of those, 2 patients experienced recurrence and required conversion to microsurgical clipping. The remaining 2 patients remained in relatively stable condition. Procedure-related complications occurred in 3 patients (20%, with thromboembolic complications in 2 patients and intraprocedural rupture in 1). Clinical outcome was excellent: Glasgow Outcome Score 4 or 5 in 12 of 15 patients (80%). There was no rebleeding during follow-up.

CONCLUSIONS

Ruptured proximal PICA aneurysms may be effectively treated with endovascular coil embolization. A variety of coil embolization techniques are required to obliterate an aneurysm without parent artery occlusion. Given that recurrence is possible, follow-up is required. Surgical clipping can be performed for recurrence with a relatively low risk of complications, because the aneurysm is unruptured. Coil embolization of a proximal PICA aneurysm in the acute phase can be a good treatment modality with good patient outcomes.