Background: Aneurysms located at distal posterior inferior cerebellar artery (PICA) are rare. These aneurysms are difficult for surgical or endovascular treatment, especially for ruptured aneurysms.
Aims: To investigate the clinical and radiologic efficacy of parent artery occlusion (PAO) with embolic agent Onyx in the treatment of distal PICA aneurysm.
Materials and methods: Case records of 15 consecutive patients with 15 ruptured distal PICA aneurysms treated with Onyx embolization were reviewed retrospectively. The follow-up ranged between 6 and 52 months. Cerebral angiography or cerebra computed tomography-angiogram (CTA) was performed for follow-up radiological study. Two aneurysms had origin from tonsillomedullary segment, nine from telovelotonsillar segments, and four from cortical segments. All patients were treated with Onyx to occlude aneurysm and proximal portion of vessel in front of aneurysm via endovascular approach.
Results: Aneurysm was occluded completely in every patient. One patient died because of intra-procedure haemorrhage. Fourteen patients had good recovery and the last follow-up Glasgow outcome scale was 5. Head CT scan was performed in every survived patient before discharge. CT in 3 patients revealed cerebellar infarctions but without any neurological deficits. None of the 14 patients had rebleeding or fresh neurologic deficits during the follow-up period. Aneurysmal recanalization had not been observed in any of the survived patients.
Conclusions: Onyx occlusion of proximal parent artery and aneurysm in the treatment of distal PICA aneurysm is safe and effective according to this study. Morphology and location of aneurysm are important to decide the therapeutic strategy.