Detachable coil embolization for saccular posterior inferior cerebellar artery aneurysms

Abstract

Objective: Surgical treatment of posterior inferior cerebellar artery (PICA) aneurysms is challenging due to limited surgical accessibility. Endovascular approach has a benefit of avoiding direct injury to the brainstem or lower cranial nerves. Therefore, it has recently been considered an alternative or primary modality for PICA aneurysms. We retrospectively assessed outcomes following detachable coil embolization of saccular PICA aneurysms.

Methods: From February 1997 to December 2007, we performed endovascular procedures to treat 15 patients with 15 PICA aneurysms. Fourteen patients with 14 PICA aneurysms morphology of which was saccular were reviewed retrospectively. Twelve patients had ruptured aneurysms. The aneurysms arose from the PICA origin site (n = 12), the PICA lateral medullary segment (n = 1), or the PICA tonsilomedullary segment (n = 1).

Results: Complete aneurysm occlusion was achieved in 10 patients, residual neck in 3, and residual sac in one. Radiological follow-up was performed in 7 patients with mean duration of 34.7 months (range, 1-97 months) and showed stable or complete occlusion in 6 patients. There were no rebleeding or retreatment after endovascular treatment. Thromboembolism was the only procedure-related complication (n = 4 ; 28.6%). Asymptomatic PICA infarction occurred in two patients and symptomatic PICA infarction in two elderly patients with poor clinical grade. Of these procedural PICA infarction cases, 1 symptomatic PICA infarction patient developed ventriculitis and septic shock leading to death. The clinical outcome was good in 10 patients (71.4%).

Conclusions: In the present study, detachable coil embolization has shown as an efficient modality for PICA saccular aneurysms challenging indications of microsurgery. However, thromboembolic complications should be considered, especially in poor clinical elderly patients with ruptured aneurysms.

Keywords: Endovascular; Microsurgery; Posterior inferior cerebellar artery; Thromboembolism.

Fig. 1

Case 7. A 27 year-old male presented with ruptured posterior inferior cerebellar artery (PICA) aneurysm in the lateral medullary segment. A and B : Anteroposterior and working projection view of left vertebral artery reveals the bilobulated saccular aneurysm in the left lateral medullary segment of PICA. C : Working projection view of left vertebral artery after guglielmi detachable coil embolization shows main PICA trunk occlusion with no contrast filling of aneurysm sac. D : Brain computed tomography reveals low density in left cerebellum correlating with PICA territory four day after coil embolization. However, the patient had no neurological deficit but mild headache after detachable coil embolization.

Fig. 2

Case 1. A 28 year-old female presented with subarachnoid hemorrhage. A : 3D reconsruction working projection view on the left vertebral artery revealed a saccular aneurysm at the vertebral artery- posterior inferior cerebellar artery junction. B : Working projection view on the left vertebral artery immediately after coil embolization demonstrates complete occlusion of the aneurysm. C : Lateral angiogram on left vertebral artery 9 days after coil embolization shows minimal coil compaction and contrast filling of the aneurysm neck. D : Compared with previous follow-up angiography, magnetic resonance DSA 9 month after coil embolization reveals no further progression of coil compaction.