Introduction: Surgical clipping of posterior inferior cerebellar artery (PICA) aneurysms is challenging and carries a potentially significant risk of morbidity and mortality. Experience with endovascular therapy has been limited to a few studies. We assess the safety and efficacy of endovascular therapy in the largest series of proximal and distal PICA aneurysms to date.
Methods: A total of 50 patients, 39 with proximal and 11 with distal PICA aneurysms, underwent endovascular treatment at Jefferson Hospital for Neuroscience between 2004 and 2011.
Results: Hunt and Hess Grades were 0 in 12 patients, I-II in 7 patients, III in 12 patients, and IV-V in 19 patients. Mean aneurysm size was 5.9 mm. Endovascular treatment was successful in 37 (95%) patients with proximal aneurysms and 8 (72%) patients with distal aneurysms. Selective aneurysm coiling was performed in 32 patients, proximal coil occlusion of the PICA in 6, balloon-assisted coiling in 4, and stent-assisted coiling in 3. There were 5 (11.1%) overall procedural complications, 4 (8.9%) cerebellar infarcts (2 occurring after deliberate coil occlusion of PICA) and 1 (2.2%) intra-procedural rupture. Procedure-related permanent morbidity and mortality were 2.2% and 0% respectively. Complete or near-complete aneurysm occlusion was achieved in 84.4% of patients. One patient (2.2%) treated with selective aneurysm coiling suffered a rehemorrhage on post-operative day 15. Aneurysm recanalization and retreatment rates were respectively 30% and 26% at a mean angiographic follow-up time of 18.2 months. Favorable outcomes (GOS 4 and 5) were seen in 100% of patients with unruptured aneurysms and 54.5% of those with ruptured aneurysms.
Conclusions: Endovascular therapy is a feasible, safe and effective treatment in patients with proximal and distal PICA aneurysms. The long-term incidence of aneurysm recanalization is high and requires adequate angiographic follow-up.
Patient Care: This is the largest study to assess the feasibility, safety and efficacy of endovascular therapy in patients with PICA aneurysms. The data provided will help neurosurgeons make evidence-based clinical decisions and optimize the management of these patients.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Discuss the advantages and limitations of endovascular therapy in the treatment of PICA aneurysms. 2) Optimize the management of patients with proximal and distal PICA aneurysms.