Object: Surgical clipping of posterior inferior cerebellar artery (PICA) aneurysms can be challenging and carries a potentially significant risk of morbidity and mortality. Experience with endovascular therapy has been limited to a few studies. The authors assess the feasibility, safety, and efficacy of endovascular therapy in the largest series of proximal and distal PICA aneurysms to date.
Methods: A total of 76 patients, 54 with proximal and 22 with distal PICA aneurysms, underwent endovascular treatment at Jefferson Hospital for Neuroscience between 2001 and 2011.
Results: Endovascular treatment was successful in 52 patients (96.3%) with proximal aneurysms and 19 patients (86.4%) with distal aneurysms. Treatment consisted of selective aneurysm coiling in 60 patients (84.5%) (including 4 with stent assistance and 4 with balloon assistance) and parent vessel trapping in 11 patients (15.5%). Specifically, a deconstructive procedure was necessary in 9.6% of proximal aneurysms (5 of 52) and 31.6% of distal aneurysms (6 of 19). There were 9 overall procedural complications (12.7%), 6 infarcts (8.5%; 4 occurring after deliberate occlusion of the PICA), and 3 intraprocedural ruptures (4.2%). The rate of procedure-related permanent morbidity was 2.8%. Complete aneurysm occlusion was achieved in 63.4% of patients (45 of 71). One patient (1.4%) treated with selective aneurysm coiling suffered a rehemorrhage on postoperative Day 15. The mean angiographic follow-up time was 17.2 months. Recurrence and re-treatment rates were, respectively, 20% and 17.1% for proximal aneurysms compared with 30.8% and 23.1% for distal aneurysms. Favorable outcomes (moderate, mild, or no disability) at follow-up were seen in 93% of patients with unruptured aneurysms and in 78.7% of those with ruptured aneurysms.
Conclusions: Endovascular therapy is a feasible, safe, and effective treatment in patients with proximal and distal PICA aneurysms, providing excellent patient outcomes and adequate protection against rehemorrhage. The long-term incidence of aneurysm recanalization appears to be high, especially in distal aneurysms, and requires careful angiographic follow-up.