Background: Aneurysm recurrence after coil therapy remains a major shortcoming in the endovascular management of cerebral aneurysms. Flow diversion has emerged as a promising treatment for intracranial aneurysms. The safety and efficacy of this new technology is under investigation. The current study assesses the yield of further angiographic follow-up in aneurysms that have achieved adequate occlusion after treatment with the Pipeline Embolization Device (PED).
Methods: Inclusion criteria were as follows: 1) treatment of one or more aneurysms with the PED, 2) available short-term (<12 months) follow-up digital subtraction angiography (DSA), 3) complete (100%) or near-complete (>95%) occlusion on short-term follow-up DSA, and 4) available further angiographic follow-up (DSA or MRA).
Results: A total of 175 patients matching the inclusion criteria were identified. Aneurysm size was 9.0 mm on average. Mean angiographic follow-up was 23.4 months. On short-term follow-up DSA images, 154 (88%) had complete aneurysm occlusion and 21 (12%) had near-complete occlusion. Seven patients (4%) had further DSA follow-up alone, 39 patients (22%) had further DSA and MRA follow-up, and 129 patients (74%) had further MRA follow-up alone. On further angiographic follow-up (DSA or MRA), no patient had a decrease in the degree of aneurysm occlusion (recurrence) or required retreatment. Of the 21 patients with near-complete occlusion on initial DSA images, 5 patients (24%) progressed to complete aneurysm occlusion on further angiographic follow-up. No patient had evidence of new in-stent stenosis on further angiographic follow-up.
Conclusion: In this study, the diagnostic yield of repeat angiography in adequately occluded aneurysms with the PED was very low. Based on these findings, we do not recommend further angiographic follow-up once aneurysms have achieved adequate occlusion with the PED.