Introduction: The flow-diverting Pipeline Embolization Device is still a young but promising device. Only few studies have addressed the challenging intra-operative decision-making process to determine the necessary per-aneurysm number of devices. The authors report long-term results after PED implantation, comprehensively characterize complex and standard aneurysms and introduce a modified flow disruption score.
Methods: The authors reviewed a consecutive series of 40 patients treated with 54 successfully deployed PEDs. Aneurysm complexity was assessed using our proposed classification. Immediate angiographic results were analyzed using previously published grading scales and our novel flow disruption score. Longterm follow-up was available for 36 patients with a mean follow-up time of 18 months.
Results: Forty-six aneurysms were classified as complex according to our new definition. The majority of interventions were performed in paraophthalmic and cavernous ICA segments. Excellent neurological outcome (mRS 0 and 1) was observed in 94% of patients. Our data demonstrate low permanent procedure-related mortality (0%) and morbidity rates (3%). The long-term angiographic follow-up showed complete occlusion in 81% and near total obliteration in further 14%. All standard aneurysms with one-year-follow-up, achieved complete obliteration after deployment of a single PED. The new BD score significantly demonstrated a predictive value among complex aneurysms: All aneurysms with a high BD score showed complete occlusion at follow-up irrespective of PED number. Among complex cases treated with a single device, a third of patients, all of them diagnosed with a low BD score, failed to show complete occlusion at follow-up.
Conclusions: Our data suggest that treatment with the Pipeline Embolization Device should be recognized as a primary management strategy for a highly selected cohort of predominantly complex intracranial aneurysms. We further show that a priori assessment of aneurysm complexity and our new post-interventional angiographic flow disruption score predict the occlusion probability and may help to determine the adequate number of per-aneurysm devices.
Patient Care: Our data suggest that treatment with the Pipeline Embolization Device should be recognized as a primary management strategy for complex intracranial aneurysms and considered as an available treatment option for standard but proximal ICA aneurysms. We further show that a priori assessment of aneurysm complexity and the modified immediate post-interventional angiographic flow disruption score help to determine the adequate number of per-aneurysm devices and predict the occlusion rate.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Describe the importance of preselecting complex aneurysms for flow diverter treatment, 2) Discuss, in small groups, the impact of immediate flow disruption on long term occlusion rates, 3) Identify the a priori assessment of aneurysm complexity and the modified immediate angiographic flow disruption score as supportive tools, helping surgeons to determine the adequate number of per-aneurysm devices and predict the occlusion rate.