From the Guidelines
Pipeline flow diversion devices achieve high brain aneurysm occlusion rates, with complete occlusion occurring in approximately 70-80% of cases at 6 months and increasing to 85-95% at 1 year post-procedure, as supported by the most recent guidelines from the American Heart Association/American Stroke Association 1. The Pipeline Embolization Device (PED) works by redirecting blood flow away from the aneurysm while providing a scaffold for endothelial growth across the aneurysm neck, leading to gradual thrombosis and occlusion. Some key points to consider when using pipeline flow diversion devices include:
- Patients undergoing pipeline treatment require dual antiplatelet therapy (typically aspirin 325mg daily and clopidogrel 75mg daily) for at least 3-6 months post-procedure to prevent device thrombosis, followed by aspirin indefinitely 1.
- Follow-up imaging is essential, with angiography typically performed at 6 months and 1 year to assess occlusion status.
- The occlusion process is progressive, with many aneurysms showing increasing occlusion over time, even beyond the first year.
- Factors that may negatively impact occlusion rates include very large or giant aneurysms, fusiform morphology, and inadequate antiplatelet response. It's also important to note that the use of stent-assisted coiling and flow diverters has a higher risk of thrombogenicity than primary coiling, necessitating dual antiplatelet therapy, and their use in ruptured aneurysms is associated with a higher risk of hemorrhagic complications 1. Overall, pipeline flow diversion devices are a effective treatment option for brain aneurysms, with high occlusion rates and relatively low risks of complications, as supported by the most recent guidelines from the American Heart Association/American Stroke Association 1.
From the Research
Brain Aneurysm Occlusion Rates with Pipeline Flow Diversion
- The occlusion rates for brain aneurysms treated with pipeline flow diversion vary depending on the study and the location of the aneurysm.
- A study published in 2023 2 reported a complete occlusion rate of 78% for unruptured aneurysms treated with pipeline embolization device (PED) over a median radiographic follow-up of 5.0 years.
- Another study published in 2019 3 reported a complete occlusion rate of 82% for anterior circulation aneurysms treated with PED at a mean follow-up of 14 months.
- A study published in 2019 4 reported a complete occlusion rate of 68% at 6 months and 78% at 12 months for posterior circulation aneurysms treated with PED.
- A study published in 2021 5 reported a complete occlusion rate of 60% for fusiform aneurysms treated with PED, with a favorable occlusion result (OKM C1-3 and D) in 76% of cases.
Predictors of Aneurysm Occlusion and Persistence
- A study published in 2019 3 identified predictors of aneurysm persistence after flow diversion, including increasing aneurysm size and incorporation of a branch vessel.
- The same study found that adjunctive coiling predicted occlusion.
- A study published in 2019 4 found that fusiform or dissecting morphology and large or giant aneurysm size were predictors of aneurysm persistence at 6 months.
Safety and Efficacy of Flow Diversion
- A study published in 2023 2 reported a major, non-fatal neurologic complication rate of 3% and a mortality rate of 2% for patients treated with PED.
- A study published in 2019 4 reported a major complication rate of 8% for posterior circulation aneurysms treated with PED.
- A study published in 2021 5 reported an overall complication rate of 26.7% and a neurological morbidity rate of 6.7% for fusiform aneurysms treated with PED.