Introduction: Endovascular flow diversion is a recognized therapy for cerebral aneurysms that are technically difficult to treat by surgical or coiling methods alone. After deployment of a flow-diverting stent, the success of aneurysm occlusion is variable. Persistent filling of an aneurysm may be addressed by placement of a second flow-diversion stent, however, the decision-making process can be unclear and follow a lengthy period of surveillance. At our institution, we have a consecutive series of 150 patients treatment with flow diversion. We intend to compare aneurysm, patient, and procedural variables of aneurysms that did or did not go on to complete occlusion at 12 months from initial flow diversion procedure.
Methods: We retrospectively reviewed a prospectively maintained database of 150 consecutive patients that underwent pipeline embolization device for cerebral aneurysms. Variables collected include aneurysm size, number of pipeline embolization devices deployed, presence of an incorporated vessel, P2Y12 data, degree of oversizing (if any) between parent vessel and stent.
Results: We utilized flow diversion in the treatment of aneurysms in 150 patients. 95% (143/150) of aneurysms treated were in the anterior circulation. The most common regions were paraophthalmic (41%, 61/150), paraclinoid (21%, 31/150), and cavernous (18%, 27/150). 76% (114/150) of flow diversion stents were done with the Pipeline Classic Embolization Device with the rest performed with the Pipeline Flex. Preliminary follow-up shows available radiographic follow-up in 59% (89/150) of patients with 84% (75/89) showed complete occlusion prior to or at 12 months and 16% (14/89) showing residual aneurysm. Of those aneurysms with residual filling, 36% (5/14) went on to completely occlude.
Conclusions: We hope to identify variables related to the aneurysm morphology, patient factors, or flow-diversion stent deployment that can predict which aneurysms will go on to complete occlusion by 12 months and those that will likely remain patent and require additional interventions.
Patient Care: Clinical decision making for the management of persistent aneurysm filling is unclear. Knowledge of variables that may predict occlusion with continued surveillance may prevent an additional flow-diversion stent with its associated risks.
Learning Objectives: By the conclusion of this session, participants should be able to: 1) Understand the role of flow diversion as a useful therapy to otherwise challenging aneurysms, 2) Describe advantages/disadvantages of management strategies for persistent aneurysm filling, 3) Describe how aneurysm morphology, patient factors, and flow-diversion stent deployment technical factors may affect success of aneurysm occlusion by 12 months.