P-034 Reduced efficacy of the pipeline embolization device in the treatment of posterior communicating region aneurysms with fetal posterior cerebral artery configuration

Introduction Aneurysms at the origin of the posterior communicating artery (PcommA) have been demonstrated to be effectively treated with the Pipeline Embolization Device (PED). Much less is known about the efficacy of the PED for aneurysms associated with a fetal posterior cerebral artery (fPCA) variant. Herein, the largest series of patients with ICA aneurysms at the origin of the PcommA or fPCA treated with the PED is presented. Methods A prospectively maintained university database of aneurysm patients treated with the PED was retrospectively reviewed. Demographics, treatment details, and imaging were reviewed for all PcommA and fPCA aneurysms. Results Out of a total of 285 patients treated with PED, 50 patients (mean age 57.5±12.2 years, 42 females) with unruptured PcommA (9 fPCA) aneurysms were identified. Mean follow-up duration was 14.0±11.6 months (48 patients). Roy-Raymond Class I occlusion on follow up Magnetic Resonance or catheter angiography (mean time 11.7±6.8 months) was achieved in 30 patients (62.5%), Class II occlusion in 11 patients (22.9%) and Class III occlusion in 7 patients (14.5%). The PcommA was occluded in 56% of patients without any clinical symptoms. No deaths or permanent neurological complications occurred. In fPCA aneurysms, Class I occlusion was seen in 1 patient, Class II occlusion in 2 patients, and Class III occlusion in 6 patients (figure 1). Multivariate analysis revealed an independent association between incomplete occlusion and fPCA configuration (OR 73.65; 95% CI [5.84–929.13]; p=0.001). The current literature on flow diversion treatment of fPCA aneurysms was reviewed and added to the current series and found to be associated with a low rate of aneurysm occlusion (5/23 or 22%; table 1). Conclusion PEDs are a safe and effective choice in the treatment of PcommA aneurysms. The presence of fetal anatomy, however, should increase consideration of traditional intra-saccular endovascular techniques or surgical clipping. Longer follow-up is needed to determine the ultimate efficacy of PED treatment for these aneurysms. Disclosures A. Roy: None. B. Howard: None. D. Haussen: None. J. Osbun: None. S. Halani: None. S. Skukalek: None. F. Tong: None. R. Nogueira: None. J. Dion: None. C. Cawley: None. J. Grossberg: None.