Is Contrast Stasis After Pipeline Embolization Device Deployment Associated with Higher Aneurysm Occlusion Rates?

To assess the association of degree of contrast stasis in intracranial aneurysms (IAs) immediately after Pipeline embolization device (PED; Medtronic, Dublin, Ireland) deployment with 6- and 12-month angiographic occlusion rates.

This retrospective cohort study included consecutive patients undergoing PED deployment for saccular IA treatment at a large-volume cerebrovascular center over a 4-year 9-month period. Angiographic images obtained immediately after PED deployment were graded according to amount of intra-aneurysmal contrast flow during the late venous phase: 0 = no stasis; 1 = <50% contrast stasis; 2 = 50%-75% stasis; and 3 = >75%-99% stasis. Follow-up occlusion rates were determined by digital subtraction angiography, computed tomographic angiography, or magnetic resonance angiography.

The study included 119 patients in whom 182 PEDs were deployed to treat 141 aneurysms. A single PED was deployed in 105 (74.5%) aneurysms. The internal carotid artery was the commonest aneurysm site (119 [85%]). Fifty-two (36.9%) aneurysms were grade 0; 33 (23.4%) were grade 1; 46 (32.6%) were grade 2; and 10 (7.1%) were grade 3 immediately post-treatment. A 6-month follow-up angiogram available for 101 aneurysms showed complete occlusion (no flow into the aneurysm) in 74 (73.3%) aneurysms. A 12-month follow-up study available for 132 aneurysms showed complete occlusion in 79.5%. At last follow-up, occlusion rates were not significantly different for different contrast stasis grades (P = 0.60). Mean angiographic follow up for all IAs was 23v±v17.7 months. IA size, sex, age, and smoking were not significant predictors of occlusion.

The degree of aneurysm contrast stasis immediately after PED deployment is not statistically associated with 6- and 12-month angiographic occlusion rates.