Introduction: Arterial bifurcations are common locations for aneurysm development given the altered hemodynamic forces and shear stress variations present at these locations. Recent reports indicate that a wide basilar artery (BA) bifurcation angle is an independent predictor of aneurysm development, growth, and subsequent rupture.
Methods: To determine the effect of BA bifurcation angle on rates of initial occlusion, recanalization, and retreatment of BA apex aneurysms following coil embolization, the records of 46 patients with BA apex aneurysms treated with endovascular coil embolization from 2007 to 2013 were analyzed.
Results: A wide BA bifurcation angle was associated with a Raymond-Roy Occlusion Classification (RROC) III occlusion in univariate analysis, but was not a statistically significant factor in multivariate modeling. An increasing BA bifurcation angle was not associated with aneurysm recanalization or retreatment following coil embolization. Increasing packing density (P < .01) was the only statistically significant predictor of a RROC I or II closure. The initial RROC designation was the most powerful predictor of both eventual aneurysm recanalization (P = .01) and retreatment (P = .02). While increasing aneurysm size (P < .01), increasing aneurysm volume (P < .01), and increasing neck size (P < .01) were associated with wide BA bifurcation angles, neck size (P = .03) was the only statistically significant predictor of BA bifurcation angle on multivariate analyses.
Conclusions: BA bifurcation angle fails to predict rates of initial occlusion, recanalization, and retreatment on multivariate modeling in our series. BA apex aneurysm neck size independently correlates with BA bifurcation angle.
Patient Care: With an increased understanding of the factors that influence initial occlusion, recanalization, and retreatment rates of BA apex aneurysms following coil embolization, neuroendovascular specialists can more effective develop treatment approaches for these formidable aneurysms.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Describe the importance of basilar artery (BA) bifurcation angle in BA apex aneurysm formation and ruptured.
2) Describe the effect of BA bifurcation angle on rates of initial occlusion, recanalization, and retreatment of BA apex aneurysms after coil embolization.
3) Discuss, in small groups, the factors that influence recanalization and retreatment of BA apex aneurysms after coil embolization.
4) Identify effective treatment strategies for untreated and previously treated BA apex aneurysms.