Introduction: The Modified Raymond Roy Classification (MRRC) was developed to augment the original Raymond Roy Occlusion Classification (RROC) for the qualitative assessment of intracranial aneurysm occlusion following endovascular coil embolization. In the MRRC, RROC III occlusions are further dichotomized to IIIa (residual opacification within the interstices of the coil mass) and IIIb (residual opacification between the coil mass and aneurysm wall) closures, with IIIa occlusions portending a more favorable prognosis.
Methods: To demonstrate in an external intracranial aneurysm cohort the predictive accuracy of the MRRC, the records of 326 patients with 345 intracranial saccular aneurysms treated with endovascular coil embolization from January 2007 to December 2013 were retrospectively analyzed.
Results: Within this cohort, 84 aneurysms (24.3%) and 83 aneurysms (24.1%) had IIIa and IIIb closures at the time of initial coil embolization, respectively. Significant factors associated with an initial IIIb closure included cavernous internal carotid artery location (P < .01), increasing aneurysm size (P < .01), increasing aneurysm volume (P < .01), increasing aneurysm neck size (P < .01), increasing aspect ratio (P = .02), presence of blebs or dome irregularities (P = .02), presence of intraluminal thrombus (P < .01), aneurysm rupture (P < .01), and decreasing coil packing density (P < .01). Progression to complete aneurysm occlusion was more likely to occur in IIIa than IIIb closures (53.6% versus 19.2%, P = .02), while aneurysm recurrence was more likely to occur in IIIb than IIIa closures (65.1% versus 27.4%, P < .01).
Conclusions: The present study demonstrates that initial MRRC designations following endovascular coil embolization reliably predict eventual progression to occlusion or recurrence. We recommend that this updated intracranial aneurysm occlusion scale be adopted into widespread neuroendovascular practice.
Patient Care: With use of the Modified Raymond Roy Classification, neuroendovascular specialists will have clearer sense of the angiographic prognosis of intracranial aneurysms treated by endovascular coil embolization.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) describe the Raymond Roy Occlusion Classification and the Modified Raymond Roy Classification for intracranial aneurysms treated by endovascular coil embolization;
2) list the factors associated with MRRC IIIb occlusions that portend a worse angiographic outcome for intracranial aneurysms treated by endovascular coil embolization.