RT Journal Article SR Electronic T1 Validation of the Modified Raymond–Roy classification for intracranial aneurysms treated with coil embolization JF Journal of NeuroInterventional Surgery JO J NeuroIntervent Surg FD BMJ Publishing Group Ltd. SP 927 OP 933 DO 10.1136/neurintsurg-2015-012035 VO 8 IS 9 A1 Christopher J Stapleton A1 Collin M Torok A1 James D Rabinov A1 Brian P Walcott A1 Justin R Mascitelli A1 Thabele M Leslie-Mazwi A1 Joshua A Hirsch A1 Albert J Yoo A1 Christopher S Ogilvy A1 Aman B Patel YR 2016 UL http://jnis.bmj.com/content/8/9/927.abstract AB Background The Raymond–Roy Occlusion Classification (RROC) qualitatively assesses intracranial aneurysm occlusion following endovascular coil embolization. The Modified Raymond–Roy Classification (MRRC) was developed as a refinement of this classification scheme, and dichotomizes RROC III occlusions into IIIa (opacification within the interstices of the coil mass) and IIIb (opacification between the coil mass and aneurysm wall) closures.Methods To demonstrate in an external cohort the predictive accuracy of the MRRC, the records of 326 patients with 345 intracranial aneurysms treated with endovascular coil embolization from January 2007 to December 2013 were retrospectively analyzed.Results Within this cohort, 84 (24.3%) and 83 aneurysms (24.1%) had MRRC IIIa and IIIb closures, respectively, during initial coil embolization. Progression to complete occlusion was more likely with IIIa than IIIb closures (53.6% vs 19.2%, p≤0.01), while recanalization was more likely with IIIb than IIIa closures (65.1% vs 27.4%, p<0.01). Kaplan–Meier estimates demonstrated a significant difference in the test of equality for progression to complete occlusion (p=0.02) and recurrence (p<0.01) between class IIIa and IIIb distributions. For the entire cohort, male gender (p<0.01), ruptured aneurysm (p=0.04), intraluminal thrombus (p<0.01), and MRRC IIIb closure (p<0.01) were identified as predictors of recanalization. For aneurysms with an initial RROC III occlusion, MRRC IIIa closure was found to be an independent predictor of progression to complete occlusion (p=0.02).Conclusions This study confirms that the MRRC enhances the predictive accuracy of the RROC.