Article Text

Original research
Validation of the Modified Raymond–Roy classification for intracranial aneurysms treated with coil embolization
  1. Christopher J Stapleton1,2,
  2. Collin M Torok2,
  3. James D Rabinov2,
  4. Brian P Walcott1,
  5. Justin R Mascitelli3,
  6. Thabele M Leslie-Mazwi2,4,
  7. Joshua A Hirsch2,
  8. Albert J Yoo5,
  9. Christopher S Ogilvy6,
  10. Aman B Patel1,2
  1. 1Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
  2. 2Neuroendovascular Program, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
  3. 3Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, New York, USA
  4. 4Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA
  5. 5Texas Stroke Institute, Plano, Texas, USA
  6. 6Neurosurgical Service, Beth Israel Deaconess Medical Center, Brain Aneurysm Institute, and Harvard Medical School, Boston, Massachusetts, USA
  1. Correspondence to Dr Aman B Patel, Department of Neurosurgery, Massachusetts General Hospital, 15 Parkman Street, Wang 745, Boston, MA 02114, USA; abpatel{at}


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.

  • Aneurysm
  • Angiography
  • Coil

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