Predicting Outcomes for Cerebral Aneurysms Treated with Flow Diversion: A Comparison Between 4 Grading Scales

Area of Science:

• Neurosurgery
• Interventional Radiology
• Vascular Medicine

Background:

• Several grading scales exist for angiographic outcomes after flow diversion for cerebral aneurysms.
• No single scale has achieved widespread adoption or independent validation in neurosurgical literature.

Purpose of the Study:

• To evaluate the predictive ability of four reported grading scales for aneurysm occlusion after flow diversion.
• To determine if any scale could reliably predict treatment success.

Main Methods:

• A retrospective analysis of a prospectively maintained institutional database was performed.
• Four previously reported grading scales were applied to 99 aneurysms in 90 patients treated with flow-diverting stents.
• Patient and aneurysm factors were analyzed to compare scale performance.

Main Results:

• The Flow-Diverting Stent Score (FDSS) was the only scale significantly associated with aneurysm occlusion (P=0.004).
• Lower FDSS scores correlated with higher rates of occlusion.
• The OKM, Kamran-Byrne, and SMART scales did not predict occlusion, even after adjustments. The FDSS AUC was 0.675.

Conclusions:

• While the FDSS showed a significant association with occlusion, its predictive power was below the threshold for broad clinical utility.
• The high overall occlusion rates following flow diversion may limit the value of predictive grading scales.
• Further research may be needed to develop more robust predictive tools for flow diversion outcomes.