The middle meningeal artery Patency After Coil Embolization (PACE) score: A novel descriptor of angiographic occlusion.

Introduction: A scoring system to characterize the efficacy of middle meningeal artery (MMA) embolization is lacking and would help predict the likelihood of subdural hematoma resolution.

Methods: We developed a simple angiographic classification system ranging from 0 to 3 for quantifying MMA Patency After Coil Embolization (PACE) based residual flow distal to the embolization. MMA embolizations using coils at our institution were used to validate the PACE score system using procedural angiograms. Follow-up CT scans following embolization were reviewed for acute blood products, and to characterize long-term resolution.

Results: 60 patients were included in the study, with a total of 80 subdural hematomas with follow-up imaging that were available for analysis. 37 patients had a PACE score of 0, 18 had a PACE score of 1, 4 had a PACE score of 2, and 1 had a PACE score of 3. The presence of acute blood products was significantly lower in PACE 0 compared to PACE 1, 2, or 3. The cross-sectional area of the chronic subdural collections was statistically lower on follow-up CT scans after coil embolization.

Conclusions: Coil embolization of the MMA may reduce the incidence of acute blood products after embolization and decrease the cross-sectional area of chronic subdural hematoma on long-term follow-up. Lower PACE scores may correlate with lower rates of acute blood products after the procedure and increased resolution of chronic subdural hematoma on follow-up. A larger cohort is required to characterize the superiority between the PACE scores.