Nonopacification of Frontal and Parietal Branches After Middle Meningeal Artery Embolization: A Radiographic Benchmark.

Background: Middle meningeal artery embolization (MMAE) has revolutionized the armamentarium for chronic subdural hematoma (CSDH) treatment. Technical and angiographic benchmarks to guide procedural and clinical success are less well established.

Methods: A single-center database was reviewed to compare outcomes after standalone MMAE with and without resultant residual angiographic opacification of frontal and parietal (F/P) branches. Primary outcome was surgical rescue for CSDH progression. Secondary outcomes included the efficiency and accumulated efficacy of hematoma resolution. Effect sizes were adjusted via multivariable regression.

Results: Of 147 standalone MMAE for CSDH, the overall rate of surgical rescue was 6.8%. Nonopacification of F/P branches via proximal middle meningeal artery or meningo-ophthalmic anastomosis was achieved after 83% of procedures and was associated with a 7-fold decreased rate of surgical rescue (3.3% vs. 24%, P = 0.001). At 90-day follow-up, a higher rate of hematoma resolution ≥50% was achieved if no residual opacification was identified (82% vs. 56%, P = 0.03). The median time to 50% hematoma resolution was 44 days for the no-residual group versus 71 days for the residual group (P < 0.001). The unfavorable effects of residual opacification of F/P branches were verified in a multivariate analysis: a higher risk of surgical rescue (adjusted odds ratio 24.6; P = 0.001) and poor hematoma resolution were both confirmed (adjusted hazard ratio 0.3; P = 0.001).

Conclusions: MMAE with nonopacification of F/P branches was associated with augmented efficacy. Nuanced MMAE adequately tackling culprit dural feeders should be considered for more effective procedures.