General Anesthesia versus Monitored Anesthesia Care for Middle Meningeal Artery Embolization for Chronic Subdural Hematomas: Multicenter Propensity Score-matched Study

Introduction: The choice of general anaesthesia (GA) versus monitored anesthesia care (MAC) in middle meningeal artery embolization procedures (MMAE) for chronic subdural hematomas (cSDH) tend to differ between institutions and are left to care-team discretion given the lack of standard guidelines. We compare the outcomes of GA versus MAC in MMAE.

Methods: Series of consecutive patients undergoing MMAE for cSDH at 13 North American centers (2018-2022) were included for this analysis. Patients were categorized into GA or MAC groups. Clinical baseline and SDH characteristics and technical/clinical outcomes were compared between groups. Utilizing propensity score matching (PSM) algorithm, patients were matched using nearest-neighbor controlling for: age, gender, concurrent/prior surgical evacuation, hematoma thickness and midline shift (both in millimeters), pre-procedure platelets count and antiplatelet/anticoagulation therapy. The primary endpoint was treatment failure defined as hematoma reaccumulation or clinical deterioration requiring reintervention within 90days from index procedure. Technical feasibility and radiological improvement (i.e., ≥50% reduction in hematoma thickness within 90days/last available follow-up) were assessed as secondary outcomes.

Results: Over the span of 3 years, 538 patients (mean age 72.3 years, 27.2% females) underwent 625 MMAE procedures, of which 348 (64.7%) were performed under MAC and 190 utilizing GA (35.3%). After running the PSM algorithm, 72 matched pairs were generated with similar clinical and radiographic characteristics. There was a trend for higher rates of treatment failures requiring re-intervention in the GA group compared to the MAC cohort (13.9% vs 2.8% respectively; p=0.09). Technical failures rates were comparable between the groups (4.2% vs 3%, respectively; p=0.82). Similarly, radiological improvement in terms of ≥50% reduction of hematoma thickness on last follow-up were similar between GA and MAC groups (81.8% vs 83.9% respectively; p=0.85).

Conclusion : In our data, there was no significant difference between GA and MAC in terms of radiological improvement and clinical outcomes.