Abstract Number ‐ 44: Middle Meningeal Artery Embolization: 294 Non‐Acute Subdural Hematomas with Outcomes and Risk Factors for Recurrence

Introduction Treatment of non‐acute subdural hematoma (NASDH) remains challenging due to recurrence ranging from 2–37%. Middle meningeal artery embolization (MMAe) has emerged as a minimally invasive procedure uniquely poised to improve outcomes in NASDH. The goal of this study is to evaluate the clinical and radiographic characteristics of patients undergoing MMAe for NASDH, and how outcomes for MMAe differ when utilized upfront, prophylactically, or as a salvage modality after surgical evacuation. Furthermore, we investigated how independent patient risk factors, such as oncologic history and anticoagulant/antiplatelet (ACAP) medication use, may impact MMAe and NASDH outcomes. Methods This prospective study followed patients undergoing MMAe for NASDH from 2016–2021. All patients were diagnosed with a NASDH on non‐contrast CT imaging and underwent MMAe by the lead neurosurgeon. The primary outcome was NASDH recurrence post‐MMAe requiring surgical evacuation, repeat MMAe, or both within the one‐year follow up period. Additional radiographic outcomes included reduction of hematoma width and midline shift at longest follow‐up. Subgroup analyses stratified outcomes by MMAe indication: upfront (previously untreated and nonoperative NASDH), prophylactic (MMAe 1–5 days after surgical evacuation), or salvage (individuals with radiographic and clinical NASDH recurrence). Outcomes among oncologic, coagulopathic, and ACAP patients were also assessed. The modified Rankin scale (mRS) quantified post‐MMAe clinical outcomes. Results A total of 236 NASDH patients underwent 294 MMAe. Of these, 115 (48.7%), 92 (39.0%), and 29 (12.3%) patients received upfront, prophylactic, and salvage MMAe, respectively. Upfront MMAe was performed more frequently than prophylactic and salvage for patients with co‐existing malignancy (29.6%, 12.0%, 20.7%; P 0.99). Clinical outcomes did not differ between MMAe indications at longest follow‐up. Within the prophylactic group, radiographic and clinical outcomes were similar between MMAe paired with twist‐drill craniostomy or with craniotomy. Subgroup analysis revealed MMAe also effectively decreased NASDH recurrence in ACAP, oncologic, and coagulopathic patients. However, patients with both an oncologic history and concurrent ACAP use less frequently achieved improved clinical status at follow‐up compared with those harboring ACAP/coagulopathic history alone, oncologic history alone, or neither (31.4%, 45.9%, 50.0%, 57.3%; P = 0.049). Conclusions MMAe is emerging as a viable treatment for curtailing recurrence and improving NASDH outcomes, with similar clinical outcomes when performed prophylactically, upfront, or as salvage treatment. NASDH patients presenting with an oncologic history and concurrent ACAP use may be less likely to achieve improved clinical status after MMAe

Neurosurgery subspecialty practice during a pandemic: a multicenter analysis of operative practice in 7 U.S. neurosurgery departments during COVID-19

OBJECTIVE: Changes to neurosurgical practices during the COVID-19 pandemic have not been thoroughly analyzed. We report the effects of operative restrictions imposed under variable local COVID-19 infection rates and healthcare policies using a retrospective multi-center cohort study and highlight shifts in operative volumes and subspecialty practice. METHODS: Seven academic neurosurgery departments\u27 neurosurgical case logs were collected; procedures in April 2020 (COVID-19 surge) and April 2019 (historical control) were analyzed overall and by 6 subspecialties. Patient acuity, surgical scheduling policies, and local surge levels were assessed. RESULTS: Operative volume during COVID-19 decreased 58.5% from the previous year (602 vs 1449, p=0.001). COVID-19 infection rates within departments\u27 counties correlated with decreased operative volume (r=0.695, p=0.04) and increased patient categorical acuity (p=0.001). Spine procedure volume decreased by 63.9% (220 vs 609, p=0.002), for a significantly smaller proportion of overall practice during the COVID-19 surge (36.5%) versus the control period (42.0%) (p=0.02). Vascular volume decreased by 39.5% (72 vs 119, p=0.01) but increased as a percentage of caseload (8.2% in 2019 vs 12.0% in 2020, p=0.04). Neuro-oncology procedure volume decreased by 45.5% (174 vs 318, p=0.04) but maintained a consistent proportion of all neurosurgeries (28.9% in 2020 vs 21.9% in 2019, p=0.09). Functional neurosurgery volume, which declined by 81.4% (41 vs 220, p=0.008), represented only 6.8% of cases during the pandemic versus 15.2% in 2019 (p=0.02). CONCLUSIONS: Operative restrictions during COVID-19 led to distinct shifts in neurosurgical practice, and local infective burden played a significant role in operative volume and patient acuity