An Algorithm for Treatment of Symptomatic Chronic Subdural Hematomas

Introduction: Although chronic subdural hematoma (CSDH) is a common neurosurgical disease, there is a lack of algorithms for the treatment of asymptomatic and symptomatic CSDH. The purpose of this article is to describe an algorithm developed using our institutional experience for the treatment of symptomatic CSDH that aims to decrease symptoms and/or hematoma size or to completely resolve both. Our algorithm for treatment of symptomatic CSDH includes subdural drain (SDD) placement via twist-drill craniostomy (TDC) as the first-line treatment, followed by supplemental tissue plasminogen activator (tPA) as second-line treatment, with possible middle meningeal artery embolization (MMAE), followed by craniotomy as the last therapeutic option. This study investigated the efficacy of our institution's algorithm in treating symptomatic CSDH. Methods: A retrospective study was conducted from 2019 to 2023 identifying patients with CSDH treated with TDC. Electronic medical records were used to gather patient demographics, clinical presentation, radiographic findings, treatment modalities, and clinical outcomes. Results: There were a total of 109 patients with 128 SDD placements. All 109 patients underwent TDC; among them, 37 patients received tPA instillation with three patients requiring craniotomy. Factors including age, gender, race, mechanism of injury, blood thinner usage, Glasgow Coma Scale (GCS), neurologic exam, thickness of CSDH, and midline shift were comparable for all patients regardless of treatment received. The mean number of neomembranes was higher in patients who eventually required craniotomy (4.5) compared to those treated with TDC only (1.8) and TDC+tPA (2.1) (p=0.0035). There was a greater mean hematoma drainage in patients who received tPA instillation without craniotomy (586.7 mL) than those treated with TDC only (293.0 mL) (p<0.0001). Clinical improvement was found in 52/72 patients (72.2%) treated with TDC only, 23/34 patients (67.6%) treated with TDC+tPA only, and 0/3 patients (0.0%) treated with TDC+tPA+craniotomy. Radiographic improvement in mean thickness of CSDH and midline shift, respectively, was found in patients treated with TDC only (p<0.0001; p<0.0001) and TDC+tPA (p<0.0001; p<0.0001) but not in TDC+tPA+craniotomy (p=0.1494; p=0.0762). There were also fewer neomembranes after TDC+tPA treatment only (2.1 vs. 0.5, p<0.0001). Seven patients were readmitted that did not follow the algorithm and only patients treated following the algorithm showed clinical and radiographic improvement. Conclusions: Using our institutional algorithm, our study demonstrates successful clinical outcomes in treating symptomatic CSDH and recurrent CSDH with minimally invasive therapeutic interventions including SDD via TDC and tPA, thereby minimizing the utilization of more invasive interventions including craniotomy.