Acute Surgery vs Conservative Treatment for Traumatic Acute Subdural Hematoma.

Importance: It is unclear whether performing surgery for most patients with an acute subdural hematoma (ASDH) and traumatic brain injury (TBI) is superior to conservative treatment. Objective: To compare the effectiveness of a strategy preferring acute surgical ASDH evacuation with one preferring initial conservative treatment. Design, Setting, and Participants: This comparative effectiveness study used data from February 1, 2014, to July 31, 2018, from the prospective observational Transforming Research and Clinical Knowledge in Traumatic Brain Injury Study, conducted at 18 Level 1 trauma centers in the US. The study included patients with nonpenetrating TBI presenting to the emergency department and admitted within 24 hours after injury with ASDH detected on acute head computed tomography scan. Statistical analysis was performed from December 1, 2022, to December 20, 2024. Exposures: Acute surgical hematoma evacuation vs initial conservative treatment, comparing outcomes between centers according to treatment preferences, measured by the case mix-adjusted probability of undergoing acute surgery (vs conservative treatment) per center. Main Outcomes and Measures: Functional disability at 6 months was assessed with the Glasgow Outcome Scale-Extended at 6 months, analyzed with ordinal logistic regression adjusted for prespecified confounders, quantified with a common odds ratio (OR). Variation in center preference was quantified with a median OR (MOR). Results: Of 2697 included patients, 711 (mean [SD] age, 46.5 [19.4] years; 539 men [76%]) had an ASDH, of whom 148 (21%) underwent acute cranial surgery and 563 (79%) underwent initial conservative treatment. The acute surgery cohort had lower mean (SD) Glasgow Coma Scale scores (6.8 [4.4] vs 11.4 [4.6]), more pupil abnormalities (both pupils unreacting: 43 of 133 [32%] vs 41 of 477 [9%]), and fewer isolated ASDHs (eg, more with concurrent intracranial lesions; 92 of 133 [69%] vs 297 of 563 [53%%]) compared with the conservative treatment cohort. In the surgical cohort, 129 of 148 patients (87%) underwent decompressive craniectomy (DC), and 17 of 148 (11%) underwent craniotomy. In the conservative treatment cohort, 67 of 563 patients (12%) underwent delayed cranial surgery (DC or craniotomy). The proportion of patients undergoing acute surgery ranged from 0% to 86% (median, 17% [IQR, 5%-27%]) between centers, with up to a 3-fold higher probability of prognostically similar patients receiving acute surgery in one center compared with another random center (MOR, 2.95 [95% CI, 1.79-7.47]; P = .06). Center preference for acute surgery over initial conservative treatment was not associated with a better outcome (OR, 1.05 [95% CI, 0.88-1.26] per 22% [IQR, 5%-27%] increase in acute surgery at a given trauma center). Conclusions and Relevance: In this comparative effectiveness study, similar patients with traumatic ASDH were treated differently due to center-specific treatment preferences. Outcomes were similar in centers preferring surgical evacuation and those preferring initial conservative treatment. This study suggests that, for a patient with ASDH for whom a neurosurgeon experiences clinical equipoise between acute surgery vs (initial) conservative treatment, conservative treatment may be considered.