Predictors of recurrence and reintervention in non-acute subdural hematoma: A multimodal analysis of radiological, clinical, surgical, and endovascular factors.

Non-acute subdural hematomas (naSDH), encompassing subacute and chronic subdural hematomas, are a common neurosurgical condition in older adults with substantial recurrence rates after treatment. Management has become increasingly multimodal, combining surgical and endovascular strategies; however, the influence of clinical, radiological, surgical and technical factors on recurrence and reintervention remains under investigation. We conducted a retrospective multicenter cohort study including patients from six high-complexity neurosurgical and neurointerventional referral centers in Colombia between January 2023 and June 2025. Adult patients with symptomatic non-acute subdural hematoma confirmed by CT were included. Hematomas were managed with surgery alone, combined surgery and middle meningeal artery embolization, or embolization alone. Recurrence and reintervention were evaluated as outcomes. Univariable and multivariable logistic regression analyses were performed to identify factors associated with the primary outcomes. A total of 247 naSDH were analyzed. Recurrence occurred in 51 hematomas (20.6%) and reintervention in 44 (17.8%). In multivariable analysis, smoking (OR 9.59, 95% CI 1.93-47.52), hypertension (OR 5.23, 95% CI 1.14-23.93), increasing age (OR 1.07, 95% CI 1.00-1.16), and greater hematoma thickness (OR 1.20, 95% CI 1.05-1.37) were independently associated with recurrence. Combined surgery with embolization was associated with reduced recurrence (OR 0.44, 95% CI 0.22-0.88). Among surgical variables, post-drain pneumocephalus significantly increased recurrence risk (OR 13.32, 95% CI 2.83-62.65), whereas longer durostomy drainage duration reduced the recurrence (OR 0.51, 95% CI 0.30-0.85). Endovascular technical factors were not independently associated with recurrence. Clinical factors showed the strongest association with recurrence. Combined surgery and embolization showed a protective association, while postoperative pneumocephalus and drainage duration significantly influenced possible outcomes.