Hematoma cavity separation and neomembrane thickness are potential triggers of recurrence of chronic subdural hematoma

BACKGROUND: Chronic subdural hematoma (CSDH) is the anomalous and encapsulated accumulation of fluid of complex origin consisting of old blood, mostly or totally liquified and cerebrospinal fluid (CSF) in the subdural space usually after a head injury in the elderly. Almost all the research on surgical techniques and endoscopic assisted evacuation of CSDH focused on the just the evacuation and not abnormal anatomical structures that causes recurrences. OBJECTIVES: We investigated abnormal anatomical structures that triggers recurrence of CSDH during craniotomy as well as burr-hole craniostomy with endoscopic assistance. MATERIALS AND METHODS: We retrospectively analyzed all patients with CSDH who underwent craniostomy and burr-hole craniotomy with endoscopic assisted evacuation of hematoma between April 2017 and November 2020 at our institution. Clinical data obtained was categorized into patient-related, radiology as well as surgery and endoscopic evaluations. RESULTS: A total of 143 patients (109 men and 34 women) aged 43–94 years (mean age, 68.35 years) with CSDH were included in this study. We observed a recurrence rate of 4.9% (7/143). Recurrences occurred between 2 and 6 months after the operation in patients with recurrences. Our data revealed that, age, hypertension, history of injury, diabetes, antiplatelet or anticoagulant use were not associated with hematoma recurrence. Nevertheless, all the patients with recurrence of hematoma were males. Interestingly, our univariate and multivariate analyses found neomembrane thickness and hematoma cavity separation as independent risk factors (OR,45.822; 95% CI,2.666-787.711; p = 0.008) for the recurrence of CSDH (p < 0.05). Also, we observed thickened membranes connecting/separating the dura and the thickened arachnoid/pia matters in all the 7 patients with hematoma recurrence. CONCLUSIONS: The treatment of patients with CSDH ought to include the identification and resection of abnormal thickened membranes connecting/separating the dura and the thickened arachnoid/pia matters to avoid recurrence. Comparatively, endoscopy showed hematoma cavity separation or neomembrane thickness just as seen during craniotomy.