Background: Chronic subdural hematoma (CSDH) is a frequently encountered neurosurgical condition, especially in the elderly. We investigated predictive factors for surgical and functional outcomes after burr-hole drainage (BHD) surgery.
Methods: All patients with CSDH treated by BHD between January 2012 and December 2014 were included in this study. All patients were classified by symptom, clinical grade, time, location, hematoma density, midline shift, and other characteristics. Pre- and postoperative CT evaluation was performed at 0, 3, and 6 months. Clinical grades were classified as described in Markwalder et al. Surgical and clinical outcomes were evaluated with the brain expansion rate and modified Rankin Scale (mRS). Brain expansion rate was calculated as the ratio between post- and pre-operative hematoma thickness. Recurrence was defined as the occurrence of symptoms and hematoma on CT within 6 months.
Results: This study included 130 patients over 2 years. Among the variable parameters, young age (<75), iso-density of hematoma on CT, and short duration from symptom to surgery were correlated with good brain expansion. Patients with good brain expansion had fewer recurrences. In terms of mRS, young age, iso-density, and good clinical grade were correlated with good functional outcomes.
Conclusions: Clinicians should be more aware of general conditions and medical problems, especially in elderly patients. Membranectomy should be considered in patients with a long duration of symptoms or hypo-dense hematomas to promote good brain expansion and good mRS scores.
Keywords: Burr-hole drainage; Chronic subdural hematoma; Functional outcome; Predictive factors; Surgical outcome.