Independent predictors for recurrence of chronic subdural hematoma.

BACKGROUND: Chronic subdural hematoma is characterized by blood in the subdural space that evokes an inflammatory reaction. Numerous factors potentially associated with recurrence of chronic subdural hematoma have been reported, but these factors have not been sufficiently investigated. In this study, we evaluated the independent risk factors of recurrence.
METHODS: We analyzed data for 420 patients with chronic subdural hematoma treated by the standard surgical procedure for hematoma evacuation at our institution.
RESULTS: Ninety-two (21.9 %) patients experienced at least one recurrence of chronic subdural hematoma during the study period. We did not identify any significant differences between chronic subdural hematoma recurrence and current antiplatelet therapy. The recurrence rate was 7 % for the homogeneous type, 21 % for the laminar type, 38 % for the separated type, and 0 % for the trabecular type. The rate of recurrence was significantly lower in the homogeneous and trabecular type than in the laminar and separated type. We performed a multivariate logistic regression analysis and found that postoperative midline shifting (OR, 3.6; 95 % CI, 1.618-7.885; p = 0.001), diabetes mellitus (OR, 2.2; 95 % CI, 1.196-3.856; p = 0.010), history of seizure (OR, 2.6; 95 % CI, 1.210-5.430; p = 0.014), width of hematoma (OR, 2.1; 95 % CI, 1.287-3.538; p = 0.003), and anticoagulant therapy (OR, 2.7; 95 % CI, 1.424-6.960; p = 0.005) were independent risk factors for the recurrence of chronic subdural hematoma.
CONCLUSIONS: We have shown that postoperative midline shifting (≥5 mm), diabetes mellitus, preoperative seizure, preoperative width of hematoma (≥20 mm), and anticoagulant therapy were independent predictors of the recurrence of chronic subdural hematoma. According to internal architecture of hematoma, the rate of recurrence was significantly lower in the homogeneous and the trabecular type than the laminar and separated type.