Influence of Postoperative Thrombosis Prophylaxis on the Recurrence of Chronic Subdural Hematoma After Burr-Hole Drainage

OBJECTIVES: Chronic subdural hematoma is a commonly encountered disease in neurosurgic practice, whereas its increasing prevalence is compatible with the ageing population. Recommendations concerning postoperative thrombosis prophylaxis after burr-hole drainage of chronic subdural hematoma are lacking. The aim of this study was to analyze the correlation between recurrence of chronic subdural hematoma and postoperative application of thrombosis prophylaxis. DESIGN: Retrospective, consecutive sample of patients undergoing burr-hole drainage for chronic subdural hematoma over 3 years. SETTING: Single, academic medical center. PATIENTS: All patients undergoing surgical evacuation of a chronic subdural hematoma with burr-hole drainage. Exclusion: patients under the age of 18 years, who presented with an acute subdural hematoma and those who underwent a craniotomy. INTERVENTIONS: We compared patients receiving thrombosis prophylaxis treatment after burr-hole drainage of chronic subdural hematoma with those who were not treated. Primary outcome measure was reoperation of chronic subdural hematoma due to recurrence. Secondary outcome measures were thromboembolic and cardiovascular events, hematologic findings, morbidity, and mortality. In addition, a subanalysis comparing recurrence rate dependent on the application time of thrombosis prophylaxis (textless 48 vs textgreater 48âEuro‰hr) was undertaken. MEASUREMENTS AND MAIN RESULTS: Overall recurrence rate of chronic subdural hematoma was 12.7%. Out of the 234 analyzed patients, 135 (57.3%) received postoperative thrombosis prophylaxis (low-molecular-weight heparin) applied subcutaneously. Recurrence of chronic subdural hematoma occurred in the thrombosis prophylaxis group and control group in 12 patients (8.9%) and 17 patients (17.2%), respectively, showing no significant difference (odds ratio, 0.47 [95% CI, 0.21 - 1.04]). A subanalysis comparing recurrence rate of chronic subdural hematoma dependent on the application time of thrombosis prophylaxis (textless 48 vs textgreater 48âEuro‰hr) showed no significant difference either (odds ratio, 2.80 [95% CI, 0.83-9.36]). Higher dosage of thrombosis prophylaxis correlated with recurrence rates of chronic subdural hematoma, both in univariate and multivariate analyses. CONCLUSIONS: Our data suggest that the application of postoperative thrombosis prophylaxis after burr-hole drainage for chronic subdural hematoma does not result in higher recurrence rates of chronic subdural hematoma. In addition, it seems that early administration of thrombosis prophylaxis (textless 48âEuro‰hr) has no influence on recurrence rates; however, high dosage seems to increase recurrence rates.