Recurrence of chronic subdural haematomata with and without post-operative drainage.

Chronic subdural haematoma is a common disease causing morbidity and mortality. Recurrence after surgical treatment is common, varying from 5% to 30% of cases. Several methods for reducing recurrence have been advocated. The aim of this study was to investigate the effect of post-operative subdural drainage. Three hundred forty-four patients were included in a retrospective study. Treatment was performed by burr hole irrigation. Groups were separated into those with post-operative drainage compared to those without. Recurrence occurred in 14% in the drained group, significantly less than 26% in the undrained group (p=0.011). There were no differences in the complication rates. Post-operative drainage reduces recurrence of chronic subdural haematoma without increasing the complication rate. These results support those reported in several other studies. We recommend the use of post-operative subdural drainage.