Prospective randomized placebo-controlled double-blind clinical study of adjuvant dexamethasone with surgery for chronic subdural haematoma with post-operative subdural drainage: interim analysis

Most chronic subdural haematomas (CSDH) are successfully treated neurosurgically. However, operative recurrences occur with a frequency 3–30%, consume resources and potentially prolong length-of stay (LOS). The only adjuvant factor proven to significantly decrease CSDH recurrence rate (RR) is post-operative subdural drainage. Corticosteroids have been used to conservatively manage CSDH. One non-randomised study also compared dexamethasone (DX) as an adjunct to surgery without post-operative drainage: whilst a null effect was observed, the ‘surgery-alone’ group consisted of only n = 13. We present an interim analysis of the first registered prospective randomised placebo-controlled trial (PRPCT) of adjuvant DX on RR and outcome after CSDH surgery with post-operative drainage. Participants were randomised to either placebo or a reducing DX regime over 2 weeks, with CSDH evacuation and post-operative drainage. Post-operative mortality (POMT) and RR were determined at 30 days and 6 months; modified Rankin Score (mRS) at discharge and 6 months. Post-operative morbidity (POMB) and adverse events (AEs) were determined at 30 days. Interim analysis at approximately 50% estimated sample size was performed (n = 47). Recurrences were not observed with DX: only with placebo (0/23 [0%] v 5/24 [20.83%], P = 0.049). There was no significant between-group differences in POMT, POMB, LOS, mRS or AEs. Conclusions: In this first registered PRPCT, interim analysis suggested that adjuvant DX with post-operative drainage is both safe and may significantly decrease recurrences. A 12.5% point between-groups difference may be reasonable to power a final sample size of approximately n = 89. Future studies could consider adjuvant DX for longer than the arbitrarily-chosen 2 weeks