Subperiosteal versus Subdural Drain After Burr-hole Drainage Under Blood Thinners: A Subanalysis of the cSDH-Drain RCT

OBJECTIVE: The chronic subdural hematoma (cSDH)-Drain trial compared recurrence rates and clinical outcome associated with the use of subperiosteal drain (SPD) and subdural drain (SDD) after burr-hole drainage for cSDH. This subgroup analysis aimed to determine whether one drain type is preferable for patients treated with platelet inhibitors (PI) or anticoagulants (AC). METHODS: This subanalysis included 133 patients treated with PI/AC of the 220 patients from the preceding cSDH-Drain trial. For these patients the association between the drain type used and recurrence rates, mortality, as well as clinical outcome at 6 weeks and 12 months follow-up were analyzed using a logistic regression analysis model. Additionally, recurrence rates, clinical outcome, and mortality were assessed for each PI or AC type separately. RESULTS: The insertion of SPD was associated with 7.35% recurrence rates compared to 13.85% with SDD in patients treated with PI or AC (OR 0.41, 95% CI 0.06-2.65, P = 0.36). Outcome measurements and mortality did not differ significantly between both groups at 6-week and 12-month follow-up. In addition, there was no statistically significant association between drain type and recurrence rate or mortality when comparing data for each PI or AC type. At 24 hours postoperatively, significantly more patients under phenprocoumon and natrium-dalteparin had a Glasgow Coma Scale score between 13 and 15 in the SDD group compared with the SPD group (P = 0.006), whereaas at 6-week follow-up significantly more patients in the SDD group treated with ASA had a good modified Rankin scale score (P = 0.01). At 12 months, no significant difference in outcome measurements was seen for all PI and AC types. CONCLUSIONS: In patients treated with PI or AC, the insertion of SPD after burr-hole drainage of cSDH showed comparable recurrence, mortality, and long term outcome rates when compared with SDD.