Subdural Drain Removal After Burr Hole Craniostomy for Chronic Subdural Hematoma
Remove the subdural drain 48 hours postoperatively when drainage output is low (<50-100 mL/24h), becomes macroscopically serous, and there are no signs of infection or neurological deterioration. 1, 2, 3
Timing of Drain Removal
Standard practice supports drain removal at 48 hours post-burr hole craniostomy, which represents the most widely validated approach in chronic subdural hematoma management 3, 4. This fixed-time drainage strategy has demonstrated:
- Recurrence rates of 6-13% when drains are used for 48 hours 4, 5, compared to 18% without drain placement 4
- Significant reduction in early postoperative clinical deterioration when closed-system drainage is maintained for 2-4 days 6, 3
Criteria for Safe Drain Removal
The drain can be removed when all of the following conditions are met:
- Drainage output is minimal (<50-100 mL/24h) and becoming serous rather than sanguineous 7
- No active bleeding or reaccumulation on clinical assessment 3
- Neurological status is stable or improving 1, 2
- No signs of infection at the drain site or systemically 4
Evidence Supporting 48-Hour Protocol
The Helsinki experience demonstrated that routine subdural drain placement for 48 hours reduced 6-month recurrence from 18% to 6% (OR 0.28,95% CI 0.09-0.87, P=0.028) with no increase in infections or complications 4. This real-world implementation study validates the randomized controlled trial data supporting drain use 4.
Burr hole craniostomy with closed-system drainage for 2-4 days should be the method of choice for initial treatment of chronic subdural hematoma 3. The 104-patient series by Ernestus et al. showed good clinical outcomes (72.3% with no or mild deficits) using this approach 3.
Alternative Approach: Exhaustive Drainage
An emerging strategy involves "exhaustive drainage" where the drain remains until output is minimal, rather than fixed-time removal 8. This approach aims to minimize postoperative hematoma volume, which significantly increases recurrence risk 8. However, this remains investigational and the standard 48-hour protocol is currently recommended 3, 4.
Critical Pitfalls to Avoid
- Do not remove drains earlier than 24-48 hours, as this increases risk of early postoperative deterioration and reaccumulation 6, 3
- Avoid chest tube stripping or breaking the sterile field to maintain drain patency, as these techniques are ineffective and potentially harmful 7
- Do not delay drain removal beyond 4 days without clear indication, as prolonged drainage increases infection risk without additional benefit 3
- Monitor for drain clogging, which occurs in up to 36% of cases and may require active clearance methods to prevent retained blood complications 7
Post-Removal Monitoring
After drain removal: