Related Experiment Video
Updated: Nov 10, 2025
Double Direct Injection of Blood into the Cisterna Magna as a Model of Subarachnoid Hemorrhage
Published on: August 30, 2020
Risk factors for need of reoperation in bilateral chronic subdural haematomas
Shaian Zolfaghari1, Jiri Bartek2,3,4, Felix Djärf5
1Department of Neurosurgery, Institution of Clinical Sciences, Lund University, Lund, Sweden. Shaian.zolfaghari@med.lu.se.
Insights
Upfront bilateral evacuation of bilateral chronic subdural haematoma (bCSDH) is linked to a lower reoperation risk compared to unilateral evacuation. This finding suggests a need for revised treatment guidelines for bCSDH management.
Area of Science:
- Neurosurgery
- Neurology
- Surgical Outcomes
Background:
- Bilateral chronic subdural haematoma (bCSDH) is a common neurosurgical condition.
- bCSDH accounts for 20-25% of chronic subdural haematoma (CSDH) cases and has a higher recurrence rate.
- Current treatment strategies for bCSDH lack a clear consensus regarding unilateral versus bilateral evacuation.
Purpose of the Study:
- To investigate risk factors associated with reoperation in patients diagnosed with bCSDH.
- To compare reoperation rates between unilateral and bilateral evacuation approaches for bCSDH.
Main Methods:
- A retrospective cohort study included 326 patients with radiological evidence of bCSDH.
- Patients were categorized into primary unilateral (n=193) or bilateral (n=133) evacuation groups.
- Reoperation within 3 months was the primary outcome, analyzed using multivariable logistic regression.
Main Results:
- The overall reoperation rate was 26.4%.
- Unilateral evacuation had a significantly higher reoperation rate (32.1%) compared to bilateral evacuation (18.0%, p=0.005).
- Unilateral evacuation (OR 1.91) and complications (OR 2.20) were identified as risk factors for reoperation.
Conclusions:
- Unilateral evacuation of bCSDH is associated with an increased risk of reoperation compared to upfront bilateral evacuation.
- The study highlights the need for further discussion on surgical criteria for bCSDH, given differing center practices.
- Standardizing treatment approaches for bCSDH may improve patient outcomes and reduce reoperation rates.
Background:
Chronic subdural haematoma (CSDH) is one of the most common neurosurgical diseases. A subtype of CSDH is bilateral chronic subdural haematoma (bCSDH) which represents 20-25% of patients with CSDH and has a higher recurrence rate. There is no clear consensus on how bCSDH should be treated regarding upfront unilateral- or bilateral evacuation of both haematomas. The purpose of this study was to identify risk factors associated with reoperation of bCSDH.
Methods:
A total of 326 patients with radiological evidence of bCSDH were included in this retrospective cohort study where 133 (40.8%) patients underwent primary bilateral evacuation and 193 (59.2%) primary unilateral evacuation. The two centres operated using different surgical approaches. Analyses were performed to identify risk factors associated with reoperation of bCSDH. Reoperation rate was defined as reoperation of CSDH on either side of the hemisphere within 3 months after primary evacuation.
Results:
The cohort had a total reoperation rate of 26.4%. Patients which underwent unilateral evacuation had a reoperation rate of 32.1%, and the bilateral group had a reoperation rate of 18.0% (p=0.005). Multivariable logistic regression identified unilateral evacuation (OR 1.91, p=0.022) and complications according to Ibanez (OR 2.20, p=0.032) to be associated with the need of reoperation of bCSDH. One-burr hole craniostomy with active subgaleal drain was primarily performed in bilateral approach (69.4%) whereas patients operated with minicraniotomy with passive subdural drain were primarily operated by unilateral evacuation of the larger symptomatic side (92.8%).
Conclusions:
Unilateral evacuation of bCSDH was associated with a higher risk for reoperation than upfront bilateral evacuations in this study. There is a need to further discuss the criteria for uni- or bilateral evacuation since patients are treated differently at different centres.
