Embolization of the Middle Meningeal Artery for the Prevention of Chronic Subdural Hematoma Recurrence in High Risk Patients (EMPROTECT)

Introduction: chronic SDHs are some of the most frequently encountered neurosurgical emergencies. The gold standard treatment of symptomatic chronic SDHs is burr-hole surgery followed by temporary closed system drainage. Post-operative recurrence rates may be as high as 10 to 20% and are a major source of morbidity and repeated surgery. MMA embolization is a promising minimally invasive procedure recently proposed as a treatment of chronic SDH. It is hypothesized that post-operative MMA embolization may reduce recurrence rate in patients at high risk of recurrence.

Aims: the primary objective of the trial is to assess the efficacy of MMA embolization in reducing the risk of chronic SDH recurrence at 6 months after burr-hole surgery as compared with standard medical treatment in patients at high risk of post-operative recurrence. Secondary objectives include evaluating the impact of post-operative MMA embolization on rate of recurrence requiring new surgery (at 6 months), rate of functional dependency (at 1 and 6 months) , mortality (at 1 and 6 months) , cumulative hospital stay duration, related to the SDH, and complication rate at 6 months.

Methods: multicenter open label randomized controlled trial. Eligible patients will be assigned either to the intervention or a control arm through blocked randomization with randomblock sizes and stratified on the center, antiplatelet/anticoagulant therapy and unilateral vs bilateral SDH. Patients in the intervention group will undergo a CT angiography scan of the supra aortic trunks, followed by MMA embolization procedure within 7 days of the burr-hole surgery in addition to standard medical care. Patients in the control group will receive standard medical care only. Outcomes will be evaluated at 1 and 6 months. The primary outcome measure will be the rate of chronic SDH recurrence 6 months after index burr-hole surgery, as defined bellow. In order to demonstrate a decrease in recurrence rate from 15 to 5% between the intervention and control arms with a power of 80%, bilateral global alpha risk of 5%, with two planned sequential tests according to the method of Lan & Demets, and 20% patients lost to follow-up, 342 patients are required, 171 in each arm. The primary outcome will be analyzed according to intention to treat.

Inclusion criteria

Patient:

• Aged ≥ 18 years
• Operated for a SDH recurrence or operated for a first episode of SDH if at least one of the following recurrence risk factors is present:
• Chronic alcoholism defined by a daily alcohol consumption > 30g/day
• Or liver cirrhosis
• Or antiplatelet therapy
• Or anticoagulant therapy
• Or thrombocytopenia with a platelet count < 100 x10(3) per µL
• Or surgery without use of external drain
• With affiliation to a social security scheme
• Having signed an informed consent form or for whom a delegate close relative or a support person has signed an informed consent

Exclusion criteria

• SDH evacuation by craniotomy or twist-drill craniostomy rather than burr-hole surgery
• Beyond 7 days after the index surgery (surgery for recurrent SDH or first surgery in case of a risk factor as indicated in the inclusion criteria)
• Functionally dependant patient with an mRS score ≥ 4 before the SDH
• Patient with a life expectancy < 6 months
• Patient with renal failure as defined by a creatinine clearance < 30 ml/min
• Pregnancy
• History of allergy to a iodinated contrast agent
• Procedure deemed unachievable under local anesthesia (because of patient agitation or discomfort for instance) in a patient with a contraindication to both conscious sedation and general anesthesia.
• Patient refusal
• Patient for whom follow-up is deemed problematic (living abroad or homeless for instance )
• Patients under legal guardianship or trusteeship