Prospective Study on the Use of Middle Meningeal Artery Embolization for Chronic Subdural Haematoma

Subdural haematoma is a common neurosurgical condition that results in different levels of neurological deficits in patients. It can be further classified into acute and chronic, which have different pathophysiology. Acute haematoma is a common result of traumatic injuries involving the tearing of the bridging veins, while chronic subdural haematoma can be both a result of traumatic injuries or recurrence following surgical management of the acute counterpart. For symptomatic patients, they are often surgically managed by haematoma drainage via burr-hole drainage and craniotomy. Recurrent bleeding following close monitor or surgical evacuation of haematoma is however very high. Recent studies approximate the recurrence rate of 2%-33.3%. Recent evidence suggests the angiogenesis of middle meningeal arteries (MMA) in response to inflammation and healing process contributes to the development of chronic subdural haematoma, and its high recurrence chance. Several studies have looked into the use of middle meningeal artery embolization to halt the bleeding of a chronic subdural haematoma, and have found promising results in terms of haematoma reduction and prevention of surgical rescues.

The primary goal of the study is to assess the safety and efficacy of middle meningeal artery embolization in treating patients presenting with subdural haematoma. Previous studies and trial in other countries have shown promising results. This study aims to serve as the pilot clinical study of the procedure in Hong Kong and setting the ground work for a future multi-centre randomised trial.

Patients presenting with subdural haematoma will be assessed clinically and radiologically. Patients' demographic information, clinical information, and past medical history will be recorded for the purpose of the study. Symptomatic patients will undergo haematoma removal either by burr-hole drainage or craniotomy. They will undergo a series of CT-scans before and after treatment to assess the characteristics of the haematoma (size, side, site, composition of the haematoma, etc). Patients will then be divided into the embolization group and the control group. Patients with residual or recurrent haematoma (higher than 10mm thickness of haematoma at any dimension) following prior surgical evacuation of haematoma will be admitted to the Embolization Group and undergo embolization of MMA. Serial CT scans will be taken at times of presentation of the residual or recurrent haematoma, 1-day, 1-week, 1-month, 3-month, and 6-month following embolization. Size of haematoma will be measured for comparison to the Control Group. Clinical examinations will be done at the same setting. For the control group, after the initial treatment of haematoma removal, they will be monitored clinically for signs of neurological deficits, presentation of symptoms. They remain in control group should they refuse entering the MMA embolization group. They will have the same clinical and radiological follow-up as the embolization group.

MMA embolization will be performed with a liquid embolization agent with local anaesthesia. Selective angiography will be performed before embolization to select MMA branch targets and detect potentially dangerous collateral vessels. If no dangerous collaterals are found, MMA branches supplying to the dura of convexity will be targeted and embolized according to findings of the selective angiography using a liquid embolization agent. If dangerous collaterals are identified, the microcatheter will be advanced more distally or the collaterals will be coiled prior to embolization. Procedure will be concluded once the flow stasis of MMA is confirmed. Embolization is considered successful if all MMA targets are embolized without procedural complications.

Patients with existing use of antiplatelet or anticoagulation medication will not undergo medication reversal for the embolization procedure.

Patients will be discharged following treatment based on the results of the post-operative assessments.

Eligibility Criteria:
Inclusion Criteria:

* Patients (age 18 or above) with chronic subdural haematoma diagnosed by computed tomography and clinical presentation.

Exclusion Criteria:

* SDH with thickness of 10mm or less, lack of mass effect.
* SDH secondary to existing conditions (brain tumour, arachnoid cyst, spontaneous intracranial hypotension, previous craniotomy not due to chronic SDH)
* Patients in poor medication condition or with life expectancy less than 6 months.