CEREBRAL VASCULAR MALFORMATIONS are congenital or acquired lesions made up of vessels and located in the brain or on its surface. They can take the form of intracerebral or pericerebral (subarachnoid) haemorrhage. Some can cause serious bleeding, while others have a very low risk of bleeding and are therefore completely benign. When treatment is required, there are a number of possible therapeutic modalities (surgery, endovascular treatment through the interior of the vessels, radiotherapy) depending on the type, size and configuration of the malformation and the patient’s general condition. These modalities are discussed in multidisciplinary consultation in order to offer the optimum therapeutic solution for each patient.
Type of cerebrovascular malformation
We distinguish :
- arterial aneurysms
- arteriovenous malformations
- dural fistulas
- cavernomas
- venous angiomas
- telangiectasias
What vascular malformations have in common is that they can manifest themselves suddenly as haemorrhage:
- haemorrhage around the brain in the subarachnoid spaces called subarachnoid haemorrhage or meningeal haemorrhage
- cerebral hemorrhage or cerebellar hemorrhage in the brain or cerebellum
- cerebro-meningeal hemorrhage when the hemorrhage is both in the sub-arachnoid spaces and in the brain.
These vascular malformations may also be discovered incidentally during a CT or MRI scan performed to look for something else.
Finally, they can manifest as epilepsy.
Therapeutic methods used in neurosurgery
-
Surgery
Excluding an aneurysm or arteriovenous malformation sometimes requires opening the skull. In the case of aneurysms, after dissection of the aneurysm sac and surrounding major arterial branches, a clip (a kind of micro-clamp) is applied to the base of the aneurysm to exclude the aneurysm from the bloodstream. This prevents the sac from rupturing, or re-rupturing if the aneurysm has already ruptured.
-
Bypass
Bypass surgery in neurosurgery is the equivalent of coronary bypass surgery in cardiac surgery. This involves connecting two arteries using micro-sutures to revascularize a brain territory. This technique is reserved for the treatment of Moya-Moya disease, complex aneurysms or revascularization of insufficiently perfused areas of the brain. Bypass surgery may also be necessary when a major cerebral vessel is infiltrated by a tumor and must be sacrificed to allow removal of the tumor.
-
Embolization
Embolization of an aneurysm, arteriovenous malformation or dural fistula is a procedure that avoids opening the skull. Microcatheters are inserted by puncture of the femoral artery (artery of the leg), allowing injection of a contrast medium that outlines the normal vascular tree and its anomalies. Various materials are then inserted into the malformation, through the interior of the vessels, to eliminate/block the malformation. Several devices can be inserted using this method, such as coils (metal microspires), stents, microparticles or glue. The aim is to prevent blood flowing into the vascular malformation by filling it with the chosen material and/or blocking access to blood flow (stent).
-
Radiosurgery
Radiosurgery is most often used for brain tumors, but can also be applied to other areas of neurosurgery, including the treatment of arteriovenous malformations. We use radiation whose trajectory is precisely calculated to reach only the target without irradiating the healthy brain around the malformation. Depending on the technology used, this technique involves fitting a frame over the head under local anaesthetic, or a face mask. It’s a painless, outpatient procedure requiring one or more sessions.
Each patient presenting with a surgical neurovascular pathology is presented at a multidisciplinary meeting attended by the neurosurgical team (Prof. S. Froelich’s department), the interventional neuroradiology team (Prof. E. Houdart’s department) and the neurology team (Prof. M. Mazighi). A therapeutic decision is made on the basis of clinical and radiological findings.
Research and training
The neurosurgery, interventional neuroradiology and neurology departments are developing research and training activities in the field of vascular pathologies in order to:
- Better understand the origin and development mechanisms of aneurysms and AVMs in order to optimize their therapeutic management
- Enable combined neurosurgical and endovascular procedures
- Better understand the vascularization of certain skull base meningiomas in order to adapt the surgical procedure
- Better understanding of certain pathologies such as “benign” idiopathic intracranial hypertension
- Develop training in vascular neurosurgery in Prof. S. Froelich’s experimental neurosurgery laboratory.
CERVCO Network, Reference Center for Rare Vascular Diseases of the Brain and Eye
The Neurosurgery Department also participates in the CERVCO network, a reference center for rare vascular diseases of the brain and eye, whose missions are to :
- Improve care for rare diseases, in conjunction with clinicians at national level and in coordination with the family associations concerned.
- Set up protocols for the management of these conditions, and adapt them regularly in line with developments in research,
- Disseminate all useful information to patients, their families, and to all doctors and caregivers in charge of these pathologies at national level,
- Improve knowledge of the mechanisms of these diseases through research developed at CERVCO.