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Endovascular neurosurgery is a discipline that
combines neurosurgery with a field called “interventional neuroradiology.”
Instead of open operations, this minimally invasive technique uses x-ray imaging,
catheters, and various embolic (clotting) agents to treat diseases of the blood vessels of
the brain and spine. The “surgery” is performed in a fluoroscopy suite
rather than an operating room, and the procedure is done within the blood vessels by
using catheters to fill blood vessel abnormalities with obstructing particles, polymers or
stents. (see "An Aneurysm Treatment Primer" below to understand the
illustrations)
Diagnostic neuroradiology was invented by a neurosurgeon, Egas Moniz, many years ago. More recently interventional neuroradiology is becoming more commonplace. The more common diseases treated include carotid artery stenosis, cerebral aneurysms, arteriovenous malformations (avms) of the brain and spine, and dural avms of the brain and spine. Occasional brain tumors can also be treated with a combination of endovascular surgery and open neurosurgical procedures.
Historically, the techniques of interventional neuroradiology
were used along with open neurosurgery. Currently, many of these techniques can be
the only treatment necessary for various diseases. An example of this is the
treatment of complex cerebral aneurysms when the risk of open operations exceed the
risk of endovascular surgery. Some aneurysms, due to the size or location within the
brain are very difficult to treat successfully and safely with traditional neurosurgical
techniques. Over the last decade, the effectiveness and safety of endovascular
neurosurgery has improved and catheter techniques have become the treatment of
choice for certain aneurysms. This can be the case with cerebral aneurysms near the
brainstem, such as basilar artery aneurysms. Previously the death rate from
operations to repair these aneurysms was greater than 30%. Currently the risk of
surgery is lower, but still substantial.
Endovascular surgery of cerebral aneurysms is performed by placing
a flexible catheter within the femoral artery ( the artery supplying the leg) and
floating the catheter in the bloodstream into the aneurysm. From here Guglielmi
Detachable Coils (GDCs) can be deposited into the aneurysm to block the flow of blood into
the aneurysm and cause the aneurysm to become clotted.
Endovascular techniques can treat a variety of intracranial disorders:
Case study: An aneurysm of the basilar artery, situated at the base of the brain and technically difficult to operate was successfully treated by endovascular coils.
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A side view of the rounded aneurysm filled with dye at the top of the basilar artery |
After six coils have been placed through a catheter in the basilar artery, the aneurysm no longer fills with blood |
*An aneurysm treatment primer:
A cerebral aneurysm is a saccular bulging of the wall of an artery. The cause is a structural weakness in the wall of the artery. For hydrodynamic reasons, these bulges appear at places where arteries divide into smaller branches. These aneurysms slowly enlarge with time and may rupture, causing bleeding within the brain. Most individuals do not survive spontaneous hemorrhage for aneurysms.
Individuals who survive an initial hemorrhage may be treated by open surgery to obliterate the aneurysm or endovascular methods to fill the aneurysm with clot. Endovascular methods avoid open surgery but can only be used in selected cases. This new method of aneurysm treatment has much future potential and is performed by our newest member, Dr. Tantuwaya.
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Aneurysms occur at the division of arteries |
Pulsating blood flow causes bulging of the weak arterial wall which may rupture with fatal outcome | A surgically applied clip excludes the aneurysm from circulation, preventing rupture and hemorrhage | An catheter within the artery can fill the aneurysm with clotting material to exclude it from circulation |