Endovascular neurosurgery is a super specialized field of neurosurgery that uses minimally invasive techniques to treat various disorders of the brain, including stroke, cerebral aneurysm, and arteriovenous malformation (AVM). The term "endovascular" refers to the technique of treating the problem from inside the blood vessel.
A stroke, sometimes called a "brain attack," occurs when blood flow to the brain is interrupted. When a stroke occurs, brain cells in the immediate area begin to die because they stop getting the oxygen and nutrients they need to function. An ischemic stroke is caused by a blood clot that blocks or plugs a blood vessel or artery in the brain. Hemorrhagic stroke is caused by a blood vessel in the brain that breaks and bleeds into the brain.
Acute stroke therapies try to stop a stroke while it is happening by quickly dissolving the blood clot causing an ischemic stroke or by stopping the bleeding of a hemorrhagic stroke. Endovascular treatment includes the Penumbra System, which helps restore brain blood flow by using suction to grab blood clots in the brain for treatment of acute ischemic stroke. The Merci Retrieval System is another treatment option that has been proven to restore blood flow in the larger vessels of the brain by removing blood clots. The system is a tiny corkscrew shaped device that works by wrapping around the clot and trapping it. The clot is then retrieved and removed from the body.
Cerebral aneurysm is the dilation, bulging, or ballooning-out of part of the wall of an artery in the brain. There are four main types of aneurysm, but most occur where an artery branches. Aneurysms can rupture and cause bleeding into the brain.
The endovascular treatment option to prevent rupture is called coiling, where the tip of a catheter is inserted into an artery in the groin and advanced through the blood stream to the site of the aneurysm. There it is used to insert platinum coils that induce clot formation within the aneurysm.
Arteriovenous malformations (AVMs) are defects of the circulatory system that can develop in many different sites. Those located in the brain can have especially widespread effects on the body. Most people with neurological AVMs experience few, if any, significant symptoms. But for about 12 percent of the affected population, these abnormalities cause symptoms that vary greatly in severity.
Endovascular treatment includes embolization or gluing of the AVM. With endovascular embolization, the surgeon guides a catheter though the arterial network until the tip reaches the site of the AVM. The surgeon then introduces a substance that will plug the malformation, correcting the abnormal pattern of blood flow. This process is known as embolization because it causes an embolus (an object or substance) to travel through blood vessels, eventually becoming lodged in a vessel and obstructing blood flow. The embolic materials used to create an artificial blood clot in the center of an AVM include fast-drying biologically inert glues, fibered titanium coils, and tiny balloons. Since embolization usually does not permanently obliterate the AVM, it is usually used together with surgery or radiosurgery to reduce the blood flow through the AVM and make the surgery safer.