Neurointerventional radiology, or endovascular neurosurgery, is a newly developed and rapidly evolving specialty that uses minimally invasive procedures to diagnose and treat vascular disorders of the brain and spine. With advanced imaging for guidance, neurointerventionalists use microcatheters (tiny tubes) to treat many complex disorders. In general, these disorders are treated either by closing (embolization) or opening (recanalization) the abnormal vessels. Many disorders that previously needed ‘open’ neurosurgery can now be treated with these techniques. This minimally invasive approach can be beneficial to patients as these procedures can be less frightening, less disfiguring, and potentially safer for patients while allowing a quicker recovery.
In neurointerventional radiology, embolization refers to the closing of vascular channels. Several items may be used to close the vessel, depending on the nature of the vascular abnormality. Micro-particles and coils can be used to close the multiple vessels of tumors (benign and malignant), vascular shunts (DAVF, SDAVF), and nosebleeds (epistaxis). N-BCA, an acrylic glue, may be used to treat arteriovenous malformations (AVM) and arteriovenous fistulas (AVF). Sclerosing agents, such as ethanol, are used to treat superficial vascular lesions (angiomas, lymphangiomas and hemangiomas). Detachable platinum coils are used to embolize intracranial aneurysms.
Alternatively, neurointerventional techniques are used to open stenosed (narrowed) or even occluded vessels. Examples of stenosed vessels include carotid artery stenosis, intracranial arterial stenosis and vasospasm after subarachnoid hemorrhage. Angioplasty balloons, stents and medicines are used to open these stenoses. An example of an occluded vessel is an acute ischemic stroke. Medicines such as r-tPA and mechanical devices are used to reopen the occluded vessel.
In all neurointerventional cases, an initial diagnostic angiogram is performed to detect and characterize the abnormality to be treated. The neurointerventionalist puts a small catheter into the femoral artery in the groin area. The catheter is then moved into the aorta, then into the vessels of the neck. Multiple pictures are taken of the vessels in the neck and head while contrast (dye) is injected. These pictures, the angiogram, are then analyzed by the neurointerventionalists.
When an interventional therapy is to be performed, a slightly larger guide catheter is advanced from the femoral artery into the vessels of the neck. Through this guide catheter, a smaller microcatheter (less than 1mm diameter) is advanced to the vascular abnormality and the intervention is performed.
Patients are given sedating medications for all diagnostic procedures. Most neurointerventional procedures require the patient to be under general anesthesia.
