Interventional Neuroradiology Service
Brain Tumor Embolization
On occasion, it is helpful to reduce the blood supply to a brain tumor prior to surgery in order to allow for its safe removal. In such instances, a catheter may be threaded through the vein or artery that leads to the artery. Small particulate material, such as polyvinyl alcohol foam, is then injected into the tumor blood supply to reduce blood flow to the artery. This makes surgery safer and easier and reduces a patient’s blood loss during surgery.
Balloon Angioplasty with Stenting
While carotid endarterectomy is the gold standard for the treatment of stroke and stroke-like symptoms due to atherosclerotic disease involving the carotid arteries, interventional neuroradiology offers a viable alternative for some patients. In the past fewyears, in fact, balloon angioplasty with stenting has become a preferred alternative procedure to surgery for many patients. In this procedure, a radiological catheter is threaded through the artery to the narrowed region. A stent is then placed within the artery, compressing the plaque that has narrowed the opening and thereby enlarging the space available for blood flow. Radiographic results of these procedures can often be spectacular, although, in contrast to carotid endarterectomy, this procedure has not yet conclusively proven to reduce the incidence of stroke. This procedure should only be attempted by an experienced cerebral vascular team with the input of a neurologist or neurosurgeon specializing in this area.
If treated within the first three hours of onset, the effects of a stroke often can be reversed using a proven front-line therapy called intravenous thrombolysis. This procedure involves the direct injection of the "clot busting" drug t-PA. However, some patients fall outside the three-hour window or fail to respond to the drug. In such instances, another treatment alternative that is available is intra-arterial thrombolysis. In this procedure, a catheter is threaded into the cerebral arteries, and an angiogram is performed to reveal the exact location of the artery blockage. The catheter may be advanced into the clot to mechanically disrupt the clot as well as used for infusion of local TPA. Like intravenous thrombolysis, this can be a very effective means of reversing the effects of stroke for patients.
The photos below show a case of a right middle cerebral artery embolus that was treated with intra-arterial thrombolysis. The first slide is with the right middle cerebral artery occluded. The second is recanalization after IA t-PA.
(1) The right middle cerebral artery is occluded.
(2) Recanalization after IA t-PA.
Guglielmi Detachable Coil (GDC)
Introduced in the early 1990s, GDC is a technique that involves advancing a platinum coil into an aneurysm and then subsequently removing it by electrolysis. This procedure can only be used under certain circumstances and with the joint input of a neurovascular surgical team. This technique has proven particularly effective in preventing aneurysms from re-rupturing, at least in the short term. The ability of the GDC to prevent hemorrhage over many years, as has been demonstrated with aneurysm clipping, is still being determined. At CNI, each patient with an intracranial aneurysm is evaluated on an individual basis for GDC treatment. Learn more about aneurysms.
Patients suffering subarachnoid hemorrhage due to an aneurysm in many cases will undergo cerebral vasospasm. This results in a narrowing of the blood vessels in the brain as blood from the hemorrhage leaks into the brain cavity, irritating the large vessels at the base of the brain. This narrowing can reduce blood flow to that area of the brain, resulting in a complete stroke. Cerebral angioplasty has proven to be an effective and enduring treatment to reverse this sequence of events. With this procedure, a catheter is threaded through the vessels to the area of the vasospasm, and a balloon is inflated to reopen the artery and restore proper blood flow.
Beginning in the late 1980's, the surgery on AVM's was facilitated by embolization using substances such as polyvinyl alcohol. As with brain tumors, this decreased the amount of bleeding seen at the time of surgery. However, since AVM's carry a particularly large amount of high pressure blood flow, the risk of blood loss can be prohibitive, rendering many large lesions inoperable. At CNI, Dr. Yakes has pioneered a new type of treatment that infuses the AVM with absolute ethyl alcohol. This has resulted in immediate sclerosis of the embolized vessels. In lesions in which he has been able to obtain a complete radiographic obliteration of the lesion, he has experienced at 69% cure rate. This type of treatment has not been duplicated elsewhere. Dr. Yakes has been invited to many destinations around the globe to educate others about this technique.