Patient Education

• Angiogram
• Arteriovenous Malformations (AVM) & Arteriovenous Fistualas (AVF)
• Artery Stenosis
• Brain Aneurysm
• Brain Tumors
• Ischemic Stroke
• Pain Management Injections
• Spinal Vascular Malformation and Fistula Embolizations
• Stroke
• Venous Stenosis
• Vertebral Compression Fractures

Angiogram

What is an angiogram?

• Cerebral angiography is a form of angiography which shows images of blood vessels in and around the brain, thereby allowing detection of abnormalities such as aneurysms, arteriovenous malformations, fistulas, and tumors.
• Typically a catheter is inserted into a large artery (such as the femoral, brachial, or radial artery) and threaded through the circulatory system to the carotid, vertebral, or subclavian artery, where a contrast agent (dye) is injected. A series of radiographs are taken as the contrast agent spreads through the brain’s arterial and venous systems.
• For some applications, and in particular when dynamic information is useful or necessary, this method yields better diagnostic information than less invasive methods, such as computed tomography angiography (CTA) and magnetic resonance angiography (MRA).
• In addition, cerebral angiography allows certain treatments to be performed immediately, based on its findings. If, for example, the images reveal an aneurysm, metal coils may be introduced through the catheter already in place and maneuvered to the site of aneurysm; over time these coils encourage formation of connective tissue at the site, strengthening the vessel walls.
• Venography (also called phlebography or ascending phlebography) is a procedure in which an x-ray of the veins, a venogram, is taken after a special dye is injected into the arteries and/or veins. The dye has to be injected via a catheter, making it an invasive procedure. Normally the catheter is inserted by the vessels in the groin and moved to the appropriate site by navigating through the vascular system.
• Venography can also be used to distinguish blood clots from obstructions in the veins, to evaluate congenital vein problems, and to measure pressure difference between different venous structures across areas of narrowing.

Arteriovenous Malformations (AVM) & Arteriovenous Fistualas (AVF)

• Arteriovenous malformations (AVMs) and arteriovenous fistulas (AVFs) occur when an abnormal connection develops between arteries and veins in the brain or dura (i.e. coverings of the brain).
• The mainstay of treatment for acute ischemic stroke involves administration a clot dissolving drug called tPA (tissue plasminogen activator) through a vein in the arm or leg.
• A brain AVM is an abnormal connection between the cerebral arteries and veins, bypassing the capillary system, located within the brain parenchyma. Although many AVMs are asymptomatic, AVMs in the brain can cause headache, intracranial bleeding, and lead to other serious neurologic problems, such as seizures. Vascular malformations can be treated endovascularly with embolization using liquid embolics, such as Onyx and n-BCA, by open surgery, or by gamma knife radiosurgery. Sometimes these lesions are treated by a combination of the above mentioned therapies.
• A dural arteriovenous fistula (dAVF) is an abnormal direct connection (fistula) between a meningeal artery and a meningeal vein or dural venous sinus. Like other vascular malformations, a dural AVF can be treated endovascularly with embolization using liquid embolics, such as Onyx and n-BCA, by open surgery, or by gamma knife radiosurgery. Sometimes these lesions are treated by a combination of the above mentioned therapies.

Artery Stenosis

What can we do to prevent strokes before they occur?

• The carotid arteries are blood vessels in the neck that circulate oxygenated blood and nutrients from the heart to the brain. The carotid arteries are located anteriorly on both sides of your neck and carry blood to the majority of the brain. The vertebral arteries are the smaller, more posteriorly located arteries located on both sides of your neck that carry blood to the back of the brain and brainstem.
• Carotid stenosis is a condition in which these arteries become narrowed or blocked. Stenosis occurs when atherosclerotic plaque builds up in the lining of these arteries. This plaque can ulcerate and form thromboemboli that can dislodge and go to the brain causing an acute ischemic stroke.
• Carotid artery angioplasty and stenting is performed for the treatment of carotid artery stenosis. The technique of the procedure involves mechanically widening narrowed or obstructed carotid arteries that is usually the result of atherosclerosis.
• An empty and collapsed balloon on a guide wire, known as a balloon catheter, is passed into the narrowed carotid artery and then inflated to a fixed size. The balloon forces expansion of the blood vessel wall for improved flow, and the balloon is then deflated and withdrawn.
• A stent (tubular piece of mesh) is then routinely deposited to ensure that the vessel remains open. An embolization protection device may be used during the procedure to prevent the atherosclerotic plaque from the narrowed vessel wall from migrating to the brain during the procedure and causing symptoms of stroke.

What is intracranial angioplasty and stenting?

• Intracranial angioplasty and stenting is performed for the treatment of stenosis of an intracranial artery (an artery in the brain) that is causing recurrent strokes and/or transient ischemic attacks (TIAs) that are refractory to optimal medical management (ie. medical control of hypertension, diabetes, and dyslipidemia in conjunction with dual antiplatelet therapy). The procedure is technically similar to that described for cervical carotid artery angioplasty and stenting, although the angioplasty balloons and intracranial stents are smaller and more flexible than those used in the cervical circulation.

Brain Aneurysm

What is an aneurysm?

• An intracranial aneurysm (also called cerebral aneurysm or brain aneurysm) is a cerebrovascular disorder in which weakness in the wall of a cerebral artery causes a localized outpouching or ballooning of the blood vessel. This area is weak and prone to rupture.
• If an aneurysm ruptures, blood leaks into the thin coverings of the brain called the subarachnoid space. This is called a subarachnoid hemorrhage. This classically presents as a sudden, severe headache (ie. “thunderclap headache”) worse than any previous headaches.
• In patients with brain aneurysms, approximately 2-3% rupture each year. Factors such as size, shape, and location of the aneurysm affect the rupture risk, as do patient risk factors, including high blood pressure, smoking, age, overall health, and family history.
• If a brain aneurysm ruptures, there is an approximately 50% chance of sudden death. In those that survive, many will be left with significant disability.

Brain Tumors

• Intracranial and Extracranial Tumor Embolizations
• Various tumors in the brain, head, neck, and spine can be treated pre-operatively with embolization to reduce the risk of bleeding during open surgery.
• The list of tumors amenable to this therapy is very broad and includes meningiomas, glomus tumors, paragangliomas, nasopharyngeal angiofibromas, as well as metastatic cancerous tumors from the lung, breast, kidney, skin, and bowel.
• The procedure involves diagnostic angiography followed by angiographic guided selection of the small arteries that supply blood flow to the tumor.
• Next, small particles are injected in order to reduce blood flow and induce ischemia within the tumor tissue.

Ischemic Stroke

What is an ischemic a stroke?

• Mechanical Thrombectomy and Intra-arterial Thrombolysis (IA t-PA)
• Whether it is the mechanical retrieval of a thromboembolic occlusion of a blood vessel in the brain or medical dissolution of a blood clot using direct infusion of medicine at the clot face, large vessel occlusions responsible for symptoms of acute stroke may be treated with interventional neuroradiology, as an adjunct to intravenous tPA (clot buster) administration, which is the current standard of care.
• A stent is a tubular piece of mesh that can be placed inside of a blood vessel to maintain the blood vessel’s patency. In the setting of acute ischemic stroke, stent placement enables entrapment of the thrombus between the stent and the vessel wall to provide fast recanalization and to restore antegrade blood flow.
• Flow restoration may rapidly re-establish oxygen supply in the brain region that has been deprived of oxygen and nutrients that the blood. Flow restoration also enhances the efficacy of thrombolytic drugs (ie. clot busters), such as tissue plasminogen activator (tPA).
• “Stent retrievers”, as they have been named, are a technology that have revolutionalized the treatment of acute ischemic stroke. Stent retrievers allow thrombectomy to be performed by first deploying the stent inside of the clot and then pulling back the deployed stent into the guide catheter. In this scenario, the struts of the stent engage the thrombotic material and allow removal of the clot from the patient’s body.
• Particularly advantageous is that the stent is applicable repeatedly and can be used even in small peripheral brain blood vessel branches (eg, M2 segments). In contrast to conventional stent systems, stent retrievers require no anticoagulation, as the stent is not deployed permanently.

Pain Management Injections

• Epidural Steroid Injections
  Epidural steroid injection (ESI) is a technique for relieving pain from spinal stenosis and spinal disc herniation. Using a needle, relatively small amounts of corticosteroids together with a local anesthetic are injected into the epidural space around the spinal cord and spinal nerves. This injection can be performed from a translaminar or a transforaminal approach. The anti-inflammatory effect of the corticosteroid is responsible for providing pain relief when radiculopathy exists.
• Facet Joint Injections
  The zygapophysial joint or facet joint is a synovial joint between the superiorarticular process of one vertebra and the inferior articular process of the vertebra directly above it. There are two facet joints at each spinal motion level. The biomechanical function of each pair of facet joints is to guide and limit movement of that spinal motion level.
• Facet syndrome is a syndrome in which the facet joints cause back and/or neck pain. Facet syndrome can progress to spinal osteoarthritis, which is known as spondylosis.
• Facet joint injection is the injection of anesthetic and/or anti-inflammatory medication into the facet joint under imaging guidance for the diagnosis and treatment of facet syndrome.
• Synovial Cyst Injection and Rupture
  A synovial cyst of the facet joint is a non-neoplastic cystic lesion that develops as a response to the biomechanical stressors that are placed upon the synovial lined joints of the spine, the facet joints. When cysts arise from these joints, they may press upon critical neurologic structures, including the ventral nerve roots and the spinal cord. These benign yet painful cysts may be treated by performing synovial cyst injection and rupture. The procedure involves cyst puncture under CT or fluoroscopic guidance followed by the high pressure injection of fluids, including injection of long acting local analgesics and corticosteroid suspensions.

Spinal Vascular Malformation and Fistula Embolizations

• Spinal arteriovenous fistulas (AVFs) are uncommon vascular lesions that occur in the spine. They may be acquired in adulthood for reasons that are not entirely understood. Spinal AVFS typically occur when a radiculomeningeal artery feeds directly into a radicular vein near the spinal nerve root. Spinal dural AVFs are most commonly found in the thoracolumbar region.
• Patients become symptomatic because the AVF causes spinal cord venous congestion and hypertension, resulting in hypoperfusion, hypoxia, and edema of the spinal cord. Due to the slow-flow nature of most spinal dural AVFs, hemorrhage rarely occurs.
• Spinal arteriovenous malformations (AVMs) are an even more uncommon vascular lesion the spine. Spinal AVMs are an abnormal cluster of blood vessels in the spinal cord parenchyma. One or more arteries are directly connected to one or more veins. Spinal AVMs are extremely rare lesions that develop before birth or develop at a very early age for reasons that are not entirely understood.
• Both spinal AVFs and spinal AVMs can be treated endovascularly with embolization using liquid embolics, such as Onyx and n-BCA, and with open surgery.

Stroke

What is a stroke?

• The term stroke, or cerebrovascular accident (CVA), is a broad term generally indicating a sudden neurologic deterioration secondary to one of two etiologies: 1) a clot in one of the arteries supplying flow to the brain, or an “ischemic stroke”, or 2) bleeding into the brain. An ischemic stroke occurs when there is interruption of the blood supply to any part of the brain. If blood flow is blocked for longer than a few seconds, the brain does not get enough oxygen leading to brain cells death.
• The mainstay of treatment for acute ischemic stroke involves administration a clot dissolving drug called tPA (tissue plasminogen activator) through a vein in the arm or leg.
• However, the treatment of acute ischemic stroke is continuously evolving as new technology develops. Currently available devices are able to be navigated through the arteries in the neck and brain to retrieve or aspirate clots and remove large blockages that may not dissolve with intravenous tPA administration.
• Furthermore, these mechanical methods for flow restoration may be offered to some patients that cannot safely receive intravenous tPA, either because they have a contraindication to receiving the medication or because too much time has lapsed between their symptom onset and their arrival at the hospital.

Venous Stenosis

• Angioplasty and Stenting for Dural Venous Sinus Stenosis and Idiopathic Intracranial Hypertension / Pseudotumor Cerebri
• Idiopathic intracranial hypertension (IIH), sometimes called by the older names benign intracranial hypertension (BIH) or pseudotumor cerebri (PTC), is a neurological disorder that is characterized by increased intracranial pressure (pressure around the brain) in the absence of a tumor or other disease.
• The symptoms are headache, nausea, and vomiting, and sometimes pulsatile tinnitus (buzzing in the ears synchronous with the pulse), diplopia (double vision) and other visual symptoms. The increased pressure may lead to swelling of the optic disc in the eye. Swelling of the optic disc can progress to vision loss.
• Older treatments of IIH included repeat lumbar punctures, medications that decrease production of CSF, surgical decompression of the optic nerve (optic nerve sheath fenestration), surgical shunting of the CSF from the spine to the abdomen (lumboperitoneal shunt), CSF shunting from the brain to the abdomen (ventriculoperitoneal shunt), and even CSF shunting from the brain to the heart (ventriculoatrial shunt).

Vertebral Compression Fractures

• Vertebral Augmentation (Vertebroplasty & Kyphoplasty)
• Vertebral augmentation is a general medical term used to describe a group of procedures that include vertebroplasty, kyphoplasty, and sacroplasty. Vertebral augmentation is a minimally invasive procedure for the treatment of painful compression fractures of the spine or sacrum. In these procedures, bone cement is injected through a small hole in the skin (percutaneously) into a fractured vertebra or the sacrum (“tail bone”) with the goal of relieving back pain or pelvic caused by vertebral compression fractures or sacral fractures.