There are three major treatment methods that may be useful either alone or in combination to treat an AVM. The specific treatment for an individual is based on the patient’s history, symptoms, and anatomy of the AVM including its size, feeding arteries, draining veins, and location within the brain.
ENDOVASCULAR SURGERY- Endovascular embolization for permanent occlusion or preoperative
Treatment of AVM’s may include embolization, surgical excision, radiation treatment or any combination of all. In many cases, embolization is used to block supply to the AVM and make definitive treatment safe. This may include reduction in size of the AVM, closure of large fistulas, and treatment of aneurysms, which are associated with the AVM core or arterial supply. Before a patient is treated he or she may undergo a series of tests such as MRI, functional MRI, CT. Diagnostic angiography is also performed. The multidisciplinary team of physicians carefully reviews this data. If embolization is determined to be part of the treatment plan, then it is explained to the patient and their relatives in detail.
Embolization is performed under general anesthesia. A sheath and catheter system is placed in the femoral artery, usually in the right groin. The catheter system is brought up to the neck and diagnostic angiogram is obtained. Using this information and live fluoroscopic visualization, a microcatheter is placed through the guide catheter and navigated into the arteries supplying the AVM. Another angiogram is done to determine whether it is a safe artery to block off and its a good position in the AVM nidus. If so, then liquid embolic agent is used such as ONYX or N-butyl cyanoacrolate in a mixture with radio-opaque material. This process is repeated up to several times after which the catheters are removed. The patient is awakened from anesthesia and transferred to the Neurointensive care unit. Patients are usually in the hospital for elective procedures for 2-3 days. Blood flow to the AVM may be treated in stages to prevent thrombosis or hemorrhage from occurring. In more than 60% of cases, embolization may fully treat a lesion, but a subset of patients will undergo associated surgical resection or radiation therapy. Angiography is used following these treatments to insure the lesion is fully treated.
Embolization of an AVM is usually performed before treatment by either radiosurgery or open surgery. Embolization is often able to decrease the size of the AVM making the radiosurgery or surgery much safer than would otherwise be the case.
However, the blood flow from certain AVM’s may be totally blocked by embolization techniques, and no further therapy may be required.
Gamma Knife Radiosurgery is a technique which uses focused beams of radiation to treat AVMs that are sufficiently small and located in appropriate areas of the brain. Despite the name, no opening of the skull is required. Instead, the radiation causes scarring in blood vessels of the AVM, thereby eliminating it. After treating the AVM with radiosurgery, a period of two to three years is required for the full effect of the treatment to be determined.
Open surgical treatment involves removing a portion of the skull so that surgical instruments can be inserted to remove the AVM. Surgical treatment is often performed after embolization has closed portions of the AVM. The combination of embolization followed by surgical resection is frequently safer than surgical resection alone in treating an AVM.
CAROTID CAVERNOUS FISTULAE
Carotid-cavernous fistulae are a specific type of abnormal connection of the arteries directly into the venous system. Patients present with proptosis, ecchymosis of eye (redness), and pain around the affected eye. These symptoms are a result of increased blood flow and pressure from the arteries to the veins in this region. There are two types of abnormal connection:
- Direct fistulas are usually caused by injury to the internal carotid artery. Blood flow is shunted directly into the cavernous sinus and then into the superior and/or inferior ophthalmic veins.
- Indirect fistulas are caused by abnormal channels connecting the internal carotid artery or other arterial branch from external carotid artery or vertebral artery to the cavernous sinus with outflow into the veins of eyes.
It is important to treat this group of patients quickly to avoid compromise of vision, as venous pressure will eventually lead to blindness. Treatment is accomplished by endovascular closure the fistula. This is a done under general anesthesia. A sheath (large plastic tube with valve) is placed in the femoral artery in the groin, and a diagnostic catheter is used to obtain a cerebral angiogram. Treatment options may include balloon occlusion of a direct connection from the internal carotid artery and cavernous sinus or packing of the cavernous sinus with platinum coils. Balloon assisted reconstruction or stent may be considered. For some lesions, access to the venous side such as the facial vein or a cut down approach to the superior ophthalmic vein may be used. In some patients the internal carotid artery may need to be occluded in order to trap the lesion. Patients are usually followed in the Neuro-intensive care unit for at least a few days. Other teams involved in the care of these patients may include the Neurosurgery, Neurology and Neuro-ophthalmology services.
DURAL ARTERIOVENOUS FISTULAE
Arteriovenous fistulae (AVF) are abnormal connections of the arteries to veins. Normally, the high-pressure arteries branch into smaller vessels until the capillaries supply the tissues with oxygen and nutrients. Blood then flows into veins, which are of low pressure and high capacitance. When there is a short circuit of this system, the high flow arteries overwhelm the veins inside the head or spine. Patients may present with symptoms such as headache, pulsatile tinnitus, cranial nerve deficit, seizure, intracranial bleeding, hydrocephalus, neurologic decline or stroke-like symptoms.
Detection of DAVF is often accomplished by MRI/MRA. Cognard and Borden have categorized these lesions according to angiographic anatomy and physiology. Different subtypes have a graduated risk profile and those with retrograde flow into the cortical veins are at significant risk for intracranial bleeding. Treatment for these patients is recommended and this can often be accomplished by endovascular means.
Embolization of a DAVF is performed under general anesthesia. A sheath is placed in the femoral artery in the groin, and a catheter is passed through this into the aorta and eventually into the carotid and vertebral arteries supplying the head and neck. Angiography is performed with contrast and x-rays to obtain a map of the arteries and veins. The abnormal connection of the arteries and veins are identified. A microcatheter is passed though the larger guide catheter and positioned in the fistula site. Materials may be used to block these connections such as coils, PVA particles, gelfoam, or liquid agents such as N-BCA, ONYX or pure alcohol. A final angiogram is done to identify the changes after treatment. Some of these lesions need to be treated by blocking off the venous side of the A-V fistula. This is accomplished using a catheter system through the venous system also accessed in the groin. Patients treated electively may spend 2-3 days in the hospital while patients who have had intracranial hemorrhage as a presenting symptom may spend 2 weeks or more in the hospital. Some patients with complicated lesions may require multiple stages of treatment.
Some lesions may require additional therapy to disconnect the abnormal A-V fistula such as surgery. Large and complicated DAVF’s may need treatment by combined procedures of embolization with neurosurgery or radiotherapy targeted to the lesion. These patients are followed by imaging until the lesion is optimally treated.
CAROTID ANGIOPLASTY & STENTING
Angioplasty and stenting for the treatment of cerebrovascular disease has grown in last decade. It is known that patients with symptomatic carotid stenosis of more than 60% benefit from carotid angioplasty and stenting. Carotid endarterectomy (CEA, open surgery) has been the gold standard for treatment with a 9% stroke rate compared to 26% with medical treatment over 2 years and a 3.3 % risk of cerebrovascular event according to the North American Symptomatic Carotid Endarterectomy Trial (NASCET). In high risk patients, the Stenting and Angioplasty in Patients with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) Trial has shown that carotid stenting with a distal protection device is safer than CEA (open surgery) with a Major Adverse Event rate of 11.9% vs. 19.9% at one year. Patients in this group include those with previous neck surgery, radiation treatment, high carotid artery bifurcation, cardiac or pulmonary disease and poor general anesthesia risk. Now-a-days, stenting is preferred over surgery because it is safer. There are no trials for the treatment of disease of the carotid artery origins, vertebral arteries or intracranial stenoses, but these areas are accessible to Neurointerventionalists and done routinely in our centre.
Patients are screened for this procedure by a team of physicians including Interventional Neuroradiology and Neurology. This insures a patient is selected by proper criteria and receives long-term follow up. Typically, a patient should be symptomatic and have at least 60% stenosis of the affected carotid artery. Patients may have had previous stroke or TIA’s (transient ischaemic attacks – warning signs). Most will have undergone MRI/MRA or CTA and carotid/Transcranial Doppler Ultrasound to determine if an artery is narrow. If a patient has had a large stroke, the procedure may be done several weeks afterward to limit the chances of bleeding from the anticoagulation regimen used in stenting. Medication instituted prior to the procedure includes aspirin and plavix with heparin used during the procedure itself. This prevents clot from developing on the catheters or stent and causing a stroke.
The procedure is done under monitored anesthesia care with the patient sedated but awake or rarely with general anesthesia depending on medical condition. Under sterile conditions the femoral artery is accessed in the right or left groin area. A sheath is placed through which a catheter is placed for diagnostic angiography. This shows the Neurointerventionalist the precise location and degree of narrowing in the artery and the collateral circulation around the brain. Under direct fluoroscopic visualization, a guide catheter is placed in the affected artery, and a small guide wire is passed beyond the stenosis. This wire may have a built in protection device to collect any debris from the angioplasty, which follows. The next step is placement of the stent over this guidewire and possibly a second angioplasty to secure the stent in place. Any debris collected by the protection device is retrieved, and the catheters are removed. Patients usually spend 3 days in the hospital the first of which is in the Neuro-intensive care unit. Instructions on care of the arteriotomy site in the groin are standard for angiography. Patients are continued on aspirin and plavix and followed by our staff and Neurology following discharge from the hospital.
Precautions are taken to avoid potential complications such as stroke. Anticoagulation is used as described above to limit the possibility of stroke. Angioplasty can cause temporary bradycardia due to pressure on the carotid body, and we may administer atropine for heart rate or blood pressure control. Reperfusion syndrome is a rare problem, which may occur in patients who have extremely tight stenosis. The cerebral vasculature loses its normal autoregulation and in some cases patients may develop cerebral edema and blood pressure control must be strictly regulated. Transient ischemic events are uncommon but can happen with the use of angioplasty balloon despite distal protection devices.
ACUTE STROKE THERAPY
Stroke is the leading cause of serious, long-term disability with approximately 500,000 cases of stroke each year. It accounts for about 160,000 deaths, and in stroke survivors, there is a 25-29% recurrence rate over 5 years (4-14% annual rate). The goal of treatment of these patients is to diagnose the problem as quickly as possible and triage them to the appropriate therapy. The Interventional Neuroradiology/Endovascular Neurosurgery service participates in a multidisciplinary effort to prevent and treat acute stroke.
Along with the Neurology department, we evaluate patients in the emergency room according to physical exam using the NIH stroke scale and clinical history. Non-contrast head CT is performed followed by a CT angiogram (CTA) and if necessary CT perfusion (CTP) study. This takes just a few minutes to review and gives us information about the nature of the stroke. We look for evidence of hemorrhage or edema from brain swelling. 80% of strokes are ischemic (clot in vessel) and 20% are hemorrhagic (brain hemorrhage). The CTA defines the location and cause of the blockage in the artery from the aortic arch up through the brain. The CTP shows is how the brain is affected by the change in blood flow, identifying the tissue undergoing and at risk of stroke. In some cases an MRI may be performed instead with diffusion and perfusion scans.
We have worked with our colleagues to design a treatment algorithm, which is based on research defining the risks of natural history. This accounts for a progressive risk of bleeding into the injured brain in patients treated in the late stages of stroke. For patients reaching the hospital within three hours of onset of symptoms, IV tissue plasminogen activator (tPA) is the FDA approved treatment. In addition, these patients may receive intra-arterial therapy with a catheter system placed in the artery, which is blocked. This is usually done under general anesthesia and usually takes a few hours. Patients reaching the hospital within 3-6 hours are treated with only the catheter system using tPA or thrombectomy. This is administered with a catheter placed directly into the blockage. Patients reaching the hospital between 6-8 hours following a stroke may be offered endovascular treatment with a clot removal device such as the stents. These procedures are performed under general anesthesia. Patients are then followed in the Neuro-intensive care unit.
Intracranial atherosclerotic disease (ICAD)
Intracranial atherosclerosis is hardening of the arteries that supply the brain, causing narrowing and blockage of these vessels. It is similar to hardening of the arteries (atherosclerosis) elsewhere in the body such as the heart or legs. If a vessel becomes completely blocked or even severely narrowed, blood flow to part of the brain can be threatened and a stroke can occur. Each year, large number of patients is diagnosed with intracranial atherosclerotic disease (ICAD) related strokes in eastern India. Until recently, the only treatment options widely available have involved the use of drug therapies such as aspirin and blood thinners. Although these therapies work for many, they are ineffective for thousands.
The same risk factors that are associated with atherosclerosis elsewhere (such as in the vessels of the heart, causing heart attacks) are associated with intracranial atherosclerosis. They include diabetes, high blood pressure, high cholesterol, and smoking.
Intracranial atherosclerosis has recently been recognized as a significant risk factor for ischemic stroke. Stroke rates with maximal medical therapy (aspirin, blood thinners) range from as low as 10% to as high as 30% per year, making intracranial atherosclerosis about four to five times more dangerous than an unruptured aneurysm or AVM.
Unfortunately, unlike atherosclerosis of the arteries leading to the brain (carotid arteries), which often causes transient ischemic attacks (TIAs or ministrokes), intracranial atherosclerosis often is only found when a major stroke occurs. For this reason, it is important to treat intracranial atherosclerosis when it is found.
ICAD Treatment Options
ENDOVASCULAR SURGERY-ANGIOPLASTY, STENTING
The Wingspan Stent: An exciting treatment to unblock arteries in the brain and promise new hope to stroke victims.
Similar to how clogged arteries may cause a heart attack, excess plaque can also build up and block arteries within the brain, leading to a stroke.
The Wingspan Stent / Solitaire Stent is used in individuals diagnosed with intracranial atherosclerotic disease (ICAD) — excess plaque build-up in the arteries within the brain. The idea is to use the stent to ensure a steady flow of blood to the brain and to prevent blood clots that are the major cause of ischemic strokes. The stent is currently used in patients who have had a transient ischemic attack, often referred to as a TIA or mini-stroke, or patients who suffer a stroke while on aspirin or other medical therapy to prevent stroke.
What is the Stent Procedure Like?
An endovascular neuroradiologist directs a catheter through the femoral artery in the leg to gain access to the blocked artery in the brain. A balloon catheter is threaded through and expanded to open the blood vessel to its full capacity. Next the Stent, a tiny wire-mesh tube, is inserted and placed carefully in the area that was ballooned open. A protective sheath is removed, and the stent self-expands to brace open the inside of the vessel wall.
The Stent applies minimal pressure to the blood vessel wall and is designed to adapt to the vessel opening. This allows the blood to flow more freely though the artery. The stent’s flexibility also allows it to conform to curves and various sizes of blood vessels, while providing the ability to treat arteries in areas of the brain that are impossible to treat with traditional neurosurgery techniques.
The Stent is often used in conjunction with or following medical therapy. The blood flow in the brain is vital for a person’s survival, and it requires an experienced physician to carefully manage the pressure and flow so to not overwhelm the brain tissue with a sudden rush of blood.
Ischemic stroke; symptoms, evaluations
Each year, approximately 700,000 Americans suffer from strokes. A stroke, or “brain attack,” occurs when the blood flow to the brain is cut off. The deprived brain loses its supply of oxygen and nutrients and within a few minutes begins to die. Depending on the part of the brain affected, the person suffering the stroke may become paralyzed, blind, or unable to speak.
Warning Signs of Stroke
If you notice one or more of these warning signs – don’t wait! Dial 911 or get to hospital right away:
- Sudden loss of speech, or slurred speech;
- Sudden loss of vision, or blurry or double vision;
- Sudden paralysis;
- Sudden numbness or weakness in the face, arms or leg, especially on one side of the body;
- Sudden dizziness;
- Sudden, severe headache, often accompanied by neck stiffness and vomiting.
Remember that brain damage increases every minute brain cells are deprived of oxygen. The chances for survival and recovery improve when patients receive medical attention within the first few hours following the onset of warning signs.
Risk Factors for Stroke
Many health factors increase the risk of stroke. Some factors can be combined, while others cannot.
- High blood pressure: Strokes are 4 to 6 times more likely to occur in people with high blood pressure.
- High cholesterol: People with high cholesterol are at double the risk of having a stroke.
- Heart disease: Strokes are 6 times more likely to occur in people with heart disease.
- Being overweight: Excess weight can lead to heart disease and high cholesterol, which in turn, increases the chances of having a stroke.
- Heavy drinking increases the risk of having a stroke.
- Smoking: Smokers are at twice the risk of stroke over non-smokers.
- Men are more likely to have strokes than women.
- African-Americans have a higher rate of stroke than other races.
- After the age of 55, there is an increased likelihood of having a stroke.
- Diabetics are at a higher risk of stroke.
- Those with a family history of stroke or those who have had a prior stroke are at greater risk.
To reduce your risk of stroke you must:
- Control your blood pressure;
- Determine if you have heart disease, especially an irregular heartbeat known as atrial fibrillation (AF);
- Do not smoke;
- Determine if you have a diseased carotid artery (arteries that impede blood flow to the brain);
- Lower your cholesterol;
- Limit alcohol consumption;
- Control your weight; and
- If you have diabetes, manage the disease.
For patients at risk for stroke, medications for blood pressure, diabetes, and high cholesterol are important preventive measures. Smoking must stop! A person who has had transient ischemic attacks (also known as TIAs or mini-strokes) or a stroke may be treated with aspirin or other antiplatelet or anticoagulant medications to reduce the chances for another attack.
BALLOON OCCLUSION TEST
Several vascular diseases may be best treated by deconstructive (occlusive) endovascular procedures. These include giant cavernous carotid artery aneurysms, tumor involving the base of skull and end stage head and neck cancer, which involve the carotid artery. Physicians need to know whether there is enough collateral circulation (circulation from nearby vessels) in the brain to supply the brain without the risk of stroke.
The angiogram and test occlusion is a 1 hour procedure done with the patient awake with conscious sedation. Following a standard angiogram of the head and cervical vessels, a temporary balloon is placed in the carotid artery to be tested. Patients are given heparin for anticoagulation to prevent strokes from occurring. The balloon is inflated to block flow in the artery, and our Neurology team helps to evaluate the patient with neurologic tests for the next 20-25 minutes. During this time our Anesthesiologists will give a closely monitored hypotensive challenge to mimic physical activity. At the end of the test, the balloon is deflated and another angiogram and final neurologic test are performed. Patients are then observed for a few hours before discharge. Some patients may be admitted to undergo a permanent occlusion of the artery on the following day if the angiographic study, neurologic exam and hypotensive study are in accord.
Patients with epilepsy can sometimes be helped by neurosurgical methods. In preparation there are several tests a patient may undergo. MRI with high-resolution imaging through the temporal lobes at 1.5 field strength can delineate anatomic changes. However, angiography may be required to define the laterality of language function. This is essential in choosing the appropriate therapy. A WADA test is an angiographic procedure, which is done in concert with the Epilepsy service at our hospital. A catheter is placed in the femoral artery in the groin and advanced into the aorta. The catheter is navigated into one of the carotid arteries and an angiogram is done to look at the anatomy. Sodium amytal (125 mg) or brevital (7-8 mg) is then administered through the catheter, which temporarily anesthetizes that part of the brain. Over the next few minutes the Neurology doctors test the patient’s motor and language skills. After 20 minutes the catheter is navigated into the other carotid artery and the process is repeated. At the end of the procedure, the catheter is removed and manual compression is used to achieve groin hemostasis. The patient will need to keep his or her leg straight for 3-8 hours depending on their anatomy and closure method used.
TREATMENT OF VASOSPASM
Patients who present to INK with subarachnoid hemorrhage may have a range of neurologic status from wide-awake and minimal headache to comatose. Because of the 4% risk of rebleeding patients are treated within 24 hours or at the earliest depending upon the conditions to secure the aneurysm. These patients are watched in the Neuro-intensive care for 14 days for several reasons. These include hydrocephalus (fluid buildup in brain ventricles), fevers, infections, cardiac abnormalities, and vasospasm, which is a reaction of the arteries in the brain to blood products. Approximately one third of patients experience vasospasm, which can lead to stroke if blood flow to the brain is significantly impaired. Patients are watched for signs of clinical deterioration such as decreased awareness, focal neurologic deficit or rising velocity of the Transcranial Doppler Ultrasound studies. MRI, MR angiography/perfusion or CT angiography/perfusion studies may also be helpful.
Clinically, these patients are treated with a combination of hypertension, hypervolemia and hemodilution. Some patients need additional therapy to prevent strokes, and the Interventional Neuroradiology department can help these patients by delivering treatment through catheter systems. Under general anesthesia, diagnostic arteriography is done to confirm the diagnosis. Medications such as intra-arterial Nimodipine, a calcium channel blocker, can be administered to relax the arterial spasm or in some cases balloon angioplasty can be used in the larger arteries. Some patients may require more than one treatment.
VEIN OF GALEN MALFORMATIONS
A subgroup of arteriovenous fistulae occurring in the brain involves shunting of arteries to veins involving the Vein of Galen. This is a large venous channel in the center of the head into which the arteries enter directly or indirectly. There are three clinical presentations seen with Vein of Galen Malformations:
- Neonates presenting with congestive heart failure and a cranial bruit
- Infants presenting with developmental delay and increasing head size
- Older children with a large head, seizures or stroke
The Vain of Galen Malformation is a spectrum of vascular malformations occurring in infants and young children with a one common feature, a large draining deep vein. This is a very rare condition affecting the blood vessels of the brain. The abnormality occurs during embryonic development and results in abnormal communications between the arteries and the veins in the blood vessels of the developing brain. The capillaries which normally connect arteries to veins and function to slow blood flow allowing for exchange of oxygen and nutrients to the brain are missing.
Since vein of Galen malformations lack capillaries, there is a shunt, meaning the blood flow is very fast in its return to heart and this in turn increases the work of the heart. Blood drainage is towards a single deep draining vein, which becomes markedly enlarged (vein of Galen aneurysm). The result can be heart failure. The high flow of blood can also interfere with the normal blood drainage of the brain potentially causing hydrocephalus or ‘water on the brain’ or even causing stroke by stealing blood from other parts of the brain. This rare malformation develops in utero.
The Vain of Galen Malformation or Vein of Galen Aneurysm is a misnomer. In reality the dilated venous structure anatomically is not a Vain of Galen that has very important implications in endovascular treatment.
There are several different types of malformations by anatomic criteria, however by clinical presentation there are clearly two distinct categories with a wider spectrum of presentation in the second category.
Those who present early with a heart failure ( large shunt) and those with more progressive course without a heart failure (small or smaller shunt) either presenting in infancy or as an older children.
THE LARGE SHUNT CATEGORY
Neonates that present with congestive heart failure and a loud intracranial bruit (noise made by blood turbulence).
Sometimes this malformation can be detected during a prenatal ultrasound, but not always. In particularly severe cases, the growing baby has difficulty coping with this abnormal shunt and it develops heart failure. Sometimes this is so severe that the baby will die in utero. Often this is not the case and the baby is born, but rapidly goes into heart failure after birth. Sometimes this can be managed medically until the baby is a bit bigger, but sometimes the baby has to be treated in the neonatal period. Sometimes the heart failure is so severe that it affects all the other organs, including the lungs, liver, kidneys and brain and then despite treatment the baby will not survive.If the baby has only mild heart failure it is safer to try and grow the baby until it is a little easier to treat.
SMALLER SHUNT CATEGORY-INFANTS
Infants presenting with abnormally enlarging head (hydrocephalus), and developmental delay.
SMALLER SHUNT CATEGORY-OLDER CHILDREN
Older children presenting with a large head and possibly seizures (epileptic fits) and maybe a stroke. They also may have learning difficulties.
Small or smaller shunt category children with vein of Galen malformations never develop heart failure, but because of the abnormal communications between the arteries and veins, the water that is inside the head and brain cannot be properly absorbed. This leads to an accumulation of water within the baby’s head, so that the baby starts to develop a very large head. Often these babies are a little bit ‘floppy’ and sometimes just a little developmentally delayed.
These children can be treated at a few months of age or even little older and some at few years of age because of late presentation. Their heads often remain large, but they ‘grow into’ their head size over time.
ENDOVASCULAR SURGERY – endovascular embolization
The most effective treatment for the malformation has been endovascular embolization rather than surgery. By feeding a narrow catheter through the arteries that lead to the defect, endovascular neurointerventionist can introduce materials that block the blood flow through the malformation and form a clot that closes it off. The materials used can vary from a kind of fast-acting glue to coils. The procedure is often not 100% successful on the first try. By gradually closing off remaining areas of blood flow in subsequent efforts, he can usually shutdown the pathway. There are two general approaches in the course of treatment. Navigation of catheters from the arterial or venous side of malformation for embolization. Frequently both routs are used for more effective treatment. After successful embolization, patients can go on to full and active lives. Sometimes these abnormalities can be detected in utero, and they can be severe enough to affect survival. Complications include hydrocephalus and seizures and even systemic organ failure. Treatment can be considered to close off arterial connections with platinum coils and liquid embolic agents such as N-BCA sometimes in combination. Treatment is often done in stages to gradually alter the blood flow back to a more normal pattern. No open conventional surgical treatment proved beneficial in these patients.
Patients with epistaxis, persistent severe nose bleeding may also benefit from embolization. Although collateral circulation may open up within two weeks after the embolization, it is usually enough to allow adequate healing in 90% of patients with epistaxis. A few patients may need a second treatment, and there are some blood vessels, which arise from the ophthalmic artery, which are not within our pervue to treat. Often patients receive nasal packing, which may decrease bleeding. Patients are medically evaluated, labs checked including hemtatocrit and BUN/Cr, blood bank sample and evaluated by CTA to exclude neoplasm or abnormal anatomy.
If it is appropriate to treat the patient, he or she is brought to cathlab and placed under local or general anesthesia. A sheath is placed in the femoral artery in the groin. A catheter is placed through the sheath and advanced into the aorta and eventually into the internal and external carotid arteries for angiography. Once the diagnostic angiogram is completed, a microcatheter is passed through a guide catheter in the appropriate external carotid artery. Branches of this vessel supplying the nasal region are embolized with PVA particles, Gelfoam, coils or other material. For patient with epistaxis bilateral sphenopalatine arteries and the ipsilateral distal facial arteries are embolized. Some highly vascular lesions such as hemangiomas in the vertebral bodies may be treated with pure alcohol, a sclerosing agent, which decreases blood flow. The procedure takes 4-6 hours. Afterward, the patient’s leg needs to be kept straight for up to six hours after taking out the sheath.
Vascular malformations of head, face, neck
Vascular malformations of the head, face, and neck” is often used as a general term and includes a number of different abnormalities that usually occur in children or young adults. They may appear as a cosmetic blemish or mass, or may come to attention by causing a disturbance of function. Vascular malformations have received different names depending on the cause.
A hemangioma is a benign blood vessel tumor appearing within the first month of life. The tumor may grow rapidly, disproportional to the child’s growth, during what is known as the proliferative phase, and usually reaches a maximum size when the child is between one and three years of age. The hemangioma then begins to get smaller during the involutive phase.
Eventually, in most cases, all that remains is some excess fatty fibrous tissue (like wrinkled skin) that can easily be removed by a plastic surgeon. Generally, hemangiomas only require treatment early in life if they bleed or result in some obstruction of normal function, for example the inability to close the eye. Embolization of the hemangioma may be performed to stop bleeding or preserve function.
A true vascular malformation, on the other hand, is usually present at birth, grows proportionally with the child, does not go through a proliferative or involutive phase, and does not disappear. Vascular malformations may become apparent later in life as blood flow increases through this abnormal connection between arteries and veins. They may cause cosmetic deformities of the head and neck, face and facial bones, mouth, tongue, nose or eyes, and interfere with normal function in these areas. At times the lesion can result in severe or uncontrollable bleeding.
Vascular malformations may be influenced by hormonal changes occurring during puberty and pregnancy. As opposed to hemangioma, most vascular malformations will require treatment.
Venous vascular malformations, another type of vascular anomaly of the head, neck and face, appear as a bluish discoloration of the skin, lips or inside of the mouth. They tend to increase in size with effort such as crying, pushing or other maneuvers that increase pressure in the venous system. While they can be disfiguring, they usually are not life-threatening. The treatment of venous vascular malformation has markedly advanced with the use of fluoroscopic (viewed by x-ray) guided sclerotherapy.
Sclerotherapy refers to the direct injection of a substance that will produce scarring within the vascular lesion. Different substances (sclerosing agents) have been used to achieve this goal.
A multidisciplinary team of specialists, including endovascular neuroradiologist, plastic and reconstructive surgeons, oral and maxillofacial surgeons, psychologists and other specialists is frequently required to treat these complex problems.
There are several groups of patients in whom bleeding from a tumor needs to be controlled. This may include pre-operative treatment of neck masses (paragangliomas and juvenile angiofibromas) or skull base lesions (meningiomas) to decrease the time and risk of surgery. Other patients with radiation and recurrence of head and neck cancers of the tongue or pharynx/larynx may require treatment to stop bleeding while more definitive treatment is implemented. These patients are usually treated one day to two days prior to surgery.
PARENT ARTERY OCCLUSION & COVERED STENTS
Specific blood vessel lesions are amenable to deconstructive surgery. Patients who have giant cavernous aneurysms may present with headaches and double vision. If there is collateral circulation in the brain, carotid occlusion may be the treatment of choice. When direct flow and pressure is taken off the aneurysm, it may regress and symptoms of double vision resolve. Another group of patients who may benefit from carotid occlusion are those with advanced squamous cell cancer involving the carotid artery in the neck and also skull base tumor affecting the carotid artery. Also some patients with dissecting aneurysms or fistulas may require trapping of an abnormal segment of an artery. Temporary balloon occlusion test is done in these patients to identify those patients at risk for stroke. In some of these cases a covered stent may also be considered if the artery shows signs of tumor invasion and bleeding but cannot be sacrificed. Some trauma patients may need to have an artery blocked off to prevent life threatening blood loss. This may be accomplished with balloons or coils.
The procedure is done under general anesthesia. A sheath is placed in the femoral artery in the groin, and a catheter is navigated into the affected artery. Under fluoroscopic visualization a series of detachable balloons or coils are placed to close off the artery. The catheter is then removed and the patient is wakened from anesthesia. The patient is then kept flat for 24 hours and given bold pressure raising medications to ensure there is sufficient perfusion pressure to the brain. Over the next 3 days, the patient is advanced slowly into an upright position with close neurologic supervision. Patients receive a specific anticoagulation regimen during this time.
SPINAL DURAL AVM/AVF
Vascular lesions affecting the spine and spinal cord are categorized into 4 basic types:
- Arteriovenous fistula (DAVF) arising within the dura of a nerve root with drainage into spinal veins
- Arteriovenous malformation (SAVM) in the spinal cord tissue
- Juvenile AVM (metameric) which involves all of the tissue at contiguous levels
- Perimedullary arteriovenous fistula on the surface of the spinal cord
These malformations lack the normal small blood vessels or capillaries that lay between the arteries and veins, and that serve to slow blood flow and allow it to provide oxygen and nutrients to the tissues. The resulting increase in blood flow may cause an increase in the pressure within the veins that drain off the spinal cord, and a decreased ability of these veins to clear blood from the area. This can result in a loss of spinal cord function or hemorrhage (bleeding) into the spinal cord or the liquid surrounding the spinal cord.
SAVMs may present with abrupt pain, progressive loss of strength or sensation, or bowel, bladder or sexual dysfunction. The diagnosis of this condition can usually be made with MRI images of the spine, but spinal angiogram is required to confirm the diagnosis and to delineate the spinal cord vascular anatomy, which is essential for planning treatment.
A multidisciplinary team of specialists including endovascular surgeons, neurosurgeons, neurologists and neurophysiologists is required to treat this condition.
Treatment options are dictated by the location of the lesion and the patient’s condition. Lesions on the surface of the spinal cord may be safely treated with embolization. The new generation of liquid embolic material and microcatheters has made interventional treatment of spinal cord malformations safer and with better results. Microcatheterization is very important in achieving effective results. Delivery of embolic material to the nidus of the lesion reduces the spinal malformation and reduces the risk of inadvertent embolization of normal vessels.
AVM’s consist of artery to vein abnormal connections, which pass through a nidus of rapidly shunting channels. AVF’s are direct end to end connections from artery to vein with fast flow, and they may be single or multiple. Some AVM’s have fistulous components. This group of spinal lesions is treated differently from one another depending on the arterial supply to the lesion, degree of cord involvement, and location arteries supplying the cord itself. They may be treated by a single modality or they may require a combination embolization, surgery or radiation therapy.
As part of the work up for a spinal vascular lesion most patients undergo an MRI study with gadolinium contrast enhancement. MRA with gadolinium may also be of assistance to identify the levels of involvement. The definitive diagnostic study is spinal angiography, which may be done under local anesthesia. The goal is to identify both normal and pathologic vascular anatomy to allow proper decision-making. We work closely with our Neurology department in the care of these patients.
Research indicates that osteoporosis can be caused by a diet lacking in calcium, excessive alcohol consumption (particularly in men), menopause, chronic steroid therapy and smoking. It is estimated that 1 in 3 women and 1 in 8 men over the age of 50 has osteoporosis-worldwide. Fractures, which result from abnormal bone thinning, can result in pain and disability. Vertebroplasty and kyphoplasty are minimally invasive methods of treating patients with compression fractures of the spine. Medical bone cement is injected into the collapsed vertebral body to stabilize and in some cases improve vertebral body height. Vertebroplasty can also be used to stabilize vertebrae affected by tumors such as hemangiomas, metastases, lymphoma or myeloma. Patients are evaluated in our department and may undergo tests such as plain x-rays, CT scan or MRI of the spine to identify their condition.
In most cases vertebroplasty is performed as day procedure with local anesthesia which also may include IV medications for relaxation and pain control. Patients are placed prone on the procedure table. After sterile preparation and administration of local anesthesia, a needle is placed in the affected vertebral body along the pedicles. Under direct fluoroscopic visualization, a mixture of polymethyl methacrylate cement (PMMA) and an opacifying agent such as barium are injected into the bone. When the appropriate amount has been administered, the needle is removed and a bandage is placed over the small incision. Many patients experience instant relief of painful symptoms. These are safe procedures and patients are watched for several hours in the hospital and can be sent home the same day.
Advantages of Vertebroplasty -
Vertebroplasty is considered for patients with painful compression fractures in the spine, often caused by osteoporosis. Because the treatment often results in a dramatic decrease in pain, the advantages are numerous.
Decreased pain— A compression fracture causes sharp and debilitating pain. Those suffering from these fractures are often prescribed bed rest and pain medication which may cause gastric and renal problems. Vertebroplasty eliminates pain in more than 90% of cases and in some cases eliminates the need for pain medication, and it also restores mobility in many patients.
Increased functional abilities— The pain from a compression fracture is usually sharp and debilitating, leaving people unable to perform everyday tasks. Vertebroplasty stabilizes the fracture, decreases pain immediately and allows a return to the previous level of activity at the earliest.
Prevention of further vertebral collapse—The cement fills spaces in bones made porous by osteoporosis, strengthening the bone so that it does not fracture again. None of these can be accomplished with analgesics, oral calcium and braces alone.
Kyphoplasty is a minimally invasive spinal surgery procedure. It is used to treat painful progressive vertebral body collapse/fracture (VCFs). The VCFs may be caused by osteoporosis or the spread of tumor to the vertebral body.
Osteoporosis is age related softening of bones. It causes the building blocks of the spine to weaken and collapse. This results in severe pain and a progressive hunchback. Certain forms of cancer also weaken the bone and cause the same problems.
Kyphoplasty is not appropriate for:
* Patients with young, healthy bones or those who sustained a vertebral body fracture or collapse in a major accident
* Patients with spinal curvature such as scoliosis or kyphosis that is due to causes other than osteoporosis
* Patients who suffer from spinal stenosis or herniated discs with nerve or spinal cord compression and loss of neurological function not associated with a vertebral compression fracture
The kyphoplasty procedure involves the use of a balloon to restore the vertebral body height and shape. This is followed by bone cement to strengthen it. The procedure may be performed under intravenous sedation. The patient may need local anesthetic or general anesthetic. The patient lies face-down on the operating room table. The interventionist makes two small (less than 3mm) incisions. He or she inserts a thin metallic tube into the center of the vertebral body. Through this tube, balloons are placed in the center of the vertebral body. Then the balloons are inflated. This pushes the bone back towards its normal height and shape. It also helps create a cavity. Then the cavity is filled with the bone cement.
Early results show kyphoplasty is a safe and effective method of vertebral reconstruction and stabilization in the treatment of osteoporotic compression fractures. Like all surgeries, kyphoplasty does have risks.
Complications may require additional treatments. These may be medications or surgery. Kyphoplasty is associated with excellent pain relief due to the vertebral body collapse. Well over 95 percent of patients rate their treatment a success. They are able to return to all of their pre-fracture function. Patients typically do not need any form of physical therapy or rehabilitation after a kyphoplasty procedure. Because bone cement hardens within 15 minutes, there is really no healing that needs to happen from the patient’s standpoint.
Occasionally, patients complain of persistent pain after kyphoplasty. This may be due to irritation of tissues involved in the procedure itself. It is more likely due to the underlying arthritis and degeneration of the spine.
* Pain due to the procedure will typically diminish within two weeks.
* If the pain is due to the arthritic degenerative changes in the spine, the usual treatment is medications and an ongoing exercise program.
Restoring vertebral body height and size is best accomplished when kyphoplasty is performed soon after the fractures happen. After kyphoplasty, severe osteoporosis may cause other fractures at other levels in some patients. All patients must take bone-strengthening medications during treatment. If more vertebrae collapse, kyphoplasty can also be used at those other levels. Kyphoplasty has a tendency to help prevent more fractures. It keeps the spine lined up in its native upright position.
* The usual risks of local or general anesthetics apply. These risks depend on the patient’s overall health.
* There is a small risk of the bone cement leaking from within the boundaries of the vertebral body. In most cases, this rare event (occurrence less than 10 percent) does not cause any problems.
* In very rare circumstances the cement may irritate or damage the spinal cord or nerves. This can cause pain, altered sensation, or even, very rarely, paralysis (estimated risk is less than 1 in 10,000). Should the cement leak further, more significant surgery may be needed to stop the irritation of the nerves or spinal cord.
* There is also a very small chance of the cement traveling to lungs. There is an even smaller chance of the cement block becoming infected at the time of surgery or even years later.
VENOUS SINUS OCCLUSIVE DISEASE
An uncommon vascular abnormality is that of venous occlusive disease. This may result from a variety of hypercoagulable states such as paraneoplastic syndromes, birth control pills, and genetic variations in which clotting factors are abnormal. As a result the slow flow within the veins may lead to clot formation. This affects normal circulation in the brain and can lead to edema, stroke or hemorrhage. In the hospital a CT venogram or MR venogram will be obtained to make the diagnosis. The Neurologist will likely treat with anticoagulation medications including heparin and possibly oral anticoagulant medications. If patients present with serious neurologic deficit, an interventional procedure to lyse the clot may be necessary. This is accomplished under general anesthesia, and the procedure may last 4-6 hours. A sheath is placed in the femoral artery, and an angiogram is done to look at the circulation in the brain from the arteries to the veins. When the clot is identified, a second sheath is placed in the vein and a catheter is placed next to the clot in the affected venous sinus. A microcatheter is passed through the clot and medication is administered to break up the thrombus (tPA or urokinase). The sheaths may be left in for a few days in case a second treatment is necessary. Patients are monitored in the Neuro-intensive care unit.
PETROUS SINUS SAMPLING
Bilateral simultaneous sampling of the inferior petrosal sinuses is an extremely sensitive, specific, and accurate test for diagnosing Cushing disease and distinguishing between that entity and the ectopic ACTH syndrome. It is also valuable for lateralizing small hormone-producing adenomas within the pituitary gland. The inferior petrosal sinuses connect the cavernous sinuses with the ipsilateral internal jugular veins. The anatomy of the anastomoses between the inferior petrosal sinus, the internal jugular vein, and the venous plexuses at the base of the skull varies, but it is almost always possible to catheterize the inferior petrosal sinus. In addition, variations in size and anatomy are often present between the two inferior petrosal sinuses. Advance preparation is required for petrosal sinus sampling. Teamwork is a critical element, and each member of the staff should know what he or she will be doing during the procedure. The samples must be properly labeled, processed, and stored. Specific needles, guide wires, and catheters are recommended for this procedure. The procedure is performed with specific attention to the three areas of potential technical difficulty: catheterization of the common femoral veins, crossing the valve at the base of the left internal jugular vein, and selective catheterization of the inferior petrosal sinuses. There are specific methods for dealing with each of these areas. Images must always be obtained to document correct catheter position. The patient must be given an adequate dose of heparin, and injection of contrast material into the inferior petrosal sinuses and surrounding veins must be done gently and carefully. When the procedure is performed, both inferior petrosal sinuses can be catheterized in more than 98% of patients. The complication rate is low, and the theoretical risk of major morbidity or death is less than 1%.
A cirsoid aneurysm of the scalp is an abnormal fistulous connection between the feeding arteries and draining veins, without an intervening capillary bed. Soft tissue arteriovenous fistulae occur most commonly in the scalp. Although only 14% of the body surface area is in the head, 50% of the integument arteriovenous fistulae occur in this region. When these abnormal fistulae enlarge to a size that is clinically recognizable and there are large, dilated draining veins, the lesions are termed cirsoid aneurysms.
Most congenital lesions become symptomatic in the third decade of life. Sixty per cent of the affected persons are male. The location of scalp cirsoid aneurysms is roughly evenly distributed among the frontal, temporal and parietal regions.
Although controversy still exists regarding the cause of these lesions, it is generally accepted that they may be either of congenital or traumatic origin. In our series, 20% of the lesions could be directly related to trauma (blunt, non-penetrating trauma in the majority). Penetrating trauma as a cause is well described, including iatrogenic-induced fistulae after hair transplantation, arthroscopy of the temporomandibular joint and craniotomy for intracranial procedures. Almost all patients present with a scalp swelling that has gradually increased in size from birth or after head trauma. Rapid increases in size have been reported to occur at puberty, during menstruation and during pregnancy. Associated symptoms and signs include pain, throbbing headaches and bruits. Hemorrhage from the lesion is uncommon. Large lesions have also been associated with scalp necrosis.
The diagnosis is clinical in the majority of patients. Angiography is undertaken to delineate the lesion and to exclude an intracranial component. This takes the form of an enlarged middle meningeal artery with fine feeding vessels running through the bone feeding the malformation.
Indications for treatment are the prevention of hemorrhage, tinnitus and the cosmetic relief of the pulsatile swelling. Treatment options include surgical transarterial and transvenous embolization, injection of sclerosant into the nidus and surgical excision. In the past, treatment of arteriovenous malformation of the scalp and face was primarily reliant on surgical excision or ligation of the feeding arteries. Some lesions were so large that excision was not possible. Ligation of feeding arteries has been particularly troublesome because of the recruitment of a collateral vessel supply and the loss of access to the fistula for further embolization. Transarterial and transvenous embolization of scalp cirsoid aneurysms has been used as an adjunct to surgery or as definitive therapy. Embolization alone could remedy a scalp arteriovenous fistula and improve the grotesque feature without scalp ischemia.
In direct-puncture embolization, the targeted vessel is the venous structure just distal to the arteriovenous connection. Occlusion of the vascular structures with this technique thus involves no risk of ischemic skin complications. Immediate venous occlusion allows continuous redistribution of the embolic agent to adjacent vascular spaces and effective devascularization occurs without complications. In most lesions, a large, high-flow arteriovenous fistula often is associated with the aneurysm and the embolus must, therefore, be large; otherwise, the embolus may pass into the pulmonary circulation. Temporary manual compression of the venous drainage during NBCA injection slows down the blood flow and can prevent inadvertent washout into the distal venous outflow tract and pulmonary circulation.
Lodging of embolic materials like coils in proximal feeding vessels lessens the blood supply and has been a helpful adjunct to surgery but rarely is curative. Recent developments in the design of microcatheters and distal navigation techniques have made possible the catheterization of feeding arteries close to the nidus. Injection of NBCA with a microcatheter wedged into the nidus may lead to permanent devascularization of an arteriovenous malformation without risk of ischemia of the adjacent normal tissue. But total devascularization involving transarterial embolization of the multiple feeding arteries may, however, be ineffective or technically difficult. So transarterial route of embolization can only be used as an adjunct to direct-puncture embolization of cirsoid aneurysms.
RENAL STENTING FOR RENOVASCULAR HYPERTENSION
What is renal stenting?
A small metal tubular structure called a stent is inserted into the renal artery that supplies essential blood flow to the kidneys. The stent acts as scaffolding, keeping the artery stretched open and maintaining adequate blood flow through the vessel after it is opened with a balloon.
When does a patient’s condition require renal artery stenting?
Plaque build-up (atherosclerosis) and sometimes other abnormalities of the renal artery may cause enough narrowing or blockage so that blood supply to the kidney is reduced and the risk of kidney damage becomes very high. Because the kidneys serve as a filter to remove waste products and excess fluids from blood, the kidneys receive almost one third of the blood flow from the heart. The kidneys also play a major role in regulating blood pressure. If left untreated, renal artery stenosis can lead to a form of high blood pressure called renovascular hypertension, poor functioning of the kidneys, and/or kidney failure.
What tests can determine a need for renal artery stenting?
A renal arterial duplex ultrasound is a noninvasive test that uses sound waves to create an image of the renal arteries and to measure the speed at which blood flows through them in order to detect any narrowing or obstruction in the renal arteries. It is useful as a screening test and for follow up studies.
Computed tomography angiography (CTA) is a type of CAT scan that uses x-ray beams taken from different angles around the patient to create pictures of cross-sections of the body. Contrast medium is injected into the veins at the time of the CT scan so that the arteries will also be visualized. Using computerized techniques, the scanner can be programmed to show pictures of only the arteries, which is a CT angiogram.
A Magnetic Resonance Angiogram (MRA) is a variant of an MRI study that uses radio waves and a magnetic field to take pictures of blood vessels. Unlike CTA and invasive angiography, MRA does not use x-rays or any form of radiation. MRA also uses a different type of contrast medium that does not have the same potential for side effects and complications. Not all patients can have MRA.
A nuclear kidney scan, a form of radionuclide imaging, tracks a small amount of nuclear tracer as it moves through the renal arteries. Images are recorded and blockages or narrowing in the renal artery may be detected, but the test is only an indirect assessment of arterial blockage.
A renal angiogram, or arteriogram is an invasive procedure involving insertion of a catheter, usually through a leg artery, up to the renal arteries where contrast medium is injected and X-ray pictures are taken to show the inside of the renal vessels. A renal angiogram is the most accurate tests in the diagnosis of renal artery disease, and is used to pinpoint the location and severity of plaque build up and blockage.
How is renal artery stenting performed?
Renal stenting is a catheter- based procedure. The catheter acts as a guide to place the stent in the renal artery to open a narrowing or blockage. The stent is deployed at the time the blockage in the artery is dilated with a balloon. Stents come in a variety of strengths, sizes, and other properties. Stent selection for each procedure depends upon many factors, including the size of the artery, the location of the plaque build-up or blockage and the severity of arterial narrowing.
What should be expected after renal artery stenting?
Renal artery stents are exposed to blood flow and may cause clots to form until they become covered with tissue by the body. Medications are taken during this time, and possibly longer, to prevent thrombosis.
Sometimes new blockages develop in the renal arteries months or years later at a different site in a renal vessel. Occasionally, renal stents re-narrow (restenosis).
The usual recommendation for renal stent follow up is a diagnostic study at:
- Six weeks
- Six months
- One year
- Then Annually
STENTING FOR AORTOILIAC DISEASE
Peripheral arterial disease (PAD) affects huge population in the world per year. One subset of PAD is aortoiliac occlusive disease (AIOD). AIOD can occur anywhere from the distal aorta to the common femoral arteries and is therefore called an “inflow lesion.” Stenoses may be short- or long-segment, calcified, ulcerated, concentric or eccentric, single or multiple, unilateral or bilateral and may involve the aorta or iliac arteries alone or together. Hypoplastic aortoiliac syndrome is seen most commonly in female smokers, in which the atherosclerotic effects of smoking narrow an already small aorta and iliac arteries. Patients may have no symptoms, intermittent claudication (IC), or critical limb ischemia (CLI). Asymptomatic patients with PAD would be unlikely to benefit from endovascular or surgical treatment and may experience treatment-related complications, and, therefore, intervention should be limited to those with lifestyle-limiting claudication or limb-threatening ischemia.
IC of the legs is classically muscular pain brought on by activity and relieved by short rest. The prevalence of IC is 3% in those less than 40 and 6% in those older than 60.Intermittent claudication caused by AIOD typically involves the thigh/buttock and may cause male impotence. Patients with IC should have lifestyle-limiting symptoms and be expected to have reasonable symptom improvement from either endovascular or surgical revascularization prior to undergoing evaluation for revascularization.
CLI is defined as pain at rest and/or tissue loss. The differential diagnosis for rest pain includes diabetic neuropathy, complex regional pain syndrome, nerve root compression, and musculoskeletal disorders. In blue-toe syndrome, patients embolize distally, and this may occur even in the absence of claudication or significant stenosis. Symptoms must be present for more than 2 weeks to be considered chronic.
Risk factors for development of AIOD include nonwhite ethnicity, smoking, diabetes mellitus, dyslipidemia, hypertension, age, male gender, C-reactive protein elevation, hyperhomocystinemia, hyperviscosity/hypercoagulability, and chronic renal insufficiency. Optimization of modifiable risk factors is an important component of successful management of patients with AIOD.
The noninvasive methods for the evaluation for lower-extremity PAD include a focused history and physical examination, physiological ultrasound, computed tomographic angiography and magnetic resonance (MR) angiography. Patients with CLI should undergo an expedited vascular evaluation. The Society of Interventional Radiology standard of practice regarding physiological evaluation of extremity arteries suggests the use of segmental blood pressures, continuous Doppler waveforms, and/or volume plethysmography to evaluate for PAD. Color flow duplex ultrasonography may also be helpful to characterize stenoses, although in the aortoiliac system, this may be difficult based on patient body habitus. Computed tomographic angiography may be used to localize and diagnose severity of stenoses in individuals with PAD, especially in those with a contraindication to MR angiography. MR angiography should be performed with gadolinium. Impaired renal function prevents using gadolinium due to the association with nephrogenic systemic fibrosis.
Because of the usefulness and ready availability of noninvasive imaging modalities, catheter angiography is rarely used now as a primary diagnostic modality but rather as a problem-solving tool. When necessary, digital subtraction angiography should be used when evaluating the aorta, iliac, and runoff vessels. Digital subtraction angiography is most often combined with simultaneous endovascular treatment, when appropriate.
Smoking cessation and hyperlipidemia, diabetes, and hypertension management as well as antiplatelet therapy according to current treatment guidelines is recommended for asymptomatic patients. Aspirin and other antiplatelet agents (clopidogrel) are important to reduce the risk of cardiovascular events in those with PAD, but they have not been shown to reduce claudication. Also to be considered is the use of angiotensin-converting enzyme inhibiting medication for cardiovascular risk reduction in asymptomatic individuals with PAD. Smoking cessation and successful management of hypertension and dyslipidemia can slow the progression of PAD. Supervised exercise therapy may also be effective in some, especially older male patients.
Severe lifestyle-limiting claudication; rest pain, nonhealing ulcer, gangrene, or tissue loss; stenosis of the iliac system preventing other endovascular treatment; and decreasing renal function or hypertension in patients with renal transplant are indications for aortoiliac endovascular intervention. Contraindications include lack of symptoms, uncorrected anticoagulation, or operator inexperience with lack of appropriate surgical backup in the event of complication. Endovascular treatment options include angioplasty and/or stenting. After endovascular intervention, primary patency is defined as patency without any additional treatment. Many studies have shown that both angioplasty and stenting of infrarenal abdominal aortic stenoses, ileofemoral stenoses are safe treatments. Immediate complications include thrombosis, distal embolization, pseudoaneurysm, and arterial rupture. Long-term complications include stent fracture, intimal hyperplasia, and thrombosis.
UTERINE FIBROID EMBOLIZATION
Uterine fibroids are very common non-cancerous (benign) growths that develop in the muscular wall of the uterus. They can range in size from very tiny (a quarter of an inch) to larger than a cantaloupe. Occasionally, they can cause the uterus to grow to the size of a five-month pregnancy. In most cases, there is more than one fibroid in the uterus. While fibroids do not always cause symptoms, their size and location can lead to problems for some women, including pain and heavy bleeding.
Fibroids can dramatically increase in size during pregnancy. This is thought to occur because of the increase in estrogen levels during pregnancy. After pregnancy, the fibroids usually shrink back to their pre-pregnancy size. They typically improve after menopause when the level of estrogen, the female hormone that circulates in the blood, decreases dramatically. However, menopausal women who are taking supplemental estrogen (hormone replacement therapy) may not experience relief of symptoms
Uterine fibroids are the most common tumors of the female genital tract. You might hear them referred to as "fibroids" or by several other names, including leiomyoma, leiomyomata, myoma and fibromyoma. Fibroid tumors of the uterus are very common, but for most women, they either do not cause symptoms or cause only minor symptoms
These develop under the outside covering of the uterus and expand outward through the wall, giving the uterus a knobby appearance. They typically do not affect a woman's menstrual flow, but can cause pelvic pain, back pain and generalized pressure. The subserosal fibroid can develop a stalk or stem-like base, making it difficult to distinguish from an ovarian mass. These are called pedunculated. The correct diagnosis can be made with either an ultrasound or magnetic resonance (MR) exam.
These develop within the lining of the uterus and expand inward, increasing the size of the uterus, and making it feel larger than normal in a gynecologic internal exam. These are the most common fibroids. Intramural fibroids can result in heavier menstrual bleeding and pelvic pain, back pain or the generalized pressure that many women experience.
These are just under the lining of the uterus. These are the least common fibroids, but they tend to cause the most problems. Even a very small submucosal fibroid can cause heavy bleeding - gushing, very heavy and prolonged periods.
Prevalence of Uterine Fibroids
Twenty to 40 percent of women age 35 and older have uterine fibroids of a significant size. Uterine fibroids are the most frequent indication for hysterectomy in premenopausal women and, therefore, are a major public health issue.
Uterine Fibroid Symptoms
Most fibroids don’t cause symptoms—only 10 to 20 percent of women who have fibroids require treatment. Depending on size, location and number of fibroids, they may cause:
- Heavy, prolonged menstrual periods and unusual monthly bleeding, sometimes with clots. This can lead to anemia.
- Pelvic pain and pressure
- Pain in the back and legs
- Pain during sexual intercourse
- Bladder pressure leading to a frequent urge to urinate
- Pressure on the bowel, leading to constipation and bloating
- Abnormally enlarged abdomen
Imaging Expertise Enables Interventional Radiologists to Provide Gynecologists and Their Patients Better Diagnosis and Nonsurgical Treatment Options!!
Women typically undergo an ultrasound at their gynecologist’s office as part of the evaluation process to determine the presence of uterine fibroids. It is a rudimentary imaging tool for fibroids that often does not show other underlying diseases or all the existing fibroids. For this reason, MRI is the standard imaging tool used by interventional radiologists.
Magnetic resonance imaging (MRI) improves the patient selection for who should receive nonsurgical uterine fibroid embolization (UFE) to kill their tumors. Interventional radiologists can use MRIs to determine if a tumor can be embolized, detect alternate causes for the symptoms, identify pathology that could prevent a women from having UFE and avoid ineffective treatments. Using an MRI rather than ultrasound is like listening to a digital CD rather than a record – the quality is better in every way. By working with a patient’s gynecologist, interventional radiologists can use MRIs to enhance the level of patient care through better diagnosis, better education, better treatment options and better outcomes.
TAKE a Second Opinion Prior to Hysterectomy!!
For true informed consent before surgery, patients should be aware of all of their treatment options. Patients considering surgical treatment should also get a second opinion from an interventional radiologist, who is most qualified to interpret the MRI and determine if they are candidates for the interventional procedure. You can ask for a referral from your doctor or call our Interventional Neuroradiology & Endovascular therapy Department to know more about this!
Uterine fibroid embolization (UFE), also known as uterine artery embolization, is performed by an endovascular interventional radiologist, a physician who is trained to perform this and other types of embolization and minimally invasive procedures. It is performed while the patient is conscious, but sedated and feeling no pain. It does not require general anesthesia. The vascular interventional radiologist makes a tiny nick in the skin in the groin and inserts a catheter into the femoral artery. Using real-time imaging, the physician guides the catheter through the artery and then releases tiny particles, the size of grains of sand, into the uterine arteries that supply blood to the fibroid tumor. This blocks the blood flow to the fibroid tumor and causes it to shrink and die.
UFE Recovery Time
Fibroid embolization usually requires a hospital stay of one night. Pain-killing medications and drugs that control swelling typically are prescribed following the procedure to treat cramping and pain. Many women resume light activities in a few days and the majority of women are able to return to normal activities within seven days.
- On average, 85-90 percent of women who have had the procedure experience significant or total relief of heavy bleeding, pain and/or bulk-related symptoms.
- The procedure is effective for multiple fibroids and large fibroids.
- Recurrence of treated fibroids is very rare. Short and mid-term data show UFE to be very effective with a very low rate of recurrence. Long-term (10-year) data are not yet available, but in one study in which patients were followed for six years, no fibroid that had been embolized regrew.
Effect on Fertility
There have been numerous reports of pregnancies following uterine fibroid embolization, however prospective studies are needed to determine the effects of UFE on the ability of a woman to have children. One study comparing the fertility of women who had UFE with those who had myomectomy showed similar numbers of successful pregnancies. However, this study has not yet been confirmed by other investigators.
Less than two percent of patients have entered menopause as a result of UFE. This is more likely to occur if the woman is in her mid-forties or older and is already nearing menopause.
UFE is a very safe method and, like other minimally invasive procedures, has significant advantages over conventional open surgery. However, there are some associated risks, as there are with any medical procedure. A small number of patients have experienced infection, which usually can be controlled by antibiotics. These complication rates are significantly lower than those of hysterectomy and myomectomy.
Bronchial Artery Embolization
Life-threatening hemoptysis is one of the most challenging conditions encountered in critical care and requires a thorough and timely investigation. Despite advances in medical and intensive care unit management, massive hemoptysis remains a serious threat. Conservative management of massive hemoptysis carries a mortality rate of 50%–100%. The cause of death is usually asphyxiation, not exsanguination. The reported mortality rates for surgery performed for massive hemoptysis range from 10-20%. However, the mortality rate increases significantly, up to about 40%, when the surgery is undertaken as an emergency procedure.
Bronchial artery embolization (BAE) has become an established procedure in the management of massive and recurrent hemoptysis. The efficacy, safety, and utility of BAE in controlling massive hemoptysis have been well documented.
Definition and Causes
Massive hemoptysis has been described as the expectoration of an amount of blood ranging from 100 mL to more than 1,000 mL over a period of 24 hours, and the most widely used criterion is the production of 300–600 mL per day. However, depending on the ability of the patient to maintain a patent airway, a life-threatening condition may be caused by a rather small amount of hemorrhage. Thus, a more functional definition of “massive” as an amount sufficient to cause a life-threatening condition should be used in deciding whether to undertake interventional management.
Massive hemoptysis may result from various causes, and the frequency with which these causes occur differs greatly between the Western and the non-Western world. In the non-Western world, pulmonary tuberculosis, including tuberculosis bronchiectasis, is the most common underlying cause of massive hemoptysis. Bronchogenic carcinoma and chronic inflammatory lung diseases due to bronchiectasis, cystic fibrosis, or aspergillosis are the more prevalent causes of hemoptysis in Western countries. Other causes include lung abscess, pneumonia, chronic bronchitis, pulmonary interstitial fibrosis, pneumoconiosis, pulmonary artery aneurysm (Rasmussen aneurysm), congenital cardiac or pulmonary vascular anomalies, aortobronchial fistula, ruptured aortic aneurysm, and ruptured bronchial artery aneurysm.
The source of massive hemoptysis is usually the bronchial circulation (90% of cases) rather than the pulmonary circulation (5%).
Bronchial Artery Embolization
Prior to BAE, the number and origin sites of bronchial arteries from the aorta should be carefully evaluated to determine the optimal angiographic approach. This can be accomplished with a preliminary descending thoracic aortogram. Abnormal bronchial arteries are visualized on an initial thoracic aortogram in the majority of affected patients. A descending thoracic aortogram is also useful in the detection of nonbronchial systemic arteries that supply parenchymal lesions.
Angiographic findings in massive hemoptysis include hypertrophic and tortuous bronchial arteries, neovascularity, hypervascularity, shunting into the pulmonary artery or vein, extravasation of contrast medium, and bronchial artery aneurysm .
A variety of embolic materials are used for BAE. Absorbable gelatin sponge is widely used because it is inexpensive, easy to handle, and has a controllable embolic size. However, disadvantages of absorbable gelatin sponge are its resolvability and lack of radiopacity. Its use may lead to recanalization of the embolized artery and may sometimes be responsible for recurrent bleeding . Polyvinyl alcohol particles are nonabsorbable embolic materials, and particles 350–500 μm in diameter are the most frequently used worldwide. Their use may prevent the early recurrence of hemoptysis due to recanalization of the embolized artery, as might be anticipated with absorbable gelatin sponge.
BAE is very effective in controlling acute massive hemoptysis. Long-term recurrence rates have been reported to be 10%–52%. However, the long-term success rate can be improved with repeat BAE. Hemoptysis may recur after successful BAE if the disease process is not controlled with drug therapy or surgery because embolization does not address the underlying disease but rather treats the symptom. Massive hemoptysis constitutes a significant and often life-threatening respiratory emergency. Bronchial and nonbronchial systemic artery embolization is a safe and effective nonsurgical treatment for patients with massive hemoptysis. Knowledge of bronchial artery anatomy, together with an understanding of the pathophysiologic features of massive hemoptysis are essential for performing BAE. The pulmonary artery can be the source of massive hemoptysis in a minority of cases, and pulmonary arterial disease should be considered in cases of recurrent hemoptysis. CT scan is useful in diagnosing the disease that causes massive hemoptysis, localizing the bleeding site, and selecting vessels to be embolized. The patient can be then treated for the original disease that led to massive haemoptysis.