At Santa Barbara Cottage Hospital we have a group of specialists that evaluate each patient and decide the best treatment for the patient’s specific vascular pathology. Neuro Endovascular Procedures have a continuously advanced development addressing multiple cranial and spinal vascular pathologies. In these minimally invasive procedures our Neuro Interventional Radiology team accesses the arterial system through a blood vessel in the groin followed by the insertion of a catheter. We diagnose and treat intracranial aneurysms and side effects of a subarachnoid hemorrhage as well as other intracranial and spinal vascular disorders such as Arteriovenous Malformations, Dural Arteriovenous Fistulae, Arteriovenous Fistulae, Tumors, Carotid Stenosis and Stroke in a broad range of the population. After every procedure the patient goes to the Neurocritical care unit where a skilled staff is actively involved in their integral care.
Endovascular Embolization and Stenting
Endovascular Embolization is a procedure used to treat cerebral aneurysm, vascular malformations, and certain tumors. An embolization device is a material placed in the blood vessel to occlude or block off blood flow in the vessel, thereby preventing bleeding and rupture. It is an alternative to open surgery (craniotomy) when dealing with aneurysms, but embolization of an AVM is a helpful adjunct for subsequent open surgery and/or radiosurgery. Embolization of the vessels in an AVM is intended to reduce blood loss during surgical removal of an AVM. Onyx is one of the embolization devices we use to treat AVM’s. The liquid Onyx is selectively placed within one of the feeding vessels of an AVM. Hardening of the Onyx begins immediately upon contact with blood, closing off the blood vessel. Aneurysm coiling is an embolization procedure whereby flexible (MRI-compatible) platinum coils are inserted within the aneurysm, reducing or blocking blood flow feeding the aneurysm. Assisted techniques such as balloon remodeling and placement of small intracranial stents are also used for selected intracranial aneurysms. A stent, which is a small mesh tube, is used in this procedure if the neck of the aneurysm is wide. The stent covers the neck of the aneurysm and helps to hold the coils in place. This method of stent placement prior to coil placement has allowed for treatment of certain aneurysms that were previously considered untreatable. In other cases a balloon may temporarily be inflated at the neck of the aneurysm to help hold coils inside the aneurysm.
Stenting is a minimally invasive non-surgical technique used to open narrowed blood vessels of the brain, as in the case of artery dissections or narrowing from plaque in the walls of the artery. A tiny mesh wire tube, called a stent, is placed in the real lumen of the stenosed or dissected artery, reducing or completely eliminating the narrowing in the vessel. Narrowing due to atherosclerosis or plaque is treated in the same manner if it is thought to represent a danger of stroke to the patient. By restoring or enhancing blood flow through the carotid or vertebral arteries, the risk of a potentially life-threatening stroke may be reduced, or prevented. Cases involving plaque buildup in the artery generally require Angioplasty and Stenting. In this particular procedure, a tiny balloon is threaded by the catheter to the area where the carotid artery is clogged. The balloon is then inflated to widen the artery, and a stent is subsequently placed to keep the artery from narrowing again.
The traditional treatment method for restoring blood flow to the carotid arteries used to be open surgery. Although carotid artery stenting is a more recently FDA-approved procedure, the minimally-invasive technique that provides an alternative to surgery is now seen as an alternative to carotid endarterectomy for symptomatic patients at average or low risks for complications, with stenosis greater than 70%. Vertebral artery narrowing cannot be treated surgically and has been effectively treated with endovascular stenting for many years. Carotid and vertebral stents remain permanently in place. They are made of stainless steel or other metal alloys that resist rust and they are not noticed by metal detectors.
All Embolization and Stenting procedures are performed by neurosurgeons, neurologists, or neuroradiologists who are trained in endovascular techniques. This procedure is performed in an angiography suite and involves the assistance of an anesthesiologist.
What Factors Determine Intervention Type?
Physical condition of the patient, aneurysm shape and location, and arterial system anatomy are all factors considered in determining the best method of treatment for each patient. Older or sicker patients tend to have better outcomes with embolization/stenting rather than surgery because they may not be strong enough to undergo an open surgery. If an aneurysm has a wide neck, or does not have a clearly defined opening, the physician will generally recommend clipping as the best method of treatment. Embolization is the method of choice for aneurysms, malformations or tumors located in a difficult, or risky location, such as the brainstem. Patients with a convoluted arterial system are better candidates for clipping.
Risks Associated with Embolization and Stenting
It is important to be aware of the possible risks of the procedure. Of course your physician will be carefully monitoring for any complications and is fully trained to respond if one arises.
- Some patients can have an unusual allergic reaction to the anesthesia or contrast. Reactions range from mild skin irritation, itching, a drop in blood pressure, difficulty breathing, and loss of consciousness or death. These reactions only happen in approximately 1/50,000 to 1/150,000 people. You should tell your doctor of a previous allergy history prior to iodine.
- Delayed bleeding at the site of catheter insertion is very uncommon but this area will continue to be observed in the neurocritical care unit.
- Very rarely, the catheter can injure the vessel wall.
- Bleeding from aneurysm rupture
- Loss or alteration of brain function
- Visual disturbances or defects
- Sensory problems
- Muscle weakening or paralysis
- Dislodged coil or balloon
- Failure to completely treat the abnormal blood vessel
Factors that may increase the risk of complications include:
- High blood pressure
This document will help to prepare you for an Endovascular Embolization and/or Stenting procedure. It will be done in the Radiology Department at Santa Barbara Cottage Hospital by our Neuro Interventional Radiology team. You will check in at the front entrance (Pueblo and Bath) of the hospital. Prior to the procedure you will need to give your informed consent. This means you will speak with the physician or one of our Nurse Practitioners and acknowledge the potential risks of the specified procedure in order for us to provide appropriate treatment. This is also your opportunity to have any questions answered about the procedure.
Preparing for the Procedure
Your doctor will prescribe you Plavix, to be taken 7 days prior to the procedure, in conjunction with baby aspirin. Additional medications may be prescribed by your doctor, depending on your general health and other medications you are taking.
Women should let their doctor know if they are pregnant or planning to become pregnant prior to scheduling the procedure.
Patients will have a pre-op appointment at the hospital the day before the procedure. At this time, the nurse will go over instructions; including what time you need to check-in at the hospital (generally between 6 and 7am) the next morning. The nurse will also discuss your medical history and order routine tests that all patients are required to have prior to surgery. Due to the early arrival time the morning of your procedure, it is recommended to make plans to stay overnight in a nearby hotel if you are travelling from out of town.
You will undergo a series of exams and diagnostic procedures to fully assess the size, shape, and location of your aneurysm, AVM, stenosis, or tumor. Your doctor will use this information to plan the most appropriate course of treatment. Exams and procedures will generally include the following:
- Medical history review
- Physical examination
- Blood tests
- Neurological examination
- Imaging (CT, MRI)
- Diagnostic Cerebral Angiogram
- Discussion of allergies, current medications, recent illness or conditions, risks and benefits of the procedure
The Morning of the Procedure
- Be sure to ask your doctor which of your medications you should still take on the day of the surgery. You will bring these with you to the hospital on the morning of your surgery and take them there, with a SMALL sip of water.
- You may be asked to stop taking certain medicines, such as the diabetic medication, Glucophage (Metformin). You will stop taking this 48 hours before your procedure and will not resume taking Metformin until 48 hours after your procedure. Be sure to go over this with your physician/nurse and let them know if you are on any other diabetic medications.
- You will be asked not to eat or drink anything after midnight the night before the surgery.
During the Procedure
After a nurse prepares you for surgery, you will be taken to the neuro angiography suite, where an IV is placed in your arm for sedation and general anesthesia. The doctors will continue to monitor your blood pressure, heart rate, and pulse for the duration of the procedure. The nurse will shave and sterilize the groin area. The neurosurgeon and/or interventional neuroradiologist will insert the catheter into the femoral artery. At this point, a special type of liquid that can be seen with x-ray machines is injected into the blood vessel. The physician then guides the catheter to the brain using real-time X-ray visualization and high-speed radiographic filming techniques. Once the weakened or malformed area is located, a micro-catheter is inserted through the larger catheter and guided to the site where medicine, coils, stent, or man-made material is inserted to the site. During an embolization procedure, imaging tests will be done to make sure the blood vessels have closed. During a stenting procedure, imaging tests will be done to make sure the blood vessels have opened up.
Neurological and neurophysiological testing is performed before and after a medicine, coils, stent, or manmade materials is inserted into the artery to be occluded. This can help to determine if the vessel that feeds the AVM also feeds normal and important portions of the brain. After this, a permanent agent is injected into the AVM and the catheter is removed. This is repeated for each vessel that feeds the AVM. Coiling an aneurysm is generally done within one procedure, although additional coils can be added at a later date if the physician deems necessary. For AVM embolization, additional procedures are sometimes required to optimize AVM size reduction.
Immediately After Procedure
After the procedure is completed, the puncture site is closed. The incision site can be closed by applying pressure for 15-20 minutes to stop bleeding, or by using a special closure device. When the bleeding stops, a thick dressing is placed on the incision.
Average Hospital Stay
Following the procedure, the patient is admitted to the Neurocritical care unit with vital signs, neuro exams, and groin check. The typical length of stay in the Neurocritical care unit is two days, although this can vary based on your medical state and/or complications you might be experiencing. You will likely experience some pain and tenderness in the groin area where the catheter was inserted into your femoral artery. Additionally, it is not uncommon for patients undergoing intracranial embolization procedures to have a headache and nausea the evening after the procedure. Most headaches at this point are produced by thrombosis. Usually the greater the headaches are, the more thrombosis is produced. A head CT is generally obtained after the procedure is finished to ensure the embolized material is in the correct location and to exclude hemorrhage. Following embolization procedures with Onyx, patients will smell a strong garlic-like odor which is caused by the metabolism of the solvent used in the Onyx system. This odor should disappear within 24-48 hours.
You may return to regular activities within a week. When you return home, do the following to help ensure a smooth recovery:
- Rest for a few days.
- Clean the incision site with lukewarm water and mild soap. Use a soft wash cloth to gently wipe the incision area and keep it dry.
- Ask your doctor about when it is safe to shower, bathe, or soak in water.
- Take medicine as directed.
- Engage in rehabilitative therapy as directed.
- Follow all of your doctor’s instructions.
If your AVM was sufficiently reduced in size by the embolization procedure, you will be scheduled for surgical resection of the AVM. Your doctor will prescribe appropriate medications to prepare you for the surgery.
Patients return for a follow-up angiogram at 6 months and one year after treatment to ensure the aneurysm remains completely occluded and has not enlarged. Overall, aneurysms need additional coils about 20% of the time.
You will continue with anti-platelet medication, which will be prescribed by the physician performing the procedure.
All patients who undergo an embolization or stenting procedure will be scheduled for a 4 week follow-up in our office. At this time, the doctor will go over any symptoms or deficits you may be experiencing and will let you know his recommended course of treatment. Following this appointment, your doctor will recommend routine follow-up studies in order to ensure that the affected area looks good and doesn’t need any further treatment. The date of the follow-up and the type of studies recommended will be determined by the treating physician.
When to call your Doctor
After you leave the hospital, call your doctor if any of the following occurs:
- Any changes in physical ability (balance, strength, or movement)
- Any changes to mental status (consciousness, memory, thinking)
- Weakness, numbness, tingling
- Signs of infection including fever and chills
- Redness, swelling, increasing pain, bleeding, or discharge from the incision site
- Changes in vision
- Pain that you cannot control with the medicines you have been given
- Nausea, vomiting
- Trouble controlling your bladder and/or bowels
Call 911 or go to the emergency room right away if any of the following occurs:
- Shortness of breath or chest pain
- Loss of consciousness