What is the Endovascular treatment of aneurysms?
Coil embolization is an alternative to surgery. This treatment has been offered at Toronto Western Hospital since 1992. This is done in the Neuroangiography suite under fluoroscopy. The Neurointerventional radiologist will make a small incision in the groin through which a tiny catheter is guided through the femoral artery into the brain vessels. The catheter is carefully guided into the aneurysm. Soft platinum coils are deposited through the microcatheter into the aneurysm. When in position, the coil is released by an application of a very low voltage current causing the coil to detach from the pusher wire.
The softness of the platinum allows the coil to conform to the often irregular shape of an
aneurysm. An average of 5-6 coils are required to completely pack an aneurysm. The goal of
this treatment is to prevent blood flow into the aneurysm sac by filling the aneurysm with coils and thrombus. This should prevent aneurysm bleeding or re-bleeding.
Embolization does not repair areas of the brain already injured. The patient will be admitted either the night prior or the morning of the procedure. The treatment is done under a general anaesthetic. A minimum 2-night stay is required after the procedure.
The Procedure
Embolization is not an open surgical procedure and requires specialized training. Most endovascular therapists are neuroradiologists or neurosurgeons who have completed training (ranging from one to two years) in endovascular techniques after their medical (five years) and speciality training (five to seven years).
Before admission
Preadmission will be done one day or two prior to the embolization and routine blood tests may be done. After midnight, no food or drink is allowed.
The Day of the Procedure
After midnight, no food or drink is allowed. You will be taken from the “same day unit” or “preadmission area” to the Neuroangiography suite where the procedure will be performed. Just before the procedure, the nurses will shave one or both groins. Embolization is done under general anaesthesia. After the anaesthetic is administered, a catheter will be threaded up a blood vessel in your groin all the way up into the aneurysm. Very tiny catheters are used. This is a similar procedure to a cerebral angiography except that in addition to dye being injected to show the aneurysm, these tiny catheters are positioned near the aneurysm and platinum coils are inserted into the aneurysm to embolize it.
The length of the procedure is often not predictable, and waiting family members need not to be frightened because a case may takes longer than expected. If the doctors do not think that they can safely embolize the aneurysm, then the embolization procedure will be discontinued.
After Treatment
You will be taken to the Neurosurgical Intensive Care Unit or Step-down Unit where you will be observed closely overnight. Your doctor will instruct you to remain still, lying flat in bed for up to eight hours. This rest period allows the groin artery to heal.
If all goes well, you will be transferred to a neuroscience floor the next day and discharged home the following day. Most patients treated by embolization will also need to return for a follow-up angiogram or magnetic resonance angiogram (MRA), usually performed several months after the treatment to confirm that the outcome of the treatment is stable in time.
What are the Side Effects?
The risk of embolization is low. Possible complications include stroke like symptoms such as weakness in one arm or leg, numbness, tingling, speech disturbances and visual problems.Serious complications such as permanent stroke or death are rare.The estimated risk should be discussed with your doctor.
Detachable balloon occlusion
Sometimes the size, shape or location of an aneurysm makes coil embolization and surgery impossible. In this case the doctor may choose to block off the parent artery itself. A preliminary test occlusion is often required. A balloon occlusion of the parent artery may be required for an aneurysm at the base of the skull or a very large aneurysm.
A detachable balloon may be placed distal and proximal to the aneurysm. This will permanently close the artery, therefore no blood will reach the aneurysm. The patient is often tested in advance to assure he can tolerate the occlusion of the artery. This is called a balloon test occlusion.
