Endovascular treatment |
Embolization of an unruptured brain aneurysm

A brain aneurysm is a focal bulging of a blood vessel in the head. The most common treatment for this is called coiling or embolization. In the following you will get information about the events surrounding this treatment. With this information we don’t want to unnecessarily scare you for the procedure, but we want to try to give you a better idea of the condition, treatment and possible, yet rare risks and complications, so you are better prepared for the procedure.

The aneurysm

A brain aneurysm is a localized bulge of the blood vessel wall. These protrusions have an increased risk of bleeding due to bursting of this weak spot. Such a stroke can have different symptoms, such as sudden severe headache with nausea and vomiting and even death.

Treatments aneurysm 1
  1. CT scan shows SAH
  2. 3D shows aneurysm reconstruction
  3. Angiography confirms aneurysm before coiling
  4. Angiography shows complete closure after aneurysm coiling

Fortunately, an aneurysm is sometimes discovered in time before a stroke occurs. This can be a incidental finding in a scan study. Some patients with cerebral hemorrhage due to an aneurysm can have additional cerebral aneurysms at another site in the head. Finally, an aneurysm can grow so large that it creates pressure on nearby brain or nerve tissue leading to neurological symptoms (such as reduced vision, double vision, paralysis ...). To prevent a future stroke the endovascular treatment is performed.

For a more detailed explanation of the cerebral aneurysm can look at the chapter diseases.

Before the treatment

  • It is important to inform the doctor or nurse on the following:
    • Pregnancy
    • Allergies, especially contrast allergy
    • Medication use
  • Use of medication should be consulted with your physician. Especially important to discuss is the use of blood thinners (aspirin, Ascal, Asaflow, Plavix, Clopidigrel, Ticlid, Marevan, Warfarin, fraxiparin, etc).

  • If you are contrast allergic, you should be premedicated. Generally, you need to take a Medrol 35mg tablet the evening before the examination.

  • You need to be sober for the treatment. This means that from midnight the day before the examination you should no longer eat or drink. On the day of the study, only take the necessary medication with a little water.

Illness or foreclosure

Ordinarily, your doctor or you yourself made an appointment for the examination. If due to any reason you are unable to pass the examination, kindly get in touch with the radiology department. This can be done via the telephone 03 821 3803. Please make a new appointment, if possible.


During the treatment you have to lie perfectly still. This requires that you be completely put to sleep (general anesthesia). This is done by a specialist doctor (anesthesiologist). In order to undergo the narcosis as safe as possible you might get an appointment for a consultation with the anesthesiologist in the period prior to the treatment. It is also possible that you should undergo some additional studies (eg EKG, blood test, heart or lung examination, ...).

Because of the anesthesia, you should be sober for at least 6 hours, but usually longer. Often alongside an intravenous drip, a urinary catheter is inserted during anesthesia.

Hospital admittance

You are at least 2 to 3 days (sometimes longer) in the hospital. This is usually on the ward A4 (4th floor) at the neurosurgery department. On the morning of the admittance you need to be sober (last meal taken before midnight). You check in at the central reception area of the hospital, then you will be referred to the ward. There, you will received by a nurse who can arrange all the practical issues. At the ward there is a attending physician present.


To close the aneurysm, it is filled with very fine metal wires, called coils. This ensures that the weak spot no more fills with blood and no new bleeding can occur. This endovascular treatment is called embolization with coils or "coiling". This procedure is performed by specialized interventional neuroradiologists on the angiography room of the radiology department. The duration of the investigation can vary from one to several hours depending on the accessibility and the size of the aneurysm.

Treatments aneurysm coil
– VSeveral examples of micro-coils used for the closure of a brain aneurysm –

The anesthesiologist will put you to sleep. So you will feel nothing during the procedure. Then a thin catheter (small tube) is placed from the femoral artery (usually right) in one of the head and neck arteries. Through this catheter an even thinner tube (micro catheter) is then guided very carefully into the aneurysm. Subsequently the aneurysm is gradually filled with coils until it is isolated from the bloodstream. Usually, in addition to the coil micro catheter a small balloon micro catheter is also inserted. This balloon micro catheter is placed at the neck of the aneurysm for temporary additional support to the coiling.

Sometimes a stent needs to be placed to support the neck the aneurysm (to keep the coils inside the sac). With stent placement it is necessary to take anticoagulation several days before the procedure until minimally 3 to 6 months after the stent treatment.

After treatment, the catheters are removed and the hole in the femoral artery is closed with a special plug (Angioseal ®). This Angioseal® is naturally degraded by the body in about 2 to 3 months. During this period caution should be exercised with any re-puncture of the groin.

Coiling aneurysm stent
– Coiling of an aneurysm with stent –

After the treatment

The patient wakes up in the angio room or in the recovery room (recovery, PACU or recovery room). The patient is constantly monitored. The puncture site in the groin is regularly controlled. If everything goes well, the patient will be transported to the ward. Sometimes it is necessary to be monitored on the medium care (MC) or intensive care unit (ICU). The patient has strict bed rest until the next day. To prevent a bleeding at the puncture site (groin) the patients has to keep his/her right leg immobile for at least 4 hours and needs to lie on his/her back. Try not to use the abdominal muscles (no coughing or sneezing, no toilet, ….). Depending on the condition of the patient he/she stays for 2 or 3 days in the hospital with a recovery in about a week. After this period, the patient can return to normal daily (work- and sport) activities, provided that the doctor gives his permission.

At hospital discharge you get instructions for medication and an appointment for a consultation at the neurovascular consultation (approximately 6 weeks after treatment). Usually a control angiography is performed to see if the aneurysm is closed off, about 3 to 6 months after treatment.

Pain and discomfort

During the treatment you will be under general anesthesia and feel nothing. Afterwards the puncture site in the groin can be sore. Seldom a bleeding can also occur in the groin at the puncture site. You need to notify the nurse or doctor when you have pain or other symptoms. Rarely, allergic reactions (redness, rashes, swelling, hoarseness, chest tightness, ...) or adverse effects on the kidneys (especially in people with preexisting poorer kidney function) can occur because of the use of contrast and / or medication.

Complications and risks

Sometimes a bleeding in the groin can happen (bruising and swelling) which usually resolves itself within a few weeks.

The risk of serious complications during embolization with coils is less than the risk of a brain haemorrhage when an aneurysm is left untreated. Hence, we advice in most cases a treatment. The most feared complication is the occurrence of a bleeding during or after the procedure. Fortunately, this is rare, but when it happens it can have serious consequences (up to death). The other serious complication is the occurrence of cerebral infarction (stroke) by the formation of blood clots (thrombi) or vasospasm. This can result in paralysis, aphasia among others. To prevent blood clots, blood thinners are given around and after the procedure.

For most complications, there are treatments and recovery is frequently possible. The list of complications is not exhaustive, but the above are the most drastic.

The specific risks of the treatment (thrombosis, thrombo-embolic events, bleeding) en possible consequences will be discussed before the procedure by the treating physicians.

Alternative to embolization with coils

An aneurysm can also be treated with a skull operation by placing a vascular clip on the neck of the aneurysm (transition from the aneurysm to the normal blood vessel). Of course there are specific advantages and disadvantages associated with this procedure (see the chapter surgical aneurysm clipping).

Treatments aneurysm coiling Treatments aneurysm clipping
  1. aneurysm coiling
  2. aneurysm clipping

Before a treatment is proposed, the various treatment options and their risks are discussed within the team of interventional neuroradiologists and neurosurgeons.

Additional questions

If you have any further questions, please feel free to contact your treating physician, neurosurgeon, specialist nurse or interventional neuroradiologist via the telephone number of the department of angiography of the UZA (03-821 3803).