Surgical clipping, a microsurgery, is performed by a team of doctors and led by a neurosurgeon. It is an "open surgery" involving the cutting of the skull, separating the two lobes of the brain and attempting, with a minimum of brain handling, to get at the aneurysm. The operation is done under general anesthesia. Neurosurgeons tend to rule out patients for this procedure based on the location of the aneurysm (Johnston, et al. Endovascular and surgical treatment of unruptured cerebral aneurysms: comparison of risks. Ann Neurol. 2000 Jul;48(1):11-9), the most problematic being the cavernous carotid. Barring complications, the hospital stay is usually 4-6 days, with post-operation recovery 3-6 weeks (American Stroke Association; 2003).

3-D Volumetric CT scan of cranium with a clip represented in blue.
Courtesy of Dr. Kieran Murphy, Johns Hopkins University, Department of Radiology

Clipping Procedure

After making a usually straight or zigzag incision at the back of the head or near the hairline, depending on the location of the aneurysm, the neurosurgeon will remove a small section of bone from the skull. With the aid of a microscope the neurosurgeon will navigate past the exterior of the brain tissue without cutting into it in order to gain access to the arteries and the aneurysm. A tiny metal spring clip is then placed permanently across the neck of the aneurysm sealing it off from the normal blood circulation in the artery.

Aneurysm clipping.

There are several types of clips which may be used. The section of bone is then replaced and secured and the incision is closed.

Types of spring clips.

Complications

While there is the possibility of partial or incomplete clipping, residual aneurysm activity is uncommon. Possible complications from treatment include infection at the incision site, rupturing the aneurysm during surgery, damage to the artery and bleeding into the brain which could result in brain damage. This could lead to:

Weakness or paralysis of an arm or a leg
Difficulty with speech or understanding
Vision impairment
Confusion, memory loss and/or seizures

The anesthesia used during the procedure also has the associated risks:

Infection
Bleeding
Kidney damage from X-ray dyes

If there are complications from surgery or a hemorrhage event, the hospital stay could be 1-4 weeks or more.

See Treatment – Recovery and Treatment – Risks for more details.

Preparing for the Surgery

If treatment is undertaken following a rupture, it is likely that it will be done within a short time of your arrival in the hospital emergency room. It is important to have as thorough a discussion of treatment options with your doctor as your situation permits. If more time is available, as in the case where the aneurysm is discovered prior to rupture, you will have the opportunity to question the neurosurgeon more closely about the risks and benefits of the treatment and what to expect during and after treatment. Important questions may include: the frequency and success rate of the doctor and the hospital performing the procedure, location and type of incision and stitches, possibility and arrangement of blood transfusion from personal or family donation or from the blood bank, potential complications, recovery time in the hospital and at home, and the advisability of screening close family members for aneurysms.

Assuming an unruptured aneurysm, you will first attend a pre-operative appointment scheduled, usually the day before your surgery, wherein you will undergo testing (blood tests, EKG, chest X-ray, etc.). The doctor will explain the procedure, risks, and ask you to sign release forms. You should come prepared to discuss your medical history including any medications you are currently taking. Make sure you are aware of the guidelines for your hospital with respect to not eating before general anesthesia.

Also in the pre-operative appointment, an anesthesiologist will discuss the use of anesthesia during the procedure. General anesthesia is typically used in this procedure for patient comfort, to keep the head immobile and to assure the quality of the X-ray image. Let the doctor know ahead of time if you have a problem recovering from anesthesia. There are medications that can assist in your recovery. On the day of surgery, the course of action should have been completely explained to you. One of the first steps will be to shave a section of the head. This may or may not be done before you are sedated. Urine production will have to be monitored and a catheter will be inserted for this purpose.

An IV or intravenous line will be inserted to monitor blood and deliver medications. Throughout the operation you will be unconscious. After the surgery, you will wake up somewhat cold and slightly dizzy with possible nausea and sore throat. The feeling has been likened by some to a hangover. You will then be asked to do breathing exercises. After the operation you will likely be moved to the ICU where you will be closely monitored overnight.

See Treatment - Recovery and Treatment - Risks for more details.