How are brain aneurysms treated?

Brain aneurysms can be treated with surgery or with a procedure called coiling.

Brain aneurysms (also called cerebral aneurysms) are not always treated immediately. Sometimes, if the aneurysm is very small and is not leaking, your doctor may prefer to monitor it for a while, especially if there are other medical conditions that need to be managed. Your doctor may recommend imaging every year or on a regular basis to observe the aneurysm and determine if it is growing.

When it is time to treat the aneurysm, there are three main options:

  • Clipping: This procedure requires the neurosurgeon to enter the brain to place a small clothespin-like clip around the base of the aneurysm where it protrudes from the blood vessel. The clip blocks the blood flow to the aneurysm, so there is no more pressure applied to the weakened wall of the blood vessel. The blood that remains in the aneurysm clots, and there is no longer a threat the aneurysm will burst and bleed into the skull.
  • Parent vessel occlusion: Sometimes an aneurysm has damaged the blood vessel so much that the neurosurgeon must clamp off the entire artery. This is a more complicated surgery that may also require a bypass to reroute the blood around the clamped section of the vessel. The choice of treatment is primarily determined by the size, shape and location of the aneurysm, as well as your medical condition, overall health and family history.
  • Coiling: Coiling is a minimally invasive procedure used to repair the aneurysm from inside the blood vessel. An interventional neuroradiologist threads a very thin, hollow tube (microcatheter) through the blood vessel to the location of the aneurysm. This tube is used to transport a tiny, tightly coiled bundle of platinum fibers to the aneurysm.

While viewing the procedure on a monitor, the surgeon inserts the coil into the aneurysm to protect the weakened wall of the blood vessel from the pressure of the blood flow. Sometimes a tiny splint-like sheath (stent) is inserted into the blood vessel to help strengthen that section of the vessel and to help keep the coil in place.

Surgical "clipping" and endovascular surgery are commonly used to treat a brain aneurysm.

There are three primary surgical treatments for both ruptured and unruptured brain aneurysms. One is surgical clipping, which involves a surgeon locating the blood vessel that feeds the aneurysm, and attaching a metal clip to the base of the aneurysm to cut off blood flow to it. The second method is endovascular coiling. This involves a surgeon inserting a coil wire into the artery leading to the aneurysm and then coiling the wire inside the aneurysm, which prevents blood flow and forces a clot to form. The third method is occlusion and bypass. If the artery has been damaged by the rupture, a surgeon will cut off flow to that part of the artery and use a blood vessel graft to reroute blood flow. Other treatment options include the use of drugs to treat symptoms, like Tylenol for pain. For unruptured aneurysms, the treatment may be simply to regularly monitor the brain aneurysm for changes in size and adjust treatment as necessary.

The goal of treating brain aneurysms is to prevent them from rupturing and causing bleeding in the brain, which can be potentially fatal. Brain aneurysms can be treated by open surgical (craniotomy) clip ligation or by endovascular means. For the open surgical option, a hole is made in the skull and a metal clip is placed at the base of the aneurysm to prevent blood from entering. Endovascular treatments are less invasive (without opening the skull) and entail coiling of the aneurysm, injecting liquid agents (i.e. Onyx), and/or stenting with or without the aid of a balloons. 

The decision on which modality is the ideal one, will depend on the age and health of the patient as well as the size and location of the aneurysm. Both treatment options have benefits and risks. The open surgical option is more invasive but the endovascular option has a higher chance of requiring retreatment in the future. Follow up with X-Rays, CT scans and/or MRI scans is necessary after both treatments.

Dr. Geoffrey P. Colby, MD

The traditional treatment is called aneurysm clipping. A craniotomy is performed, opening a window in the bone of the skull. A surgical microscope is used to locate the aneurysm, then microsurgical techniques are used to close it off with a spring-loaded clip. The clip squeezes the aneurysm closed and seals it at the level of the normal blood vessel. This prevents blood from getting into the aneurysm and eliminates the risk of a hemorrhage.

This is a very well-established and durable technique that has been used routinely since the 1960s. Once an aneurysm is treated by clipping, the risk of the aneurysm regrowth or bleeding later is extremely small—1 percent or less. Once sealed, blood can't get into the aneurysm and a rupture isn't possible. Endovascular techniques, or minimally invasive techniques performed from the inside of the blood vessel, were developed to treat aneurysms in the late 1980s.

These treatments, of which aneurysm coiling is the most common, have gained significant popularity since their introduction because they are minimally-invasive with rapid recovery of the patient. A newer endovascular treatment option includes a technique called flow diversion. This involves placement of a special high-mesh density stent across the neck of the aneurysm. Over time, the inner lining of the blood vessel wall grows onto the stent and heals the blood vessel. This vessel reconstruction closes off the opening to the aneurysm effectively reconstructing the blood vessel wall. It is best to speak with an aneurysm expert to learn more about these treatment options and what is the most appropriate option for your aneurysm.

If your doctor determines that a brain aneurysm requires treatment, there are two major approaches. The first is surgery to place a clip at the neck of the aneurysm, which blocks this weak-walled outpouching. This would be performed by a neurosurgeon and requires entry through the skull to access the blood vessels between folds of the brain. The second approach is "endovascular," and this involves angiographic technology, such as is used with cardiac catheterization, to thread a catheter through an artery in the groin up to the brain vessels. Using x-ray guidance, the interventional specialist would place a synthetic coil in the aneurysm, which closes off the aneurysm and protects it from rupture.

Time is of the essence in aneurysm treatment. In this video, stroke neurologist Dr. Carolyn Brockington describes how aneurysms are handled.

Doctors determine the best treatment for each aneurysm patient by weighing factors including the patient's age and overall health and the size, shape and location of the aneurysm. Treatment options include:

  • Endovascular coiling or embolization: In this minimally invasive approach, surgeons fill the aneurysm with tiny platinum coils or a "super-glue" to promote the aneurysm's healing and eliminate the potential for a future rupture.
  • Aneurysm clipping: In this microneurosurgical treatment surgeons place a tiny metal clip at the base of the aneurysm to seal it off from the normal blood supply and to prevent it from growing or rupturing.
  • Extracranial-intracranial bypass: Doctors may consider a combined surgical and neuroendovascular approach for large and complex aneurysms. In this relatively uncommon approach, doctors first reroute blood flow around the aneurysm, then treat it with clipping or endovascular embolization. This approach combines two complementary procedures to ensure the safe obliteration of these aneurysms.

If the aneurysm is located in or near critical areas of the brain they may also use special brain mapping to ascertain special approaches to delicate areas with great precision and to avoid injury during surgery.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.