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The Pipeline flow diversion procedure is a minimally invasive and effective approach for treating cerebral aneurysms, but this relatively new technique is not for everyone. Depending on the nature of your aneurysm, your age and your general health level, your doctor may determine that an alternative to the Pipeline procedure, such as clipping surgery or endovascular coiling, is right for you.

What Is a Pipeline Flow Diversion Procedure?

An aneurysm forms when an artery in the brain develops a weak spot, causing the artery wall to balloon outward. As blood flows through the artery, it fills the aneurysm, which can enlarge or rupture, causing a stroke, or even death. Many treatment procedures aim to stop the flow of blood to the aneurysm and eliminate the risk of a rupture. In many cases this can be done by clipping the “neck” of the aneurysm to close it, or by filling it with metal coils to block the blood flow.

In contrast, the Pipeline procedure focuses on the artery that feeds the aneurysm’s blood supply, not the aneurysm itself. In Pipeline procedures, a catheter is inserted into the artery through a single incision in the femoral artery in the groin.

Using imaging technology, neurosurgeons direct a wire mesh sheath, called a Pipeline Embolization Device, or PED, into the artery next to the aneurysm. There, the PED opens and expands, blocking the flow of blood from the artery to the aneurysm. Deprived of its blood supply, the aneurysm gradually shrinks and disappears.

Since this procedure is less invasive than alternative procedures recovery time is typically short. Patients can expect to stay in the hospital for a day or two after the procedure. Recovery will continue at home for about a week before resuming most normal activities.

Alternatives to the Pipeline Procedure

The Pipeline procedure offers new hope for resolving certain kinds of large or “wide-necked” aneurysms whose size, shape and location make them difficult to treat with clipping or coiling. For people who have allergies to blood-thinning medications such as aspirin or clopidogrel (brand name is Plavix), or to the metals in the Pipeline device itself, this procedure may not be appropriate. In this case, your doctor may opt to treat your aneurysm with another widely used alternative. Other limitations are the location of your aneurysm, as it can only be deployed in certain types of arteries.

Aneurysm Clipping Surgery

Clipping surgery is the original approach for treating cerebral aneurysms and about 80 percent of aneurysms treated this way are obliterated, requiring no further procedures. Clipping surgery is also the most invasive of today’s options for treating cerebral aneurysms, making it riskier than other procedures.

How it works

Clipping surgery resolves an aneurysm by placing a metal clip across its neck, where the aneurysm protrudes from the artery wall. That closes off the aneurysm from the artery and cuts off its blood supply. Clipping surgery requires a craniotomy, in which the skull is opened and brain tissue is cut to reach the aneurysm and place the clip.


Aneurysm clipping is an invasive procedure that carries the usual surgical risks of infection, bleeding and swelling, but also risks related to the clipping procedure itself.


The clipping procedure can cause blood clots or bleeding, which can cause a stroke.

Aneurysm Rupture

An aneurysm can also rupture during the placement of a clip.


Swelling and irritation in the brain can trigger seizures, which can continue in the days and weeks after surgery. Doctors may prescribe seizure medications during recovery.

Clip Placement Problems

An incorrectly placed clip may not completely close off the aneurysm, so that it can still rupture or bleed. Clips may also be erroneously placed across a normal blood vessel rather than across the aneurysm.

This procedure can eliminate many different kinds of aneurysms, but risks include rupturing the aneurysm and neurological damage from trauma to the brain, as well as typical surgical risks involving infection. Like a pipeline flow diversion procedure, clipping surgery is performed under general anesthesia, requiring a neurosurgeon and full surgical team.


Because aneurysm clipping is open surgery that requires a craniotomy, your recovery in the hospital can take 3 to 5 days  for an unruptured aneurysm and several weeks for a ruptured aneurysm.

For the first day or two after surgery, you can expect to recover in the hospital intensive care unit while staff monitors your progress and watches for any complications. After that, monitoring continues as you gradually increase activity levels and prepare to return home.

If clipping was performed on a ruptured aneurysm, hospital recovery typically takes place in the intensive care unit, while staff checks for neurological deficits related to the rupture and monitors closely for signs of vasospasm.

At home, recovery typically takes 4 to 6 weeks. You can expect to resume most normal activities in a few days, although you may be restricted from driving or returning to work for about a month. During this time, you can expect to see your doctors for follow-ups to monitor your progress.

Endovascular Coiling

How it works

Less invasive than clipping surgery,  endovascular coiling procedures treat an aneurysm by filling it with coils of fine, flexible platinum wire. In this procedure, a catheter is directed through an incision in the femoral artery in the groin to the aneurysm. Wire is fed through the catheter until it fills the aneurysm. This blocks the flow of blood to the aneurysm and induces clotting, so that the aneurysm is sealed off from the parent artery.


Coiling is a relatively safe and minimally invasive procedure, but it does have risks, some serious.

Aneurysm Rupture

Because coiling is performed directly on the aneurysm, placing the coils in the aneurysm can cause it to rupture and bleed, leading to stroke or seizure.

Blood Clots

Blood clots can form inside the catheter guiding the placement of the coils, on the coils themselves or in the artery itself, which can cause a stroke.

Coil Settling

Over time, the coils placed in the aneurysm can settle or become compacted, so that blood can start filling it again. This may require another procedure to add more coils or place a stent in the main vessel to support the coils.

Coil Positioning

Coils may stick out of the aneurysm into the artery or travel out of the aneurysm into a smaller artery nearby, causing a stroke.

Coiling is not appropriate for all aneurysms, especially very small ones or those with certain shapes. This procedure may be a safer option than clipping surgery for older patients or those with health conditions that make surgery more risky.


After an endovascular coiling procedure, you can expect to spend the first few hours in the hospital’s intensive care unit for monitoring. You will have to lie flat on your back for several hours and keep the affected leg as straight as possible.

If coiling is done to treat an unruptured aneurysm, your hospital stay is likely to be only a day or so. When you return home, you can expect to gradually return to normal activities within about a week or so. During that time, you may be told not to drive and to avoid lifting or doing strenuous activities.

If a coiling procedure was performed on a ruptured aneurysm, recovery in the hospital typically takes 14 to 21 days in the intensive care unit. During this time, specialized staff continue to monitor for signs of neurological deficits caused by the rupture and to watch for vasospasm — a sudden constriction, or spasm, of an artery that can occur within three to 14 days after surgery.

What Factors Affect Treatment Options?

When an aneurysm is diagnosed, doctors determine the best treatment based on a number of factors, including:

  1. The status of the aneurysm: Whether an aneurysm has ruptured, or is at risk for rupture – or if it has no symptoms at all – can play a key role in determining treatment options.
  2. The location, shape and size of the aneurysm: Aneurysms with large or wide “necks,” very small ones, or those found in areas that are difficult to access for surgery, can require different approaches to treatment.
  3. Age and general health: Younger patients typically fare better with clipping surgery, while coiling and pipeline procedures can produce better outcomes for older people. Diseases such as diabetes and heart conditions may also raise risks for surgery.
  4. Lifestyle factors: Doctors take lifestyle factors, such as obesity, smoking or an unhealthy diet, into consideration. These factors can increase the risks associated with any procedure and play a role in how well a person recovers.

For many people, the Pipeline flow diversion procedure offers an option for treating “difficult” aneurysms with minimal risk and a relatively fast recovery time. Depending on your unique circumstances however, other options may be more appropriate. Your healthcare team will work with you to develop the best plan for your successful recovery.cerebrovascular treatments