Treatment

UNRUPTURED ANEURYSM

Not all brain aneurysms rupture. Doctors are now able to detect unruptured brain aneurysms with an increased frequency. An unruptured brain aneurysm may or may not cause symptoms. Unruptured aneurysms are no less frightening or life altering, but require different diagnostic questions and potential treatments.

Things doctors consider in deciding whether or not to treat an unruptured aneurysm:

• Risk of Hemorrhage
• Is it probable or not that the aneurysm will rupture?
• Size and Location
• Age and Health of Patient
• Family History - Is there a family history? Have any of those aneurysms ruptured?
• Surgical Risks

If the unruptured aneurysm is treated, usually the recovery period is shorter for survivors of unruptured brain aneurysm treatment than people who had ruptured brain aneurysms. Although, survivors of unruptured brain aneurysm treatment may suffer many of the same physical and emotional symptoms as a survivor of a rupture, they will have a shorter hospital stay, require less rehabilitative therapy, and return to work more quickly.

RUPTURED ANEURYSM

A ruptured aneurysm (patient has already experienced a subarachnoid hemorrhage, SAH), generally requires treatment as soon as possible due to the high re-bleeding rate. Treatment options of the SAH patient are the same procedures (coiling and clipping) as for unruptured aneurysm, however, the decision is made by the attending physician as the patient is often unconscious or unable to participate in the decision-making. Treatment time and option decisions are made based on similar criteria: size, location and shape of the aneurysm and the added factors of the hemorrhage as well as the patient’s overall medical condition.

One caution the family of a ruptured aneurysm patient might want to take at this juncture is to ensure that both an interventional radiologist and a neurosurgeon consult over the case as time and the patient’s condition permit. In some cases either technique could be used, and the recommendation on how to proceed will be influenced by a number of considerations including, the age and condition of the patient and the experience and skills of the attending physicians.

• Clipping
• Occlusion and Bypass
• Endovascular Embolization or Coiling
• Pipeline Embolization
• Onyx Liquid Embolic System (Onyx HD-500)

Once a hemorrhage has occurred, several consequences might develop.

• Damage to the brain cells
• Fluid Build-up in the brain
• Vasospasm
• Hydrocephalus

Clipping

Clipping is still the most common surgical treatment for brain aneurysms. It is an effective, well researched surgical procedure with excellent results.

Microvascular clipping involves cutting off the flow of blood to the aneurysm. Under anesthesia, a section of the skull is removed and the aneurysm is located. The neurosurgeon uses a microscope to isolate the blood vessel that feeds the aneurysm and places a small, metal, clothespin-like clip on the aneurysm's neck, halting its blood supply. The clip remains in the patient and prevents the risk of future bleeding. The piece of the skull is then replaced and the scalp is closed. Clipping has been shown to be highly effective, depending on the location, shape, and size of the aneurysm. In general, aneurysms that are completely clipped surgically do not return.

Occlusion and Bypass

In some cases, it may be best to stop blood flow through the artery leading to the brain aneurysm. This is known as an occlusion. Sometimes the aneurysm has caused severe damage to the artery, so the doctors go in and completely shut down that part of the artery and reroute the blood. This procedure is usually done as an open surgery, which requires similar surgical preparation as in a clipping procedure such as having your head shaved, and a section of the bone plate removed.

Endovascular Embolization or Coiling

Endovascular (meaning within the blood vessel) embolization, or coiling, uses the natural access to the brain through the bloodstream via arteries to diagnosis and treat brain aneurysms. The goal of the treatment is to safely seal off the aneurysm and stop further blood from entering into the aneurysm and increasing the risk of rupture or possibly rebleeding.

With the advent of this remarkable new treatment, some patients who were told they had inoperable aneurysms were now given hope and chance for survival. Other patients, because of advanced age, serious medical problems or other factors, could not undergo open brain surgery, so the GDC system became the alternative to their treatment.

Once the patient has been anesthetized, the doctor inserts a hollow plastic tube (a catheter) into an artery (usually in the groin) and threads it, using angiography, through the body to the site of the aneurysm.

Using a guide wire, detachable coils (spirals of platinum wire) or small latex balloons are passed through the catheter and released into the aneurysm. The coils or balloons fill the aneurysm, block it from circulation, and cause the blood to clot, which effectively destroys the aneurysm. The procedure may need to be performed more than once during the patient's lifetime.

Patients who receive treatment for aneurysm must remain in bed until the bleeding stops. Underlying conditions, such as high blood pressure, should be treated. Other treatment for cerebral aneurysm is symptomatic and may include anticonvulsants to prevent seizures and analgesics to treat headache. Vasospasm can be treated with calcium channel-blocking drugs and sedatives may be ordered if the patient is restless. A shunt may be surgically inserted into a ventricle several months following rupture if the buildup of cerebrospinal fluid is causing harmful pressure on surrounding tissue. Patients who have suffered a subarachnoid hemorrhage often need rehabilitative, speech, and occupational therapy to regain lost function and learn to cope with any permanent disability.

Sometimes an occlusion is combined with a bypass. A bypass reroutes blood flow around the occluded artery. Doctors take a small blood vessel from another part of your body, usually the leg, and graft it to a section of the brain artery where it makes most sense. This new artery (bypass) brings blood to the part of the brain that had been fed by the damaged artery.   

Pipeline Emoblization

The Pipeline Embolization Device (PED) is a minimally invasive procedure where a braided, platinum and nickel-cobalt chromium alloy wire mesh device, is placed within an artery in the leg, giving doctors the ability to treat some of the most complex and dangerous brain aneurysms. The treatment is focused on reconstruction or remodeling of the weak blood vessel harboring the brain aneurysm.  

The PED is a new class of embolization device designed to divert blood flow away from the aneurysm. It is composed of multiple, fine, individual strands of platinum and cobalt chromium which are braided into a flexible, mesh tube. The device is threaded up through a catheter placed in a blood vessel in the leg up to the brain. Once the device is implanted across the neck of an aneurysm, the PED essentially rebuilds the diseased brain artery by rerouting blood flow away from the aneurysm and along the course of the normal, reconstructed blood vessel.  

The PED is intended to treat adults with large or giant, wide-necked brain aneurysms of the major artery supplying the front of the brain called the internal carotid artery. It is a less open (invasive) treatment, performed with the use of a catheter placed inside the blood vessel, compared to an open surgical procedure with the use of clips to block the aneurysm. It is an alternative to placing materials such coils or a liquid embolic to treat the aneurysm.  

The thinness of the device also allows for telescoping or endovascular bypass, a technique where multiple PEDs are placed within each other with less risk of narrowing the artery while creating a new and stronger blood vessel.

By causing the aneurysm to be completely blocked, treatment with PED is intended to reduce the likelihood of an aneurysm rupture or reduce the likelihood of an increase of the size of the aneurysm, which also increases its risk of rupturing. A successfully treated aneurysm will often shrink in size over time.  Click here to watch a pipeline emolization procedure.  

Onyx Liquid Embolic System

Onyx HD-500 is an artificial material used to block blood flow into aneurysms. The material is used to fill the aneurysm space, or pocket, and prevent the aneurysm from rupturing or increasing in size.
This material is an ethylene vinyl alcohol copolymer dissolved in the organic solvent dimethyl sulfoxide (DMSO) opacified with tantalum powder. Once coming into contact with an ionic solution the DMSO dissipates and the Onyx solidifies into a spongy, cohesive material. This substance is delivered to the aneurysm via a microcatheter once the neck of the aneurysm is temporarily occluded by a balloon which reduces the risk of the copolymer exiting the aneurysm and entering the native circulation.

WHAT HAPPENS WHEN AN ANEURYSM BLEEDS (CONSEQUENCES OF A HEMMORHAGE

Damage to Brain Cells

Blood from an Aneurysm can leak into the CSF (cerebrospinal fluid) in the space around the brain (subarachnoid space). The pool of blood forms a clot. Blood can irritate, damage, or destroy nearby brain cells. This may cause problems with body functions or mental skills.

Fluid Build-up in the Brain

Blood from a torn aneurysm can block CSF circulation. This can lead to fluid buildup and increased pressure on the brain. The open spaces in the brain, called ventricles, may enlarge. This is known as hydrocephalus. It can make a patient lethargic, confused, or incontinent. Fluid may also build up in the brain after surgery. To stop fluid buildup, a drain may be placed in the ventricles. This removes leaked blood and trapped CSF.

Narrowing of Nearby Arteries

Within the few days after an aneurysm ruptures narrowing of the blood vessels can occur, and at times not enough blood is supplied to the brain and a stroke may result. This can create a problem called vasospasm.  

Vasospasm

The blood sprayed around the base of the brain can also produce a problem called vasospasm. Vasospasm typically develops 5-8 days after the initial hemorrhage. Narrowing of the blood vessels can occur, and at times not enough blood is supplied to the brain and a stroke may result. To treat vasospasm, blood pressure is often elevated with medicines. Certain medications are also given to try to ease vasospasm. Finally, catheters can be introduced inside the artery in an attempt to use balloons or medications delivered to the vessel directly to open up these narrowed vessels. Vasospasm does relax over several days.

Cerebral vasospasm can be classified into three types, namely, "subangiographic", "angiographic", and "clinical" vasospasm:

• Subangiographic vasospasm is the type that cannot be detected by the imaging method for vasospasm detection known as cerebral angiography .This means that vasospasm is actually occurring at a physical level, but we just can't see it due to limitations of available imaging methods. Specifically, either the narrowing is too mild to detect, or the spasm is happening in a part of the arterial tree which is most difficult to look at using angiography - this part involves the smaller of the brain arteries. The patient may or may not be "clinically affected" by subangiographic vasospasm so a physician may or may not be able to detect its presence. Surprisingly, some patients with subangiographic spasm still suffer symptoms that, to the exclusion of all other causes, are thought to be due to the vasospastic process taking place in their brain arteries, which is beyond the level of angiographic detection.
• Angiographic vasospasm is the type that can be detected by cerebral angiography. The patient may or may not be clinically affected by angiographic vasospasm. Generally, it is thought that if one can detect spasm angiographically then the patient should be affected in such a way that it can be picked up by a physician at the patient's bedside. However, there are exceptions to this rule. The reasons for this are unknown, but may relate to differences between individuals in terms of the unique capacities of their brains to tolerate the same degree of arterial spasm, or to differences in the "road-maps" of their brain circulation (e.g., presence of back-up routes of blood supply or "collateral circulation"). In general, in vasospasm due to aneurysmal bleeding, the vasospastic arteries (if detected) tend to be close to the site of the aneurysm rupture. However, more distant or remote arteries can also be affected in a "diffuse" or "generalized" manner.
• Clinical vasospasm is the type that, regardless of the angiographic findings, can be detected by a physician on physical examination of a patient.

Hydrocephalus

When an aneurysm rupture results in bleeding in the space between the brain and surrounding tissue (subarachnoid hemorrhage) — most often the case — the blood can block circulation of the fluid surrounding the brain and spinal cord (cerebrospinal fluid). This condition can result in hydrocephalus, an excess of cerebrospinal fluid that increases pressure on the brain and can damage tissues. Too much cerebrospinal fluid puts a harmful amount of pressure on tissues in the brain - treatment is needed to release this pressure. Hydrocephalus can be congenital (present at birth), or develop later in childhood or adulthood. Normal pressure hydrocephalus (NPH) is a type of hydrocephalus, which usually develops in people over 60, because the drainage of the CSF gradually becomes blocked.