The treatment of a brain aneurysm is decided by factors including shape, size, and location. Treatment is performed endovascularly or surgically.
Endovascular treatment is performed by inserting a catheter into the femoral artery and feeding up into the brain. The femoral artery entry point is in the groin. These treatments are usually called “procedures,” rather than surgery because of the minor surgical incision.
Alternately, clipping is performed with a major incision and cut in the skull (craniotomy) and is considered a surgical procedure or surgery.
Some use these terms interchangeably, others strictly use “procedure” to describe endovascular treatments.
Angiogram
An angiogram is a diagnostic test used to view the arteries of the brain. A long catheter is inserted in femoral artery and fed up into the brain. Contrast dye is delivered in the blood stream which allows the blood vessels to be visible in x-rays. This gives the neuroradiologist the most clear, detailed, and accurate images of the blood vessels and abnormalities. The angiogram itself is diagnostic, but many other procedures are an extension of the angiogram.
Endovascular Coiling
Endovascular coiling, or coiling, uses platinum coils to fill the aneurysm and block the flow of blood to the weakened area. As with the angiogram, the neurosurgeon inserts a catheter in the femoral artery leading it up into the cartorid artery of the brain. Platinum coils are then inserted into the aneurysm causing the blood to clot and prevent more blood from getting into it. (Think of these coils as tiny steel wool pads, really tiny!) Coils are added until the aneurysm is filled and there is no blood flow in the area. Typically, it is minimally invasive and recovery time (if the aneurysm has not ruptured) can be short. Coiling is almost a standard in the case of rupture and also widely used for the treatment of unruptured aneurysms.
John’s Hopkins University defines “Endovascular coiling as a procedure performed to block blood flow into an aneurysm (a weakened area in the wall of an artery)”
Surgical Clipping
Performed by a neurosurgeon, clipping is a surgical procedure used to treat a brain aneurysm. The surgical incision is made through the skin and skull (craniotomy) to reach the aneurysm site. The titanium clip will be permanently placed across the aneurysm where it emerges from the blood vessel. This, of course, prevents blood flow into the weakened area. The piece of skull is then reattached with screws and the scalp is stitched. Clipping is considered highly effective and clipped aneurysms rarely need further care.
Flow Diversion Stents
Approved by the FDA in April 2011, the Pipeline Embolization Device (PED) is a flexible mesh tube made of platinum and nickel-cobalt chromium alloy that can be used to block off large, giant, or wide-necked aneurysms in the internal carotid artery. Currently, the PED is the only approved flow diversion device used in the United States, but there are others in the process of being approved. The device reduces the likelihood that an aneurysm will rupture and is often used for the treatment of aneurysms that would not be good candidates for clipping or coiling. They are also used in connection with coils to hold the coils in place if the neck of the aneurysm is large. Natural healing happens over time and the aneurysm will often shrink as the blood is diverted away from the weakened area.
As with the angiogram, the procedure is done through a catheter inserted in the femoral artery. The PED device is fed through the catheter into the brain to the aneurysm location. The device is expanded against the walls of the parent blood vessel and across the neck of the aneurysm, cutting off blood flow to the aneurysm. The blood remaining in the blocked-off aneurysm forms a clot which reduces the likelihood the aneurysm will grow bigger or rupture. Aneurysms successfully treated with the Pipeline will often shrink over time.
Occlusion and Bypass
Usually a result of severe damage to the artery, occlusion and bypass reroutes the blood through a donor replacement vessel and then coils the diseased vessel. This is a two part procedure involving endovascular coiling of the vessel (not just the aneurysm sac) and microsurgery to reroute the blood flow. Occlusion and bypass is both an endovascular and surgical procedure.
Liquid Embolics
Coiling has been a mainstay of endovascular embolization of cerebral aneurysms. However, in 2007, Onyx liquid embolic material (Onyx HD 500, a surgical glue) was introduced as an alternate method of treatment. The procedure is very similar to coiling. Instead of using platinum coils, the onyx liquid embolic material is injected into the aneurysm sac. A balloon is temporarily inflated in the parent artery across the neck of the aneurysm to hold the liquid in place. When the liquid is in contact with blood, it solidifies. The balloon is then removed.