Revascularization is a surgery that restores blood flow to the brain, decreasing the chance of stroke or other damage to brain tissue.
When is Revascularization performed?
Revascularization is performed to treat several conditions that reduce blood flow to the brain. Such conditions include moyamoya syndrome, carotid artery disease, and atherosclerosis of the cerebral arteries. Each of these conditions puts the brain at risk of cerebral ischemia or ischemic stroke. Each condition may also cause transient ischemic attacks (TIAs). In addition, the delicate new vessels that form as a part of moyamoya syndrome are at risk for leaking into the brain and causing hemorrhagic stroke.
Revascularization may also be performed to bypass a damaged artery. For example, it is sometimes used to route blood past an aneurysm. The danger posed by an aneurysm is that blood might leak or burst out through the weak area, causing a hemorrhagic stroke. Some aneurysms cannot be treated with standard procedures that clip them shut or seal them off. In these cases, a revascularization procedure can provide an alternative blood flow path. Then the section of the artery with the aneurysm can be completely shut down, safely preventing hemorrhagic stroke.
A bypass may also be necessary when a skull base tumor becomes entangled with one of the major arteries that enter the brain. Removing the tumor may require removing part of the artery. A bypass provides an alternative route for blood flow, allowing the safe removal of the tumor.
How should I prepare for Revascularization?
There are two main types of revascularization procedures.
In a direct revascularization, two blood vessels are surgically linked. Often, a blood vessel from outside the skull is connected to a blood vessel inside the skull, in a procedure called an EC-IC bypass. Sometimes a blood vessel taken from the arm or leg is used to connect the target vessels. The technical name for the new connection between blood vessels is anastomosis. In direct revascularizations, the anastomosis establishes the new blood flow immediately.
When it is necessary to use a vessel from the arm or leg as a graft for direct revascularization, the neurosurgeon connects the vessels using the tools and techniques of microsurgery. Once the vessels are connected, the anastomoses are tested for a perfect seal. A permanent hole in the skull is made for the blood supply to pass from outside the skull to inside the skull. Then the rest of the craniotomy is closed with titanium plates and screws.
Bypass procedures are all forms of direct revascularization.
In an indirect revascularization, a neurosurgeon diverts a blood supply from its normal location onto the surface of the brain. The blood supply may be a single blood vessel or nearby tissue, such as muscle tissue, rich with blood vessels.
When an indirect revascularization uses a single blood vessel (procedures called pial synangiosis and EDAS), the neurosurgeon detaches the vessel from its usual location for several inches. Then the neurosurgeon removes a small window of skull in order to place the vessel on the surface of the brain. Before replacing the piece of skull, the neurosurgeon cuts little notches at either end that allow the blood vessel to enter the skull and leave it again. However, if a vessel-rich muscle tissue is used, it is simply freed from its normal attachment at one end and placed on the surface of the brain. It does not need to leave the skull again.
The body naturally grows new blood vessels from this supply into the areas of reduced blood flow. The new blood supply is not immediate, though; the new blood vessels take several months to grow.
All revascularization procedures are performed under general anesthesia. A craniotomy provides access to the target vessels and the brain.
How is Revascularization performed?
Make sure you understand the goals and risks of the procedure. Our specialists have extensive experience with revascularization surgery, and our complication rates are very low, but no surgery is completely without risk. Risks of revascularization surgery include stroke and seizure.
What can I expect after Revascularization?
You will be monitored as you wake up from anesthesia, and then you will move to a recovery room. Every few hours, a nurse with a specialization in neurology will perform a neurological exam to test your feeling and movement. The nurse may also check your blood vessels with a Doppler ultrasound.
How long will I stay in the hospital?
Most patients go home one to two days after surgery.
Will I need to take any special medications?
After the procedure, discomfort is controlled with pain medication. You may temporarily be prescribed an anticonvulsant to prevent seizures and/or blood thinners to prevent clots.
Will I need rehabilitation or physical therapy?
Rehabilitation and physical therapy usually are not required. Immediately after surgery, the focus should be on resting and recovery. By two to four weeks after surgery, most people return to work.
Will I have any long-term limitations due to revascularization?
After some revascularization procedures that involve the temple area, it is important that eyeglasses not fit too tightly over the ear. Too much pressure from the arms of eyeglasses could damage a vessel graft there. Other recommendations will vary by case, so discuss your specific situation with your surgeon.