In certain cases when the brain aneurysm cannot be safely clipped using standard techniques, and the aneurysm cannot be treated with coils, the patient may require a reconstruction of the arterial tree allowing for blood flow to “bypass” the aneurysm. Bypass procedures involve grafting a blood vessel from the neck or harvesting a vein or artery from the arm or leg and attaching it to the blood vessel of the brain feeding the aneurysm using microscopic sutures. The aneurysm is then treated by placing either surgical clips or endovascular coils in the blood vessel that supplies the aneurysm. Using this technique, the normal blood flow to the brain is not disturbed, and the aneurysm no longer receives any blood flow.