Interventional Neuroradiology
Balloon Occlusion Test
Balloon test occlusion of an internal carotid artery or vertebral artery is and alternative treatment for inoperable aneurysms, fistulas, pseudoaneurysms, dissections, or as part of the treatment of neck and skull-base tumors.
The procedure first involves an angiogram, which is an examination of the blood vessels using x-rays, that determines how well blood moves through the vessels of the brain, lung, abdomen, arms or legs. After the pictures are taken of the blood vessels, a catheter with a small non-detachable silicone balloon on the end is threaded up from the femoral artery at the groin into the blood vessel of interest. This tube is placed through the same hole as the other catheter making it unnecessary to stick the artery again. After the balloon is placed in the artery to be tested it is gently inflated to block flow through the artery. A dose of blood thinning medicine is given through a vein just before this so that the blood does not clot when the flow stops.
While the balloon is inflated, clinical testing of the patient is conducted. Every few minutes, testing is performed to check patient's hand grip, foot flexion and extension, language, memory, orientation, and facial expression. If the patient has good connections or collaterals, the other arteries send enough blood to the brain so there is no change in the brain function. In this case the balloon is usually left in place for thirty minutes, then deflated and removed. If their brain lacks these connections and not enough blood gets to the brain, the patient may develop weakness in an arm, or difficulty speaking. In this event the balloon is immediately deflated and removed. Once removed, the blood flow is restored and the weakness goes away, usually within seconds.
