- Direct Retrograde Cerebral Venography (DRCV) and Manometry: A DRCV is a non-experimental procedure to look at the veins of the brain. This procedure is done by inserting a catheter (soft plastic tube) through a vein in the groin (upper leg) and guide it though the veins all the way to the neck. It is done under local anesthetic and moderate sedation. After placing the catheter in the neck, a special dye (contrast) is injected through this catheter into the veins, while X-ray cameras take multiple pictures of the veins. Then, a smaller catheter is further advanced to the area of narrowing and by this catheter we will measure the blood pressure at that point. This helps us to identify the severity of the narrowing. If the pressure before and after the narrowing is significantly different, than we will continue with the placement of the stent in order to reopen the narrowing.