This is for the surgical treatment of porto caval or hepatic shunts. This specially designed product is used to encircle a blood
vessel. A special material (hygroscopic compressed casein) inside the donut shaped constrictor imbibes fluid over time. It slowly
occludes the blood vessel. A small key is used to lock it in place after it is slipped over the blood vessel. Sizing: about a 25%
reduction in the blood vessel diameter should be achieved upon initial surgical placement for the best results. Sterile.