A passive artificial sphincter includes a tension member, an outer sleeve, and a connecter. The tension member has first and second ends. The outer sleeve contains the tension member and is formed of a biocompatible material. The connecter is configured to couple the first and second ends together to form an artificial sphincter ring. The artificial sphincter ring is configured for implantation around the lumen to provide passive constriction of the lumen.In a method, an artificial sphincter comprising a tension member contained within an outer sleeve is positioned around a lumen of a patient. The lumen is constricted responsive to the tension in the tension member. The passage of material through the lumen and past the artificial sphincter ring is resisted responsive to the constriction of the lumen.