[Code of Federal Regulations] [Title 21, Volume 8] [Revised as of April 1, 2002] From the U.S. Government Printing Office via GPO Access [CITE: 21CFR874.3850] [Page 344] TITLE 21--FOOD AND DRUGS CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PART 874--EAR, NOSE, AND THROAT DEVICES--Table of Contents Subpart D--Prosthetic Devices Sec. 874.3850 Endolymphatic shunt tube with valve. (a) Identification. An endolymphatic shunt tube with valve is a device that consists of a pressure-limiting valve associated with a tube intended to be implanted in the inner ear to relieve the symptoms of vertigo. The device directs excess endolymph from the distended end of the endolymphatic system into the mastoid cavity where resorption occurs. The function of the pressure-limiting inner ear valve is to impede the flow of endolymph so that a physiologically normal endolymphatic pressure is maintained. The device is made of silicone elastomer and polyamide and contains gold radiopaque markers within the silicone elastomer sheath. (b) Classification. Class III. (c) Date PMA or notice of completion of a PDP is required. No effective date has been established of the requirement for premarket approval. See Sec. 874.3.