The use of medical devices has greatly increased during the past decade. Indeed, more than 8000 new medical devices are marketed in the United States annually.1 The US Food and Drug Administration (FDA) is responsible for assuring the safety and effectiveness of devices prior to and following approval for use in the United States. The FDA classifies medical devices according to risk of causing harm. Class I and II devices are considered to be low risk and approval may be accomplished through a relatively simple “premarket notification” or 510(k) clearance, which does not require clinical data. Class III devices are those considered high risk; Class III devices generally require a premarket approval (PMA) process that includes clinical data showing safety and effectiveness. When Congress established device classes in 1976, its intent was that all Class III devices eventually would be required to undergo premarket review through the more stringent PMA process.2(p17)