I agree with srg36 that there is always the potential for unforeseeable risks that were not visible to the manufacturer or the FDA at the time of approval. Last month medical device maker Abbott voluntarily recalled 465,000 pacemakers to install a firmware update to patch cybersecurity vulnerabilities in the devices. The vulnerabilities could allow an attacker to modify the devices’s pacing commands or cause premature battery depletion. The updated firmware will limit the number of commands the devices can receive wirelessly and prevent transmission of unencrypted data. This is an example of a problem that was not an issue when the medical device was approved (nor FDA or manufacturer could have predicted it), although it became a problem due to evolving technology and treats that come with it. This is a wake up call to device manufacturers that they should be always reevaluating their devices for potential risks introduced by its design, manufacturing processes, use errors, and hackers!

http://raps.org/Regulatory-Focus/News/2017/08/30/28370/Abbott-Recalls-465000-Pacemakers-for-Cybersecurity-Patch/