An older CI can't be explanted unless there is a medical reason for doing so -- or unless someone has $50,000 insurance coverage/funding for the surgery. I plan on going bilateral at some point, but was told getting insurance approval will be an uphill battle. Some insurance carriers will not pay for bilaterals while others will. As for how long a CI works, I know someone who has had their CI for 21 years and it's still working perfectly. Other people I know have had their CI for 17-18 years, so they do last considerably longer than a few years.