It's only been 17 months since my MV repair, but my surgeon whom I saw recently at the valve clinic of the hospital (I think they do statistics at the valve clinic) said first it should last at least 20 years (I have a feeling they say 20 years because modern repair techniques don't go back much more than that). I said to him "There's longevity in my family. It has to last at least 30 years!" He said, "It'll last 30 years!! Who knows? I sure hope so. My repair was not the usual type where they cut out a section since my annulus was too calcified. He used Goretex to repair the ruptured chordae and pull down the valve, and he put an Edwards ring around the annulus.
Ruth, from what I've read, an annuloplasty improves the length of time the repair will last.