Cosmetic surgery, inconclusive as to outcome (3,3,4)
I believe the answer is:
nip and tuck
This clue is a double definition.
'cosmetic surgery' is the first definition.
(I've seen this before)
'inconclusive as to outcome' is the second definition.
(I've seen this before)
(Other definitions for nip and tuck that I've seen before include "Neck and neck - plastic surgery" , "operation" , "Very close" , "Hard to separate" , "Inconclusive as to the outcome (race, match, etc)" .)