Is aware of discussing one patient's operation (4,3)
I believe the answer is:
Here is my best explanation:
'operation' is the definition.
(nose job is a kind of operation)
'is aware of discussing one patient's' is the wordplay.
'is aware of' becomes 'knows' (I've seen this before).
'discussing' shows a homophone (sound like).
'one patient's' becomes 'job' (I can't justify this - if you can you should give a lot more credence to this answer).
'knows' is a homophone of 'nose'.
Can you help me to learn more?