Sorry,. I have to agree..., if you wife was asking because she wanted it, that might be different. HOWEVER, having lived with a stent more then once, I too find your question
pretty selfish! The stone surgery will leave her sore, and the stent can be irritating too,
asking the physical activity of sex to the trauma is not kind.
I'm not sure what else to say to this question besides... FAIL
Your wife had a kidney-stone procedure of some description, and now has a urinary stent 'installed', and all you can think of is to ask the good folks of MH if you can have sex with her?
FAIL
Go and masturbate. Safer for her, and you don't deserve much else.