I've eaten them in a pinch--with the caveat I tend to eat them in order of protein, veggies, and will either leave or eat very little of the carb item (a lot of their meals include things like potatoes, rice, pasta, etc).
I'm not sure how far out from surgery you are, but a lot of the standard Lean Cuisines include more carbs/less protein than your team would probably want you to eat, and may be more than you're able to consume right now.
You'd probably be better off eating a Lean Cuisine panini than a "standard" one from a restaurant or another brand that isn't intended to be "diet food". If it's a craving that just won't quit and it otherwise complies with where you are in your recovery (i.e. you're not on purees or soft foods anymore), you could do worse.