Clear answer:

• For genuine medical need / to reduce suffering: Not the same as paap in the harsh sense, because the intention is to cure illness and reduce suffering. Still, any surgery involves some हिंसा, so some karmic bandha can occur, but it is much less blameworthy when done out of necessity and with care.
• For attractiveness / vanity: This is more likely to be paap, because it is driven by attachment, pride, and appearance-based desire.

In Jain view, the main factor is bhav (intention). If the surgery is to heal, preserve life, or reduce serious pain, it is generally seen as need-based. If it is only for beautification or ego, it is more karmically binding.

So the short answer is:

• Medical necessity: generally not sinful in the same way, though some karmic effect still exists.
• Attractiveness: more likely paap due to attachment and vanity.