I'm just relaying what my friend who is studying to become a doctor told me, but by his account there's a wealth of techniques for each procedure or even parts

I'm just relaying what my friend who is studying to become a doctor told me, but by his account there's a wealth of techniques for each procedure or even parts of it, like tying up the dangling bits after kidney removal. Ultimately it boils down to what a given surgeon practiced in their career.