[killjoywashere]

There's generally a consent process but the patient is often in no position to decline or comprehend what they're signing. In the case of heart surgery, or even a catheterization procedure, they may not be conscious to consent.

[walshemj]

Well when I had my ops they always (in the UK) go through what can go wrong and the odds - my major one had a long list of possible outcomes the surgeon (cheerfully ) ended on 1/5000 chance of death.