You can't leave money for your kids in the USA unless you have several million dollars lying around, because health care will eat up all of your savings in old age.
Then, your family will have a choice as to whether to spend that money on you/your spouse or to not spend it on you and to rely on Medicaid.
No one actually pays $50k out of pocket for surgery. Most of it is covered by insurance.
I've watched both my parents go through this, with significant chronic health issues. They had good private insurance on top of Medicare, they routinely had $10-30K annual itemized deductions for health related expenses that were not covered by their insurance. And that was with a daughter who is an MD who invested a massive amount of time and effort to get insurance to cover as much as possible.