Things are forever changing in medicine and on the whole getting better all the time.
There was a time when they would never even consider major surgery on some one of your age.
These days they routinely operate on people of all ages right up to extreme old age.
No doubt they will take extra care that you are fit enough for the operation.
Checks on your heart, lungs and all other vital functions etc. But I would not think
they will operate on you unless they consider you fit enough to get through the surgery.
As with most things in medicine we have to trust the people we look after us and they
will not operate on you unless they consider you are fit enough to take the surgery.