If it is anything like other surgeries done at vets, the risky part with such an old animal is the sedation, not the surgery itself. And with animals you usually need to fully sedate them, as they don’t understand that they need to stay still.
This is always risky in older humans as well. My grandfather broke his wrist ~10 years ago from a fall. He was doing fine, they kept him for observation because he also hit his head, and he needed surgery to set his wrist. They put him under general anaesthetic, he vomited, aspirated and they broke 5 ribs reviving him. He was in ICU for a week. Still alive today though.
If it is anything like other surgeries done at vets, the risky part with such an old animal is the sedation, not the surgery itself. And with animals you usually need to fully sedate them, as they don’t understand that they need to stay still.
This is always risky in older humans as well. My grandfather broke his wrist ~10 years ago from a fall. He was doing fine, they kept him for observation because he also hit his head, and he needed surgery to set his wrist. They put him under general anaesthetic, he vomited, aspirated and they broke 5 ribs reviving him. He was in ICU for a week. Still alive today though.