Thanks for your question on Health Care Magic.
I can understand your concern.
Yes, this surgery is very risky and chances of death on operation table is highly, roughly 50-60%.
This is because of the location of tumour.
When tumour is around major blood vessel like
aorta, chances of bleeding are more.
So sudden massive bleeding during surgery can happen and it can cause death of patient.
So this surgery is definitely very risky.
Hope I have solved your query.
I will be happy to help you further.
Wish you good health. Thanks.