Welcome @partyon, Surgery of any kind can be a little scary. I'm not familiar with the Bentall procedure but did find some information while we wait for others with experience to respond. @martiellen, @jdgreene2008, and @tazzy have mentioned having the procedure in other discussions and may be able to share more with you.

Here is a description of the procedure:
"What is the Bentall procedure?
Bentall procedures mainly involve the insertion of a mechanical valve conduit to replace the aortic root. It is regarded as a long-term solution, while it requires long-life anticoagulation (3,4). Aortic root dilatation with or without aortic valve dysfunction may cause spontaneous dissection and rupture of the aorta."
--- Bentall procedure as a lifesaving surgery: A single center experience
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9887084/.
Are you able to discuss your questions and concerns with your doctor or surgeon? Did they explain why you need the Bentall procedure?