Hi Fionab-
I don't think any have a desire to inspire a nervous reaction so much as merely to say "put it all out in front of your doctor" for their honest appraisal and reaction. There is deep deep merit in your family need for the trip. That is well understood. Even so, the surgery you contemplate is serious business, gosh, I had nothing planned to get in the way, and they have dragged me along now five full months of "you know, this is serious stuff don't you?" style caution. Given such a reaction from my medical group, I just imagined your doctors would want to know your travel intentions as they may affect their medical thoughts.
All will work out,
Mark56