I'd ring the hospital and explain the situation and see if there is anything they can sort out for you. Usually they will try and be as helpful as possible.
I've just had a second surgery on my elbow yesterday, got to go to a follow up again in 4/5 weeks, luckily our trip isn't until the end of August but I was supposed to be going elsewhere in the US in June and I've had to call that off so I can understand your upset. I was pretty gutted to have to cancel my June trip!