I just spent 3 weeks in the hospital undergoing major surgery here in Osaka. It may sound strange, but it was a great way to practice Japanese (but I must admit with all the drugs in ICU I was speaking a language that was neither English nor Japanese). Here's a list of words I found very useful, in case anyone else has to go under the knife while staying in Japan (a few of these might end up on JLPT too)
Let me file that under "Japanese words I NEVER WANT TO HAVE TO USE"
Oddly enough, the 4th chapter of my current textbook is on hospitals and having an exam (nothing as serious as your stuff, just standard stuff like 検査、結果、診察室、レントゲン, etc), and as I sprained my knee I had to go to the hospital last week for treatment and use it all Fortunately (?) as a 血友病が持ってる人 I'm all too familiar with my hospital so I can manage everything in Japanese.
Sucks to hear about your surgery - good luck with your recovery! You're a braver man than I, If I need major surgery again I'd have it done in the US.
i wanted to get the surgery done in the States, but I don't have insurance back home, and the operation would've cost me at least $100,000! Here in Japan I have 国民保険 so I had to pay 30%, which ended up being around $3000 total. A world of difference when it came to costs. (those unfamiliar with the health care fiasco should watch "Sicko")