Hello, I am sorry to hear about your Dad and the complications. No one told me about possible hernia, but I did have one. Actually, the one hernia surfaced quite soon after my surgery 5 years ago, but I didn't want to do anything about it then. I just left it alone and pushed it back in when it was bothersome. It was in the incision near my navel. About 6 months ago, it became painful and quite bothersome and I had forgotten about a lot of the past surgery so I opted to get it fixed. When the surgeon got inside, he found that the scar tissue had wrapped itself around the hernia and also the "daughter" hernia that he found. Anyhow, what was to be a quick in and out surgery kept me in the hospital for 3 -1/2 days and I experienced all the old symptoms. (Lots of vomiting & constipation) My intestines shut down and had to wait until the intestines decided to "wake up". The surgeon said that is quite common and most people's intestines don't like to be touched. He also told me that the hernia's are quite common and of course so is the scar tissue, etc. All in all, it is over and now I find I am not vomiting again. When I asked the surgeon, he said the hernia and scar tissue build up could make vomiting occur, so when he cleaned it up I was fine.
Breathing. I don't know much about this, other than my breathing is compromised and I use a rescue inhaler. I don't have any life threatening problems there. Radiation can damage the lungs.
I also found from this website: http://www.ards.org/learnaboutards/whatisards/brochure/  that aspiration of contents into the lungs can cause ARDS. Of course, all of us who have had esophageal surgery deal with the aspiration problem. My doctor puts me on antibiotics immediately after I have had a bout with aspirating contents into my lungs. I have only had 2 serious aspirations in the 5 years so I am very blessed.
I hope your Dad gets better fast and has no further complications.