I was the child who had tubes put in her ears. It helped temporarily, but I later had problems again with fluid build up. The doctors wanted me to have my adenoids and tonsils removed. At this point my parents got a second opinion and I was put on Dimetapp for 2 weeks. I went from being legally deaf to hearing just fine without surgery.
Fast forward to my kids. My eldest daughter started having problems with excess fluid build up, so I did some research. I began to suspect allergies and told the doctor so. He looked at me a little strangely, but consented to the allergy panel anyway. It turned out she was allergic to dust mites and since I have taken all the necessary measures to clear out the house of them, she doesn't have problems with it anymore. Then I went a step further when it became clear the allergies were getting worse over time (not at home, but when she visited others) I looked into treating it homeopathically. She has been on the homeopathic drops for dust, yeast, and mold for about 6 months now and is doing great! She even reintroduced a couple of stuffed animals to sleep with without any problem.
So, long story short, I would look into possible allergies that may be causing the problem before I subjected my child to surgery. Good luck!