What Causes Inflammation In Scar Tissue Of Trachea Causing Breathing Problems?

I have a very narrow trachea due to scar tissue from numerous surgeries over the past 13 years and a tracheal repair in 2006. Three or four times a year the scar tissue becomes inflamed and I end up in the emergency room for a breathing treatment and steroids. The problem I have been experiencing lately is what seems to be saliva getting into the trachea, either when I swallow or when I sleep. Is it possible the epiglottis isn't working properly or the trachea is sagging a bit keeping the epiglottis from covering the opening properly? Or maybe the saliva is getting caught on the scar tissue in the esophagus, right in front of the trachea and then slipping into it. It doesn't happen all the time but four or five times a day. The only time I cannot clear it out is if I have been sleeping and it gets in without my being able to catch it.