Patent just means open.  He is saying you are very open.  In my opinion the body tries to compensate by collapsing the nasal valve or by redeviating the septum to lessen the airway on it's own.  The ostium is just the dranaige hole.  It is larger then normal.  Whether the surgeon enlarged it is not clear.  Normally that would not be done.  I do not think that is causing you symptons but I could be wrong.  Sometimes you get recirculation when it does not drain right.