we see the reason of this surprising success on the one hand in some special steps during operation ( consequent silastic sheeting , preservation of the posterior bony canal with a deep middle ear cleft , visualisation of the tympanic orifice of the tube , widening of the natural connection between tympanon and mastoid without opening the chorda-facial-angle , some times mastoidectomy ) , on the other hand in a consequent postoperative follow up together with the surgeon until the ear is surely aerated controlled by self-insufflation ( valsalva ) .
C0446908
mastoid
C0198154
mastoidectomy