Are water precautions necessary after tympanostomy tube placement? A cadaver study.

Objectives: To determine whether Armstrong pressure equalization tubes allow passage of water into the middle ear with complete submersion in water up to 76 cm for 2 min.

Methods: 10 adult cadaver heads were first assessed for the presence of fluid in both middle ears with zero-degree rigid endoscopes, after being submerged for 2 min in a plastic receptacle filled with 76 cm of water. A 25% perforation was then made in the tympanic membrane of one ear. A myringotomy was then made in the tympanic membrane of the contralateral ear, with the placement of a beveled Armstrong pressure equalization tube. The head was then submerged again for 2 min. Both ears were then examined for the presence of fluid in the middle ear using a rigid endoscope and with suction.

Results: Eight out of ten (80%) of the heads showed the presence of fluid in the middle ear on the perforation side after submersion, whereas none of the heads showed fluid in the middle ear on the side with the pressure equalization tube.

Conclusions: At depths of 76 cm, total submersion in water for 2 min does not facilitate the passage of water into the middle ear via an Armstrong pressure equalization tube.