Posterior Vs. Anterior Tympanostomy Tube Placement

The tympanic membrane can be divided into quadrants: posterior superior, anterior superior, posterior inferior, and anterior inferior. Traditional training dictates that tympanostomy tubes should be placed in the anterior-inferior quadrant, with the thought that this would lead to longer indwelling time in the tympanic membrane, avoidance of damage to the ossicular chain, and prevention of hearing loss due to residual perforation over the round window following tympanostomy tube extrusion. However, more recent work has challenged these assumptions. Notably, there is a 2-16% risk of chronic perforation following tympanostomy tube extrusion, with a proposed annual incidence of more than 40,000 post-tympanostomy tube perforations in the United States each year. While perforations in the posterior tympanic membrane can often be repaired using transcanal approaches, anterior perforations are more likely to require more invasive postauricular or endoaural approaches or canalplasty. To our knowledge, there are no studies reporting outcomes following tympanostomy tube placement in the posterior-inferior quadrant. If this study demonstrates no difference in hearing, tube indwelling time, and sequelae following posterior-inferior placement compared with anterior-inferior, it would allow otolaryngologists greater flexibility to consider patient characteristics such as factors placing them at increased risk for perforation or anatomy of the auditory canal when selecting the section of tympanic membrane in which to place tubes.

Upon completion of screening, patients will be randomized using a random number generator in order to have an equal distribution of left and right ears with tympanostomy tubes placed in the anterior and posterior quadrants. Consented patients will receive an ear tube in the usual location (anterior-inferior) in one ear and a new location (posterior-inferior) in the other ear during surgery. Follow-up will include standard-of-care post-operative visits and may be completed at 2-12 weeks and 5-7 months. Clinicians will examine the child's ears and determine whether otorrhea and occlusion are present. During the visit, audiologists may conduct standard of care ear-specific pure tone average, air-bone gap, and sound field audiometry. At these follow-up visits, otolaryngology providers will complete a form describing the status of the tympanic membrane. This will add <1 minute to the visit. Caregivers will also complete a form asking about the status of their child's tympanostomy tubes and any ear problems their child has experienced since surgery. This will take <5 minutes to complete. Results of audiology testing will be collected from the electronic medical record. Additional follow-up will include administration of the caregiver questions via phone, mail, or REDCap email at 12, 18, 24, 30, and 36 months. If the child has other follow-up clinic visits prior to 37 months post-surgery, the provider form will be completed again during these visits. Further research activities will include viewing medical charts of the included subjects.