The possibility of an ear tube, or tympanostomy tube, falling inward is a concern for patients and parents. Ear tubes are small, hollow cylinders placed through the eardrum to treat chronic middle ear fluid buildup or frequent ear infections. This procedure, called a myringotomy with tube insertion, is a common operation aimed at ventilating the middle ear and equalizing pressure. This action restores hearing and prevents infection. While the tube is designed to eventually fall out, movement toward the middle ear space is a rare but recognized complication.
Understanding How Ear Tubes Work and Are Placed
The eardrum, or tympanic membrane, is a thin barrier separating the outer ear canal from the middle ear cavity, which contains the hearing bones. The primary goal of tube placement is to bypass the non-functioning Eustachian tube, which normally equalizes pressure and drains fluid. The procedure involves the surgeon making a small incision in the eardrum (myringotomy) to suction out any trapped fluid.
The tiny tube is then inserted into this incision, where its structure holds it in place. Most short-term tubes are shaped like a spool or grommet, featuring two flat ends, called flanges, with a narrow central shaft. The inner flange rests against the middle ear side of the eardrum, and the outer flange rests against the ear canal side. This design seats the tube securely within the tympanic membrane, allowing air to flow freely while preventing displacement.
The Mechanism of Tube Migration
The eardrum constantly renews itself through epithelial migration, where skin cells move across the surface. This migration is the primary force that naturally pushes the ear tube outward, toward the ear canal. As new cells accumulate beneath the outer flange, they gradually extrude the device, causing the tube to fall out on its own, typically within 6 to 18 months.
The possibility of the tube falling inward, known as medial migration or tube retention, is a rare deviation from this normal path. This happens when the tube is displaced behind an intact eardrum, ending up in the middle ear space instead of the ear canal. The reported incidence of this complication is very low, estimated to occur in less than 1% of patients.
Inward movement is favored by persistent negative pressure within the middle ear cavity, often due to significant Eustachian tube dysfunction. If this negative pressure is strong, it can counteract the natural outward migration of the eardrum’s skin layer. If the tube’s opening becomes blocked by debris or earwax, the negative pressure effect can be intensified, pulling the tube inward. Technical factors, such as an initial myringotomy incision that is too large, may also contribute by preventing the eardrum tissue from gripping the tube securely.
Symptoms and Resolution of a Retained Tube
When a tube migrates inward, it often produces no immediate symptoms and may be discovered incidentally during a routine follow-up examination. However, a retained tube can act as a foreign body, leading to persistent symptoms. These symptoms can include a sensation of ear fullness, ongoing ear drainage unresponsive to treatment, or a conductive hearing loss due to interference with the hearing bones.
Medial migration is confirmed when the provider cannot see the tube in the eardrum, but imaging or microscopic examination reveals the tube lying in the middle ear space. While asymptomatic tubes may be monitored, a medially displaced tube should generally be removed to prevent long-term complications. Resolution involves a minor surgical procedure, often performed under general anesthesia, where an incision is made in the eardrum to retrieve the tube using specialized instruments. This procedure is sometimes called a tympanotomy.
Post-Procedure Monitoring and When to See a Doctor
Following tube placement, regular follow-up appointments with the ENT specialist are necessary to monitor the tubes’ function and position. The first check-up is usually scheduled within a few weeks to confirm the tubes are patent and properly seated. Subsequent visits track the tubes’ status until they naturally extrude, which is the expected outcome.
Patients should remain vigilant for signs that may indicate a complication. Persistent or foul-smelling drainage (otorrhea) is a common sign of infection; prolonged drainage warrants a call to the doctor. Other concerning signs include sudden changes in hearing, new or severe ear pain not relieved by medication, or changes in balance. Attention to these signs ensures that any issue is addressed promptly and effectively.