Many physicians who work in acute care settings, especially those who see pediatric patients, will encounter patients who have a foreign body (FB) in the external auditory canal (EAC). Depending on specialty and location of practice, some doctors will encounter this condition more frequently. The goal of this section is to give physicians an understanding of the scope of this condition as well as some methods for managing an FB in the external auditory canal.
While more common in pediatric patients, adults can also present with FB, most commonly an insect, in the external auditory canal. The most commonly removed FB tends to be beads (most common), paper/tissue paper, and popcorn kernels. These combined for just over half of the foreign bodies removed in one study. There may also be a slight male predominance, but not all studies have shown this. Certain types of FB, such as button batteries, do require urgent removal. However, for most inorganic objects there does not appear to a significant issue with the length of time the FB has been in the external auditory canal before attempted removal.
The external auditory canal, along with the outer layer of the tympanic membrane (TM), is formed from the first branchial cleft. The medial two-thirds are bone covered with stratified squamous epithelial skin, while cartilage makes up the outer third, consisting of both bone and cartilage. The skin lining the cartilaginous portion of the external auditory canal has hairs and modified sweat glands that secrete earwax. Innervation of the external auditory canal is mostly from cranial nerves V3 (mandibular branch) and X. Cranial nerves VII and IX have lesser contributions. The external auditory canal is nearly straight in children, becoming nearly adult size, about 2.5 cm long, at about nine years old. In adults, it becomes more sigmoid shaped with the cartilaginous portion angling posteriorly and superiorly with the bony portion angling anterior inferiorly. As a result, in adults, pulling the helix posterior and superior straightens the external auditory canal and allows for better visualization of the TM. Of significant importance for FB management, the external auditory canal has two natural narrowings. The first point is at the bone and cartilage junction, and the other is just lateral to the TM. Another important anatomic feature of the TM is the potential blind spot in the tympanic sulcus generated as the TM slopes obliquely away from the external auditory canal as it goes inferiorly.
Indications for this procedure include the presence of an FB in the external auditory canal for removal, the appropriate equipment for removal of an FB in the external auditory canal, and a cooperative patient (or the ability to safely sedate the patient).
Contraindications to the removal of an FB from the external auditory canal are related to the cooperativeness of the patient, location of the FB in the external auditory canal, lack of appropriate tools for removal of the FB, and the type of FB may make certain methods of removal inappropriate.
An uncooperative patient and the inability to safely sedate an uncooperative patient would be a contraindication to attempting FB removal.
An FB lodged against the TM, or an FB that cannot be grasped easily, such as a hard spherically shaped FB, may require specialized equipment not readily available. Specific methods might also be contraindicated in certain situations. For example, irrigation would be contraindicated with a suspected TM perforation, removal of organic material, or removal of a battery. It may also be contraindicated if the suspected foreign body is made of a spongy material that may swell and enlarge if hydrated.
Multiple options exist for removal of external auditory canal foreign bodies. Which piece of equipment to use will be influenced by the type of FB, the shape of the FB, the location of the FB and the cooperativeness of the patient.
Commonly used pieces of equipment are curettes, alligator forceps, and plain forceps. Other equipment options include using a right angle hook, balloon catheter, such as a Fogarty catheter. The use of a hemostat, dental pick, skin hooks, fine tissue forceps, and transforming a paper clip into a right angle hook have also been described.
Irrigation is another common option, and this can be performed by attaching an angiocatheter to a 20 mL to 30 mL syringe. Alternatively, modifying a butterfly catheter by cutting off the needle and then attaching the remaining tubing to the syringe.
Suction is also an option and usually is performed with a soft tip suction catheter.
Another potential method is using cyanoacrylate (superglue) or tissue glue applied to the blunt end of a cotton-tipped applicator and then placed against the FB so the glue adheres to the FB and both the FB and applicator can be pulled out of the external auditory canal together.
In a cooperative patient, it is possible to remove an FB from the external auditory canal by a single provider. Depending on how cooperative the patient is, one or more assistants may be required to maintain the patient in the proper position and keep the patient still.
Evaluation should include noting any injury to the external auditory canal and tympanic membrane (TM) before removal attempts. The patient's hearing should also be assessed, especially if there is suspicion for TM injury/perforation or middle ear injury. Patient positioning is important. Cooperative patients can either sit or lie down with the affected ear turned towards the provider. For younger children, there are several options to for positioning. The patient can sit in the parent’s lap with the parent holding the patient’s body with one hand and the other around the head with the head turned. The patient can also lie down, either supine or prone, on the stretcher with their head turned.
The technique for removal of an FB from the external auditory canal should be based on the initial evaluation of the patient for possible TM injury, the type of FB and location in the external auditory canal, as well as the ability of the patient to cooperate. The appropriate method for removal of the FB should be selected and after positioning the patient as indicated above the FB should be removed. Before beginning the procedure, the physician should determine how many attempts will be made (usually only one or two) and if more than one attempt is planned, what technique should be used for the subsequent attempt. If unsuccessful after one or two attempts, further attempts should be aborted, and the patient should be referred to an ear, nose, and throat (ENT) specialist. Consider examining the contralateral ear and nose for other foreign bodies as well.
Manual instrumentation (e.g., forceps, curettes, angle hook)
These are ideally used in conjunction with the operating head of an otoscope, but can also be used with the diagnostic head. The pinna should be retracted, and the FB visualized. When using forceps, the FB can be grasped and removed. Both curettes and right angle hooks should be gently maneuvered behind the FB and rotated so the end is behind the FB, which can then be pulled out.
This can be performed with either an angiocatheter or section of tubing from a butterfly syringe. Using body temperature water, retract the pinna, and squirt water superiorly in the external auditory canal, behind the FB which will then be washed out of the canal.
This should be performed with a soft suction tipped catheter that has a thumb controlled release valve. Insert the suction against the FB under direct visualization and then activate the suctions and remove the FB, maintaining suction until the FB is completely out of the external auditory canal.
Apply a small amount of cyanoacrylate or skin glue to the blunt end of a cotton-tipped applicator. Once the glue is tacky, insert it against the FB under direct visualization and hold in place until the glue dries. Once the FB is secured onto the applicator, it can be removed onto the applicator.
The first step is to kill the insect, which will allow the patient to be more comfortable and allow for removal of the insect after. There are multiple recommended agents for killing the insect. Studies indicate that mineral oil is the most effective, followed by lidocaine. Both can be instilled in the external auditory canal, and once the insect is neutralized, it can be removed by any of the above methods.
Complications from the placement of an FB into the external auditory canal and attempts at removal of the FB include excoriations and lacerations of the external auditory canal, and as a result, it is important to document a pre-removal and post-removal exam. These typically heal rapidly with keeping the external auditory canal clean and dry. Antibiotic eardrops can be considered as well.
Physicians involved in acute patient care can expect to manage patients with an FB in the external auditory canal during the course of their career. As such, it is important to recognize both provider skill and equipment limitations. The type and location of FB in the external auditory canal, along with the ability of the patient to cooperate are the key factors in determining whether an attempt should be made. Referal to a specialist or a location where sedation can be performed is recommended if the FB removal is not practical after the initial evaluation. In general, complications tend to be minor and easily managed.