Removal of impacted cerumen is one of the most common otolaryngologic procedures performed by nonotolaryngologists.1 This procedure is also believed to be the most common cause of iatrogenic otolaryngologic complications referred to specialists.2 Approximately 8 million ears are irrigated annually in the United States to remove cerumen.3,4
The S-shaped external auditory canal (EAC) is 2.5 cm long in adults.5 The lateral or distal third is cartilaginous, with thicker skin, more hair follicles, glands, and subcutaneous tissue than the medial or proximal two-thirds, which is bony and has a thinner, more fragile layer of skin.5,6 The narrowed isthmus is located between the cartilaginous and bony portions.5 The canal ends medially at the tympanic membrane (TM), which is situated obliquely to increase the surface area for carrying sound energy to the middle ear.6 The anteroinferior EAC is 0.6 mm longer than the posterosuperior portion.5 Auriculotemporal branches of cranial nerves V, VII, IX, and X and the greater auricular nerve of the cervical plexus supply sensation to the EAC.5
Cerumen is a mixture comprising secretions of the ceruminous glands of the lateral two-thirds of the EAC, the pilosebaceous glands located at the roots of EAC hairs, and sloughed squamous epithelial cells.5,7 Cerumen forms a barrier against infection, has antimicrobial activity, and protects the skin of the EAC as it is water repellant. It is expelled naturally by migration assisted by chewing movements.7,8
There are many reasons for cerumen to become impacted.4,6,7 The most common is self-cleaning with cotton-tipped applicator swabs that can push cerumen further into the EAC. The abundant hairs in the EAC, more common in males than females, can obstruct cerumen migration. A small (especially in children), tortuous, or scarred EAC will obstruct cerumen migration. Some people produce large quantities of cerumen. Diseases such as Parkinson's can alter the consistency of the cerumen and inhibit its migration. Hearing aids, stethoscope earpieces, or any other object in the EAC may compact the cerumen. Deficits in the substances that cause sloughed squamous epithelial cells to separate will inhibit the movement of cerumen. Nonimpacted cerumen exposed to water can swell and obstruct the EAC.
Recently, the term “impaction” has been defined more clearly as cerumen that causes patient symptoms or prevents a necessary examination of the EAC or TM.4 The primary indication for removal of cerumen is symptomology of impaction.2,4 The most common complaint is hearing loss, which is often abrupt and expressed as a “blocked ear.” Hearing remains normal or nearly so as long as there is a small space in the EAC through which sound can pass and cause vibration of the TM. The hearing loss becomes subjectively significant when the canal is completely obstructed or when the TM is compressed by cerumen and cannot freely move.4,...