The placement of myringotomy tubes remains an effective treatment of recurrent acute otitis media and chronic otitis media with effusion. Infants and young children are prone to these entities because of their immature anatomy and immunology. Several host, pathogenic, and environmental factors contribute to the development of these conditions. The identification and modification of some these factors can preclude the need for intervention. The procedure continues to be one of the most common outpatient pediatric procedures. Close vigilance and identification of potential complications is of utmost importance in the ongoing management of the child with middle ear disease.
Key points
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Myringotomy tube insertion is one of the most common pediatric ambulatory procedures performed in the United States and is used in the treatment of recurrent acute otitis media (RAOM) and chronic otitis media with effusion (COME).
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Several anatomic, genetic, environmental, and pathogenic factors contribute to the development of RAOM and COME and should be identified when considering placement of a myringotomy tube.
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Preoperative evaluation includes a good history and physical examination with adjunctive tests such as audiometry.
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Myringotomy tubes are usually placed in children with more than 3 episodes of acute otitis media in 6 months or 4 in a year, or persistent otitis media with effusion for at least 3 months.
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Both otolaryngologists and primary care physicians should observe a child closely for complications and adverse events of myringotomy tubes including tube otorrhea, early tube extrusion, retained tubes, refractory middle ear disease, and other suppurative or otologic sequelae of chronic middle ear disease.
Introduction
The placement of myringotomy tubes is one of the most common procedures performed in children. In 2006, more than 667,000 procedures were performed in the Unites States in patients younger than 15 years. Recurrent acute otitis media (RAOM), chronic otitis media with effusion (COME), and their associated suppurative and otologic complications are commonly managed with the procedure. Eighty percent of infants experience at least 1 episode of acute otitis media (AOM), with 40% having 6 or more recurrences by the age of 7 years. The significance of the disease entity cannot be overstated. COME is one of the most important causes of preventable, acquired hearing loss in children, making optimal management of the condition vital.
In 2007, there were some 11 million primary care visits for AOM. The critical issue for any primary care provider surrounds the decision for subspecialty referral. Failure to offer myringotomy tubes in the patient with RAOM or COME can have grave sequelae. Hearing loss, speech delay, poor school performance, and decreased quality of life are significant factors in the development of a child. Inadequately managed AOM can also lead to suppurative complications, including cholesteatoma, labyrinthitis, meningitis, and sigmoid sinus thrombosis. Primary care providers should identify those patients who should be evaluated for placement of myringotomy tubes as early as possible.
In this article, the relevant developmental anatomy that predisposes the young child to middle ear disease, the clinical spectrum of diseases that can be managed effectively with myringotomy tube placement, and the indications and basic steps for the procedure are reviewed. The primary care provider plays an integral role in postoperative surveillance, and thus, we also cover some of the more common complications and issues surrounding postoperative care.
Introduction
The placement of myringotomy tubes is one of the most common procedures performed in children. In 2006, more than 667,000 procedures were performed in the Unites States in patients younger than 15 years. Recurrent acute otitis media (RAOM), chronic otitis media with effusion (COME), and their associated suppurative and otologic complications are commonly managed with the procedure. Eighty percent of infants experience at least 1 episode of acute otitis media (AOM), with 40% having 6 or more recurrences by the age of 7 years. The significance of the disease entity cannot be overstated. COME is one of the most important causes of preventable, acquired hearing loss in children, making optimal management of the condition vital.
In 2007, there were some 11 million primary care visits for AOM. The critical issue for any primary care provider surrounds the decision for subspecialty referral. Failure to offer myringotomy tubes in the patient with RAOM or COME can have grave sequelae. Hearing loss, speech delay, poor school performance, and decreased quality of life are significant factors in the development of a child. Inadequately managed AOM can also lead to suppurative complications, including cholesteatoma, labyrinthitis, meningitis, and sigmoid sinus thrombosis. Primary care providers should identify those patients who should be evaluated for placement of myringotomy tubes as early as possible.
In this article, the relevant developmental anatomy that predisposes the young child to middle ear disease, the clinical spectrum of diseases that can be managed effectively with myringotomy tube placement, and the indications and basic steps for the procedure are reviewed. The primary care provider plays an integral role in postoperative surveillance, and thus, we also cover some of the more common complications and issues surrounding postoperative care.
Development and anatomy of the middle ear and eustachian tube
The tympanic membrane (TM) is a trilaminar structure that is important in converting sound pressure waves into mechanical vibrations. The outer epithelial layer is derived from ectoderm and has migratory properties that are important in the pathophysiology of cholesteatoma. The central fibrous layer is mesodermally derived, with collagen fibers arranged within the lamina propia. The inner lamina is a mucosal layer that is a continuation of the lining of the middle ear.
Fig. 1 shows the surface anatomy of the TM. The color, mobility, integrity, and translucence of the ear drum should be assessed during the physical examination. Mobility should be assessed by pneumatic otoscopy. A normally concave TM moves easily with the application of negative and positive pressure. Disruption of this pattern could indicate eustachian tube dysfunction.
The eustachian tube is the pressure regulator of the middle ear. A negative pressure normally develops in the middle ear because of an imbalance in the atmospheric air delivered via the eustachian tube and the passive transmucosal absorption of nitrogen by the middle ear mucosa. The eustachian tube periodically opens, which reestablishes the pressure gradient. The eustachian tube also clears middle ear secretions and protects the middle ear from nasopharyngeal secretions. Eustachian tube dysfunction is dependent on its relationship to the tensor veli palatini muscle, which facilitates its opening, and how it relates to the skull base. The eustachian tube is shorter, wider, and in a more horizontal position in the young child and lies within a more adult configuration by age 7 years. This situation contributes to the increased prevalence of otitis media in younger children. Bylander and colleagues showed that even normal pediatric patients had higher prevalence of negative middle ear pressures when compared with adults, and studies have shown that children prone to ear infections had poorer eustachian tube function than age controls.
Clinical manifestations
AOM
The diagnosis of AOM is contingent on the presence of ear pain, evidence of middle ear inflammation (redness, bulging), and a middle ear effusion. An example is shown in Fig. 2 . Cases of uncomplicated AOM can be managed with antibiotics; although a period of observation in children older than 6 months is appropriate in some cases. Streptococcus pneumoniae and Haemophilus influenzae continue to be the most prevalent bacteria associated with AOM. Although antibiotic resistance continues to be a concern in the management of the disease, amoxicillin is still first choice of antibiotics in AOM.
Most children experience 1 episode of AOM by age 3 years, with studies showing that between 40% and 80% of young children experience at least 1 episode of AOM in the first few years of life. A subset of these children develop recalcitrant AOM and RAOM that require further medical therapy or consideration of surgical therapy.
Otitis Media with Effusion
Eustachian tube dysfunction leads to negative middle ear pressure, which leads to the accumulation of mucosal secretions within the middle ear. Otitis media with effusion (OME) (middle ear fluid) occurs when fluid occurs behind an intact TM without the presence of acute inflammation. On physical examination, a serous effusion can often be distinguished from a mucoid one ( Fig. 3 ). Serous otitis media seems to be more responsive to medical treatment. Mucoid effusions have been shown to have higher levels of mucin, lysozyme, secretory immunoglobulin A, and interleukin 8 and have a higher viscosity, which may make the effusion harder to treat. The pathophysiologic factors that lead to the formation of each type of effusion have not been fully elucidated.
More than 50% of children experience an episode of OME within the first year of life with upwards of 60% having had an effusion by age 2. Many of these effusions resolve, but persistent OME can cause hearing loss, with associated detriment to the social and language development of a child. An observation of 3 months is acceptable except in children who are likely to fail conservative management (eg, those with craniofacial abnormalities or immune deficiencies).
Retractions of the TM
The TM is divided into the pars tensa and the pars flaccida. Retractions of the TM often occur after long-standing hypoventilation of the eustachian tube and subsequent negative middle ear pressure. The parts of the ear drum may lie in a medial position over structures such as the incudostapedial joint and cochlear promontory. The ear drum can become inherently weak and form fibrotic scar within the middle ear ( Fig. 4 ).
Although retractions can be caused by multiple ear infections or long-standing OME, neither middle ear inflammation nor persistent middle ear secretions need be present. Retractions that are not managed effectively can lead to conductive hearing loss, chronic infections, polyps, and ossicular chain erosion. Long-standing retraction pockets may be lead to cholesteatoma formation, especially with pars flaccida retractions. Serious complications such as labyrinthine fistula have also been reported.
Causes of pediatric middle ear disease
Consideration must be given to the causes that may lead to RAOM, OME, and retractions of the TM. Understanding and identifying these factors may lead one to avoid surgical therapy or pursue more urgent therapy if indicated. These factors may be dependent on the host, the environment, or any of the offending organisms that may lead to these disease processes. A summary of these factors is shown in Table 1 .
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Host Factors
As stated earlier, the young child is more susceptible to otitis as a consequence of the anatomic differences in the configuration of the eustachian tube compared with that of an adult. The immaturity of the immune system may also have significance. Although most children between the ages of 6 and 11 months have at least 1 episode of AOM, COME and RAOM are more likely when the first episode occurs when the child is less than 6 months. There have been mixed results as to the significance of gender as it plays a role the development of chronic ear disese.
The importance of host defenses cannot be overstated. Children with primary immune deficiencies often present with AOM. This finding is especially true in entities like IgG2 deficiency, which leaves the individual especially susceptible to encapsulated bacteria. Clinical judgment is needed to determine the need for further immunologic screening, when patients with RAOM present with atypical courses that may point to an immunologic deficiency.
Although immunologic deficiencies are obvious avenues for the development of RAOM and OME, subtle differences in immunocompetence may contribute as well. Children with RAOM have been shown to have decreased IgA levels (important for mucosal defenses) when compared with children without RAOM. IgG levels within the adenoids tend to increase as a child grows, which may also contribute to the decreasing prevalence of ear infections as a child gets older. Patients with OME tend to show a slower increase in these levels when compared with children not prone to OME. Children with OME have also been shown to have an immune response that is biased toward a Th2 cytokine profile, which has been linked to other chronic inflammatory states such as chronic rhinosinusitis.
The innate immunity also plays a role in the defenses against otitis media. Epithelial cells, dendritic cells of the middle ear, and nasopharynx express pattern recognition receptors that are important for recognizing offending pathogens. Defects in toll-like receptors can lead to difficulty in the clearance of middle ear effusions and the phagocytosis and intracellular killing of organisms. Molecules such as human defensins, cathelicidins, lysozyme, bacteriocins, surfactant proteins, cationic peptides, halocidin, and xylitol also contribute to the innate immunity to both viral and bacterial otitis media.
A recently defined entity within the realm of middle ear disease is eosinophilic otitis media (EOM), which is characterized by tenacious, viscous yellow effusion that is exquisitely difficult to treat. Higher levels of IgE are found in effusions of EOM when compared with common OME, and the entity may be immunologically related to diseases such as allergic fungal sinusitis and allergic bronchopulmonary aspergillosis.
A multitude of genetically based disorders can also lead to persistent or recurrent ear infections. Disorders of ciliary motility, like Kartagener syndrome and primary ciliary dyskinesia (PCD), interfere with the effective clearance of secretions of the upper respiratory tract, including the middle ear. PCD is autosomal recessive and affects both sexes equally, with an incidence that ranges from 1 in 15,000 births to 1 in 40,000 births. Fifty percent of PCD is associated with Kartagener syndrome, which encompasses a triad including recurrent sinusitis, bronchiectasis, and situs inversus. Although conservative treatment can be pursued for RAOM and OME for these patients, myringotomy tube insertion is more often than not the most viable option in managing the disease. Patients with PCD have a high rate of persistent otorrhea (10%–50%) after placement of ear tubes.
The presence of craniofacial abnormalities may also influence the development of chronic ear issues. The middle ear, ossicles, and eustachian tube are formed by a complex interaction between the first and second branchial arches and the first branchial pouch. Disorders that affect these embryologic structures can lead to eustachian tube dysfunction with ensuing middle ear disease.
Intact paratubal musculature is also paramount to eustachian tube dysfunction. The levator veli palatini arises from the petrous apex and the medial lamina of the eustachian tube cartilage and its fibers extending downward and medially to the midline of the palate, interdigitating with the contralateral muscle. The tensor veli palatini originates from the medial pterygoid plate, with its tendon hooking around the pterygoid hamulus, with subsequent insertion on the palatine aponeurosis. The levator muscle assists in eustachian tube opening via isotonic contraction, which hinges on an intact sling along the soft palate, whereas the tensor causes direct opening via its interaction with the tubal cartilage. Disruption of normal palatal anatomy (as seen in cleft palate) results in ineffective eustachian tube opening because of isometric contraction of the levator muscle and ineffective shortening of the tensor muscle. OME in patients with cleft palate is almost universal, with a prevalence of 90%. There are mixed results as to whether cleft palate surgery with restoration of a palatal sling improved middle ear function.
Pierre-Robin sequence (and its associated cleft palate), Treacher-Collins syndrome, Apert syndrome and other syndromes associated with craniosynostosis, Down syndrome, and velocardiofacial syndrome are associated with an increased risk for the development of chronic ear problems. These children should be carefully monitored for the development of RAOM and OME. The developmental and speech delays found in these patients would be confounded by unrecognized hearing loss caused by middle ear disease, and they often require multiple ear tube insertions.
Pathogen Factors
Otitis media is an infection that is significantly influenced by the synergistic effect between bacteria and viruses. The most common upper respiratory viruses include influenza A, respiratory syncytial virus (RSV), adenovirus, and rhinovirus. The bacteria present are those that commonly colonize the nasopharynx, including Streptococcus pneumonia, nontypeable Haemophilus influenzae , and Moraxella catarrhalis . The universal pneumococcal vaccination of children has led to an increased prevalence of H influenzae isolates.
Seasonal variations in the prevalence of otitis media match the seasonal variation of common viral illnesses. These viruses alter eustachian tube function via mechanisms including decreased mucociliary action, altered mucus secretion, and a change in the cytokine profile. Children can have transient OME with an upper respiratory infection without superimposed bacterial infection. Twenty percent to 73% of viral upper respiratory infections are accompanied by OME, with RSV showing the greatest prevalence. The natural history of most virally mediated sterile OME is that of resolution, so a period of observation is warranted before any intervention is undertaken.
Bacterial otitis media is a polymicrobial infection. Most patients are treated easily with antibiotics, but this is becoming a more complicated issue. Bacteria have developed fascinating ways to combat eradication. Bacteria can be embedded in biofilms (polymeric matrices attached to a living surface) as opposed to planktonic state. Bacteria within biofilms are characterized by a slow rate of metabolism and tolerance to high concentrations of antibiotics. Biofilms within the adenoids may contribute as a reservoir for infection in both RAOM and OME, which may necessitate removal in patients who continue to have chronic ear problems despite ear tube insertion.
Although Streptococcus pneumonia, nontypeable H influenzae , and Moraxella catarrhalis are the most important bacteria in acute infections, organisms including Pseudomonas aeruginosa , coagulase-negative Staphylococcus and methicillin-resistant Staphylococcus aureus become more prevalent in chronic infections, making treatment more problematic. Antimicrobial resistance will continue to be an emerging problem. Careful selection of patients who will benefit from antibiotic treatment should be the mainstay of management.
Environmental Factors
Many environmental factors contribute to diseases of the upper aerodigestive tract, including otitis media. Parental smoking can concur a 2-fold increased risk of developing otitis media, and a dose-response relationship is evident. Tobacco smoke has many effects that can lead to increased middle ear disease in children, including damage to the respiratory mucosa, decreased mucociliary transport, increased virulence of bacteria, changes to the innate immunity, and an enhanced Th2 immunologic profile.
Breast milk has many antimicrobial, immunomodulatory, and antiinflammatory properties that compensate for the immature immune system of the growing infant. Breast milk helps to modulate the IgG profile of the infant to fight the organisms most commonly associated with otitis media. Breastfed babies have significantly lower rates of AOM and OME when compared with formula-fed infants. At least partial breastfeeding for 6 months may lead to an 80% reduction on rates of middle ear disease. There is evidence that the strong tongue-palate relationship associated with breastfeeding may help with middle ear aeration. The supine position used in bottle feeding can also lead to reflux of secretions into the middle ear.
Children attending day care and those with siblings are exposed to a large array of viral and bacterial pathogens. Day care contributes to increasing the risk of otitis media because of the large numbers of children and close person-to-person contact. Frequent exposure can also lead to the exchange of antimicrobial-resistant bacteria. Attendance in day care may be associated with up to a 30% increase in the risk of AOM, with an apparent relationship found between the number of children at the center and the burden of disease.
Pacifier use, obesity, ethnicity, and socioeconomic status have also been studied as risk factors for the development of middle ear disease, but their contributions to the development RAOM and OME require further research.
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