Tympanostomy tube otorrhea (TTO), which is active drainage through an existing tympanostomy tube, can occur in the early postoperative period or while the tubes are in place (delayed TTO). Follow-up care is required after surgery to ensure that the tubes are functional, hearing loss has been corrected, and potential complications are properly diagnosed and managed. Ototopical antibiotic drops, antimicrobial drops containing aminoglycosides, and systemic antibiotics are used to treat TTO, but complications can still arise.
More than one million tube operations are performed annually in North America, primarily in children with hearing loss from middle ear effusion or frequent acute otitis media. Tympanostomy tube insertion is the second most common operative procedure in childhood, exceeded in frequency only by neonatal circumcision. (Int J Pediatr Otorhinolaryngol 1993:25[1-3]:1.) Approximately seven percent of US children have tubes inserted by age 3, with rates up to 30 percent reported in infants in daycare. (Am J Public Health 2000;90:245; Arch Otol Rhinol Laryngol 1997;123:226.) Pediatric tympanostomy tube placement typically requires a short general anesthetic, and is performed by an otolaryngologist using an operating microscope. (Figure 1.)
The initial postoperative visit should be performed by an otolaryngologist to verify the tube's functional status. Subsequent tube checkups are scheduled at four- to six-month intervals and continued until the tubes have extruded and the eardrums have healed. (Pediatrics. 1994;93[6 Pt 1]:924; Pediatrics 2002;109:328.) An audiologic evaluation should be performed postoperatively, especially if normal hearing was not established prior to surgery, to detect children with persistent conductive or sensorineural hearing loss who require additional diagnostic evaluation. (Arch Otolaryngol Head Neck Surg 1994;120:881; Arch Otolaryngol Head Neck Surg 1998;124:421.)
Tube Design and Function
Numerous tube designs and materials are available, but two types are generally used: short-term tubes (intended to remain in the eardrum for eight to 18 months) and long-term T-tubes (intended for more than 15 months). Short-term tubes are recommended for most children because long-term tubes are associated with higher rates of otorrhea and persistent perforation of the tympanic membrane. (J Am Acad Dermatol 1989;20[5 Pt 1]:797.) The prolonged ventilation offered by long-term tubes is theoretically desirable, but only about 30 to 40 percent of children initially treated with short-term tubes require additional tubes or surgery for otitis media. Long-shafted T-tubes are also prone to clogging in young children with frequent otorrhea.
A tympanostomy tube must be unobstructed to function. The approximately 1 mm opening in a tympanostomy tube prevents pressure gradients from developing in the middle ear by permitting direct air entry from the ear canal. The tube itself does not “cure” otitis media; it bypasses the child's immature and poorly functioning Eustachian tubes. Tubes are placed in the pars tensa of the tympanic membrane in any location except the posterosuperior quadrant, which overlies the incus and stapes.
Proper tympanostomy tube function is ensured if it spans the eardrum, its lumen is unobstructed, and no middle ear effusion is present. Pneumatic otoscopy and tympanometry are helpful when tube function cannot be confirmed by visual inspection. The tube is probably functioning if an eardrum is immobile and appears translucent on pneumatic otoscopy with no other signs of middle ear effusion. A flat type B tympanogram with a large volume measurement confirms that a functioning tube or a perforation connects the ear canal and middle ear. A peaked type A or C tympanogram suggests a clogged or extruded tube without middle ear fluid. A flat tympanogram with small volume measurement indicates a nonfunctioning tube with effusion present. (Otitis Media in Infants and Children. Philadelphia: WB Saunders Co.; 1988.)
TTO occurs in the early postoperative period for about 10 to 20 percent of children. Surgical technique and ear canal preparation have no effect on early postoperative otorrhea rates. (Laryngoscope 1992;102:1103.) The relative risk of otorrhea is higher for children with inflamed middle-ear mucosa at surgery, mucoid effusion, and those with bacterial pathogens in the ear canal or middle ear effusion. About 30 percent of effusions cultured at the time of tube insertion grow bacterial pathogens. (Ann Otol Rhinol Laryngol 2000;109:24.)
Risk factors for antimicrobial resistance include young age, day-care attendance, and the number of prior antibiotic courses. Prophylactic ear drops administered after tube insertion decrease early otorrhea and tube occlusion rates. (Ann Otol Rhinol Laryngol 1994;103:54.) This effect is most pronounced when effusion is present at the time of tube insertion and is independent of the ear drop used. Oxymetazoline nasal spray instilled in the ear canal is indistinguishable from ciprofloxacin drops when used for postsurgery prophylaxis. (Arch Otolaryngol Head Neck Surg 2006;132:1294; Laryngoscope 2005;115:363.) Currently, no medication has a Food and Drug Administration indication for prophylaxis after tube placement.
Approximately 30 percent of children have at least one episode of TTO while the tube remains in place. (Figure 2.) The otorrhea is brief, painless, and nonrecurrent for most patients; only about four percent develop chronic TTO. Infants and young children with tubes inserted to control recurrent infection are more likely than older children to experience delayed otorrhea. (Am J Otol 1988;9:316.) Tube otorrhea occurs most often in the winter when upper respiratory infections are more common for infants and young children, and in the summer because of swimming, with children over age 6 principally affected.
Preventing delayed otorrhea in the summer has largely focused on measures to avoid water entry into the ear canal during bathing or swimming. Such measures make sense because most otorrhea in older children occurs during swimming season. Protecting against water exposure is not supported by prospective, controlled studies. (Laryngoscope 1999;109:536.) Routine use of earplugs, swimming caps, or prophylactic otic drops after water exposure are ineffective. (Int J Pediatr Otorhinolaryngol 2002; 66:281.) This may have to do with the reactively low bacterial concentration in chlorinated swimming pools or the failure of ear occlusive devices to exclude water from the ear canal during submersion. (Laryngoscope 2005;115:324.) Ear plugs may have greater efficacy for children who swim in contaminated water such as oceans, rivers, or lakes.
Children 2 or younger with acute TTO usually acquire it through typical acute otitis media pathogens such as Streptococcus pneumoniae, Moraxella catarrhalis, and Haemophilus influenza. (Arch Otolaryngol Head Neck Surg 1989;115:1225.) Pseudomonas aeruginosa and Staphylococcus aureus are more prevalent in older children after TTO-induced water penetration or when TTO persists despite an oral antibiotic. The natural history of untreated acute TTO is unknown, but anecdotally many episodes resolve spontaneously within several days. Similarly, viral myringitis, which is tympanic membrane erythema without purulent infection, or an early acute otitis media may abort spontaneously without drainage occurring because the tube provides middle ear ventilation. An ear infection is usually mild enough that no treatment is required if otorrhea is not visible.
Ototopical antibiotic drops have been an important part of treating draining ears for three decades. Antimicrobial drops containing aminoglycosides have a long history of safe use, despite theoretical concerns about ototoxicity, and are still commonly used outside the United States. (J Otolaryngol 1997;26:194; Arch Otolaryngol Head Neck Surg 2000;126:165.) Ofloxacin and ciprofloxacin/dexamethasone are the only topical antimicrobials currently approved by the FDA for otorrhea with a nonintact tympanic membrane. Ciprofloxacin/dexamethasone is similar in effectiveness to oral amoxicillin and clavulanate for controlling TTO in older children. (Int J Pediatr Otorhinolaryngol 1998; 46:91.) Ofloxacin appears to be less effective and may cause fungal overgrowth. (Value Health 2006;9:219; Int J Pediatr Otorhinolaryngol 2005;69:1503.)
Ototopical preparations treat only the ear. Systemic antibiotics may be needed when young children at risk for complications of otitis media show signs of systemic infection with resistant organisms or with copious otorrhea where ear drops may fail to penetrate. The best treatment for acute TTO remains controversial, but time-tested, effective treatment protocols are available.
Treat mildly ill infants with an ototopical drop, usually ciprofloxacin with a steroid, twice daily for five days. Infants with a fever and several otorrhea or those with copious otorrhea should be treated with oral antibiotics effective against the common pathogens of acute otitis media. Add an ototopical drop if otorrhea continues for more than three days. Refer to an otolaryngologist for thorough cleaning under a microscope and culture of the tube's orifice if otorrhea persists. Children over 3 or with mild episodes of otorrhea should be observed or use an ototopical drop. Remember, acute otitis media has a 70 percent spontaneous cure rate.
Children may present with persistent TTO for up to several weeks despite initial treatment with an ototopical antimicrobial or oral antibiotic. Inadequate drop penetration is a common cause because of thickened secretions or accumulated debris in the ear canal. Most cases resolve promptly after thorough cleaning, suctioning of the tube, and application of a steroid antibiotic topical drop for five to seven days.
Selecting treatment based on culture and organism sensitivity from the ear canal is recommended for refractory otorrhea. This is particularly important after prolonged antibiotic therapy (topical or oral) to detect resistant organisms or fungal overgrowth. (Laryngoscope 1983;93:661.) Prolonged use of any antimicrobial may result in fungal overgrowth. Children present with thick fungal debris and clogged, itchy, or painful ears. Most can be treated successfully by a thorough cleaning and application with topical clotrimazole cream or solution. Occasionally, systemic antifungals are required.
Removing a tympanostomy tube is sometimes necessary to stop refractory otorrhea especially when squamous debris accumulates in the tube or when it is imbedded in granulation tissue. (Figure 3.) (Laryngoscope 1982;92:1293.) Bacterial biofilms can form on implanted prostheses, including tympanostomy tubes. (Laryngoscope 2001;111:2083.) These bacterial aggregates are resistant to therapy with systemic antibiotics, but respond to mechanical cleaning and high local concentrations of antimicrobials. Biofilm formation may help explain why tube removal is sometimes curative in treating refractory otorrhea.