- Email: [email protected]
Management Strategies for Congenital Ear Malformations
Recent Advances in Pediatric Otolaryngology
0031-3955/89 $0.00
+ .20
Management Strategies for Congenital Ear Malformations
Roland D. Eavey, MD, FAAP, FACS*
As a pediatrician you are faced with an extraordinary variety of anomalies to diagnose, to treat, and about which to provide counsel. Specifically considering the ear, some conditions may be relatively common such as preauricular pits or tags. Malformations such as the combination of microtia-atresia, however, may be seen only once during a career. This article has two goals. The first is to provide information for pediatric management of congenital ear malformations. The second is to discuss recent therapeutic developments that can be offered to the patient for potential correction of hearing and the malformed auricle.
SPECTRUM OF AURICULAR APPEARANCE The embryologic formation of the ear is extremely complex. More than one branchial apparatus is involved. Various types of tissues such as squamous epithelium, fat, cartilage, bone, nerve, blood vessels, and mucous membranes constitute the temporal bone. Ectoderm, mesoderm, and endoderm are all necessary for a "normal"-appearing auricle and temporal bone. Considering such complexity, the occurrence of sporadic ear malformations is not surprising. Ear malformations can vary widely in appearance. Certain syndromes are associated with severe malformation. These include Treacher-Collins syndrome; Goldenhar syndrome; and the syndromes of microtia, hypertelorism, facial clefting, and conductive hearing loss. Other syndromes with milder auricular dysmorphic features, detailed by Konigsmark and Gorlin,5 include the syndrome of ear malformations, cervical fistulae or nodules, and mixed hearing loss; the syndrome of thickened ear lobes and incudo*Assistant Professor, Department of Otology and Laryngology, Harvard Medical School; Director, ENT Pediatric Services, Massachusetts Eye and Ear Infirmary; and Chief, Pediatric Otolaryngology, Franciscan Children's Hospital and Rehabilitation Center, Boston, Massachusetts
Pediatric Clinics of North America-Vol. 36, No.6, December 1989
1521
1522
ROLAND
D.
EAVEY
stapedial abnormalities; the syndrome of ear malformation, imperforate anus, triphalangeal thumbs, and sensorineural deafness; the lacrimoauriculodentodigital syndrome; the syndrome of malformed low-set ears and conductive hearing loss; and the syndrome of lop ears, micrognathia, and deafness. A less detailed listing of conditions associated with external ear malformation can be found in an excellent monograph by Melnick and Myrianthopoulos. 7 Common abnormalities that can be detected in the newborn are preauricular pits and minor skin tags. Preauricular pits are not likely to be associated with a syndromic hearing loss except in branchio-oto-renal syndrome (Holmes LB: Personal communication). Cervical fistulae or sinus tracts serve as a clinical marker in this syndrome to distinguish the child with increased risk of hearing loss. Therefore, mandatory audiometric workup is probably unnecessary for this common condition. Audiometric testing would be more prudently used when suspicion of hearing loss is present. Surgical resection of a preauricular pit can be offered should the pit become infected in later life (Fig. 1). Preauricular tags are often an isolated and relatively innocuous finding (Fig. 2). Tags can be occasionally associated with hearing loss, however. Therefore, a standard behavior audiometry test can be obtained during infancy if the child is developing normally. If hearing is questioned or speech is delayed, a brainstem-evoked-response audiogram should be performed. Surgical management of the preauricular tags is dependent on their size and number, and the cosmetic or functional problems that they may cause. One method of tag removal has been to place a secure loop around the base of the tag. The tag will then necrose. Although this may
Figure 1. Bilateral preauricular ear pits. The patient's left ear is infected; note preauricular swelling. (Photo courtesy of Michael J. Cunningham, MD.)
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
1523
Figure 2. Preauricular tags; right ear.
work in certain circumstances, it often still leaves the patient with a palpable and sometimes visible cartilaginous subcutaneous projection. Therefore, surgical excision with cosmetic skin closure can be more effective because the persistent cartilaginous stump can be excised from its subcutaneous position. Another relatively common "abnormality" of the pinna is the protruding ear (Fig. 3). The ear usually protrudes owing to one or two anatomic configurations. First, the antihelix is not furled into a tight y configuration; this appearance can be achieved merely be gently pushing the auricle toward the side of the head. The other anatomic design is a deep conchal bowl that projects the auricle laterally. Although technically nothing is usually abnormal with such an auricle, some of these patients do develop functional problems. They may complain that in loud situations, such as the school gym or cafeteria, that they must fold their ears medially because the sounds received are too loud. In a frigid climate, parents complain that the child's ears seem to work their way out of just about any covering that is applied. Occasionally such patients will have discomfort when they are sleeping at night if the ear gets folded forward. Their ears are sometimes
1524
ROLAND
D.
EAVEY
Fi gure 3. A , Preope rati ve view. Left ear projects from side of head . B, Postoperative poste rior view. C, Postoperative ante rior vie \v.
traumatized by playmates or pets; this is especially likely if the condition is unilateral. These patients can also develop psychologic problems because the societal perception of such a person in the United States tends to be demeaning. Surgical correction of both ears can be performed at the same setting with no need for subsequent stages. Attention is paid to the contours
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
1525
and projection of the ear and lobule to provide a relative symmetry within the range of "normal." Timing is variable. The perceived need for the procedure usually does not occur until early grade school. Technically it could be performed sooner while the cartilage is still more compliant. In fact, in adolescence correction of the ears can be somewhat difficult when the cartilage has a more definitive firmness and memory. The potential correction of a malformed auricle by tape in infants and young children deserves special mention. 8 I have personally seen this approach work. Because it seems to be a relatively harmless method of treatment and may actually obviate the need for later surgical management, it would seem prudent to permit the parents to make such an effort. Various types of moderate auricular abnormalities can occur. Although the ear is not severely micro tic, it does not look normal (Fig. 4). The first step in the management of this type of patient is to obtain a hearing test. Depending on the audiometric results, a hearing loss can be managed by amplification or possible surgical hearing correction. Surgical correction of the auricle has no set calendar for treatment. The pliability of the cartilage is greater if the child is younger. Therefore, it is not necessary to wait until the child is in grade school to contemplate correction. The patient in Figure 4 underwent correction at 4 years of age. Her cartilage pliability would likely have been diminished by the time she was 6 or 7 years of age yet was extremely helpful in terms of re-creation of her auricle.
SEVERELY MALFORMED AURICLE: MICROTIA AND ATRESIA Microtia presents usually with a misplaced, tiny cartilaginous appendage to which a piece of tissue similar to a lobule is attached. The condition is usually unilateral. The incidence of microtia is not specifically known but is estimated to be about 1 of 10,000 births according to Center for Disease Control data for metropolitan Atlanta (Cordero J: Personal communication). This rate includes syndromes such as Treacher-Collins and Goldenhar. The etiology of sporadic cases seems to be multifactional. Animal models suggest possible embryologic mechanisms of microtia and atresia. Poswillo lO has demonstrated similar conditions in mice in whom the stapedial artery has ruptured at a critical portion of embryonic development. Failure of neural crest migration has also been postulated. 9 This possibility has been strengthened somewhat owing to the known teratogenic effect of maternally ingested vitamin A, which would be taken by the mother for acne. 6 The ear that is malformed owing to vitamin A toxicity, however, also has a unique characteristic that the tragus seems to be spared. This model of malformation seems to be branchial arch selective. Because most cases of microtia do not have a preserved tragus, the neural crest migration theory may not be applicable. Also, unilaterality would be difficult to explain by neural crest migration failure. Intrauterine deformation can occur in some cases. For example, the hand can be malpositioned against the ear, causing deformation of both the ear and the hand. Occasionally an ear canal and tympanic membrane will be present
1526
ROLAND
D.
EAVEY
Figure 4. A. Lateral preoperative view of moderately severe left auricular malformation. B. Two weeks postrepair just prior to suture removal. C. Anterior view; again preoperative.
D. Six months postrepair.
despite a severely microtic appendage (Fig. 5). The usual situation, however, is absence of an ear canal and meatus. In fact, this severe situation is actually preferable to the rarer condition of a pinhole-sized canal because a collection of squamous epithelium in a narrow canal or blind pouch can lead to infection and cholesteatoma. Associated conditions to evaluate are, for example, the presence of an ipSilateral facial paralysis or paresis. Ipsilateral mandibular hypoplasia is also common. If another known syndromic condition such as Goldenhar's (hemifacial microsomia) is detected, the patient should have a careful systemic evaluation to detect potential problems with the eye, vertebral bodies, and heart.
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
1527
Figure 5. Despite the severe left auricular deformity the patient has an ear canal and tympanic membrane.
MANAGEMENT DECISIONS Infancy The first assistance that the pediatrician can provide to the parents is to reassure them this is not an unknown condition (Table 1). Microtia is not as familiar an anomaly to parents as is, for example, cleft palate or cleft lip. The parents almost universally are distressed and bewildered because they often have no family members with this condition. Additionally, because the hair growth is scant, the malformed auricle is a visible condition during the first several months or even years of life (Fig. 6). The parents further need the information that hope exists for correction of this disorder. Because developments are relatively recent and still being refined, many physicians might not be aware of the degree of correction that can be offered to the child. After the initial concerns about the condition as a whole, parental attention usually focuses on hearing. In unilateral cases, the hearing is almost invariably normal in the ear that externally appears to be normal. Normal hearing is an assumption that must be proved, however. Deaf children, for example, usually have normal auricles. The abnormal ear typically has a 60 dB conductive hearing loss but occasionally can be associated with total deafness.
1528
ROLAND
D.
EAVEY
Table 1. Points of Consideration for Management of Children with Microtia Birth Reassurance to parents Early infancy Brainstem-evoked hearing response Possible hearing amplification Evaluation of associated conditioris such as mandibular hypoplasia and facial paralysis Counseling for the parents regarding this condition and introduction of the parents to other families with similar children Surgical correction of minimal anomalies such as ear tags is possible (no substantial surgery should occur without the approval of the surgeon[sl eventually responsible for later definitive correction) Early childhood Treatment for suspected otitis media in the microtic ear Surveillance of the normal ear for otitis media with effusion Surgical correction of the moderately malformed external ear is possible Age 6 Years Consideration of surgical correction of the severely malformed ear External surgery of the auricle should precede possible otologic middle-ear surgery
Hearing should be assessed by a brainstem-evoked-response audiogram. Preferably the test will be performed within 2 months after birth. Two months is the suggested period because young infants in that age group often fall asleep spontaneously. Because the evoked-response testing is performed during sleep, chloral hydrate or other sedation is therefore unnecessary. Testing should be done at a center that is experienced in measuring the hearing of children. Evoked-response audiometry is occasionally performed by departments other than audiology departments as
Figure 6. Typical microtia appearance in an infant; right ear.
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
1529
part of a neurologic assessment of brainstem function. The hearing assessment in such a test, however, may be only a hearing screen and does not provide a precise audiometric picture. Testing done at an adult center may yield only tentative interpretations if the audiologist is inexperienced in dealing with neonates. When microtia is bilateral, it is absolutely imperative to obtain a hearing analysis. The patient will require hearing amplification because both ears would usually have a maximum conductive hearing loss of about 60 dB. This is the equivalent of an adult walking around with each ear canal tightly occluded by an index finger. Although hearing is present, it is difficult to develop normal speech and language with such a loss. This is especially critical during the age of language acquisition. The patient must be fitted with a bone conductive hearing aid. This can be secured by a headband and appears similar to the recreational portable radio and cassette devices on the commercial market. In select children the use of doublesided tape provides effective fixation and eliminates the need for the headband. Surprisingly, children usually do not remove such devices because they seem to realize that these amplification techniques are helpful to them (Fig. 7). In the occasional case in which an ear canal is present, but the middle ear and drum are not visible behind the atresia plate, a standard hearing aid may be used. The aid is adjusted to maximum gain. If successful, this type of amplification eliminates a bit of hardware for the patient to wear.
Figure 7. A, Bone conduction hearing aid secured by headband; right ear of a bilateral condition. B, Hearing aid secured by double-sided tape; left ear of a bilateral condition.
1530
ROLAND
D.
EAVEY
Radiographic studies such as CT or MRI scans are usually not performed during early infancy because they seldom change the audiologic or surgical management. Select patients may merit an evaluation to assess the course of the facial nerve or to search for an inner-ear anomaly. The pediatrician need not feel responsible for obtaining these studies because the otolaryngologist will perform these tests at a suitable time. Early Childhood An issue that is not addressed often in the literature but is especially germane to the pediatrician is the question of otitis media. No proof exists that these patients routinely get otitis media in the microtic ear. It is logical to assume that this happens, however. The eustachian tube to the nasopharynx is intact, and a rudimentary middle ear usually exists. Therefore, the patient has a stage that is set for otitis media. Rare reports demonstrate severe complications of otitis media in the microtic ear such as mastoiditis. 13 Practical advice would be to treat with antibiotics if a suspicion from indirect clinical criteria exists that otitis media might be present. A related issue of otitis media paradoxically involves the normal ear. The characteristic patient has only an isolated microtia and is using the other ear as the sole sound receptor for speech and language development. It is known that unilateral normal hearing is adequate for communication. The normal ear is at risk for acute and serious otitis media, however, as any ear might be. Personal experience has shown that a high percentage of these children will for a period in their preschool years have a prolonged effusion in the normal ear. Such an effusion can substantially interfere with overall hearing. Many of these children require temporary ventilation tube placement in the normal ear. During early childhood, growth of the malformed auricle will be proportional to the normal side. The rigidity of the cartilage also increases. The appearance of the auricle does not improve, however, and over time it merely looks like a larger version of its former self (Figs. 6 to 8).
DEFINITIVE CORRECTION TREATMENT DECISIONS The patient usually does not require surgery during the first few years of life. One exception, mentioned previously, is the merely moderately deformed auricle that can be corrected surgically before 6 years of age. Another possible exception might be a total facial paralysis that might require an eyelid tarsorrhaphy to help keep the eye closed during sleep. Hearing correction procedures can also occur earlier in the anomalous ear, but this is the unique case of the reasonably well-formed pinna, canal, and tympanic membrane. Typically then, most surgical decisions for severe microtia occur about 6 years of age. One therapeutic option would be to select no treatment at all. In the patient with unilateral microtia with no associated facial defects, this has been a traditional method of handling the problem. A lengthy hair style is maintained. Older patients, however, do at times report distress that they
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
1531
Figure 8. Adolescent with right ear microtia. A , Malformed auricle similar proportionally to infant in Fig. 5. B, Three weeks afte r second stage of auricular reconstruction (lateral view). C, Front view.
have a secret abnormality that might be discovered, and they have wished that treatment could have been offered as children. Another consideration for cosmetic treatment is the prosthetic ear. The prosthesis is usually attached by adhesive onto the microtic vestige. Although worth consideration, in practice prosthetic ears are seldom used.
1532
ROLAND
D.
EAVEY
Patients find that the prosthesis can be a nuisance. At times they fall off and are a cause of embarrassment. Other disadvantages include the fact that they soil or require color changes during various times of the year when the skin may be tanned. They also need to be replaced in size if used in a child. Despite disadvantages, however, for the patient who cannot undergo or does not choose surgery, a prosthesis offers an available alternative. In contemplating a surgical correction, two conditions compete for attention. First, the hearing is potentially able to be reconstructed in some patients. Second, the external auricle can be repaired in almost all patients. No surgery should be done that may violate the area at any age unless the surgeon(s) responsible for the eventual correction makes the decision. It is then necessary to surgically correct the external auricle before operating on the hearing. This is a situation in which coordination with the fewest number of surgeons is mandatory. The surgical maneuvers for the correction of the external ear are usually substantial rather than minor. Except for the occasional auricle that needs only some repositioning and unfurling, the pinna infrastructure is usually useless except for the presence of the lobulelike tissue and the skin that is available over the malformed cartilaginous appendage. Rather than trying to unfurl this mass of deformed cartilage it is far more preferable to remove it and reconstruct anew. A reasonably predictable method of creating an external ear is to use cartilaginous rib grafts that are carved into the shape of an auricle. This work was pioneered by Tanzer12 and then refined to a high degree by Brent. 1 The procedure is multistaged. In the first stage the ribs are harvested, carved, and implanted under the skin at the ear site. The next stage involves transposition of the lobule like tissue into a more realistic ear lobe. By this stage the auricle can appear acceptably realistic (See Fig. 8). Refinement procedures to create a tragus and elevate the new auricle from the side of the head can additionally be performed as desired. The stages can be separated by a few months. They can be shortened up to within a few weeks of one another, however. In the case of bilateral atresia, the first ear framework is used as a template for the second ear.
HEARING RECONSTRUCTION Hearing reconstruction was in part pioneered and then later refined by Schuknecht. ll Additional experience has been added by Jahrsdorfer. 4 Not all patients are candidates for repair (Fig. 9). Successful results are not even now nearly universal; some patients may experience a hearing increase but of modest proportion (Fig. 10). Surgical correction of hearing is a one-stage procedure. This consists of drilling out an ear canal and locating the misshapen ossicles. Usually the ossicles are sufficiently mobile to permit conduction of sound. A fascia layer is placed on the ossicles to be the equivalent of a replacement tympanic membrane. Another potential future method of hearing improvement for older
1533
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
Figure 9. CT scan of a patient with microtia/atresia of left ear. The patient is not a good candidate for reconstruction of hearing. Note asymmetry between sides.
AUDIOGRAM o
./
-""'b. """"tc .~
Figure 10. Audiogram of a 16year-old patient with a partial atresia. Preoperative = filled circles; postoperative = hollow circles.
~Q) ...,J
.§ tU
~
80 100
120
I
125
250
500
1K
2K
Frequency (Hz)
4K
8K
ROLAND
1534
D.
EAVEY
children involves implantation of a hearing aid coupler under the skin with a device that screws into the bone of the side of the head. 3 A percutaneous device is also available in Scandinavia. 2 To each device, a hearing amplification device can be attached externally. The subcutaneous model requires a magnetic attraction through the skin and subcutaneous tissues. The percutaneous device permits direct coupling. The percutaneous device has also been used to attach a prosthetic ear.
REFERENCES 1. Brent B: The correction of microtia with autogenous cartilage grafts: 1. The classic deformity. Plast Reconstr Surg 66:1-12, 1980 2. Carlsson P, Hakansson B, Rosenthal! U, et al: A speech-to-noise ratio test with the boneanchored hearing aid: A comparative study. Otolaryngol Head Neck Surg 94:421-426, 1986 3. Hough J, Himelick T, Johnson B: Implantable bone conduction hearing device. Arch Otol Rhinol Laryngol 95:498-504, 1986 4. Jahrsdorfer RA: Congenital atresia of the ear. Laryngoscope 88:1-48, 1978 5. Konigsmark BW, Gorlin RJ: Genetic and Metabolic Deafness. Philadelphia, WB Saunders, 1976, pp 49-73 6. Lemmer E, Chen D, Hoar R et al: Retinoic acid embryopathy. N Engl J Med 313:837841, 1985 7. Melnick M, Myrianthopoulos NC: External Ear Malformations: Epidemiology, Genetics, and Natural History, vol 15. The National Foundation-March of Dimes Birth Defects. Original Article Series. New York, Alan R. Liss, 1979, pp 122-123 8. Muraoka M, Nakai Y, Sasaki T, et al: Tape attachment therapy for correction of congenital malformations of the auricle: Clinical and experimental studies. Laryngoscope 95:167175, 1985 9. Phelps P, Poswil!o D, Lloyd G: The ear deformities in mandibulofacial dysostosis (Treacher Collins syndrome). Clin Otolaryngol 6:15-28, 1981 10. Poswil!o D: The pathogenesis of the first and second branchial arch syndrome. Oral Surg 35:302-328, 1973 11. Schuknecht HF: Reconstructive procedures for congenital aural atresia. Arch Otolaryngol 101:170-172, 1975 12. Tanzer RC: Total reconstruction of the external ear. Plast Reconstr Surg 23:1-15, 1959 13. Zalzal GH: Acute mastoiditis complicated by sigmoid sinus thrombosis in congenital aural atresia. Int J Pediatr Otorhinolaryngol 14:31-39, 1987 ENT Pediatric Services Harvard Medical School Massachusetts Eye and Ear Infirmary 243 Charles Street Boston, MA 02114
0031-3955/89 $0.00
+ .20
Management Strategies for Congenital Ear Malformations
Roland D. Eavey, MD, FAAP, FACS*
As a pediatrician you are faced with an extraordinary variety of anomalies to diagnose, to treat, and about which to provide counsel. Specifically considering the ear, some conditions may be relatively common such as preauricular pits or tags. Malformations such as the combination of microtia-atresia, however, may be seen only once during a career. This article has two goals. The first is to provide information for pediatric management of congenital ear malformations. The second is to discuss recent therapeutic developments that can be offered to the patient for potential correction of hearing and the malformed auricle.
SPECTRUM OF AURICULAR APPEARANCE The embryologic formation of the ear is extremely complex. More than one branchial apparatus is involved. Various types of tissues such as squamous epithelium, fat, cartilage, bone, nerve, blood vessels, and mucous membranes constitute the temporal bone. Ectoderm, mesoderm, and endoderm are all necessary for a "normal"-appearing auricle and temporal bone. Considering such complexity, the occurrence of sporadic ear malformations is not surprising. Ear malformations can vary widely in appearance. Certain syndromes are associated with severe malformation. These include Treacher-Collins syndrome; Goldenhar syndrome; and the syndromes of microtia, hypertelorism, facial clefting, and conductive hearing loss. Other syndromes with milder auricular dysmorphic features, detailed by Konigsmark and Gorlin,5 include the syndrome of ear malformations, cervical fistulae or nodules, and mixed hearing loss; the syndrome of thickened ear lobes and incudo*Assistant Professor, Department of Otology and Laryngology, Harvard Medical School; Director, ENT Pediatric Services, Massachusetts Eye and Ear Infirmary; and Chief, Pediatric Otolaryngology, Franciscan Children's Hospital and Rehabilitation Center, Boston, Massachusetts
Pediatric Clinics of North America-Vol. 36, No.6, December 1989
1521
1522
ROLAND
D.
EAVEY
stapedial abnormalities; the syndrome of ear malformation, imperforate anus, triphalangeal thumbs, and sensorineural deafness; the lacrimoauriculodentodigital syndrome; the syndrome of malformed low-set ears and conductive hearing loss; and the syndrome of lop ears, micrognathia, and deafness. A less detailed listing of conditions associated with external ear malformation can be found in an excellent monograph by Melnick and Myrianthopoulos. 7 Common abnormalities that can be detected in the newborn are preauricular pits and minor skin tags. Preauricular pits are not likely to be associated with a syndromic hearing loss except in branchio-oto-renal syndrome (Holmes LB: Personal communication). Cervical fistulae or sinus tracts serve as a clinical marker in this syndrome to distinguish the child with increased risk of hearing loss. Therefore, mandatory audiometric workup is probably unnecessary for this common condition. Audiometric testing would be more prudently used when suspicion of hearing loss is present. Surgical resection of a preauricular pit can be offered should the pit become infected in later life (Fig. 1). Preauricular tags are often an isolated and relatively innocuous finding (Fig. 2). Tags can be occasionally associated with hearing loss, however. Therefore, a standard behavior audiometry test can be obtained during infancy if the child is developing normally. If hearing is questioned or speech is delayed, a brainstem-evoked-response audiogram should be performed. Surgical management of the preauricular tags is dependent on their size and number, and the cosmetic or functional problems that they may cause. One method of tag removal has been to place a secure loop around the base of the tag. The tag will then necrose. Although this may
Figure 1. Bilateral preauricular ear pits. The patient's left ear is infected; note preauricular swelling. (Photo courtesy of Michael J. Cunningham, MD.)
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
1523
Figure 2. Preauricular tags; right ear.
work in certain circumstances, it often still leaves the patient with a palpable and sometimes visible cartilaginous subcutaneous projection. Therefore, surgical excision with cosmetic skin closure can be more effective because the persistent cartilaginous stump can be excised from its subcutaneous position. Another relatively common "abnormality" of the pinna is the protruding ear (Fig. 3). The ear usually protrudes owing to one or two anatomic configurations. First, the antihelix is not furled into a tight y configuration; this appearance can be achieved merely be gently pushing the auricle toward the side of the head. The other anatomic design is a deep conchal bowl that projects the auricle laterally. Although technically nothing is usually abnormal with such an auricle, some of these patients do develop functional problems. They may complain that in loud situations, such as the school gym or cafeteria, that they must fold their ears medially because the sounds received are too loud. In a frigid climate, parents complain that the child's ears seem to work their way out of just about any covering that is applied. Occasionally such patients will have discomfort when they are sleeping at night if the ear gets folded forward. Their ears are sometimes
1524
ROLAND
D.
EAVEY
Fi gure 3. A , Preope rati ve view. Left ear projects from side of head . B, Postoperative poste rior view. C, Postoperative ante rior vie \v.
traumatized by playmates or pets; this is especially likely if the condition is unilateral. These patients can also develop psychologic problems because the societal perception of such a person in the United States tends to be demeaning. Surgical correction of both ears can be performed at the same setting with no need for subsequent stages. Attention is paid to the contours
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
1525
and projection of the ear and lobule to provide a relative symmetry within the range of "normal." Timing is variable. The perceived need for the procedure usually does not occur until early grade school. Technically it could be performed sooner while the cartilage is still more compliant. In fact, in adolescence correction of the ears can be somewhat difficult when the cartilage has a more definitive firmness and memory. The potential correction of a malformed auricle by tape in infants and young children deserves special mention. 8 I have personally seen this approach work. Because it seems to be a relatively harmless method of treatment and may actually obviate the need for later surgical management, it would seem prudent to permit the parents to make such an effort. Various types of moderate auricular abnormalities can occur. Although the ear is not severely micro tic, it does not look normal (Fig. 4). The first step in the management of this type of patient is to obtain a hearing test. Depending on the audiometric results, a hearing loss can be managed by amplification or possible surgical hearing correction. Surgical correction of the auricle has no set calendar for treatment. The pliability of the cartilage is greater if the child is younger. Therefore, it is not necessary to wait until the child is in grade school to contemplate correction. The patient in Figure 4 underwent correction at 4 years of age. Her cartilage pliability would likely have been diminished by the time she was 6 or 7 years of age yet was extremely helpful in terms of re-creation of her auricle.
SEVERELY MALFORMED AURICLE: MICROTIA AND ATRESIA Microtia presents usually with a misplaced, tiny cartilaginous appendage to which a piece of tissue similar to a lobule is attached. The condition is usually unilateral. The incidence of microtia is not specifically known but is estimated to be about 1 of 10,000 births according to Center for Disease Control data for metropolitan Atlanta (Cordero J: Personal communication). This rate includes syndromes such as Treacher-Collins and Goldenhar. The etiology of sporadic cases seems to be multifactional. Animal models suggest possible embryologic mechanisms of microtia and atresia. Poswillo lO has demonstrated similar conditions in mice in whom the stapedial artery has ruptured at a critical portion of embryonic development. Failure of neural crest migration has also been postulated. 9 This possibility has been strengthened somewhat owing to the known teratogenic effect of maternally ingested vitamin A, which would be taken by the mother for acne. 6 The ear that is malformed owing to vitamin A toxicity, however, also has a unique characteristic that the tragus seems to be spared. This model of malformation seems to be branchial arch selective. Because most cases of microtia do not have a preserved tragus, the neural crest migration theory may not be applicable. Also, unilaterality would be difficult to explain by neural crest migration failure. Intrauterine deformation can occur in some cases. For example, the hand can be malpositioned against the ear, causing deformation of both the ear and the hand. Occasionally an ear canal and tympanic membrane will be present
1526
ROLAND
D.
EAVEY
Figure 4. A. Lateral preoperative view of moderately severe left auricular malformation. B. Two weeks postrepair just prior to suture removal. C. Anterior view; again preoperative.
D. Six months postrepair.
despite a severely microtic appendage (Fig. 5). The usual situation, however, is absence of an ear canal and meatus. In fact, this severe situation is actually preferable to the rarer condition of a pinhole-sized canal because a collection of squamous epithelium in a narrow canal or blind pouch can lead to infection and cholesteatoma. Associated conditions to evaluate are, for example, the presence of an ipSilateral facial paralysis or paresis. Ipsilateral mandibular hypoplasia is also common. If another known syndromic condition such as Goldenhar's (hemifacial microsomia) is detected, the patient should have a careful systemic evaluation to detect potential problems with the eye, vertebral bodies, and heart.
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
1527
Figure 5. Despite the severe left auricular deformity the patient has an ear canal and tympanic membrane.
MANAGEMENT DECISIONS Infancy The first assistance that the pediatrician can provide to the parents is to reassure them this is not an unknown condition (Table 1). Microtia is not as familiar an anomaly to parents as is, for example, cleft palate or cleft lip. The parents almost universally are distressed and bewildered because they often have no family members with this condition. Additionally, because the hair growth is scant, the malformed auricle is a visible condition during the first several months or even years of life (Fig. 6). The parents further need the information that hope exists for correction of this disorder. Because developments are relatively recent and still being refined, many physicians might not be aware of the degree of correction that can be offered to the child. After the initial concerns about the condition as a whole, parental attention usually focuses on hearing. In unilateral cases, the hearing is almost invariably normal in the ear that externally appears to be normal. Normal hearing is an assumption that must be proved, however. Deaf children, for example, usually have normal auricles. The abnormal ear typically has a 60 dB conductive hearing loss but occasionally can be associated with total deafness.
1528
ROLAND
D.
EAVEY
Table 1. Points of Consideration for Management of Children with Microtia Birth Reassurance to parents Early infancy Brainstem-evoked hearing response Possible hearing amplification Evaluation of associated conditioris such as mandibular hypoplasia and facial paralysis Counseling for the parents regarding this condition and introduction of the parents to other families with similar children Surgical correction of minimal anomalies such as ear tags is possible (no substantial surgery should occur without the approval of the surgeon[sl eventually responsible for later definitive correction) Early childhood Treatment for suspected otitis media in the microtic ear Surveillance of the normal ear for otitis media with effusion Surgical correction of the moderately malformed external ear is possible Age 6 Years Consideration of surgical correction of the severely malformed ear External surgery of the auricle should precede possible otologic middle-ear surgery
Hearing should be assessed by a brainstem-evoked-response audiogram. Preferably the test will be performed within 2 months after birth. Two months is the suggested period because young infants in that age group often fall asleep spontaneously. Because the evoked-response testing is performed during sleep, chloral hydrate or other sedation is therefore unnecessary. Testing should be done at a center that is experienced in measuring the hearing of children. Evoked-response audiometry is occasionally performed by departments other than audiology departments as
Figure 6. Typical microtia appearance in an infant; right ear.
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
1529
part of a neurologic assessment of brainstem function. The hearing assessment in such a test, however, may be only a hearing screen and does not provide a precise audiometric picture. Testing done at an adult center may yield only tentative interpretations if the audiologist is inexperienced in dealing with neonates. When microtia is bilateral, it is absolutely imperative to obtain a hearing analysis. The patient will require hearing amplification because both ears would usually have a maximum conductive hearing loss of about 60 dB. This is the equivalent of an adult walking around with each ear canal tightly occluded by an index finger. Although hearing is present, it is difficult to develop normal speech and language with such a loss. This is especially critical during the age of language acquisition. The patient must be fitted with a bone conductive hearing aid. This can be secured by a headband and appears similar to the recreational portable radio and cassette devices on the commercial market. In select children the use of doublesided tape provides effective fixation and eliminates the need for the headband. Surprisingly, children usually do not remove such devices because they seem to realize that these amplification techniques are helpful to them (Fig. 7). In the occasional case in which an ear canal is present, but the middle ear and drum are not visible behind the atresia plate, a standard hearing aid may be used. The aid is adjusted to maximum gain. If successful, this type of amplification eliminates a bit of hardware for the patient to wear.
Figure 7. A, Bone conduction hearing aid secured by headband; right ear of a bilateral condition. B, Hearing aid secured by double-sided tape; left ear of a bilateral condition.
1530
ROLAND
D.
EAVEY
Radiographic studies such as CT or MRI scans are usually not performed during early infancy because they seldom change the audiologic or surgical management. Select patients may merit an evaluation to assess the course of the facial nerve or to search for an inner-ear anomaly. The pediatrician need not feel responsible for obtaining these studies because the otolaryngologist will perform these tests at a suitable time. Early Childhood An issue that is not addressed often in the literature but is especially germane to the pediatrician is the question of otitis media. No proof exists that these patients routinely get otitis media in the microtic ear. It is logical to assume that this happens, however. The eustachian tube to the nasopharynx is intact, and a rudimentary middle ear usually exists. Therefore, the patient has a stage that is set for otitis media. Rare reports demonstrate severe complications of otitis media in the microtic ear such as mastoiditis. 13 Practical advice would be to treat with antibiotics if a suspicion from indirect clinical criteria exists that otitis media might be present. A related issue of otitis media paradoxically involves the normal ear. The characteristic patient has only an isolated microtia and is using the other ear as the sole sound receptor for speech and language development. It is known that unilateral normal hearing is adequate for communication. The normal ear is at risk for acute and serious otitis media, however, as any ear might be. Personal experience has shown that a high percentage of these children will for a period in their preschool years have a prolonged effusion in the normal ear. Such an effusion can substantially interfere with overall hearing. Many of these children require temporary ventilation tube placement in the normal ear. During early childhood, growth of the malformed auricle will be proportional to the normal side. The rigidity of the cartilage also increases. The appearance of the auricle does not improve, however, and over time it merely looks like a larger version of its former self (Figs. 6 to 8).
DEFINITIVE CORRECTION TREATMENT DECISIONS The patient usually does not require surgery during the first few years of life. One exception, mentioned previously, is the merely moderately deformed auricle that can be corrected surgically before 6 years of age. Another possible exception might be a total facial paralysis that might require an eyelid tarsorrhaphy to help keep the eye closed during sleep. Hearing correction procedures can also occur earlier in the anomalous ear, but this is the unique case of the reasonably well-formed pinna, canal, and tympanic membrane. Typically then, most surgical decisions for severe microtia occur about 6 years of age. One therapeutic option would be to select no treatment at all. In the patient with unilateral microtia with no associated facial defects, this has been a traditional method of handling the problem. A lengthy hair style is maintained. Older patients, however, do at times report distress that they
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
1531
Figure 8. Adolescent with right ear microtia. A , Malformed auricle similar proportionally to infant in Fig. 5. B, Three weeks afte r second stage of auricular reconstruction (lateral view). C, Front view.
have a secret abnormality that might be discovered, and they have wished that treatment could have been offered as children. Another consideration for cosmetic treatment is the prosthetic ear. The prosthesis is usually attached by adhesive onto the microtic vestige. Although worth consideration, in practice prosthetic ears are seldom used.
1532
ROLAND
D.
EAVEY
Patients find that the prosthesis can be a nuisance. At times they fall off and are a cause of embarrassment. Other disadvantages include the fact that they soil or require color changes during various times of the year when the skin may be tanned. They also need to be replaced in size if used in a child. Despite disadvantages, however, for the patient who cannot undergo or does not choose surgery, a prosthesis offers an available alternative. In contemplating a surgical correction, two conditions compete for attention. First, the hearing is potentially able to be reconstructed in some patients. Second, the external auricle can be repaired in almost all patients. No surgery should be done that may violate the area at any age unless the surgeon(s) responsible for the eventual correction makes the decision. It is then necessary to surgically correct the external auricle before operating on the hearing. This is a situation in which coordination with the fewest number of surgeons is mandatory. The surgical maneuvers for the correction of the external ear are usually substantial rather than minor. Except for the occasional auricle that needs only some repositioning and unfurling, the pinna infrastructure is usually useless except for the presence of the lobulelike tissue and the skin that is available over the malformed cartilaginous appendage. Rather than trying to unfurl this mass of deformed cartilage it is far more preferable to remove it and reconstruct anew. A reasonably predictable method of creating an external ear is to use cartilaginous rib grafts that are carved into the shape of an auricle. This work was pioneered by Tanzer12 and then refined to a high degree by Brent. 1 The procedure is multistaged. In the first stage the ribs are harvested, carved, and implanted under the skin at the ear site. The next stage involves transposition of the lobule like tissue into a more realistic ear lobe. By this stage the auricle can appear acceptably realistic (See Fig. 8). Refinement procedures to create a tragus and elevate the new auricle from the side of the head can additionally be performed as desired. The stages can be separated by a few months. They can be shortened up to within a few weeks of one another, however. In the case of bilateral atresia, the first ear framework is used as a template for the second ear.
HEARING RECONSTRUCTION Hearing reconstruction was in part pioneered and then later refined by Schuknecht. ll Additional experience has been added by Jahrsdorfer. 4 Not all patients are candidates for repair (Fig. 9). Successful results are not even now nearly universal; some patients may experience a hearing increase but of modest proportion (Fig. 10). Surgical correction of hearing is a one-stage procedure. This consists of drilling out an ear canal and locating the misshapen ossicles. Usually the ossicles are sufficiently mobile to permit conduction of sound. A fascia layer is placed on the ossicles to be the equivalent of a replacement tympanic membrane. Another potential future method of hearing improvement for older
1533
MANAGEMENT STRATEGIES FOR CONGENITAL EAR MALFORMATIONS
Figure 9. CT scan of a patient with microtia/atresia of left ear. The patient is not a good candidate for reconstruction of hearing. Note asymmetry between sides.
AUDIOGRAM o
./
-""'b. """"tc .~
Figure 10. Audiogram of a 16year-old patient with a partial atresia. Preoperative = filled circles; postoperative = hollow circles.
~Q) ...,J
.§ tU
~
80 100
120
I
125
250
500
1K
2K
Frequency (Hz)
4K
8K
ROLAND
1534
D.
EAVEY
children involves implantation of a hearing aid coupler under the skin with a device that screws into the bone of the side of the head. 3 A percutaneous device is also available in Scandinavia. 2 To each device, a hearing amplification device can be attached externally. The subcutaneous model requires a magnetic attraction through the skin and subcutaneous tissues. The percutaneous device permits direct coupling. The percutaneous device has also been used to attach a prosthetic ear.
REFERENCES 1. Brent B: The correction of microtia with autogenous cartilage grafts: 1. The classic deformity. Plast Reconstr Surg 66:1-12, 1980 2. Carlsson P, Hakansson B, Rosenthal! U, et al: A speech-to-noise ratio test with the boneanchored hearing aid: A comparative study. Otolaryngol Head Neck Surg 94:421-426, 1986 3. Hough J, Himelick T, Johnson B: Implantable bone conduction hearing device. Arch Otol Rhinol Laryngol 95:498-504, 1986 4. Jahrsdorfer RA: Congenital atresia of the ear. Laryngoscope 88:1-48, 1978 5. Konigsmark BW, Gorlin RJ: Genetic and Metabolic Deafness. Philadelphia, WB Saunders, 1976, pp 49-73 6. Lemmer E, Chen D, Hoar R et al: Retinoic acid embryopathy. N Engl J Med 313:837841, 1985 7. Melnick M, Myrianthopoulos NC: External Ear Malformations: Epidemiology, Genetics, and Natural History, vol 15. The National Foundation-March of Dimes Birth Defects. Original Article Series. New York, Alan R. Liss, 1979, pp 122-123 8. Muraoka M, Nakai Y, Sasaki T, et al: Tape attachment therapy for correction of congenital malformations of the auricle: Clinical and experimental studies. Laryngoscope 95:167175, 1985 9. Phelps P, Poswil!o D, Lloyd G: The ear deformities in mandibulofacial dysostosis (Treacher Collins syndrome). Clin Otolaryngol 6:15-28, 1981 10. Poswil!o D: The pathogenesis of the first and second branchial arch syndrome. Oral Surg 35:302-328, 1973 11. Schuknecht HF: Reconstructive procedures for congenital aural atresia. Arch Otolaryngol 101:170-172, 1975 12. Tanzer RC: Total reconstruction of the external ear. Plast Reconstr Surg 23:1-15, 1959 13. Zalzal GH: Acute mastoiditis complicated by sigmoid sinus thrombosis in congenital aural atresia. Int J Pediatr Otorhinolaryngol 14:31-39, 1987 ENT Pediatric Services Harvard Medical School Massachusetts Eye and Ear Infirmary 243 Charles Street Boston, MA 02114