Copyeditor: James Joseph Arguelles
Otology & Neurotology 35:1099Y1101 Ó 2014, Otology & Neurotology, Inc.
Eustachian Tube Duplication: A Unique Anomaly *Rebecca Chow Hoesli, †Jason Johnson, †Anna Meyer, and *Glenn Green *University of Michigan, Ann Arbor, Michigan; and ÞUniversity of California, San Francisco, California, U.S.A.
posterior to a microtic and atretic ear. We review the literature on eustachian tube anomalies and also consider the derivation of this anomaly. Key Words: Eustachian tubeVFirst branchial cleftVoculoauriculovertebral syndrome. Otol Neurotol 35:1099Y1101, 2014.
Very few eustachian tube anomalies have been published in the literature and have consisted of descriptions of diverticula, hypoplasia/aplasia, fistula, or aberrant associated musculature. We present a girl with a novel anomaly consisting of a eustachian tube duplication that originates in the nasopharynx and exits
CASE REPORT Computed tomography was performed with the pledget in place and revealed a membranous atresia of the right external auditory canal with a markedly hypoplastic residual bony canal. The floor of the middle ear cavity was absent, and the middle ear and mastoid air cells were completely opacified (Fig. 2A). The tegmen tympani, mastoideum, and scutum were intact. The malleus and incus were present but fused (Fig. 2B). The labyrinthine portion of the facial nerve was visualized and coursed inferior to the lateral semicircular canal but then was located in a somewhat oblique posterior location in the mastoid segment. The presence of the eustachian tube was noted in its expected location, and the neurosurgical pledget was observed just posteriorly within a tract that coursed from posterior to the auricle to the eustachian tube (Fig. 2C). It then exited anterior/inferior to the level of the torus tubarius (Fig. 2D). The inner ear structures were normal appearing. The left ear had normal middle and inner ear anatomy with underdevelopment of the mastoid air cells and a middle ear effusion. Speech and language evaluation revealed a 6- to 10-month expressive delay with recent increase in receptive and expressive vocabulary. She had hypernasal speech, and fiberoptic endoscopic evaluation of swallowing revealed velopharyngeal insufficiency with a wide right-sided port and incomplete closure of the left side, with no mobility of the right lateral pharyngeal wall and hypoplasia of the right musculature. At 25 months of age, an excision of the right anomalous eustachian tube was performed via a postauricular and parotid incision with facial nerve monitoring. The entire tract was dissected free to the internal aperture at the torus tubarius. The tract was divided at its entry to the torus and was imbricated on itself. Facial nerve monitoring revealed
A 21-month-old girl presented with persistent drainage of saliva and reflux of formula from behind her right microtic and atretic ear (Fig. 1). Her parents had also noted speech delay and reflux of formula through her right nostril. Physical examination revealed an atretic right external auditory canal and a postauricular fistula tract just behind the postauricular groove (Fig. 1). In addition, she was noted to have a House-Brackmann Grade III right-sided facial paresis, hemifacial microsomia, mild torticollis, and an asymmetric palate. At the time of her initial evaluation, she was significantly speech delayed and had no words in either English or Cantonese. Her audiologic examination revealed normal hearing in at least her better ear after placement of a pressure equalization tube in the left ear. Examination under anesthesia revealed a mucosa-lined structure extending from behind the microtic ear to the torus tubarius with no obvious connection to the middle ear. Aberrant right-sided palatal musculature was also identified with a foreshortened palate, levator veli palatini insertion more anterior than typical, and an absent palatopharyngeal arch with fusion of the salpingopharyngeus and palatopharyngeus without connection to the soft palate. A 2-in-long neurosurgical pledget was trimmed and passed through the fistula externally and was confirmed intraorally to protrude from the torus.
Address correspondence and reprint requests to Glenn Green, M.D., CW-5-702 SPC 4241, 1540 E. Hospital Dr., Ann Arbor, MI 48109-4241, U.S.A.; E-mail: [email protected] The authors disclose no conflicts of interest.
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Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
1100
R. C. HOESLI ET AL. Postoperatively, the patient’s right facial nerve was neuropraxic but fully recovered to baseline over subsequent visits. Her fistula closed completely and her velopharyngeal insufficiency resolved. Her speech was no longer hypernasal and she continued to make gains in speech acquisition. We most recently were able to open her right atretic canal by removing a large posterolaterally based aberrant tympanic ring and widening the external canal. A canal cholesteatoma was removed to reveal a normal-sized tympanic membrane. She has since been seen back with hearing present on the right.
DISCUSSION
FIG. 1. Solid arrow pointing to a fistula draining saliva behind a microtic and atretic right ear. Double-lined arrow showing a stenotic external auditory canal.
that the facial nerve coursed superior to the tract. Nerve stimulation confirmed an intact nerve at the completion of the case.
The eustachian tube derives from the first branchial pouch and is composed of endodermal tissue. The distal portion of the first branchial pouch widens into the tubotympanic recess and a primitive middle ear cleft while the proximal portion becomes the eustachian tube. This occurs between 4 and 6 weeks of gestation. The tubotympanic recess abuts the involution of the first branchial cleft, and this union forms the tympanic membrane. This process is complete by the 10th week of gestation (1). Few eustachian tube anomalies have been described in the literature. von Kostanecki (2) identified diverticula of
FIG. 2. Computed tomographic scans of patient. A, Coronal computed tomographic image of the membranous canal atresia with a hypoplastic bony canal including absence of the middle ear floor (also note the pledget in the eustachian tube entering the nasopharynx). B, Axial computed tomographic image of the right ear revealing fusion of the incus and malleus. C, Axial computed tomographic image of the pledget inserted at the external opening of the tract and extending to the eustachian tube. D, Coronal computed tomographic image of the pledget exiting the tract at the torus with air in the eustachian tube. Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
DUPLICATE EUSTACHIAN TUBE the eustachian tube and abnormal patency due to overdevelopment of the tensor tympani muscle. Altmann noted both the absence of the eustachian tube (3) and abnormal narrowing of the tube in several patients (4). Shibahara and Sando have described a congenitally collapsed eustachian tube with hypoplastic cartilage in a fetus with Down syndrome (5), and abnormal cartilage and aberrant tensor veli palatini insertion in patients with cleft palate (6). Miura et al. (7) have described 2 cases of syndromic children, one with Towne syndrome and one with oralYfacialYdigital syndrome who had poor development of the eustachian tube cartilage, aberrant or underdeveloped levator veli palatini, and slightly shortened cochlea. They have also described hypoplastic eustachian tubes in children with various chromosomal abnormalities (8). Liu et al. (9) described 2 cases of epithelially lined branchial cleft fistulas. Both children presented with drainage from a lesion near the angle of the mandible, and communication was found with the nasopharyngeal orifice of the eustachian tube. Ours is the first known description of a duplication of the eustachian tube. This anomaly has similarities to a first branchial cleft anomaly. First branchial cleft anomalies are quite rare (1% of branchial cleft anomalies) and were first described by Virchow in 1864 (10). Arnot and Work (11, 12) classified these anomalies as 2 different types. Type 1 anomalies consist of a duplication of the membranous external auditory canal and run in parallel to this structure and superior to the facial nerve. They do not contain cartilage and are ectodermal in derivation. Type 2 anomalies, which are more common, consist of squamous epithelia and cartilage and typically present as a cyst, sinus, or fistula intimately associated with the parotid gland and having a variable relationship to the facial nerve. They are ectodermal and mesodermal in origin. In contradistinction, our patient had an anomaly composed of endodermal and mesodermal tissues. Although the tract of our lesion extended from the periauricular region to the torus similar to the patients described in Liu et al., the difference in the embryologic origin suggests that our lesion is fundamentally distinct from the lesions described by Liu et al. Because of derivation from the endodermal tissue in addition to the mesodermal tissue, it was hypothesized that our lesion resulted from an abnormal development of the endoderm or pouch of the first branchial arch. The location of the lesion extending from postauricularly to the nasopharynx and exiting at the torus was consistent with an anomaly of the eustachian tube, and it was hypothesized that our lesion represented a duplication of the eustachian tube because the computed tomographic scan showed the presence of a eustachian tube in addition to the lesion. In addition, it is likely that there were abnormalities in the development of the pouch of the first branchial arch because the other structures that derive from this pouch were abnormal. Our patient has oculoauriculovertebral syndrome, and any association with eustachian tube anomalies was searched for in the literature. Oculoauriculovertebral syndrome is a defect of the first and second branchial arches with significant
1101
phenotypic variability. In addition to craniofacial abnormalities, cardiac, central nervous system, and vertebral defects occur. Typically, the syndrome consists of unilateral ear deformity and hypoplasia of the maxilla and mandible. Ear anomalies have been reported to include preauricular tags, pinna deformities, external auditory canal atresia, malformation or absence of the ossicles, microtia, and anotia. In addition to hypoplasia of the facial nerve, oval window, chorda tympani, stapedius, and semicircular canal abnormalities have been described. Children with oculoauriculovertebral syndrome and eustachian tube dilation with hypoplastic cartilage have been identified (13,14).
SUMMARY We present a unique patient with hemifacial microsomia, unilateral facial paresis, microtia, external auditory canal atresia, hypoplasia of the palatal musculature, and an endothelially lined eustachian tube duplication. This is the first case of eustachian tube duplication in the literature. REFERENCES 1. Cummings CW, Frederickson JM, Harker LA, et al. Anatomy and Physiology of the Eustachian Tube. Otolaryngology Y Head and Neck Surgery. St. Louis, MO: C.V. Mosby Co., 1986. 2. von Kostanecki 1887, in Altmann F. Malformations of the eustachian tube, the middle ear, and its appendages: a critical review. AMA Arch Otolaryngol 1951;54:241Y66. 3. Altmann F. Malformations of the eustachian tube, the middle ear, and its appendages: a critical review. AMA Arch Otolaryngol 1951;54: 241Y66. 4. Altmann F. Problem of so-called congenital atresia of the ear. Arch Otolaryngol 1949;50:759. 5. Shibahara Y, Sando I. Congenital anomalies of the eustachian tube in Down syndrome. Ann Otol Rhinol Laryngol 1989;98:543. 6. Shibahara Y, Sando I. Histopathologic study of eustachian tube in cleft palate patients. Ann Otol Rhinol Laryngol 1988;97:403Y8. 7. Miura M, Sando I, Balaban CD, Haginomori S, Orita Y. Temporal bone morphometric study on the eustachian tube and its associated structures in patients with chromosomal aberrations. Ann Otol Rhinol Laryngol 2002;111:722Y9. 8. Miura M, Sando I, Hirsch BE, Orita Y. Anomaly of the eustachian tube and its associated structures in patients with multiple congenital malformation: a histopathological and morphometric study. Int J Pediatr Otorhinolaryngol 2002;64:207Y16. 9. Liu Y, Li T, Xue J, Jia J, Xiao S, Zhao E. First branchial cleft fistula presenting with internal opening on the eustachian tube: illustrated cases and literature review. Int J Pediatr Otorhinolaryngol 2012;76: 642Y5. ¨ ber MiQbildungen am Ohr und im Bereich des ersten 10. Virchow R. U Kiemenbogens. Arch Path Anat 1864;30:221. 11. Arnot RS. Defects of the first branchial cleft. S Afr J Surg 1971; 9:93Y8. 12. Work WP. Newer concepts of first branchial cleft defects. Laryngoscope 1972;82:1581Y93. 13. Miura M, Sando I, Takasaki K, Haginomori S, Hirsch BE. Histopathologic study of temporal bone and eustachian tube in oculoauriculovertebral spectrum. Ann Otol Rhinol Laryngol 2001; 110:922Y7. 14. Haginomori S, Nonaka R, Hoshijima H, et al. Enlarged bony portion of the eustachian tube in oculoauriculovertebral spectrum. Otol Neurotol 2003;24:961Y2.
Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
Otology & Neurotology 35:1099Y1101 Ó 2014, Otology & Neurotology, Inc.
Eustachian Tube Duplication: A Unique Anomaly *Rebecca Chow Hoesli, †Jason Johnson, †Anna Meyer, and *Glenn Green *University of Michigan, Ann Arbor, Michigan; and ÞUniversity of California, San Francisco, California, U.S.A.
posterior to a microtic and atretic ear. We review the literature on eustachian tube anomalies and also consider the derivation of this anomaly. Key Words: Eustachian tubeVFirst branchial cleftVoculoauriculovertebral syndrome. Otol Neurotol 35:1099Y1101, 2014.
Very few eustachian tube anomalies have been published in the literature and have consisted of descriptions of diverticula, hypoplasia/aplasia, fistula, or aberrant associated musculature. We present a girl with a novel anomaly consisting of a eustachian tube duplication that originates in the nasopharynx and exits
CASE REPORT Computed tomography was performed with the pledget in place and revealed a membranous atresia of the right external auditory canal with a markedly hypoplastic residual bony canal. The floor of the middle ear cavity was absent, and the middle ear and mastoid air cells were completely opacified (Fig. 2A). The tegmen tympani, mastoideum, and scutum were intact. The malleus and incus were present but fused (Fig. 2B). The labyrinthine portion of the facial nerve was visualized and coursed inferior to the lateral semicircular canal but then was located in a somewhat oblique posterior location in the mastoid segment. The presence of the eustachian tube was noted in its expected location, and the neurosurgical pledget was observed just posteriorly within a tract that coursed from posterior to the auricle to the eustachian tube (Fig. 2C). It then exited anterior/inferior to the level of the torus tubarius (Fig. 2D). The inner ear structures were normal appearing. The left ear had normal middle and inner ear anatomy with underdevelopment of the mastoid air cells and a middle ear effusion. Speech and language evaluation revealed a 6- to 10-month expressive delay with recent increase in receptive and expressive vocabulary. She had hypernasal speech, and fiberoptic endoscopic evaluation of swallowing revealed velopharyngeal insufficiency with a wide right-sided port and incomplete closure of the left side, with no mobility of the right lateral pharyngeal wall and hypoplasia of the right musculature. At 25 months of age, an excision of the right anomalous eustachian tube was performed via a postauricular and parotid incision with facial nerve monitoring. The entire tract was dissected free to the internal aperture at the torus tubarius. The tract was divided at its entry to the torus and was imbricated on itself. Facial nerve monitoring revealed
A 21-month-old girl presented with persistent drainage of saliva and reflux of formula from behind her right microtic and atretic ear (Fig. 1). Her parents had also noted speech delay and reflux of formula through her right nostril. Physical examination revealed an atretic right external auditory canal and a postauricular fistula tract just behind the postauricular groove (Fig. 1). In addition, she was noted to have a House-Brackmann Grade III right-sided facial paresis, hemifacial microsomia, mild torticollis, and an asymmetric palate. At the time of her initial evaluation, she was significantly speech delayed and had no words in either English or Cantonese. Her audiologic examination revealed normal hearing in at least her better ear after placement of a pressure equalization tube in the left ear. Examination under anesthesia revealed a mucosa-lined structure extending from behind the microtic ear to the torus tubarius with no obvious connection to the middle ear. Aberrant right-sided palatal musculature was also identified with a foreshortened palate, levator veli palatini insertion more anterior than typical, and an absent palatopharyngeal arch with fusion of the salpingopharyngeus and palatopharyngeus without connection to the soft palate. A 2-in-long neurosurgical pledget was trimmed and passed through the fistula externally and was confirmed intraorally to protrude from the torus.
Address correspondence and reprint requests to Glenn Green, M.D., CW-5-702 SPC 4241, 1540 E. Hospital Dr., Ann Arbor, MI 48109-4241, U.S.A.; E-mail: [email protected] The authors disclose no conflicts of interest.
1099
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
1100
R. C. HOESLI ET AL. Postoperatively, the patient’s right facial nerve was neuropraxic but fully recovered to baseline over subsequent visits. Her fistula closed completely and her velopharyngeal insufficiency resolved. Her speech was no longer hypernasal and she continued to make gains in speech acquisition. We most recently were able to open her right atretic canal by removing a large posterolaterally based aberrant tympanic ring and widening the external canal. A canal cholesteatoma was removed to reveal a normal-sized tympanic membrane. She has since been seen back with hearing present on the right.
DISCUSSION
FIG. 1. Solid arrow pointing to a fistula draining saliva behind a microtic and atretic right ear. Double-lined arrow showing a stenotic external auditory canal.
that the facial nerve coursed superior to the tract. Nerve stimulation confirmed an intact nerve at the completion of the case.
The eustachian tube derives from the first branchial pouch and is composed of endodermal tissue. The distal portion of the first branchial pouch widens into the tubotympanic recess and a primitive middle ear cleft while the proximal portion becomes the eustachian tube. This occurs between 4 and 6 weeks of gestation. The tubotympanic recess abuts the involution of the first branchial cleft, and this union forms the tympanic membrane. This process is complete by the 10th week of gestation (1). Few eustachian tube anomalies have been described in the literature. von Kostanecki (2) identified diverticula of
FIG. 2. Computed tomographic scans of patient. A, Coronal computed tomographic image of the membranous canal atresia with a hypoplastic bony canal including absence of the middle ear floor (also note the pledget in the eustachian tube entering the nasopharynx). B, Axial computed tomographic image of the right ear revealing fusion of the incus and malleus. C, Axial computed tomographic image of the pledget inserted at the external opening of the tract and extending to the eustachian tube. D, Coronal computed tomographic image of the pledget exiting the tract at the torus with air in the eustachian tube. Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
DUPLICATE EUSTACHIAN TUBE the eustachian tube and abnormal patency due to overdevelopment of the tensor tympani muscle. Altmann noted both the absence of the eustachian tube (3) and abnormal narrowing of the tube in several patients (4). Shibahara and Sando have described a congenitally collapsed eustachian tube with hypoplastic cartilage in a fetus with Down syndrome (5), and abnormal cartilage and aberrant tensor veli palatini insertion in patients with cleft palate (6). Miura et al. (7) have described 2 cases of syndromic children, one with Towne syndrome and one with oralYfacialYdigital syndrome who had poor development of the eustachian tube cartilage, aberrant or underdeveloped levator veli palatini, and slightly shortened cochlea. They have also described hypoplastic eustachian tubes in children with various chromosomal abnormalities (8). Liu et al. (9) described 2 cases of epithelially lined branchial cleft fistulas. Both children presented with drainage from a lesion near the angle of the mandible, and communication was found with the nasopharyngeal orifice of the eustachian tube. Ours is the first known description of a duplication of the eustachian tube. This anomaly has similarities to a first branchial cleft anomaly. First branchial cleft anomalies are quite rare (1% of branchial cleft anomalies) and were first described by Virchow in 1864 (10). Arnot and Work (11, 12) classified these anomalies as 2 different types. Type 1 anomalies consist of a duplication of the membranous external auditory canal and run in parallel to this structure and superior to the facial nerve. They do not contain cartilage and are ectodermal in derivation. Type 2 anomalies, which are more common, consist of squamous epithelia and cartilage and typically present as a cyst, sinus, or fistula intimately associated with the parotid gland and having a variable relationship to the facial nerve. They are ectodermal and mesodermal in origin. In contradistinction, our patient had an anomaly composed of endodermal and mesodermal tissues. Although the tract of our lesion extended from the periauricular region to the torus similar to the patients described in Liu et al., the difference in the embryologic origin suggests that our lesion is fundamentally distinct from the lesions described by Liu et al. Because of derivation from the endodermal tissue in addition to the mesodermal tissue, it was hypothesized that our lesion resulted from an abnormal development of the endoderm or pouch of the first branchial arch. The location of the lesion extending from postauricularly to the nasopharynx and exiting at the torus was consistent with an anomaly of the eustachian tube, and it was hypothesized that our lesion represented a duplication of the eustachian tube because the computed tomographic scan showed the presence of a eustachian tube in addition to the lesion. In addition, it is likely that there were abnormalities in the development of the pouch of the first branchial arch because the other structures that derive from this pouch were abnormal. Our patient has oculoauriculovertebral syndrome, and any association with eustachian tube anomalies was searched for in the literature. Oculoauriculovertebral syndrome is a defect of the first and second branchial arches with significant
1101
phenotypic variability. In addition to craniofacial abnormalities, cardiac, central nervous system, and vertebral defects occur. Typically, the syndrome consists of unilateral ear deformity and hypoplasia of the maxilla and mandible. Ear anomalies have been reported to include preauricular tags, pinna deformities, external auditory canal atresia, malformation or absence of the ossicles, microtia, and anotia. In addition to hypoplasia of the facial nerve, oval window, chorda tympani, stapedius, and semicircular canal abnormalities have been described. Children with oculoauriculovertebral syndrome and eustachian tube dilation with hypoplastic cartilage have been identified (13,14).
SUMMARY We present a unique patient with hemifacial microsomia, unilateral facial paresis, microtia, external auditory canal atresia, hypoplasia of the palatal musculature, and an endothelially lined eustachian tube duplication. This is the first case of eustachian tube duplication in the literature. REFERENCES 1. Cummings CW, Frederickson JM, Harker LA, et al. Anatomy and Physiology of the Eustachian Tube. Otolaryngology Y Head and Neck Surgery. St. Louis, MO: C.V. Mosby Co., 1986. 2. von Kostanecki 1887, in Altmann F. Malformations of the eustachian tube, the middle ear, and its appendages: a critical review. AMA Arch Otolaryngol 1951;54:241Y66. 3. Altmann F. Malformations of the eustachian tube, the middle ear, and its appendages: a critical review. AMA Arch Otolaryngol 1951;54: 241Y66. 4. Altmann F. Problem of so-called congenital atresia of the ear. Arch Otolaryngol 1949;50:759. 5. Shibahara Y, Sando I. Congenital anomalies of the eustachian tube in Down syndrome. Ann Otol Rhinol Laryngol 1989;98:543. 6. Shibahara Y, Sando I. Histopathologic study of eustachian tube in cleft palate patients. Ann Otol Rhinol Laryngol 1988;97:403Y8. 7. Miura M, Sando I, Balaban CD, Haginomori S, Orita Y. Temporal bone morphometric study on the eustachian tube and its associated structures in patients with chromosomal aberrations. Ann Otol Rhinol Laryngol 2002;111:722Y9. 8. Miura M, Sando I, Hirsch BE, Orita Y. Anomaly of the eustachian tube and its associated structures in patients with multiple congenital malformation: a histopathological and morphometric study. Int J Pediatr Otorhinolaryngol 2002;64:207Y16. 9. Liu Y, Li T, Xue J, Jia J, Xiao S, Zhao E. First branchial cleft fistula presenting with internal opening on the eustachian tube: illustrated cases and literature review. Int J Pediatr Otorhinolaryngol 2012;76: 642Y5. ¨ ber MiQbildungen am Ohr und im Bereich des ersten 10. Virchow R. U Kiemenbogens. Arch Path Anat 1864;30:221. 11. Arnot RS. Defects of the first branchial cleft. S Afr J Surg 1971; 9:93Y8. 12. Work WP. Newer concepts of first branchial cleft defects. Laryngoscope 1972;82:1581Y93. 13. Miura M, Sando I, Takasaki K, Haginomori S, Hirsch BE. Histopathologic study of temporal bone and eustachian tube in oculoauriculovertebral spectrum. Ann Otol Rhinol Laryngol 2001; 110:922Y7. 14. Haginomori S, Nonaka R, Hoshijima H, et al. Enlarged bony portion of the eustachian tube in oculoauriculovertebral spectrum. Otol Neurotol 2003;24:961Y2.
Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
