Original Papers
ORL47: 85 90 (1979)
Treatment of Postinflammatory Acquired Atresia of the External Auditory Canal M. Tos and P. Bonding ENT University Clinic, The Gentofte Hospital, Copenhagen
Key Words. Acquired atresia • Treatment of atresia • Tympanoplasty
In a previous study {Bonding and Tos, 1975), analysing 17 cases, we tried to describe the pathology, aetiology, and pathogenesis of this rare atresia which has been reported in only a few cases (Novick, 1939; Work, 1950; Gundersen, 1960; Eichel and Simonton, 1965; Marlowe, 1972). In most cases we found the solid, fibrous atresia, the auditory canal ending in a cul-de-sac 7—25 mm laterally to the drum. In half the cases the aetiology was chronic or recurrent external otitis, in the other half chronic otitis media. In both aetiological groups long-lasting treatment with hearing aid was a contributory factor. The thickness of the atresia increases intermittently by formation of granulations, disintegration of the epithelium of the drum and medially in the auditory canal, and fibrosing of renewed épithélisation of the granulations. This process was not arrested until the atresia had spread rather far laterally in the auditory canal owing to recurrent attacks of external otitis. Several patients underwent operation. The surgical method and the results will be described. In particular, it was investigated whether renewed growth of the atresia occurred some years after the operation, especially in patients who also required a hearing aid after the operation.
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Abstract. In 11 patients postinflammatory acquired atresia of the auditory canal, 7-15 mm thick, was excised, the drum and auditory canal covered with a Thiersch graft alone or by fascia and a Thiersch graft. 2.5-5 years after the operation there was no case of recurrence of the atresia. The functional result was most favourable in cases with atresia of minor thickness. Early operation is recommended, especially as cholesteatoma was found behind the atresia in 2 patients.
Tos/Bonding
86
Fig. 1. A Incision of the skin laterally to the atresia. B Dissection of the atresia from the bone. C Excising the fibrous tissue which only is seen anteriorly on the drum (black). D The fibrous tissue totally removed from the mucous layer of the drum. E The drum is covered with fascia and a Thiersch graft. F The drum and denued bone covered with the Thiersch graft.
Gundersen (1960) treated his 3 cases of acquired atresia by modified radical operation. Eichel and Simonton (1965) and Marlowe (1972) covered the auditory canal with skin after excising the atresia and widening the canal by drilling.
The operations were performed through an ear speculum, making a circular incision into the skin laterally to the atresia, dissecting the atresia from the bone, and gradually excising the fibrous tissue until coming upon the annulus fibrosus posteriorly (fig. 1A D). The annulus was cleaned inferiorly and anteriorly, cautiously detaching the fibrous tissue from the mucous membrane of the drum which should preferably remain intact. A tear in the mucous membrane will usually result in a large perforation in the course of the continued removal of the atresia. All fibrous tissue has to be removed from the anterior tympano-meatal angle, so that the entire annulus is visualised. Where the mucous membrane was intact, the drum and auditory canal were covered with a large, exactly adapted Thiersch graft (6 cases) (fig. IF). In the event of a perforation of the mucous membrane, the perforation was covered with thin fascia as well as a Thiersch graft (4 cases) (fig. IE). In the last operated case a homograft drum with malleus was applied and covered with fascia. The auditory canal was packed with gel foam and hydrocortisone terramycin gauze for 3 weeks.
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Surgical Method
Treatment of Postintlammatory Acquired Atresia
87
Fig. 2. Atresia of the auditory meatus (black) with a cholesteatoma (white) in the auditory canal (A) and in the tympanic cavity (B).
Material The material comprises 11 patients operated upon since 1968. The solid atresia, found histologically to consist of fairly vascular fibrous tissue, was 7-15 mm thick. In 5 cases the ossicular chain was intact and mobile. In another 5 cases - in which the aetiology was chronic otitis - there were other pathological changes, such as ossicular defects, adhesive changes, and middle ear tympanosclerosis. The ossicular defects were treated in the same stage by interposition of autograft bones, types III and II, in 2 cases of tympanosclerosis also by stapediolysis. 1 patient was found to have otosclerosis, so that stapedectomy was performed in the same stage. A cholesteatoma was found in the auditory canal of 1 patient (fig. 2A) and in the middle ear of another (fig. 2B). In September 1976 a follow-up examination was conducted. At that time the follow up period was 2.5 -5 years for 9 of the patients, but only 6 months for 2.
Primarily all patients obtained hearing improvement. At follow-up 7 still had hearing improvement of more than 20 dB in the 500-2,000 Hz range and 7 had an air-bone gap of less than 20 dB. 2 patients underwent re-operation because of a small perforation of the drum, a 3rd one because of deficient removal of the atresia in the anterior tympano-meatal angle. 2.5 years after this latter operation there was no atresia, and the drum was satisfactory. At follow-up no patient had signs of recurrent growth of the atresia, although 4 still have to use a hearing aid because of cochlear disease. The drum 2.5—5 years after the operation was of normal thickness and mobile in 7 cases, while in 3 cases it was moderately thickened anteriorly in the tympano-meatal angle, but mobile posteriorly. 1 patient still had a small perforation of the drum, despite the re-operation.
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Results
Tos/Bonding
88
The auditory canal was wide and self-cleaning except in 1 patient who had mild external otitis.
In 2 out of 11 patients a cholesteatoma was found behind the atresia. This per se indicates exploratory surgery - in the presence of atresia the only possibility of disclosing minor cholesteatomas. Marlowe (1972) too found a cholesteatoma in his case. Considering that several years previously a large perforation of the drum and chronic otitis media had been diagnosed in most of the patients, the occurrence of cholesteatomas behind the atresia is not sur prising. During the formation of granulations medially in the auditory canal, keratinised squamous epithelium may become trapped in the middle ear or auditory canal. Chronic otitis for years before the development of atresia also explains the common finding of ossicular defects, the middle ear tympanic sclerosis, and adhesive changes in the middle ear which was incidentally aerated with patent Eustachian tube. At follow-up after a maximum of 5 years no patient showed renewed formation of atresia, and there is no reason to assume that it will form in the future, as the aetiological factors, namely chronic otitis media and partially also otitis externa, have been eliminated. There was also no recurrence of the atresia in patients still using hearing aids. As the osseous auditory canal is normal, removal of the atresia does not involve any problems, but it must be total, as otherwise the atresia will soon recur. It is difficult to attain an intact mucosal layer of the dmm, especially in cases developing from chronic otitis media. But it is important to restrict the defect of the mucosal layer to a minimum, as a total defect and large exposure of the auditory canal will give rise to trophic problems during the process of re-epithelisation. Even though defects of the mucosal layer of the drum were covered with fascia and Thiersch grafts, perforation occurred in 2 cases. The best results were obtained in cases in which the atresia was not too thick and the exposure of the auditory canal not too large. Early operation of the atresia, regardless of the extent of the hearing loss, is therefore absolutely indicated. This will spare the patient long-lasting complaints, as the atresia will grow in spite of all, which was observed by us in several cases (Bonding and Tos, 1975). The hearing loss was pronounced at the onset of atresia formation, being 30 dB at a thickness of 1.5—2 mm, 40 dB at 7 mm, but did not increase further in the course of further thickening.
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Discussion
Treatment of Postinflammatory Acquired Atresia
89
Since formation of an atresia starts as diffuse formation of granulations on the drum, surgical removal of these granulations and covering of the drum with fascia or with a Thiersch graft must be indicated, even though at this stage the hearing is still within the range of normal. Previously - before realising the pathogenesis of acquired atresia — we have done successful operations in 4 such cases. When the atresia has grown laterally to the cartilaginous part of the auditory canal, the complaints due to the otitis externa will decrease or disappear. On the other hand, re-epithelisation problems in the operation will increase, and this involves the risk that an ear which has just stopped discharging will start doing so again. In such cases, the indication for operation is doubtful. For this reason — and after excluding a major destructive process in the middle ear by tomography - we have omitted operation in such patients, particularly in elderly ones who were satisfied with their hearing aids. Grafting problems in congenital atresia are well known and have not been obviated by recent techniques (Beickert, 1962; Bellucci, 1972; Wigand, 1975; Schuknecht, 1975)’ In our cases of acquired atresia, however, we have had no major problems concerning epithelisation of the auditory canal, presumably because after excision the epithelial defect has not been as large as in congenital atresia and because the osseous part of the auditory canal was of normal width, and never had to be widened by drilling. Refractory or stenosing otitis externa has been treated by modified radical operation ( Tobeck, 1958), total excision of the skin of the auditory canal without {Proud, 1966) or with covering of the denuded bone by skin grafts {Neveling and Nysten, 1962; Paparella, 1966; Leek, 1967). Beales (1974) stated that the use of extrameatal skin in the auditory canal is absolutely contra-in dicated, recommending instead an acrylic prosthesis for 3 months to counteract renewed stenosing {Beales and Crawford, 1966).
Beales, P.H.: Atresia of the external auditory meatus. Archs Otolar. 100: 209 211 (1974). Beales, P.-H. and Crawford, B.S.: The treatment of post-inflammatory atresia of the external auditory meatus. J. Laryng. 80: 86 -89 (1966). Beickert, P.: Operative Möglichkeiten bei Missbildungen des Mittelohres. Z. Lar. Rhinol. Otol. 41: 33 -45 (1962). Bellucci, R.J.: Congenital auricular malformations. Ann. Otolaryng. 81: 659 663 (1972).
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References
Tos/Bonding
90
Bonding, P. and Tos, M.: Postinflammatory acquired atresia of the external auditory canal. Acta oto-lar. 79: 115-123 (1975). Eichel, B.S. and Simonton, K.M.: Stenosis of the external auditory meatus secondary to chronic external otitis treated by a simplified surgical method: Report of a case. Laryngoscope, St Louis 75: 16 21 (1965). Gundersen, T.: Atresia meatus acusticus externus als Folge von Otitis externa eczematosa. Acta Oto-lar. 52: 473-476 (1960). Leek, J.H.: Plastic surgery of the external auditory canal. Archs Otolar. 85: 367 370 (1967). Marlowe, F.I.: Acquired atresia of the external auditory canal. Archs Otolar. 96: 380-383 (1972). Neveling, R. and Nysten, H.: Die chronische nekrotisierende Gehörgangsentzündung und ihre operative Behandlung. Z. Lar. Rhinol. Otol. 41: 216-224 (1962). Novick, J.N.: Atresia of the external auditory meatus. Archs Otolar. 30: 744-748 (1939). Paparella, M.M.: Surgical treatment of intractable external otitis. Laryngoscope, St Louis 76: 1136-1147 (1966). Proud, G.O.: Surgery for chronic refractory otitis externa. Archs Otolar. 83: 54-56 (1966). Schuknccht, H.F.: Reconstructive procedures for congenital aural atresia. Archs Otolar. 101: 170-172 (1975). Tobeck, A.: Operative Behandlung doppelseitiger stenosierender chronischer Gehörgangsent zündungen. Mschr. Ohrenhcilk. Lar.-Rhinol. 92: 193-196 (1958). Wigand, M.E.: Das Konzept der endauralen Tympanoplastik bei kongenitalen Atresien. Z. Lar. Rhinol. Otol. 54: 148 154 (1975). Work, W.P.: Lesions of the external auditory canal. Ann. Otolaryng. 59: 1062-1087 (1950).
M. Tos, MD, ENT University Clinic, TheGentofte Hospital, Copenhagen (Denmark)
Downloaded by: Karolinska Institutet, University Library 130.237.122.245 - 1/12/2019 4:13:29 PM
Received: February 2, 1979; accepted: February 26, 1979
ORL47: 85 90 (1979)
Treatment of Postinflammatory Acquired Atresia of the External Auditory Canal M. Tos and P. Bonding ENT University Clinic, The Gentofte Hospital, Copenhagen
Key Words. Acquired atresia • Treatment of atresia • Tympanoplasty
In a previous study {Bonding and Tos, 1975), analysing 17 cases, we tried to describe the pathology, aetiology, and pathogenesis of this rare atresia which has been reported in only a few cases (Novick, 1939; Work, 1950; Gundersen, 1960; Eichel and Simonton, 1965; Marlowe, 1972). In most cases we found the solid, fibrous atresia, the auditory canal ending in a cul-de-sac 7—25 mm laterally to the drum. In half the cases the aetiology was chronic or recurrent external otitis, in the other half chronic otitis media. In both aetiological groups long-lasting treatment with hearing aid was a contributory factor. The thickness of the atresia increases intermittently by formation of granulations, disintegration of the epithelium of the drum and medially in the auditory canal, and fibrosing of renewed épithélisation of the granulations. This process was not arrested until the atresia had spread rather far laterally in the auditory canal owing to recurrent attacks of external otitis. Several patients underwent operation. The surgical method and the results will be described. In particular, it was investigated whether renewed growth of the atresia occurred some years after the operation, especially in patients who also required a hearing aid after the operation.
Downloaded by: Karolinska Institutet, University Library 130.237.122.245 - 1/12/2019 4:13:29 PM
Abstract. In 11 patients postinflammatory acquired atresia of the auditory canal, 7-15 mm thick, was excised, the drum and auditory canal covered with a Thiersch graft alone or by fascia and a Thiersch graft. 2.5-5 years after the operation there was no case of recurrence of the atresia. The functional result was most favourable in cases with atresia of minor thickness. Early operation is recommended, especially as cholesteatoma was found behind the atresia in 2 patients.
Tos/Bonding
86
Fig. 1. A Incision of the skin laterally to the atresia. B Dissection of the atresia from the bone. C Excising the fibrous tissue which only is seen anteriorly on the drum (black). D The fibrous tissue totally removed from the mucous layer of the drum. E The drum is covered with fascia and a Thiersch graft. F The drum and denued bone covered with the Thiersch graft.
Gundersen (1960) treated his 3 cases of acquired atresia by modified radical operation. Eichel and Simonton (1965) and Marlowe (1972) covered the auditory canal with skin after excising the atresia and widening the canal by drilling.
The operations were performed through an ear speculum, making a circular incision into the skin laterally to the atresia, dissecting the atresia from the bone, and gradually excising the fibrous tissue until coming upon the annulus fibrosus posteriorly (fig. 1A D). The annulus was cleaned inferiorly and anteriorly, cautiously detaching the fibrous tissue from the mucous membrane of the drum which should preferably remain intact. A tear in the mucous membrane will usually result in a large perforation in the course of the continued removal of the atresia. All fibrous tissue has to be removed from the anterior tympano-meatal angle, so that the entire annulus is visualised. Where the mucous membrane was intact, the drum and auditory canal were covered with a large, exactly adapted Thiersch graft (6 cases) (fig. IF). In the event of a perforation of the mucous membrane, the perforation was covered with thin fascia as well as a Thiersch graft (4 cases) (fig. IE). In the last operated case a homograft drum with malleus was applied and covered with fascia. The auditory canal was packed with gel foam and hydrocortisone terramycin gauze for 3 weeks.
Downloaded by: Karolinska Institutet, University Library 130.237.122.245 - 1/12/2019 4:13:29 PM
Surgical Method
Treatment of Postintlammatory Acquired Atresia
87
Fig. 2. Atresia of the auditory meatus (black) with a cholesteatoma (white) in the auditory canal (A) and in the tympanic cavity (B).
Material The material comprises 11 patients operated upon since 1968. The solid atresia, found histologically to consist of fairly vascular fibrous tissue, was 7-15 mm thick. In 5 cases the ossicular chain was intact and mobile. In another 5 cases - in which the aetiology was chronic otitis - there were other pathological changes, such as ossicular defects, adhesive changes, and middle ear tympanosclerosis. The ossicular defects were treated in the same stage by interposition of autograft bones, types III and II, in 2 cases of tympanosclerosis also by stapediolysis. 1 patient was found to have otosclerosis, so that stapedectomy was performed in the same stage. A cholesteatoma was found in the auditory canal of 1 patient (fig. 2A) and in the middle ear of another (fig. 2B). In September 1976 a follow-up examination was conducted. At that time the follow up period was 2.5 -5 years for 9 of the patients, but only 6 months for 2.
Primarily all patients obtained hearing improvement. At follow-up 7 still had hearing improvement of more than 20 dB in the 500-2,000 Hz range and 7 had an air-bone gap of less than 20 dB. 2 patients underwent re-operation because of a small perforation of the drum, a 3rd one because of deficient removal of the atresia in the anterior tympano-meatal angle. 2.5 years after this latter operation there was no atresia, and the drum was satisfactory. At follow-up no patient had signs of recurrent growth of the atresia, although 4 still have to use a hearing aid because of cochlear disease. The drum 2.5—5 years after the operation was of normal thickness and mobile in 7 cases, while in 3 cases it was moderately thickened anteriorly in the tympano-meatal angle, but mobile posteriorly. 1 patient still had a small perforation of the drum, despite the re-operation.
Downloaded by: Karolinska Institutet, University Library 130.237.122.245 - 1/12/2019 4:13:29 PM
Results
Tos/Bonding
88
The auditory canal was wide and self-cleaning except in 1 patient who had mild external otitis.
In 2 out of 11 patients a cholesteatoma was found behind the atresia. This per se indicates exploratory surgery - in the presence of atresia the only possibility of disclosing minor cholesteatomas. Marlowe (1972) too found a cholesteatoma in his case. Considering that several years previously a large perforation of the drum and chronic otitis media had been diagnosed in most of the patients, the occurrence of cholesteatomas behind the atresia is not sur prising. During the formation of granulations medially in the auditory canal, keratinised squamous epithelium may become trapped in the middle ear or auditory canal. Chronic otitis for years before the development of atresia also explains the common finding of ossicular defects, the middle ear tympanic sclerosis, and adhesive changes in the middle ear which was incidentally aerated with patent Eustachian tube. At follow-up after a maximum of 5 years no patient showed renewed formation of atresia, and there is no reason to assume that it will form in the future, as the aetiological factors, namely chronic otitis media and partially also otitis externa, have been eliminated. There was also no recurrence of the atresia in patients still using hearing aids. As the osseous auditory canal is normal, removal of the atresia does not involve any problems, but it must be total, as otherwise the atresia will soon recur. It is difficult to attain an intact mucosal layer of the dmm, especially in cases developing from chronic otitis media. But it is important to restrict the defect of the mucosal layer to a minimum, as a total defect and large exposure of the auditory canal will give rise to trophic problems during the process of re-epithelisation. Even though defects of the mucosal layer of the drum were covered with fascia and Thiersch grafts, perforation occurred in 2 cases. The best results were obtained in cases in which the atresia was not too thick and the exposure of the auditory canal not too large. Early operation of the atresia, regardless of the extent of the hearing loss, is therefore absolutely indicated. This will spare the patient long-lasting complaints, as the atresia will grow in spite of all, which was observed by us in several cases (Bonding and Tos, 1975). The hearing loss was pronounced at the onset of atresia formation, being 30 dB at a thickness of 1.5—2 mm, 40 dB at 7 mm, but did not increase further in the course of further thickening.
Downloaded by: Karolinska Institutet, University Library 130.237.122.245 - 1/12/2019 4:13:29 PM
Discussion
Treatment of Postinflammatory Acquired Atresia
89
Since formation of an atresia starts as diffuse formation of granulations on the drum, surgical removal of these granulations and covering of the drum with fascia or with a Thiersch graft must be indicated, even though at this stage the hearing is still within the range of normal. Previously - before realising the pathogenesis of acquired atresia — we have done successful operations in 4 such cases. When the atresia has grown laterally to the cartilaginous part of the auditory canal, the complaints due to the otitis externa will decrease or disappear. On the other hand, re-epithelisation problems in the operation will increase, and this involves the risk that an ear which has just stopped discharging will start doing so again. In such cases, the indication for operation is doubtful. For this reason — and after excluding a major destructive process in the middle ear by tomography - we have omitted operation in such patients, particularly in elderly ones who were satisfied with their hearing aids. Grafting problems in congenital atresia are well known and have not been obviated by recent techniques (Beickert, 1962; Bellucci, 1972; Wigand, 1975; Schuknecht, 1975)’ In our cases of acquired atresia, however, we have had no major problems concerning epithelisation of the auditory canal, presumably because after excision the epithelial defect has not been as large as in congenital atresia and because the osseous part of the auditory canal was of normal width, and never had to be widened by drilling. Refractory or stenosing otitis externa has been treated by modified radical operation ( Tobeck, 1958), total excision of the skin of the auditory canal without {Proud, 1966) or with covering of the denuded bone by skin grafts {Neveling and Nysten, 1962; Paparella, 1966; Leek, 1967). Beales (1974) stated that the use of extrameatal skin in the auditory canal is absolutely contra-in dicated, recommending instead an acrylic prosthesis for 3 months to counteract renewed stenosing {Beales and Crawford, 1966).
Beales, P.H.: Atresia of the external auditory meatus. Archs Otolar. 100: 209 211 (1974). Beales, P.-H. and Crawford, B.S.: The treatment of post-inflammatory atresia of the external auditory meatus. J. Laryng. 80: 86 -89 (1966). Beickert, P.: Operative Möglichkeiten bei Missbildungen des Mittelohres. Z. Lar. Rhinol. Otol. 41: 33 -45 (1962). Bellucci, R.J.: Congenital auricular malformations. Ann. Otolaryng. 81: 659 663 (1972).
Downloaded by: Karolinska Institutet, University Library 130.237.122.245 - 1/12/2019 4:13:29 PM
References
Tos/Bonding
90
Bonding, P. and Tos, M.: Postinflammatory acquired atresia of the external auditory canal. Acta oto-lar. 79: 115-123 (1975). Eichel, B.S. and Simonton, K.M.: Stenosis of the external auditory meatus secondary to chronic external otitis treated by a simplified surgical method: Report of a case. Laryngoscope, St Louis 75: 16 21 (1965). Gundersen, T.: Atresia meatus acusticus externus als Folge von Otitis externa eczematosa. Acta Oto-lar. 52: 473-476 (1960). Leek, J.H.: Plastic surgery of the external auditory canal. Archs Otolar. 85: 367 370 (1967). Marlowe, F.I.: Acquired atresia of the external auditory canal. Archs Otolar. 96: 380-383 (1972). Neveling, R. and Nysten, H.: Die chronische nekrotisierende Gehörgangsentzündung und ihre operative Behandlung. Z. Lar. Rhinol. Otol. 41: 216-224 (1962). Novick, J.N.: Atresia of the external auditory meatus. Archs Otolar. 30: 744-748 (1939). Paparella, M.M.: Surgical treatment of intractable external otitis. Laryngoscope, St Louis 76: 1136-1147 (1966). Proud, G.O.: Surgery for chronic refractory otitis externa. Archs Otolar. 83: 54-56 (1966). Schuknccht, H.F.: Reconstructive procedures for congenital aural atresia. Archs Otolar. 101: 170-172 (1975). Tobeck, A.: Operative Behandlung doppelseitiger stenosierender chronischer Gehörgangsent zündungen. Mschr. Ohrenhcilk. Lar.-Rhinol. 92: 193-196 (1958). Wigand, M.E.: Das Konzept der endauralen Tympanoplastik bei kongenitalen Atresien. Z. Lar. Rhinol. Otol. 54: 148 154 (1975). Work, W.P.: Lesions of the external auditory canal. Ann. Otolaryng. 59: 1062-1087 (1950).
M. Tos, MD, ENT University Clinic, TheGentofte Hospital, Copenhagen (Denmark)
Downloaded by: Karolinska Institutet, University Library 130.237.122.245 - 1/12/2019 4:13:29 PM
Received: February 2, 1979; accepted: February 26, 1979
