[Computed tomography findings in middle ear anomaly]

The efficacy of computed tomography (CT) of the temporal bone was studied in 45 ears with a middle ear anomaly but whose tympanic membranes were normal. The plane of the film was 30 degrees oblique to the orbito-meatal line. Four otorhinolaryngologists made radiological diagnoses of the CT film without having any information about the patients. CT films of 40 normal ears were also evaluated and served as controls. The incudo-stapedial joint (I-S joint) and the stapes were visualized in all control group subjects. The percentage of correct diagnoses was 77.8% for separation of the I-S joint, and 75.6% for fixation of the stapes. The monopedal stapes was not visualized. Fixation of the malleus and the incus could not be diagnosed correctly. Abnormalities in the location of the facial nerve were visualized in a few ears. CT of the temporal bone was clinically useful for differentiating I-S joint separation and fixation of the stapes.

The deafness, pre-auricular sinus, external ear anomaly and commissural lip pits syndrome--otological, vestibular and radiological findings

Commissural lip pits, pinna dysplasia, pre-auricular sinus and hearing loss constitute a recently described autosomal dominant branchial arch syndrome. In a large family, eight out of the 74 members were also affected by conductive hearing loss. No inner ear abnormalities could be demonstrated on the CT scans. In three patients (four ears) out of four patients (six ears), exploratory tympanotomy revealed serious ossicular chain anomalies. In one ear, round window aplasia was also present. Long-term hearing improvement could only be achieved in one ear.

Long-term surgical results for congenital aural atresia

Thirty-nine primary surgical cases for correction of congenital aural atresia were reviewed for complications and long-term hearing results. Hearing averages of 25 dB for mild atresia, 40 dB for moderate atresia, and 46 dB for severe atresia were obtained. Serviceable hearing was achieved in 64% of the cases. The two most frequent complications were stenosis and recurrent infections of the cavity and canal skin, with an incidence of 33% and 31%, respectively. Use of split-thickness instead of full-thickness skin graft was associated with fewer complications. The goal of this review is also to share the experience of the senior author in the management of this complex problem.

Classification of congenital middle ear anomalies. Report on 144 ears

The surgical findings in 144 successive ears operated on for congenital conductive hearing loss were analyzed, and the results were evaluated in terms of hearing gain. All the patients underwent middle ear surgery at the University Hospital Nijmegen between 1964 and 1990. A classification system was developed to analyze the findings. Class 1 comprises ears with congenital isolated stapes ankylosis. Class 2 comprises ears with congenital stapes ankylosis in combination with a congenital anomaly of the ossicular chain. Class 3 comprises ears with congenital anomalies of the ossicular chain and at least a mobile stapes footplate. Class 4 comprises ears with aplasia or severe dysplasia of the oval window or round window.

Potter's syndrome: a temporal bone histopathological study

Histopathological findings in seven temporal bones from four infants diagnosed as Potter's syndrome are described. The infants were labelled as Potter's syndrome after autopsy confirmed bilateral renal agenesis. Extrarenal manifestations included pulmonary hypoplasia and facial anomalies. The middle ear volume in infants with Potter's syndrome remained unchanged with age resulting in a significantly higher percentage of residual middle ear mesenchyme in these infants as compared to normal infants. Dehiscence of the facial nerve was seen in all the temporal bones studied. One ear showed the presence of eosinophilic effusion in the endolymphatic sac, an underdeveloped malleus and a wide facial nerve canal. The inner ear structures showed no significant anomalies except for the absence of the organ of Corti in the basal turn of the cochlea in one of the ears.

Facial nerve monitoring in surgery for congenital auricular atresia

Surgery for congenital auricular atresia places the facial nerve at risk because of its potential aberrancy; iatrogenic facial paralysis is a well-known potential risk. Five cases of congenital auricular atresia are presented. All patients had intraoperative monitoring of the facial nerve. The facial nerve was found to be abnormally displaced, usually due to hypoplasia of the tympanic ring. Preoperative and postoperative facial nerve function was unchanged by surgery. Facial nerve monitoring is an important adjunct in congenital ear surgery because it allows for early and precise identification of the nerve in the absence of normal surgical landmarks and provides for continuous monitoring of the nerve.

[The combined esthetic and functional treatment of microtia]

In the treatment of unilateral microtia, most authors give precedence to external reconstruction, neglecting a middle ear surgery. On the other hand, in bilateral microtia more importance is given to the functional component which has to be dealt with before a child begins his school career in order to facilitate optimal harmonious psychophysical development. One author in particular has been attempting to solve the problem in its entirety, for more than 20 years. In the last years, thanks to the close collaboration with otologists, results which confirm the existing hypothesis have been obtained. This was possible because plastic reconstruction was done before the functional procedure and also because of improvement in surgical techniques of the latter. Thus it appears that collaboration between both specialists is basically mandatory. Authors tend to aim for complete aesthetic and functional solution in bilateral microtia as well. However in these cases, external reconstruction has to performed before a child begins his school cancer.

Congenital perilymphatic fistula and associated middle ear abnormalities

To specifically determine the frequency and type of middle ear abnormalities associated with perilymphatic fistula (PLF), a retrospective chart review was performed of 94 patients (117 ears) who underwent exploratory tympanotomy for PLF from 1980 to 1989. Of the 117 ears explored, 80 (68.4%) had a PLF, and in 65 (81.3%) of these ears, a middle ear malformation was associated with the PLF. Of these 65 ears in which a congenital middle ear abnormality was observed, a malformed stapes was the most common abnormality seen (39 ears, 60%), followed by a deformed round window (20 ears, 30.8%), a deformed incus (11 ears, 16.9%), and a deformed promontory (2 ears, 3%). Often these malformations coexisted amongst themselves or with inner ear abnormalities. Sixteen children (25 ears) had an inner ear malformation identified on computed tomography (CT); all of these children had a PLF found at the time of surgery. This study demonstrated that 86.3% of the ears found to have a PLF had a deformity of the middle ear, inner ear, or both. A malformation of the stapes, most frequently identified as a deformity of its superstructure (and presumably also the anterior footplate), was the most common congenital middle ear abnormality found to be associated with PLF in children.

Ear malformation and hearing loss in patients with Treacher Collins syndrome

Although the hearing loss of patients with Treacher Collins syndrome is well documented, few studies have reported jointly on their hearing loss and ear pathology. This paper reports on the hearing loss and computerized tomography (CT) assessments of ear malformations in a large pediatric series of patients with Treacher Collins. Of the 29 subjects assessed by the Craniofacial Program between 1986 and 1990, paired audiologic and complete CT assessments were available for 23 subjects. The external ear canal abnormalities were largely symmetric, either bilaterally stenotic or atretic. In most cases, the middle ear cavity was bilaterally hypoplastic and dysmorphic, and ossicles were symmetrically dysmorphic or missing. Inner ear structures were normal in all patients. The majority of patients had a unilateral or bilateral moderate or greater degree of hearing loss and almost half had an asymmetric hearing loss. The hearing loss of all subjects was conductive, except for three whose loss was bilateral mixed. Two types of bilaterally symmetric hearing loss configurations, flat and reverse sloping, were noted. Conductive hearing loss in patients with Treacher Collins is mainly attributable to their middle ear malformations, which are similar for those of patients with malformed or missing ossicles.

The clinical features of spondyloepiphyseal dysplasia congenita resulting from the substitution of glycine 997 by serine in the alpha 1(II) chain of type II collagen

The features of a child with spondyloepiphyseal dysplasia congenita resulting from a mutation in one COL2A1 allele were studied. The child was heterozygous for a G to A transition in exon 48 that resulted in the substitution of glycine 997 by serine in the triple helical domain of alpha 1(II) chains of type II collagen. Her longitudinal growth was close to the mean growth curve for children with this chondrodysplasia. Expression of the mutation by chondrocytes would account for the abnormal growth and development of the bones of the limbs and spine. Early expression of the mutation by epithelial cells and later expression by chondrocytes of the developing craniofacial structures would also account for her complex pattern of craniofacial anomalies. The findings in this study confirm that mutations of exon 48 of the COL2A1 gene, that alter the normal Gly-X-Y triplet structure of the corresponding region of alpha 1(II) chains of type II collagen, produce the spondyloepiphyseal dysplasia congenita phenotype.

Patulous eustachian tube identification using tympanometry

The patulous, or nonclosing, eustachian tube is believed to affect as many as 7 percent of all adults, causing physical and psychological difficulties. This paper provides a brief review of the literature regarding the patulous eustachian tube (PET), its symptoms, precipitating conditions, incidence, diagnosis, and current medical management. Several case studies are also presented to illustrate the use of tympanometry in PET identification.

Office management of the draining ear

Otorrhea is one of the most common ear complaints and is usually responsive to office treatment. The various causes of this condition are discussed and appropriate treatment options are detailed in this article. Topics include otorrhea from typanostomy tubes, chronic otitis media, external otitis and otorrhea, otorrhea after trauma, congenital anomalies and otorrhea, and neoplastic otorrhea.

Recurrent meningitis and a congenital perilymph fistula

In any child with recurrent meningitis, the presence of a congenital perilymph fistula must be entertained. All of the patients must have an audiologic assessment, and if a sensorineural loss is demonstrated, CT of the temporal bones should be performed. CT is excellent in identifying malformations within the temporal bones, fistulous tracts, soft tissue densities in the middle ear, and defects in the tegmen tympani. Although MRI may provide superior discrimination of the audiovestibular and facial nerves and cerebellopontine angle, presently it does not offer any distinct advantages over CT in evaluation of the inner ear. When a fistula is suspected, an exploratory tympanotomy is recommended, and any CSF leak is sealed with muscle.

[Indications and surgical treatment of large middle ear abnormality]

Children with atresia of the external auditory canal should undergo hearing assessment and fitting of a bone conduction hearing aid as early as possible to allow speech to develop normally. Surgery is done between 5 and 6 years of age, guided by high-resolution computed tomography, which provides a more precise diagnosis based on the abnormalities seen. The temporomandibular joint lies more posteriorly than normal due to aplasia or hypoplasia of the tympanic bone, so that the middle ear must be approached through the mastoid, resulting in a less favourable coupling to the middle ear structures. In unfavourable cases bone anchored hearing aids, creation of a meatus for fitting a hearing aid or a bone conduction hearing aid must be considered.

CT evaluation of malformed external and middle ear and its surgical correlation

This study evaluated the diagnostic value of high resolution CT (HRCT) for atresia of the external auditory meatus (EAM) and isolated middle ear malformation. CT scan of the temporal bone was done in 33 patients with such disorders and 5 patients with otosclerosis etc. were studied in the same way for comparison. Coronal HRCT clearly showed conditions of the atresia plate and malformation of the malleus, incus, abnormal course of facial canal and changes in the vestibular window. The axial HRCT is useful to demonstrate the articulations in between the malleus, incus, stapes and the cochlear window. All the HRCT findings were confirmed during operation. Axial and coronal HRCT for external and middle ear deformation is highly valuable for decision making and surgical planning.

The total reconstruction of the tympanic membrane by the "crowncork" technique

PURPOSE

The "crowncork tympanoplasty" is a technique for the total reconstruction of the tympanic membrane. It is recommended in cases of ear malformation, blunting phenomena, and total deficiency of the membrane caused by chronic otitis media.

PATIENTS AND METHODS

The records of 12 patients undergoing "crowncork tympanoplasty" were reviewed. This includes 5 patients who were operated on because of middle ear malformation, 6 cases with a blunting phenomena following prior tympanoplasty, and 1 patient with chronic otitis media.

RESULTS

In each case an intact tympanic membrane was achieved. The air bone was reduced to 17, 19, 16, and 11 dB in the frequency 500, 1,000, 2,000, and 4,000 Hz.

CONCLUSION

The use of cartilage for tympanoplasty has been useful despite the comparatively worse vibration characteristics of the rigid material. Total reconstruction of selected problem cases using this "crowncork technique" has resulted in good healing with favorable hearing results and should be incorporated into the routine of the skilled otosurgeon.

Congenital anomalies limited to the middle ear

Congenital anomalies of the middle ear are occasionally encountered during surgery for conductive hearing loss and are unexpected in patients with no other deformities. We reviewed 12 such patients operated on at The New York Eye and Ear Infirmary from 1985 through 1989. Nine of the patients (75%) had unilateral conductive hearing loss whereas three (25%) had bilateral symptoms. One had bilateral congenital middle ear anomalies. Three patients (25%) had anomalies limited to the malleus and scutum. Five patients (47%) had agenesis of the oval window. After reconstructive surgery, 72% of patients had hearing improvement ranging from 13 to 38 dB. The etiology of these anomalies is discussed and their evaluation and surgical indications are presented.

A case of congenital ossicular malformation with mild auricular deformity: embryological and surgical considerations

A case of bilateral congenital conductive deafness with mild auricular deformity is presented, and the anomalous structure deformity of the ossicles was multi-focal in this case, and a previous report indicates that ossicular malformation in the ear with congenital conductive deafness is multi-focal when the external ear is only slightly deformed. Bilateral ossicular reconstruction with replacement of the stapes yielded satisfactory results.

[Stapes surgery in otosclerosis and small middle ear abnormality]

Stapes surgery in otosclerosis (first and revision operation) and in minor middle ear malformation follows the same principles, but the surgical problems are rather different. When analyzing three groups of patients, which had been operated on the same technique, we could show that the risks of the operation in malformation and revision surgery are not greater than they are in primary otosclerosis surgery. The audiologic results are more satisfying in the latter; malformation surgery and revision surgery have almost the same results which are lying somewhat below those of primary otosclerosis surgery. In the hands of an experienced surgeon, who is able to adopt his surgical technique at the individual situation, stapes surgery is nearly without risk in all these indications; an improvement of the air-conducting level of 18-23 dB can be expected and a social hearing above 35 dB can be provided in 83% of otosclerosis patients, in 79% of malformation patients and in 57% of revision patients.

Middle-ear transmission: acoustic versus ossicular coupling in cat and human

Otologic surgeons consider the action of sound pressure on the cochlear windows to be of major importance in certain cases of middle-ear pathology, yet previously published network models of mammalian middle ears do not include such a mechanism. A unified middle-ear model is developed in which it is assumed that the difference of acoustic pressures acting on the windows adds to the ossicular-chain pressure to produce cochlear input. From a network model of the cat middle-ear cavities we estimate the contributions of pressures on the cochlear windows for both normal and abnormal cat ears. For the human ear we use the model of Kringlebotn (1988) and measurements of Békésy (1947). We determine that the pressure difference across the cochlear windows is negligibly small in normal cat and human ears. Thus, it is a reasonable approximation to ignore this mechanism in normal ears. For ears with a drastically altered tympanic membrane and/or ossicular chain, acoustic coupling to the cochlear windows can--to a considerable extent--explain residual hearing in human. The model predicts hearing levels for type IV tympanoplastic reconstructions that agree with the best results obtained surgically.

First branchial cleft anomalies involving the tympanic membrane and middle ear

First branchial cleft anomalies may involve the tympanic membrane or middle ear. A complete otologic examination must be performed in any patient with a suspected first branchial cleft anomaly. A surgeon treating such a defect must be prepared to perform both the excision of the lesion and reconstructive otologic surgery.

Anatomic variations and anomalies involving the facial canal

Congenital bony dehiscences in the facial canal result from incomplete closure during development and are observed in approximately 55% of temporal bones. Anomalies involving the facial canal frequently are encountered in malformations of the temporal bone. These anomalies include aberrations of the course of one or all of the segments of the canal; abnormal relation to the oval and round window; bifurcations and trifurcations of the nerve; and associations with dysplasia of the stapes, oval window, external ear canal, and auricle. Rarely, the facial nerve may be hypoplastic or totally absent. Two abnormal vessels occasionally may accompany the facial nerve in the Fallopian canal: a persistent stapedial artery and a persistent lateral capital vein.