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At least 217 records · Page 12Linked to original sources
PubMed1997

Computed tomography data based rapid prototyping model of the temporal bone before cochlear implant surgery.

Rapid prototyping (RP) technique allows automatic fabrication of 3D model parts. This method was applied to make a temporal bone model before cochlear implant surgery. A helical CT scan is used to acquire high resolution data from the middle and the inner ear of the patient. From the scanning data bone structures and soft tissues can be separated because their different grayscale pixel values. By using a guided image processing tool the desired parts of the anatomy can be extracted and 3D data created. The segmented data are processed to the form suitable for creating a high accuracy RP model. The RP model is made in the stereolithography (SLA) process by means of a computer guided HeCd laser beam inducing polymerisation of acrylic solution as it passes layer by layer over the surface of the polymer solution. In this prototype model the anatomy of the temporal bone can be clearly visualised, including, e.g., mastoid cells, tympanic cavity, bony canal of facial nerve, and round and oval windows. The inner ear spaces including vestibule, semicircular canals and cochlear turn are also shaped. The transparent acrylic material allows bonelike mechanical handling. The RP model can be dissected and used in individual surgical planning and simulation prior to cochlear implantation.

Cochlear Implants↗
PubMed1978

Cerebrospinal otorrhea and recurring meningitis: report of three cases.

Recurrent attacks of meningitis occurring independent of a systemic bacterial infection should be considered as a cerebrospinal leak either otorrhea or rhinorrhea. Three cases each with a different cause were diagnosed chiefly on the basis of the history and a bulging noninflammatory eardrum. Subsequent use of fluorescein intrathecally not only helped to confirm the diagnosis but was very useful at surgery in locating the leak in the dura of the oval window of the ear. Many materials have been used but autogenous temporal fascia or fascia lata seemed to be most effective in these cases. The sandwiching of the dura between two pieces of fascia is not only realistic but was found to be very effective. One piece of fascia between the arachnoid and dura and another between the dura and bone give a tight seal.

Adult↗
PubMed1991

CSF otorrhea complicating osteoradionecrosis of the temporal bone.

Osteoradionecrosis of the temporal bone is a well-recognized complication of radiotherapy for head and neck malignancy. There are two mechanisms by which this condition can produce damage to nearby structures and even result in death. Osteoradionecrosis may (1) predispose the patient to an aggressive or chronic infectious process, or (2) cause destruction of tissue by direct necrosis. A review of the literature failed to disclose a cause of CSF otorrhea complicating osteoradionecrosis of the temporal bone. This paper describes a case of skull base osteoradionecrosis, including necrosis of the tympanic membrane, associated with CSF otorrhea. Successful control of this complication was achieved using a translabyrinthine approach to locate the fistula, which originated from the internal auditory canal and was discharging through the middle ear via the oval window. The leak was sealed, the resultant mastoid cavity was obliterated by rotation of a temporalis muscle flap, and the external auditory canal was closed by the Fisch technique.

Adult↗
PubMed1993

[Etiology and fate of true perilymphatic fistulae].

Perilymphatic fistulas of the round or oval window in a traumatic context or following middle ear surgery or pathology, are reported. Rapid surgical exploration secures the best clinical results.

Diagnosis, Differential↗
PubMed1990

Inner ear decompression sickness combined with a fistula of the round window. Case report.

Inner ear barotrauma with rupture of the round or oval window secondary to diving and decompression sickness (DCS) of the inner ear can be a difficult diagnosis to differentiate. The dive profile or associated elements of DCS will often confirm the diagnosis. Occasionally, diagnosis is made during recompression or during operation. The differential diagnosis is important, since immediate recompression is indicated for inner ear DCS, while it is contraindicated in cases of inner ear barotrauma. We have found no cases reported in the world literature in which both diseases have been diagnosed and proven simultaneously. We present a case of a diver who developed DCS with inner ear manifestations complicated by a round window fistula. Treatment and clinical outcome are discussed along with a brief review of the suspected cause.

Audiometry↗
PubMed1999

The anatomy of the killer whale middle ear (Orcinus orca).

The paper first reviews our present understanding of the functional morphology of the odontocete (toothed whale) ear. The tympano-periotic complex forming the ear region consists of a ventral bowl-shaped tympanic bone in direct contact with the surrounding soft tissues and the incident sound, and a dorsal periotic bone containing the inner ear. Apparently sound brings the tympanic bone, and especially its thin tympanic plate, into vibration. The ossicles in the air-filled middle ear cavity form a bridge from the tympanic plate to the periotic bone connecting the vibrating plate to the oval window and the inner ear. Our computer tomography (CT) sections and camera lucida drawings reveal two hitherto unknown features of the odontocete ear, both of them of potential relevance to sound reception and impedance matching. (1) It is well known that, in addition to the ossicular chain, two other bone structures connect the tympanic to the periotic bone. We show that the most delicate parts of these extra-ossicular connections consist of thin and folded bony sheets which apparently allow compliance in the tympano-periotic bone contacts and enable plate vibration in relation to the periotic bone. (2) The round head of the malleus, in combination with a fitting round depression on the periotic side, seems to form a joint. We propose that this (hypothetical) joint, together with the adjacent structures, forms a lever producing an amplification of the vibration velocity at the level of the oval window.

Animals↗
PubMedDate not supplied

Congenital malformations of the ear. Analysis of 94 operations.

The 94 operations analyzed were performed on 80 ears in 73 patients with congenital malformation of the ear. Operative findings included 13 patients with a congenital absence of the oval window, 5 patients with vascular anomaly of the middle ear, and 6 patients with congenital cholesteatoma. Six of 13 patients with congenital absence of the oval window had a labyrinthotomy performed to create a new opening into the vestibule. The method of surgical repair in atresia was a canalplasty with fascia graft overlay for the substitute tympanic membrane. A Silastic button was placed over the substitute tympanic membrane to lessen blunting and to anchor the center-hole skin graft in place. A modified face lift procedure was done if necessary to align the enternal ear with the new ear canal. At present no ear canals are stenosed and no ears are actively discharging. One patient sustained a temporary facial paralysis. The hearing results are discussed.

Ear↗
PubMed2005

Vestibulotomy above a severely displaced facial nerve.

CONCLUSIONS: Vestibulotomy above a severely displaced facial nerve represents a new surgical approach to achieve serviceable hearing. The lack of facial nerve injury and the potential for hearing restoration make this procedure feasible in patients who would otherwise be marginal or poor surgical candidates. OBJECTIVE: To investigate the feasibility of vestibulotomy above a severely displaced facial nerve. MATERIAL AND METHODS: Eight patients with severe congenital conductive hearing loss underwent vestibulotomy above a severely displaced facial nerve and hearing reconstruction between January 2000 and January 2002. All patients had congenital middle ear deformities. The facial nerves overhung and concealed the oval window niche or lay inferior to the oval window. The facial nerves were transposed in order to reach the oval window niche in four of eight cases. RESULTS: Hearing gain was 15 dB in 2 ears, 16-25 dB in 3 and > 26 dB in 3. There were no cases of postoperative facial paresis.

Adolescent↗
PubMed1978

[Congenital cysts of the oval window (author's transl)].

A 3 year old child with recurrent pneumococcal meningitis and a congenital cyst of the oval window is presented. An aqueous middle ear effusion was found and scintigraphy demonstrated a middle ear CSF leak. Surgical exploration revealed a cyst originating from the stapes footplate. The origin of this malformation is discussed and its possible presence in recurrent mengitis is stressed.

Child, Preschool↗
PubMedDate not supplied

Stapedectomy. Postmortem findings.

Histological studies were made of 16 temporal bones of 13 subjects who had stapedectomy operations. Photographs of the prostheses in situ are a special feature of the studies. It was found that prostheses which overlap the margins of the oval window cause incomplete closure of the air-bone gaps. Fibrous adhesions were a common consequence of trauma to the mucous membrane of the middle ear. Gelfoam implantation promotes the formation of thin oval window membranes which tend to bulge out of the oval window. Most incudes show small areas of cortical bone resorption. In at least half the cases the surgical technique of stapedectomy, as judged from these studies, was less than ideal. Surgeons who perform stapedectomy should be cognizant of the relevant surgical pathology and adopt methods which will optimize functional results and minimize complications.

Adult↗
PubMed1997

Hearing results in otosclerosis surgery after partial stapedectomy, total stapedectomy and stapedotomy.

Hearing results in a consecutive series of 407 patients with otosclerosis undergoing primary stapes surgery were analysed (437 operated ears). Partial stapedectomy was performed in 70 ears (16%), total stapedectomy in 205 ears (47%), in both groups using the House steel wire prosthesis on fascia in the oval window. The remaining 162 ears (37%) underwent stapedotomy using the Fisch 0.4 mm teflon-platinum piston. No case of cochlear loss (> 15 dB) occurred in the total series. The comparison between the three groups one year postoperatively showed that the air-bone gap was smaller for partial and total stapedectomy for all frequencies except 4 kHz. The air-bone gap was calculated as the difference between the preoperative bone conduction and the postoperative air conduction thresholds. Partial and total stapedectomy also showed larger improvements of bone conduction thresholds compared with stapedotomy for all frequencies but 4 kHz. At the 3-year follow-up, the hearing gain for all frequencies (250-8000 Hz) was larger for partial and total stapedectomy. Yet, when comparing the decline of hearing from 1 to 3 year postoperatively, the hearing gain achieved with partial and total stapedectomy seemed to deteriorate at a higher rate, which was considered to be caused by impaired sensorineural function. Our results show that in the short-term perspective partial or total stapedectomy can still compete for better hearing results even at higher frequencies, but stapedotomy seems to yield more stable hearing results over time and should therefore be considered as the method of choice.

Adolescent↗
PubMed1991

Sodium hyaluronate application to the open inner ear: an ultrastructural investigation.

The effect of 1 percent sodium hyaluronate on the open inner ear was tested in a series of guinea pigs. By removing the stapes footplate from its original position in the oval window, direct access to the vestibule from the inner ear was achieved. The oval window niche was filled with either 1 percent sodium hyaluronate or 0.9 percent NaCl. The animals were examined with regard to both the cochlear and the vestibular partitions of the inner ear. No marked differences could be seen between the test group and the controls. Thus the organ of Corti as well as the vestibular end organs presented with normal anatomy throughout. Neither did the behavior of the animals in any way indicate any signs of inner ear disturbance. It is concluded that 1 percent sodium hyaluronate does not seem to harm the inner ear sensory structures even in the case of direct access to the vestibule as can be foreseen if the compound is used during stapes surgery.

Animals↗
PubMed1992

Treatment and management of perilymphatic fistula: a New Hampshire experience.

From August of 1975 to June of 1990 the author managed 45 cases of spontaneously occurring perilymphatic fistula. Twenty-nine of the 45 cases were reported in 1988. In the series there were eight patients with bilateral involvement, seven with involvement of both oval and round window in the same ear, and seven with fistulas believed to be of congenital origin. Seventeen patients (38%) required revision surgery. Occasionally adjunct modalities (endolymphatic shunt, labyrinthectomy, blocking a cochlear aqueduct, and streptomycin ablation) were used for symptom control. Diagnosis, treatment, and management of these patients is discussed.

Adolescent↗
PubMed1983

Perilymph fistulas in infants and children.

During the years 1975 through 1981 we performed exploratory tympanotomies on 33 infants and children (44 ears) to verify the presumptive diagnosis of perilymph fistula (PLF). A PLF was identified at the round window, oval window, or both in 29 (66%) of the 44 ears explored. After surgery hearing was unchanged in 86%, improved in 5%, and worsened in 9% of the ears in which PLFs had been observed. Complaints of vertigo subsided in all children in whom a PLF was repaired. Preoperative factors determined to be highly suggestive of the presence of a PLF included the following: sudden onset of sensorineural hearing loss (SNHL), congenital deformities of the head, and abnormal findings on tomograms of the temporal bones, especially Mondini-like inner ear dysplasias. Middle ear abnormalities (primarily congenital) were observed in 20 of the 44 ears. Abnormal results of preoperative vestibular function studies, which included a fistula test, and sex were not consistently found to be associated with an observed PLF at tympanotomy.

Adolescent↗
PubMedDate not supplied

[Inner ear injuries in breath-holding divers].

Five breath-hold divers with inner ear barotrauma due to the diving to 10 meters of depth have been treated at the Department of Otorhinolaryngology, Pula Medical Centre during 1990. Because of eustachian tube dysfunction, a negative middle ear pressure is transmitted into the inner ear over the round and oval window causing a lower hydrostatic pressure of the inner ear fluids and consequent delay in microcirculation of the inner auditory artery. Together with a hypoxia in apnea the oxygen demand is increased and the inner ear neuroepithelium damage is more severe. All treated divers had irreversible sensorineural hearing loss of the attacked ear on frequency range higher than 2000 Hz to 70-80 dB.

Adult↗
PubMed1996

Normal evoked otoacoustic emissions with a profound hearing loss due to a juvenile pilocytic astrocytoma.

An interesting case is reported of an 11-year-old girl who experienced a sudden, profound right-sided hearing loss at the age of 5 years after hearing a "pop" and the sound of rushing water in her right ear. At that time the patient was thought to have Mondini's deformity, and a perilymphatic fistula of the oval window in the right ear. Six years later she was diagnosed with a juvenile pilocytic astrocytoma of the pons with an exophytic component extending into the cerebellopontine angle. Of particular interest in this case is the presence of evoked otoacoustic emissions in the right ear with a profound neural hearing loss. The presence of transient evoked and distortion product otoacoustic emissions confirmed normal sensory outer hair cell function and an intact peripheral auditory system in a clinically deaf ear, thus indicating hearing loss due to a neural component instead of a sensory component, which was previously assumed.

Acoustic Stimulation↗
PubMed1988

Temporal bone histopathology over 15 years post-stapedectomy.

Twenty-three temporal bones from 14 patients who had undergone stapedectomy more than 15 years (the longest, 28 years) preceding death were studied microscopically. Although a foreign body reaction was still found in the ears with a polyethylene prosthesis, it was seldom found in the ears with a wire or Teflon prosthesis. As the resorption of the incus was not severe, it was suggested that it occurred in the early stage of post-stapedectomy and the structural condition of the incus and prosthesis was stable for a long time (even over 15 years) after stapedectomy. In all ears, the grafts on the oval window continued to be the adequate barrier between the middle ear and inner ear. Even though cupping of the graft membrane was frequently found, it seemed not to disturb the sound conduction. The depth of the cupping was correlated somewhat with the thickness of the graft.

Aged↗