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Biomedical subjects

U Fisch

Publications and source records attributed to U Fisch.

At least 19 recordsLinked to original sources
PubMed1995

Clinical pathophysiology of vestibular neurectomy.

This study attempts to characterize the residual vestibular function remaining after incomplete supralabyrinthine vestibular neurectomy performed for disabling vertigo. Patients with bilateral vestibular neurectomy had preserved horizontal vestibulo-ocular reflexes in response to high angular accelerations with gain enhancement over time. A torsional down-beating spontaneous nystagmus and an important tilt of the subjective vertical were observed when the remaining eighth nerve was sectioned after homolateral incomplete supralabyrinthine vestibular neurectomy. These findings suggest that a reorganization of vestibular reflexes may occur after incomplete supralabyrinthine vestibular neurectomy if afferents of the inferior vestibular branch are partially spared. The vestibular function after incomplete supralabyrinthine vestibular neurectomy does not affect the postoperative control of vertiginous attacks and may have positive effects in case of deterioration of the contralateral inner ear.

Adult↗
PubMed1995

Are papillary adenomas endolymphatic sac tumors?

Papillary adenomas of the temporal bone have been considered as originating from the endolymphatic sac. The radiologic, surgical, and pathologic findings in a patient suffering from von Hippel-Lindau disease with bilateral papillary adenomas of the temporal bone cast some doubt on this site of origin. Radiologically, the center of tumor growth was at the top of the jugular bulb. Intraoperatively, the tumor was found to have reached the lateral wall of the endolymphatic sac, but the lumen was tumor-free. Both ciliated and nonciliated tumor cells were found in the resected tumor, resembling the ultrastructure of normal epithelial lining in the human mastoid. A strong positive immunohistochemical reaction for keratin and negative reactions for vimentin, glial fibrillary acidic protein, and S-100 protein in the tumor tissue of this patient are typical for middle ear mucosa. Therefore, the described papillary adenoma originated from the mucosa of the pneumatic spaces surrounding the jugular bulb, and the theory that the endolymphatic sac is the origin of all papillary-cystic tumors (adenocarcinomas) should be questioned.

Adenoma↗
PubMed1994

Management of petrous bone fractures in children: analysis of 127 cases.

Petrous bone fractures (PBF) in children are relatively frequent. They are mostly diagnosed after collisions and falls. The complications typically associated with PBF were different types of hearing disorders in 69.1% of the patients who had audiometry, liquorrhea in 16.5%, palsy of cranial nerves in 10.8% (facial nerve palsy in 9.4%), bacterial meningitis, stenosis of the external ear canal, and posttraumatic cholesteatoma in 0.7% of the fractures each. Most complications were transient; 8.6% of the patients underwent surgery because of PBF-related complications and 9.4% suffered from severe, irreversible sequelae. Management of PBF in children requires an interdisciplinary approach between pediatric surgeons and pediatric ear, nose, and throat (ENT) specialists. It basically includes daily examination for cranial nerve palsy, liquorrhea, and meningitis during hospitalization as well as routine audiometric examination and antibiotic prophylaxis. Routine vaccination against Streptococcus pneumoniae as a new standard procedure and subtotal petrosectomy after transverse fracture as a new surgical modality are strongly recommended in order to lower the incidence of posttraumatic meningitis. Severe complications such as persistent hearing loss, persistent liquorrhea, cranial nerve palsy, and posttraumatic meningitis require aggressive diagnostic and therapeutic measures in order to minimize further morbidity and irreversible deficits.

Adolescent↗
PubMed1994

Total reconstruction of the ossicular chain.

The footplate only situation remains the greatest challenge of ossicular reconstruction. This article discusses the long term results obtained with a new type of columella, the Spandrel, which combines the rigidity necessary for sound transmission with the flexibility required to comply with the dynamic movements of the neotympanum.

Audiometry, Pure-Tone↗
PubMed1994

[Pleomorphic adenoma of the parotid gland. Results of surgical treatment].

Twenty years experience of lateral parotidectomy as suspical treatment for pleomorphic adenoma are reviewed. All cases were managed at the ORL Clinic of the University of Zürich. 167 patients were followed for the frequency of possible recurrent tumors. Three patients (3/123) operated primarily developed a recurrences. Recurrences appeared after an average of 10 years, ranging from 1-30 years. The follow-up time varied from 1 to 21 years (average, 8 years). 39% (13 of 33) of the patients, who were re-operated for a recurrent tumor, developed another recurrence. The second recurrence appeared after an average of 10 years, ranging from 1-22 years. A persistent partial paresis of the facial nerve was found in 1% of the patients operated primarily and in 9% of the patients operated more than once. No paralysis was seen. We now choose "en-bloc" resections of pleomorphic adenomas without intra-operative opening of the tumor capsule as the treatment of choice. This treatment was possible in 83% of all cases, using a lateral parotidectomy. If tumor extends into the medial parotid lobe, total parotidectomy is required.

Adenoma, Pleomorphic↗
PubMed1993

Bilateral vestibular neurectomy for treatment of vertigo.

The effects of bilateral vestibular neurectomy on equilibrium and vestibular function were clinically evaluated in two patients more than 15 years after surgery. Both patients had bilateral Menière's disease and their vertiginous spells were permanently resolved after the second vestibular neurectomy. Symptoms of disequilibrium were absent in one patient and mild in the other. Reflexive horizontal eye movements on whole body rotation in darkness were absent on low angular accelerations (2 degrees/s2), but could be elicited with angular accelerations of 20 degrees/s2 or higher. Extravestibular cues generating these eye movements seemed to be unlikely because a "control" patient with complete peripheral vestibular ablation after bilateral subtotal petrosectomy did not present reflexive eye movements under the same stimulus paradigms. An incomplete deafferentiation of the vestibular end organ (rather than regeneration of vestibular nerve fibers) and a consecutive impairment of the central velocity storage mechanism may explain the good functional outcome in our bilateral neurectomized patients.

Activities of Daily Living↗
PubMed1993

The transotic approach in acoustic neuroma surgery.

A consecutive series of 147 transotic operations for the removal of acoustic neuroma is presented. The advantages of this approach over the conventional translabyrinthine technique are several, including 1) a wider surgical access with a circumferential exposure of the internal acoustic meatus and the porus acousticus; 2) the direct visualization and access to the anterior cerebellopontine angle where the facial nerve is usually tenuous and most vulnerable; and 3) the permanent closure of the ear canal and eustachian tube with complete obliteration of the surgical cavity, minimizing cerebrospinal fluid leaks. These advantages have translated into improved surgical outcomes. In our series of 147 patients spanning 11 years, total tumor extirpation was achieved in all patients, with one mortality, three CSF leaks, and one meningitis. The facial nerve was anatomically preserved in 95% of the cases. This approach is capable of attaining the widest, and the most direct access to the cerebellopontine angle without cerebellar retraction.

Cerebellopontine Angle↗
PubMed1992

Facial nerve management in temporal bone hemangiomas.

Eight patients with intratemporal hemangiomas involving the facial nerve are reported to present their symptoms, pathology, surgical management, and results. These unusual tumors have a predilection to involve the facial nerve, usually at the geniculate ganglion, internal auditory canal, or middle ear. Patients presented with facial palsy that was sudden, gradual in onset, recurrent, or associated with hemifacial spasm. Symptoms often progressed for years before the diagnosis was made. In two cases the tumor caused bony remodeling with an expansile honeycombed appearance, but no neoplastic production of bone. The facial nerve was comprised either by tumor compression or nerve invasion, as seen in two of our patients. Complete removal of the tumor and rehabilitation of the facial nerve function was attained in each case. Because of the destructive nature of these benign tumors, intratemporal facial nerve grafting was required in five of the eight cases. Results of facial nerve repair were good except in cases of long-standing facial dysfunction.

Adolescent↗
PubMed1992

Transotic approach to the cerebellopontine angle.

The transotic approach to the cerebellopontine angle for resection of tumors invading the internal auditory canal provides superior illumination and exposure for optimal preservation of facial nerve function. Separation of facial nerve from tumor is enhanced with an anterior exposure that allows visualization of the intracranial segment of the nerve before tumor removal without significantly increasing total operative time. Facial nerve grafting or hypoglossal-facial anastomosis may be incorporated into the procedure at the time of tumor resection using the transotic approach. When combined with a musculofascial patch secured to the dural defect, the initial subtotal petrosectomy with eustachian tube and middle ear cleft obliteration generally avoids the complication of an immediate or delayed postoperative cerebrospinal fluid leak. The transotic approach is indicated for tumors up to 2.5 cm in size that are not adherent to the brain stem.

Cerebellopontine Angle↗
PubMed1991

Utricle, saccule, and cochlear duct in relation to stapedotomy. A histologic human temporal bone study.

This study was performed to determine the area in which and the circumstances under which stapedotomy can be relatively safely performed. Measurements were made from central areas of the medial surface of the stapedial footplate to the utricle, the saccule, and the cochlear duct in 10 normal and 11 otosclerotic temporal bones. The mean distances to the utricle ranged from 1.9 to 2.4 mm, and those to the saccule from 1.7 to 2.1 mm. The minimal distance to the utricle was measured from the posterior (0.58 mm) and superior (0.62 mm) borders of the stapedial footplate. The minimal distances to the saccule were from the anterior (0.76, 0.86, and 1.00 mm) border of the stapedial footplate. All other measurements were of more than 1 mm. The shortest distance between the cochlear duct and the inferior border of the footplate was 0.2 mm. Statistical analysis has shown no significant differences for the mean values obtained in normal and otosclerotic temporal bones. Fathoming of the vestibule below the central and inferior thirds of the footplate surface has shown that there is no likely danger to the vestibular end organs or cochlear duct if manipulations are carried out no deeper than 1 mm below the surface. The safest place for a stapedotomy opening is in the central and inferior-central thirds of the footplate. A stapedotomy piston of 0.4 mm in diameter can be introduced relatively safely to a depth of 0.5 mm in the vestibule over the entire surface of the stapedial footplate.

Aged↗
PubMed1991

New aspects of facial nerve pathology in temporal bone fractures.

Electron microscopic examination of intratemporal facial nerve segments removed from 12 patients with persisting facial paralysis following temporal bone fractures revealed that traumatic injury at the geniculum induces retrograde degeneration through the labyrinthine and distal meatal segments of the facial nerve. Fibrosis may occur in the traumatized labyrinthine segment and block regenerating motor fibers. The surgical treatment of traumatic facial nerve injuries should be aimed to avoid or eliminate fibrosis within the labyrinthine segment of the Fallopian canal.

Biopsy↗
PubMed1991

The infratemporal fossa approach for adenoid cystic carcinoma of the skull base and nasopharynx.

The infratemporal fossa approach to the skull base is an established method of treating neoplasms of this region. The type C variation has proved an effective means of removing adenoid cystic carcinoma invading the infratemporal fossa and skull base from the nasopharynx. A classification of these tumors is proposed, the surgical technique is described, and the results are given in this article.

Adult↗
PubMed1991

Facial nerve grafting.

The techniques of facial nerve grafting have undergone several adjustments and refinements within the last 20 years. Those techniques that have stood the test of time are discussed, and new approaches to facial nerve grafting in the temporal bone are explored.

Facial Nerve↗
PubMed1991

Radical mastoido-epitympanectomy with tympanoplasty and partial obliteration: a new surgical procedure?

The modern concept of an open cavity is to combine a safe with a dry, self cleansing ear. The prerequisites to achieve this goal are: the radical exenteration of the mastoid, antrum and epitympanum, the maximal reduction of the volume of the cavity by extensive lateral removal of bone and the adequate shaping of the cavity walls by obliteration of the bone pockets. To perform correctly a radical mastoido-epitympanectomy with tympanoplasty and partial obliteration is difficult and requires a perfect anatomical knowledge of the deepest regions of the temporal bone, particularly of the supralabyrinthine space. Using the technique exposed in this article, 75 out of 79 ears (95% of our revision cases) achieved a dry and self cleansing cavity at three years follow-up.

Cholesteatoma↗
PubMed1991

Long-term results of treatment for children's cholesteatoma.

Fifty-seven of 98 children with cholesteatoma treated between 1976 and 1985 were available for long-term follow-up. The clinical records of the 57 children were analyzed retrospectively. The purpose of this study was to compare the incidence of recurrent and/or residual cholesteatoma, postoperative otorrhea, and hearing results between two groups of patients. One group (n = 40) of children was treated with a radical mastoidoepitympanectomy (RMET) and the other group (n = 17) was treated with intact canal wall tympanoplasty/mastoidectomy (ICWT). Residual cholesteatomas were twice as frequent (17% versus 7.5%) in the ICWT group while recurrent disease was the same. There was no difference in postoperative otorrhea between the two patient groups. Hearing results were equally good in the Type III and in the ICWT group with staged TORP. It is concluded that a Type III tympanoplasty is an excellent one-stage method of hearing reconstruction in patients with good eustachian tube function and an intact stapes and that a correctly performed RMET offers a safe trouble free alternative to ICWT. In selected patients with limited disease and a well pneumatized mastoid, ICWT is still used.

Child↗
PubMed1990

Intratemporal facial nerve anastomosis: a temporal bone study.

The temporal bone findings in a patient who suffered a transverse temporal bone fracture and subsequently underwent intratemporal facial nerve anastomosis are presented. The patient returned a year after surgery with otorrhea and partial return of facial function that was documented clinically, and by electromyograph 12 days before death. The temporal bone shows breakdown of the posterior external canal wall and infection of the surgical cavity. At the facial nerve anastomosis, there is a fibrosis and lack of myelination in the few regenerating nerve fibers. These results demonstrate a seldom-mentioned complication of the translabyrinthine approach, and suggest changes in the technique of facial nerve anastomosis to improve the results.

Adolescent↗
PubMed1990

Neural infiltration of glomus temporale tumors.

Biologic behavior of glomus temporale tumors in relation to cranial nerve infiltration remains unclear. An analysis of cranial nerve involvement in relation to tumor staging was undertaken in a series of 102 glomus temporale tumors. Frequent neural infiltration was noted to occur in large glomus tumors, and a grading system of infiltration with both pathologic and surgical relevance introduced.

Adolescent↗