Biomedical subjects

J Hartwein

Publications and source records attributed to J Hartwein.

At least 37 records · Page 2Linked to original sources

PubMed1992

[Follow-up of sound pressure level at the tympanic membrane at varying impedance of the tympanic membrane-ossicular system].

We investigated the influence of varying compliance of the tympanic membrane on the sound pressure level of the human ear canal using a model with adjustable compliance. Decrease of compliance augments the sound pressure close to the tympanic membrane due to the increase of reflected sound pressure. This augmentation occurs in a narrow frequency area near the maximum resonance frequency and reaches 6 dB (SPL). These experimental data correlate well with clinical investigations in patients with middle ear effusion before and after operation and in patients performing the Valsalva manoeuvre.

Acoustic Impedance Tests↗

PubMed1991

[Tensile strength of the stapes footplate. Pressure-induced inner ear damage in operated ears caused by TORP prostheses?].

In a recent textbook concerning ear surgery, it is recommended to put some connective tissue on the stapes footplate before introducing a TORP. This should avoid penetration of the shaft of the TORP into the inner ear. Experimental studies were performed to estimate the pressure needed for pushing a TORP through the footplate. We found those pressures to be much higher than those which might occur by increasing pressure in the external ear canal or decreasing pressure in the middle ear. This means that perforations of the footplate are not due to one big event of changing pressure, but rather by chronic irritations or foreign body reactions. Anyhow, we consider the protection of the footplate by a layer of connective tissue to be very useful.

Ear, Middle↗

PubMed1991

[Bifenestration--a hearing-improving operation in severe ear malformations].

Bifenestration as an operation for hearing improvement is described in a case of congenital absence of the oval and round window. Besides the classical fenestration of the horizontal semicircular duct, an artificial round window was performed in the middle ear. Due to the acoustic resonance of the mastoid cavity, the resulting conductive loss in the higher frequencies was only 20-30 dB.

Adult↗

PubMed1990

[Air temperature in the outer ear canal--experimental studies in relation to radical cavity surgery].

By means of special probes, air temperatures were determined in external auditory meatus and in "radical" mastoid cavities. Under normal conditions, there was no difference between the two groups, the temperature next to the drum head being in the same range as the body temperature. Exposure to simulated wind only lowered the temperature significantly in cases with very wide external meatus; e.g., after surgery. Suction--as is used in the daily practice of cleaning ears in the ENT surgery--caused a very abrupt decrease in temperature. In cases with open mastoid cavities, there was vertigo with nystagmus, due to the caloric vestibular stimulus. -Operative techniques such as the obliteration of such cavities or the reconstruction of the posterior wall of the meatus can considerably reduce this phenomenon.

Air Movements↗

PubMed1990

[Electron microscopy studies of the collagen fiber structure of the human tympanic membrane in an adhesive process].

In an EM study, the collagen fiber arrangement of the lamina propria in adhesive otitis media was investigated. Nine biopsies of the tympanic membrane were taken intraoperatively, and compared with two normal ones. The physiological specimens showed a regular arrangement of collagen fibrils and fibers, the typical network of the lamina propria. This confirmed results reported previously. In all adhesive otitis media samples the regular structure of the fiber arrangement was disturbed. Degenerative processes were to be found in the form of hyaline changes, with the network character of the fibers no longer in evidence. In one specimen a mass of microfibrils was observed, which was possibly a sign of reparative processes. The pathohistological findings in adhesive otitis media may be due to mechanical stresses (tubal function). Aside from that, they may also be caused by the biochemical influence of specific collagenases, which have been found by several authors in secretory otitis was well as in cholesteatoma.

Biopsy↗

PubMed1990

[Epithelial migration following surgical obliteration of radical cavities].

We investigated whether the self-cleansing mechanism of the normal ear can be restored in operatively reconstructed open cavities. Dots of Indian ink placed on the drumhead were followed for up to 10 weeks. The epithelium migrates outwards, acting as a self-cleansing mechanism. Partial obliteration of open cavities is recommended in the light of other factors (acoustic phenomena, temperature protection of the inner ear).

Carbon↗

PubMed1990

A technique for the reconstruction of the posterior canal wall and mastoid obliteration in radical cavity surgery.

The open technique in cholesteatoma surgery has, besides a higher security concerning the recurrence of disease, some disadvantages: lifelong care for the cavity, often discharging granulations, and vestibular vertigo due to the lack of labyrinthine protection. Most of the disadvantages can be avoided by the obliteration of the mastoid cavity, for which many different techniques have been described in literature. The authors recommend a new method: the reconstruction of the posterior canal wall using autograft conchal cartilage and the obliteration of the mastoid cavity with hydroxyapatite granulate. The technique can be used for the treatment of old cavities as well as for one-stage surgery. The results of 25 cases are reported. Due to the elevation of the tympanic membrane on a nearly physiologic level and suitable tympanoplastic procedures an air-bone gap of less than 30 dB can be reached in more than 70%.

Adolescent↗

PubMed1990

[Elongated styloid process as a cause of dysphagia].

An elongated styloid process or a calcified stylohyoid ligament may cause dysphagia or craniofacial and cervical pain. Palpation and radiography confirm the diagnosis provided that it is considered. The only effective treatment is surgery. Eleven patients undergoing surgery for elongated styloids or calcified ligaments are reported. In all cases the symptoms disappeared or were relieved. An evaluation of the external versus the transoral approach is presented. The authors recommend the external one, as it provides adequate anatomical exposure of the styloid process and its relationship to the structures of the parapharyngeal space.

Adult↗

PubMed1989

[High-frequency jet ventilation in emergency tracheal puncture].

A case of obstruction of the upper respiratory tract is reported, in which an intubation or insufflation by rigid tracheobronchoscopes was not possible. Due to the anatomical situation after multiple operations and irradiation, coniotomy could not be performed. Blind puncture of the trachea with subsequent High Frequency Jet Ventilation has proved successful as an emergency approach to maintain respiratory function.

Airway Obstruction↗

PubMed1989

[Initial experiences with the dentin-ossicle prosthesis].

The results of 73 implantations performed from 1.7.1986-30.6.1988 are reported in a first follow-up study. 82% reached an air-bone gap of less than 30 dB, 55% of less than 20 dB. In comparison with other materials recently reported the functional results are a little less favourable due to the high percentage of revision surgery in our patients. Only few complications had to be noticed: no single extrusion was observed, but in one case a nearly complete resorption of the DOP was seen. Two DOPs, removed by revision surgery, were examined histologically. Beside resorptive processes, bony changes as a sign of biointegration into the middle ear were found. On account of our first results, DOP seems very suitable for the reconstruction of a destroyed ossicular chain, especially in cases where the autologous ossicles are not available.

Adolescent↗

PubMed1989

[Arthur Schnitzler and laryngology].

It is not widely known that the famous Austrian writer Arthur Schnitzler (1862-1931) worked as a laryngologist in his youth. As a son of one of the most famous laryngologists of his time, Johann Schnitzler (1835-1893), he was a resident in the Laryngology Department of the Poli-clinic in Vienna from 1888 to 1893 and published several papers. He had contracts with leading specialists and was the brother-in-law of Markus Hajek (1861-1941), the "father of endonasal sinus surgery". He was never happy with his work as a doctor, and after his father's death he resigned from medicine. There are only few passages in his literary works that show the influence of his work as a laryngologist.

Austria↗

PubMed1989

[Personal experiences with audiometric detection of perilymph fistulas].

Rupture of the round window membrane is thought to be important in the pathogenesis of sudden hearing loss. In 1982 Fraser and Flood proposed an audiometric test to improve the indication for tympanoscopy which, in their experience, verified the diagnosis of perilymph fistulae in a high percentage of cases. Between 1 January 1986 and 30 June 1988 the above test was carried out on 74 patients at the ENT Department of the University of Hamburg. In 41 cases a tympanoscopy was performed. In 13 cases with a positive test result not a single perilymphatic fistula could be found intra-operatively, while in 3 cases of rupture the test was negative. In our experience this test is not helpful for the pre-operative assessment of tympanotomy in sudden hearing loss.

Audiometry↗

PubMed1988

[Differential diagnosis of parapharyngeal tumors--the vagus neurinoma].

Among the tumours of the head and neck, only a small percentage is located in the parapharyngeal space. These are divided into salivary gland, neurogenic and so-called miscellaneous tumours. Two cases of vagus neurinoma are reported, and the diagnostic and therapeutic aspects are discussed. The neoplasms usually grow to a large size before they are treated, because they grow slowly and the signs and symptoms are non-specific. A latero-cervical approach is recommended for extirpation for diagnostic purposes.

Aged↗

PubMed1988

[Topography of the round window and its significance for the surgical therapy of perilymph fistulas].

The clinical findings concerning the diagnosis of a rupture of the round window membrane vary widely. Therefore, microtopography of the round window was studied using 45 serially sectioned human temporal bones of the Wittmaack Collection, ENT Clinic, University of Hamburg. Our morphometrical data show a great variety in respect of the dimension of the round window membrane and the angle between the window membrane and the tympanic membrane. The extension and the microtopography of the promontory are as variable as the mucosal folds in the round window niche. It can be concluded that a direct view of the round window membrane is possible only in rare cases. Surgical manipulations to improve the view of the round window should be avoided because of the danger of an iatrogenic lesion of the inner ear.

Adolescent↗

PubMed1988

[Dentin ossicle prostheses (DOP)--a new concept in replacing the ear ossicles].

The variety of materials used for replacement of the ossicles is proof enough that no single material can satisfy all criteria: availability, mouldability, stability and biocompatibility. The trouble-free availability as well as the excellent mouldability enable the development of a principle of preparation of ossicular replacement prosthesis from homologous dentine. The moulding of the dentine ossicular prosthesis is simple and can be performed with an equipment available at any otologic department.

Bioprosthesis↗

PubMed1988

[Personal experiences with tympanoscopy in sudden deafness].

The rupture of the round window membrane with consecutive perilymph fistula has gained in importance in the discussion of the pathogenesis of sudden hearing loss. In a retrospective study, the results of 23 tympanoscopies performed at the ENT Department of the University of Hamburg are reported. Two confirmed perilymph fistulas were seen, whereas in three cases they could not be excluded. After obliteration of the window niches with connective tissue an improvement of the hearing loss was seen in 9 cases. In comparison with our intraoperative findings, the number of perilymphatic fistulas mentioned in literature often seems very high. Nevertheless, tympanoscopy and obliteration of the window niches have their definite place in the therapeutic concept of sudden hearing loss, although the indication must be severely restricted.

Adolescent↗

PubMed1987

[2 cases of unusual sites of pleomorphic adenomas in the area of the face].

Two pleomorphic adenomas in the face, an uncommon site, are reported. In both cases the tumors showed a slow growth and one was excessively large. Diagnostic excision showed a pleomorphic adenoma in both cases. A review of the literature shows that mucosal adenomas are common whereas they are uncommon in the face.

Adenoma↗

PubMed1987

[Histopathology of collagen fibers of the tympanic membrane].

The lamina propria of the human tympanic membrane consists mainly of collagen fibres, but vessels and nerves can also be found as solitary elastic fibres. The pathologic alterations of the collagen fibres were examined by 47 biopsies of the tympanic membrane. These biopsies were taken in various middle ear diseases, and pathological changes were found in every case, ranging from clotting to chondral metaplasia; in one case a metaplasia into osseous tissue was found. No relationship was seen between the otoscopic findings and the severity of the pathological changes.

Biopsy↗