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Biomedical subjects

M Tos

Publications and source records attributed to M Tos.

At least 145 records · Page 8Linked to original sources
PubMed1990

[Inverted papilloma of the nose and nasal sinuses. Incidence, long-term course, therapeutic results].

Inverted papilloma is an unusual tumour in the nose and nasal sinuses with a marked tendency to recurrence following surgical treatment and with a greatly increased risk for synchronous or metachronous development of carcinoma. A retrospective investigation comprising 42 patients with histological revision revealed an incidence of 0.6/100,000 per annum. Two patients had also carcinomata. No significant differences were observed between the recurrence rates following simple excision, excision via the maxillary sinus or via lateral rhinotomy. Follow-up control for ten years is recommended.

Adult↗
PubMed1990

Estrogen and progesterone receptors in acoustic neuromas.

Acoustic neuromas are more frequent, larger, and more vascular in women, and their growth rate increases during pregnancy. Estrogen receptors were claimed to be demonstrated in these neoplasms for the first time in 1981. Since then, numerous diverging studies, using various biochemical and histochemical methods, have been published on the contents of estrogen and progesterone receptors in acoustic neuromas. We determined the content of estrogen and progesterone receptors by means of an immunohistochemical method, using monoclonal antibodies, which has proved to be reliable, reasonably sensitive, and clinically relevant in other tissues, especially in breast carcinomas. No estrogen or progesterone receptors could be found in 18 consecutive acoustic neuromas from 7 men and 11 women, ranging in age from 26 to 73 years. The results do not support preoperative hormone treatment of acoustic neuromas.

Adult↗
PubMed1990

Tympanosclerosis of the middle ear: late results of surgical treatment.

The late results of one stage operation for middle ear tymanosclerosis in 73 patients during the period January 1965 to December 1980 are presented. Mean observation time was 11.2 years (range 3-20.2 years), with a follow-up rate 86 per cent. Among 64 patients with stapes fixation, 59 had removal of tympanosclerotic masses and stapes mobilization, and five cases underwent stapedectomy. The series was divided into six groups and the results analyzed. The best and most stable results occurred in the group with stapes mobilization and an intact ossicular chain followed by the group with stapes mobilization and Type II tympanoplasty with incus interposition. The poorest late results were obtained in ears with lacking stapes crura and stapes mobilization, and in ears subjected to stapedectomy. No case of post-operative sensorineural hearing loss occurred. We recommend that care is taken to preserve an intact ossicular chain at stapes mobilization performed at the same stage as myringoplasty. Also in ears with a defective ossicular chain but intact stapes with tympanosclerotic fixation we recommend stapes mobilization in one stage. In ears with fixation of the stapes footplate and defective crura, we recommend stapedectomy or stapedotomy in two stages.

Adolescent↗
PubMed1990

Point and period prevalence of otitis media with effusion evaluated by daily tympanometry.

Previous studies on daily tympanometric screening using an automatic impedance tympanoscope indicated relatively high incidences of type B tympanograms of one day's duration, which is contrary to our conceptions of the pathogenesis and pathology of otitis media with effusion. We therefore repeated the study in 51 otherwise healthy children (100 ears) attending kindergarten. Tympanometry was performed daily for one month using both the conventional impedance apparatus AZ7 and the automatic impedance tympanoscope ZS 331. The impedance apparatus did not indicate any one-day type B tympanograms and only a few short-lasting episodes occurring either in the beginning or end of the study period. Several ears had type B tympanograms on all days examined. The point prevalence was 15 per cent and the period prevalence 17 per cent, which accord well with findings of previous epidemiological studies of secretory otitis. The impedance tympanoscope indicated 16 cases of B-curves lasting only one day and considerably higher point and period prevalences, which make the impedance tympanoscope unsuited for both scientific and clinical purposes.

Acoustic Impedance Tests↗
PubMed1990

Goblet cell density in nasal polyps.

The goblet cell density was determined in 29 nasal polyps from 22 patients by use of the periodic acid Schiff-alcian blue whole-mount method. The distribution of goblet cells was found to be extremely irregular, ranging from areas completely devoid of goblet cells to areas with a relatively high density. The median density varied from 280 cells/mm2 to 10,000 cells/mm2. The total median density for all 15 polyps located anteriorly in the nose was 3,450 cells/mm2, compared with 6,050 cells/mm2 for 14 posteriorly located polyps. The density was highest in pseudostratified, cylindric epithelium, although great variations occurred among the different areas with this type of epithelium. The goblet cell density may be influenced by several factors, such as the airflow, type and thickness of the epithelium, and whether the genesis of the nasal polyps is infectious or allergic, in addition to polyp growth, size, and age.

Basement Membrane↗
PubMed1990

Gamma knife: hydrocephalus as a complication of stereotactic radiosurgical treatment of an acoustic neuroma.

Stereotactic radiosurgery is at present being marketed as a reliable alternative to conventional tumor removal in patients with acoustic neuromas. Hearing preservation is possible and treatment modality is presented as being very low. A case history is presented, in which a patient with an 18 mm tumor and normal hearing developed severe hydrocephalus and dizziness 9 months after irradiation, in addition to losing her hearing. Whether the Gamma knife is to be considered a reliable alternative to surgical removal of acoustic neuromas is discussed.

Female↗
PubMed1990

Acoustic neuroma: clinical aspects, audiovestibular assessment, diagnostic delay, and growth rate.

The diagnostic findings in 300 patients with acoustic neuromas are reported. Because of a centralized treatment of acoustic neuromas, we have a uniform diagnostic work-up of all patients, which enables us to make a nonselected comparison of the diagnostic efficiency of the various tests. In patients with hearing better than 80 dB, a normal auditory brainstem response, the presence of recruitment, and normal caloric reaction, the presence of a tumor can be excluded. In patients with poor hearing, tomography is necessary if one does not prefer to perform CT directly. If CT, even with contrast enhancement, is negative, we continue to perform air CT. Only then do we know whether or not the patient has a tumor. Magnetic resonance imaging has not been available to us, but with this diagnostic modality even intrameatal tumors are visualized. However, with the present economy involved with magnetic resonance imaging it is not realistic at the present time to use this way of imaging as a screening procedure. In spite of an intensive campaign for making early diagnosis of acoustic neuromas, our attempts have not been successful, since we have even more tumors measuring over 40 mm in diameter among the latest 100 patients than among the first one hundred. Both patients and physicians (otologists) to some extent are still ignoring the possible significance of a unilateral, progressive, sensorineural hearing impairment. Guidelines for improving this situation are given. Twenty-one patients were followed for an average of 4 years, repeated CT scans were performed, and the tumor appeared to be progressing to a size requiring surgical intervention in only three of these patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

Hearing loss in tympanosclerosis caused by grommets.

The aim of the present study was to determine the degree of hearing impairment caused by tympanosclerosis of the eardrum as a result of grommet insertion. During the period 1977 to 1978 we treated 146 children who had bilateral secretory otitis with adenoidectomy, insertion of a ventilation tube on the right side, and myringotomy on the left. The children were reexamined 2 to 3 years and again 6 to 7 years postoperatively, and hearing was evaluated at 250, 1000, and 4000 Hz. Tympanosclerosis was demonstrated in 59% of the children on the side with grommet insertion compared with 13% in the contralateral ear. Hearing was slightly inferior in ears with tympanosclerosis compared with ears without tympanosclerosis, but the difference was small and nonsignificant. The hearing impairment caused by tympanosclerosis was less than 0.5 dB, which is inconsequential and cannot serve as an argument against the use of ventilation tubes. However, further studies with longer observation periods are warranted.

Acoustic Impedance Tests↗
PubMed1989

The translabyrinthine approach for the removal of large acoustic neuromas.

The results and the sequelae are reported from a series of consecutive 400 translabyrinthine removals of acoustic neuromas comprising almost all such tumors in Denmark during a 12-year period from 1976 to 1988. There were two intrameatal, 137 median-sized, 112 large and 149 advanced tumors, the latter having a diameter exceeding 40 mm. The mortality rate in the overall series was 2%. The incidence of cerebrospinal fluid leak occurred in 11%, and persisted for more than 2 weeks in 4%. Facial nerve function was completely normal in 67% of the patients, while only 5% required a nerve anastomosis.

Adolescent↗
PubMed1989

Hearing after surgery for cholesteatoma using various techniques.

The late results in 740 patients with cholesteatoma subjected to one-stage canal wall down mastoidectomy (262 patients), modified canal wall up mastoidectomy (324 patients), and tympanoplasty without mastoidectomy (154 patients) were analyzed with regard to hearing and the condition of the drum. Mean observation time was 9.3 years, range 3-21 years. Postoperative hearing (air bone gap and pure tone average) and as hearing at the last evaluation was significantly better in the canal wall up group, than in the canal wall down group, but also the preoperative hearing was better in the canal wall up group. The postoperative hearing was best in the group with tympanoplasty only without mastoidectomy. It is concluded that no single method is optimal in all cases of cholesteatoma and that cholesteatoma surgery should be individualized.

Acoustic Impedance Tests↗
PubMed1989

Tensa retraction cholesteatoma: treatment and long-term results.

To obtain the best possible results of treatment of acquired cholesteatoma, we made a subdivision of cholesteatoma types into attic and pars tensa cholesteatomas, and subdivided the latter further into tensa retraction cholesteatoma and sinus cholesteatomas. Tensa retraction cholesteatoma is defined as arising from a retraction or perforation of the whole pars tensa, whereas sinus cholesteatoma is defined as arising from a retraction or perforation of the postero-superior part of the tensa. We present the long-term results obtained in tensa retraction cholesteatomas treated with one stage surgery from 1964 to 1980. Median observation time was 9 years, range 2 to 19 years. Sixty-one ears were treated without mastoidectomy, whereas 71 ears had canal wall-up mastoidectomy and 64 ears had canal wall-down mastoidectomy. The total recurrence rate was 13.3 per cent; 17 ears had residual cholesteatoma, and nine ears had recurrent cholesteatoma. The best results were obtained in ears with an intact ossicular chain where mastoidectomy was not performed. In 49 per cent of the cases, the cholesteatoma was confined to the tympanic cavity without reaching the aditus, antrum or mastoid process. About one-third to one-quarter of the ears had tympanoplasty only, with removal of the cholesteatoma through the ear canal.

Adolescent↗
PubMed1989

The contralateral ear after translabyrinthine removal of acoustic neuromas: is there a drill-noise generated hearing loss?

To determine whether translabyrinthine acoustic surgery may result in a drill-generated, bone-conducted sensorineural hearing impairment in the contralateral ear, the audiograms from 50 consecutive patients with acoustic neuromas undergoing the translabyrinthine approach were compared before and three months after surgery. No case of sensorineural hearing impairment could be demonstrated postoperatively.

Adult↗
PubMed1989

Late results of surgery in different cholesteatoma types.

Our series of 740 cholesteatomas, operated during the period 1969 to 1980, were seen at follow-up several times with a median observation period of 9.2 years (range 3-21 years). There were; 273 attic cholesteatomas with retraction (perforation) of Shrapnell's membrane; 271 sinus cholesteatomas with superioposterior retraction (perforation) of pars tensa, and 196 tensa retraction cholesteatomas extending from a retraction of the whole pars tensa. The late results were analyzed for each type separately, and compared. The recurrence rate was lowest (6.6%) in attic cholesteatoma and highest (13.3%) in tensa retraction cholesteatoma. In all three types no residual cholesteatomas were detected after the 4th postoperative year, whereas recurrent cholesteatomas occurred up to 10 years after surgery. The reoperation rate was lowest (15%) in attic cholesteatoma and almost the same (21%) in sinus and tensa retraction cholesteatoma. The hearing results were best in attic cholesteatoma and poorest in tensa retraction cholesteatoma. It is concluded that cholesteatoma surgery should be individualized and that both the canal wall up and canal wall down methods have their place in cholesteatoma surgery.

Adolescent↗
PubMed1989

Nasal polyps: epithelium and goblet cell density.

The density of goblet cells was determined in 14 anterior and 15 posterior nasal polyps using the whole-mount method. The specimens were then serial cut and the type of epithelium was determined in nine localities in each polyp. The goblet cell density was correlated to the epithelial type. Pseudostratified, cylindrical epithelium was the prevailing type, occurring in 62% of anterior localities and 78% of posterior localities. Transitional types of epithelium were found in 33% of the anterior and 19% of the posterior localities. Stratified squamous epithelium occurred in 5% and 3%, respectively. The goblet cell density was highest in hyperplastic pseudostratified epithelium, whereas it was four times lower in transitional epithelium and even lower in squamous epithelium. Marked differences in the distribution of epithelium and goblet cell density were found between anterior and posterior polyps, illustrating that the epithelium constantly changes under the influence of air current, contact with other polyps, infection, growth, and age of the polyp as well as other unknown factors.

Cell Count↗
PubMed1989

Sensorineural hearing loss in acute and chronic middle ear diseases.

Clinical studies of SNHL in various acute and chronic middle ear diseases are reviewed. Reported incidences of SNHL in acute otitis and secretory otitis are compared with those found in our epidemiological studies. We conclude that the overall incidence of SNHL is small. In chronic otitis, the incidence varies according to the pathology. A systematic study of 67 patients operated on for adhesive otitis, with a mean follow-up of 11 years, showed SNHL exceeding 10 dB for one of the frequencies tested in 76% of the patients. Problems involved in the study of SNHL in clinical series are discussed.

Acute Disease↗
PubMed1989

Acoustic neuroma surgery: results of translabyrinthine tumour removal in 300 patients. Discussion of choice of approach in relation to overall results and possibility of hearing preservation.

The results from the Danish model of acoustic neuroma surgery are presented. In the period from 1976 to 1985, 300 patients with acoustic neuromas were operated upon using the translabyrinthine procedure. Only one small intrameatal tumour was encountered; 96 tumours were medium sized and 203 were larger than 25 mm. Of these 118 measured more than 40 mm. Mortality rate was 2%, CSF leaks occurred in 11%, and had to be closed surgically in 5%. Facial nerve function was postoperatively normal in 66%, slightly reduced in 17%, moderately reduced in 8% and abolished in 9%. Reconstruction, most often as a XII-VII anastomosis, was performed in only 6% of the patients. Cerebellar symptoms, which occurred in 45% preoperatively were present in only 7% after surgery. The preoperative hearing in both the tumour and non-tumour ear was analysed in 72 patients with tumours smaller than 2 cm. In the tumour ear, only four patients had a PTA of 0-20 dB and SDS of 81-100%; eight patients had a PTA of 0-40 dB and SDS of 61-100%; 14 had a PTA of 0-50 dB and SDS of 51-100%. This means that only a maximum of 5% of the patients, using the broadest criteria, could be candidates for hearing-conserving surgery. In all these patients the contralateral ear had hearing within normal limits (PTA 0-20 dB and SDS 95-100%). Since preservation of hearing would be achieved in only half of those subjected to suboccipital removal and since the hearing retained in patients with successful operations generally is poorer than the preoperative level, the number of patients obtaining serviceable hearing is so modest that preservation of hearing cannot be considered a valid argument in favour of suboccipital tumour removal. From a statistical point of view the risk of losing hearing in the opposite ear after tumour removal is negligible. The general morbidity after suboccipital surgery is higher than after translabyrinthine surgery, and hearing loss must be listed low among the other sequelae after tumour removal.

Denmark↗