O. Hallén

FIVE-YEAR EXPERIENCE WITH SKIN-PENETRATING BONE-ANCHORED IMPLANTS IN THE TEMPORAL BONE

A method for stable integration of titanium-implants in bone tissue has been developed at the University of Gothenburg, Sweden. Screw shaped implants have been inserted in the temporal bone using a delicate surgical technique. After healing-in of the implants it is, in a later séance, possible to penetrate the skin to establish a reaction-free percutaneous passage. An up to 5-year clinical follow-up has shown the possibilities of this new method in the treatment of patients with e.g. certain hearing disorders or facial defects after tumour surgery.

Analysis of the Mechanical Impedance of Bone-Anchored Hearing Aids

Some patients who need hearing aids are unable to use an apparatus which transmits the sound via the external ear canal and have to use a bone conduction hearing aid. The bone vibration transducer of this aid is applied to the skin over the mastoid process and the sound is transmitted via the soft tissue and bone to the cochlea. The pressure needed to apply the transducer often gives the patient discomfort and the damping effect of the soft tissue gives poor quality of the sound transmitted. Advances in the ability to permanently implant foreign material in the body and perform permanent skin penetration has made it possible to develop a bone-anchored hearing aid. Fourteen patients have been equipped with such hearing aids. To be able to give these patients the best hearing aid, a new transducer has to be constructed to match the new situation. The impedance of the bone-anchored titaniumscrew/skull has been studied and the resistance and reactance of the mechanical impedance have been measured. The influence of a damping soft tissue layer over the bone has been analyzed. The difference between the impedance of the skull and the impedance of the soft tissue + skull was in the order of 10 to 25 dB depending on the frequency.

Quantitative Measurement Of Drooling

A method for quantitative measurement of drooling, utilizing the radioactive isotope 99mtechnetium, is introduced. The aim of this method is to evaluate results of therapy against this state. Drooling patients were given 100 μCi 99mTC intravenously. Saliva samples were repeatedly taken from the mouth for 9 hours and the isotope concentration was examined. The drooled saliva was collected in disposable bibs. From the measured radioactivity in the bibs and the saliva samples, the amount of drooled saliva could be calculated. The results show, as regards saliva production in a normal population, great variations in amount of drooled saliva within as well as between individuals. With due precautions, the method is useful for quantitative measurement of drooling.

The Healing Of The External Cochlear Wall In The Guinea Pig After Mechanical Injury

The bony and vascular repair process of the cochlea was studied after mechanical lesions on the external cochlear wall in the guinea pig. Bony healing of the bulla and the cochlear wall occurred surprisingly rapidly. Intracochlear hemorrhage appeared to be controlled by reflex closure of the supplying vessels. In those cases where the external membranous wall was dented it soon assumed its normal position. In some cases there was labyrinthitis or fibrosis of the intracochlear structures. However, most frequently all cochlear elements appeared to heal except for a gap remaining in the vascular pattern of the external wall and an increasing degeneration of the organ of Corti with time lapse postoperatively. The present investigation reveals a surprising ability of the guinea pig cochlea to heal after mechanical injury.

Middle Ear Disease in Samples from the General Population: Prevalence and Incidence of Otitis Media and its Sequelae the Study of Men Born in 1913–23

A study of 1371 men 20, 30, 50 and 60 years old and living in Göteborg was performed to obtain information on the incidence and prevalence of otitis media in a non-selected population. In addition to anamnestical data, a thorough examination of the ENT-status was made by one observer. There was no indication that otitis media has become a more rare disease since the early part of the century. However, the course of the disease does seem to be shorter and milder in more recent decades. This conclusion is supported by a substantially higher frequency of grave pathologic changes in the tympanic membranes in the two oldest cohorts compared with the two younger. A further indication is that mastoidectomies have become a rare type of operation during recent decades.

A Clinical Pilot Study On Preformed Autologous Ossicles. II

A research project concerning performed autologous ossicles has been going on for more than ten years. Animal experimental studies were followed by a clinical pilot study which showed that bone could be produced in a titanium mould placed in the proximal tibia metaphysis. In the present investigation, in which another five patients were operated on, the experimental design was changed compared to the first pilot study and bone production was improved. In addition to the tibial moulds ten titanium cylinders were placed around a bony bridge prepared in the linea temporalis of the ear to be reconstructed. Nine out of ten of these cylinders contained bone suitable for ossiculoplasty. Histology showed higher osteocyte density and a higher proportion of vital looking osteocytes in the performed grafts compared with a peroperatively sculptured graft of cortical bone. On histochemical investigation the performed graft cells seemed viable at the time of transplantation. The technique for obtaining a preformed autologous ossicle through the titanium cylinders in the temporal bone was easy to perform and the patients did not experience any discomfort. The risk of infection in this area was judged to be small.

On the Treatment of Esophageal Diverticula

A follow up study has been made on 31 patients with hypopharyngeal pouch operated during the years 1951–60 and on 8 patients from the same period which have not been operated. The patients have been interviewed about their symptoms and X-rayed. Of the operated group, six have died of other diseases, twelve are without any complaints, nine have mild and four more pronounced symptoms. One patient concludes that the operation has not made her better. The X-ray findings were not exactly correlated to the symptoms of the patients. In the non-operated group the roentgenograms did not show any increase in size of the smallest diverticulas during a ten-year period. It is concluded that the etiology of hypopharyngeal pouches is unclear, that cases in stage I should be treated conservatively, cases in stage II or III operated by a one stage lateral pharyngotomy with excision of the pouch with or without division of the cricopharyngeal muscle.

QUANTITATIVE ENZYMATIC CHANGES IN NEURONS AND GLIA OF THE LATERAL VESTIBULAR NUCLEUS DURING CENTRAL COMPENSATION AFTER UNILATERAL VESTIBULAR NEUROTOMY.

The vestibular nerve was sectioned in porus acusticus internus on the right side in two groups of rabbits. When central compensation was attained, one group was subjected to rotational stimulation for 25 min per day for 7 days. All animals were killed two weeks after operation.Succinoxidase activity was measured on isolated Deiters giant nerve cells and glial cells in the lateral vestibular nucleus. Zeuthens micro-diver technique was used for the activity determinations. In the operated group succinoxidase activity was increased 100 % in both neurons and glia of the affected side while the control side was unchanged. In the operated-and-stimulated group there was an activity increase only in the glial cells of the operated side.

Preformed Autologous Ossicles Experimental Studies

On the basis of earlier experimental investigations concerning autogenous bone transplants a project is going on with the view to have a patient to create his own bone graft suitable for being used in reconstructive surgery of the middle ear. This theory was tested in 6 rabbits and 6 dogs where a titanium form was installed in the proximal tibial metaphysis. The healing time was 6-8 months. After extraction histologic examination of the facsimile showed that it consisted of an outer form-giving thin layer ocal bone and a system of spongious bone surrounded by marrow with haemopoetic cells. Microradiologic analyses revealed a well mineralized trabecular bone tissue. By means of microangiography a microvascular architecture with a mature appearance could be demonstrated.

Local Tissue Effects Of Surface-Applied Ent Drugs

Local tissue effects caused by a selected group of topically applied ENT-drugs are analysed. By means of a testing system consisting of vital mircoscopy, infrared thermography and microangiography applied to hamsters and rabbits, an evaluation of the varying degree of tissue injury is made. According to the degree of tissue damage the tested substance could be graded in three groups (I-III). The drugs belonging to group I show fairly little microcirculatory disturbance, while those belonging to group III cause tissue necrosis. Our conclusion is that topically applied drugs should be used with caution, especially on previously injured tissues.