[Does balloon dilatation represent a breakthrough for Eustachian tube disorders ­ even in children?]. / Bringt die Ballondilatation den erhofften Durchbruch bei Tubenfunktionsstörungen ­ auch bei Kindern?

Balloon dilatation is a promising new treatment for Eustachian tube dysfunction which is becoming more and more popular in Germany. There are a number of single publications and even meta-analyses on this topic, which demonstrate good results but also reveal the need for better studies. Initially tube dilatation was applied only in adults with tube dysfunctions but recently some centers even recommend it for children with long-lasting or frequently recurring middle ear effusion, which is resistant to conventional therapy. This article provides a critical appraisal based on the current literature and emphasizes the need for controlled studies. Due to the poor definition of tube dysfunctions it may be difficult to establish informative studies but in terms of evidence-based medicine there is need for a precise definition of indications and inclusion criteria. Most important is that such studies must include control groups, which has so far not been the case. Moreover, there should be a consensus about the criteria for defining success. Although all publications claim that balloon tuboplasty is a safe method, the question whether or not preoperative computed tomography (CT) scans are needed should be considered in each individual case. Nevertheless, balloon dilatation is a very promising method offering a new approach to the problem of Eustachian tube dysfunction.

[Hearing impairment and dementia]. / Hörstörung und Demenz.

The World Health Organization (WHO) burden of disease study identified dementia and hearing problems as leading causes of loss of quality of life in the industrial world. The prevalence of dementia and hearing problems increases in aging societies. Comorbidity of these two diseases causes increasing demands on healthcare systems. The similarity and possible interaction of symptoms renders diagnosis and therapy of dementia and hearing loss a challenge for neurologists, psychiatrists, ear, nose and throat (ENT) and hearing specialists. Knowledge of both diseases enables an early intervention and helps preserve participation in society and thereby reducing the risk of developing dementia. This paper focuses on the characteristics of the diagnosis and therapy of hearing problems and dementia.

Microanatomy of the tympanic membrane in chronic myringitis obtained with optical coherence tomography.

A microscope-based optical coherence tomography (OCT) device was used to assess the microanatomy of the tympanic membrane in patients with chronic myringitis. A prospective study was designed for this purpose. OCT measurements of the tympanic membrane were done on 11 patients with myringitis with a microscope-based spectral domain OCT system. The in vivo findings were compared with those findings of a control group consisting of 36 patients with retraction pockets or atrophic tympanic membranes (n = 13), myringosclerosis (n = 12) and perforations (n = 11). In active chronic myringitis, the thickness of the tympanic membrane is increased compared to healthy membranes and to other pathological conditions of the tympanic membrane. Consistent changes of the microanatomy of the tympanic membrane were found in chronic myringitis with OCT. Serial OCT measurements revealed no biofilm suspicious findings in all patients with active chronic myringitis. Intraoperative and in vivo OCT measurements may help to detect microanatomical changes of the tympanic membrane in chronic myringitis and in other conditions of the tympanic membrane.

[Effect of fenestration of the cochlea on the vibration of the round window membrane]. / Effekt der Promontorialfensterung auf die Schwingung der Rundfenstermembran - experimentelle Studie.

Drilling a promontory window and coupling an FMT into the scala tympani may be a surgical alternative to stapes surgery in obliterative tympanosclerosis. Aim of this experimental study on human temporal bones was to measure changes of the acoustic transfer function from the tympanic membrane to the round window membrane after drilling a promontory window and insertion of a floating mass transducer.Laser vibrometry and acoustic measurements were performed on 11 temporal bone preparations equipped with a microphone attached to the round window. Calibrations were carried out to allow determination of SPLs affecting the cochlea after drilling a promontory window leaving the membranous inner ear intact and after insertion of an FMT into the cavity (with or without slight pressure).Drilling a promontory window does influence the transfer function. Insertion of the FMT with additional slight pressure further changes the transfer function.The presence of a promontory window changes the acoustic transfer function to the round window. Further investigations are needed to correlate the qualitative results with the audiological results after "third window vibroplasty" (inserted floating mass transducer without stimulation).

Intra-operative application of confocal endomicroscopy using a rigid endoscope.

OBJECTIVE: To introduce the application of confocal endomicroscopy during microlaryngoscopy, to enable intra-operative evaluation of human laryngeal epithelium. METHODS: A rigid endoscope was connected to the scanner head of a Heidelberg Retina Tomograph II confocal laser scanning system via an adapter. The endoscope was gently placed on the surface of a vocal fold through a laryngoscope during microlaryngoscopy. RESULTS: The application of confocal endomicroscopy using a rigid endoscope enabled technical improvements (i.e. improved image quality, automatic volume scan, and reduced tissue pressure due to the presence of a perforation plate with central hole at the end of the endoscope) which permitted greater sensitivity and improved handling. Confocal endomicroscopy provided good quality, in vivo, en-face images and enabled an assessment of laryngeal epithelium volume. CONCLUSION: This method enables the surgeon to monitor epithelial changes in pre-malignant lesions. The combination of confocal endomicroscopy together with optical coherence tomography (as a complementary technique that provides optical cross-sections) should be further explored in a formal clinicopathological study.

[Evaluation of the Freiburg monosyllabic speech test in background noise]. / Evaluation des Freiburger Einsilbertests im Störschall.

BACKGROUND: The Freiburg speech test has been the gold standard in speech audiometry in Germany for many years. Previously, however, this test had not been evaluated in assessing the effectiveness of a hearing aid in background noise. Furthermore, the validity of particular word lists used in the test has been questioned repeatedly in the past, due to a suspected higher variation within these lists as compared to the other word list used. PATIENTS AND METHODS: In this prospective study, two groups of subjects [normal hearing control subjects and patients with SNHL (sensorineural hearing loss) that had been fitted with hearing aid] were examined. In a first group, 113 control subjects with normal age- and gender-related pure tone thresholds were assessed by means of the Freiburg monosyllabic test under free-field conditions at 65 dB. The second group comprised 104 patients that had been fitted with hearing aids at least 3 months previously to treat their SNHL. Members of the SNHL group were assessed by means of the Freiburg monosyllabic test both with and without hearing aids, and in the presence or absence of background noise (CCITT-noise; 65/60 dB signal-noise ratio, in accordance with the Comité Consultatif International Téléphonique et Télégraphique), under free-field conditions at 65 dB. RESULTS: The first (control) group exhibited no gender-related differences in the Freiburg test results. In a few instances, inter-individual variability of responses was observed, although the reasons for this remain to be clarified. Within the second (patient) group, the Freiburg test results under the four different measurement conditions differed significantly from each other (p>0.05). This group exhibited a high degree of inter-individual variability between responses. In light of this, no significant differences in outcome could be assigned to the different word lists employed in the Freiburg speech test. CONCLUSION: The Freiburg monosyllabic test is able to assess the extent of hearing loss, as well as the effectiveness of a fitted hearing aid, in the presence or absence of background-noise (CCITT-noise). The present study could not evidence statistically significant differences in outcome when using the different word lists in this test battery.

[Mastoid obliteration with a highly porous bone grafting material in combination with cartilage]. / Mastoidhöhlenobliteration mit einem hochporösen Knochenaufbaumaterial (NanoBone®) und Conchaknorpel.

BACKGROUND: An open mastoid cavity might lead to various problems for the patient. Chronic inflammation of the cavity with secretion, changes in the acoustic behavior, vertigo in restricted situations and an impaired self-cleaning function might affect the patient. For surgical treatment reducing of the size of such cavities have been described. Besides autologous materials such as hydroxyapatite or alloplastic substances as tricalcium phosphate have been previously used. A very slow resorption of these materials with rejection has been described. The new ceramic NanoBone® was fabricated in a sol-gel process at 700 °C depositing unsintered hydroxylapatite in a SiO2 structure. This method provides a nano/microstructure of high porosity of the resulting matrix. MATERIAL AND METHODS: 20 patients were reexamined after an average of 2 years and 5 months after obliteration of the open mastoid cavity with NanoBone®. We compared pre- and postoperative findings in terms of otorrhea, frequency of medical consultation, vertigo and otoscopic findings. In 5 patients, in addition, a postoperative CT scan of the temporal bones was used for evaluation of osteoinduction and osteointegration. RESULTS: After obliteration of the open mastoid cavity with NanoBone ® we observed an uneventfully healing. After surgery we achieved a reduction of vertigo, otorrhea and frequency of medical consultations for the single patient. CONCLUSION: The obliteration of an open mastoid cavity with NanoBone ® is a safe alternative method relative to the surgical techniques with autologous materials.

Matrix change of bone grafting substitute after implantation into guinea pig bulla.

BACKGROUND: Many different surgical techniques have been developed to remove open mastoid cavities. In addition to autologous materials, alloplastic substances have been used. A very slow absorption of these materials and extrusion reactions have been reported. We investigated a newly developed, highly porous bone grafting material to eliminate open mastoid cavities, in an animal model. To characterise the transformation process, the early tissue reactions were studied in relation to the matrix transformation of the bone material. MATERIAL AND METHODS: NanoBone (NB), a highly porous bone grafting material based on calcium phosphate and silica, was filled into the open bullae from 20 guinea pigs. The bullae were examined histologically. Energy dispersive X-ray spectroscopy (EDX) was used to investigate the change in the elemental composition at different sampling times. The surface topography of the sections was examined by electron microscopy. RESULTS: After 1 week, periodic acid-Schiffs (PAS) staining demonstrated accumulation of glycogen and proteins, particularly in the border area of the NB particles. After 2 weeks, the particles were evenly coloured after PAS staining. EDX analysis showed a rapid absorption of the silica in the bone grafting material. CONCLUSIONS: NanoBone showed a rapid matrix change after implantation in the bullae of guinea pigs. The absorption of the silica matrix and replacement by PAS-positive substances like glycoproteins and mucopolysaccharides seems to play a decisive role in the degradation processes of NB. This is associated with the good osteoinductive properties of the material.

[Eustachian tube and middle ear mechanics]. / Tube und Mittelohrmechanik.

Even the most sophisticated prostheses for reconstruction of the ossicular chain do not work in the presence of Eustachian tube dysfunction. This review gives an update on the mechanisms of middle ear pressure regulation and middle ear ventilation, as well as methods for measuring the opening and closing function of the Eustachian tube. So far, in most tube function tests pressures are applied far beyond the physiological range in order to open the tube or force it to open. New methods like sonotubometry with perfect sequences (PSEQ) or the application of pressure in the nasopharynx with the Estève technique seem very promising. However, these measurements only provide snapshots of tube function. Presently, new tests are being developed for long-term measurements even in cases with perforated tympanic membranes. Attempts to improve impaired tube function have recently included laser surgery and balloon tuboplasty, yielding positive long-term results requiring verification in larger controlled studies. Eustachian tube dysfunction does not only mean blockage but can also include abnormal patencies of the Eustachian tube, for which new approaches are discussed here. In the case of suspected tube dysfunction, cartilage should be used to avoid early tympanic retraction or recurrent perforation; external ventilation using ventilation tubes should be considered.

[Optotensometry for measuring the tube function - a feasibility study on a middle ear model]. / Optotensometrie Langzeitmessung der Tubenfunktion - erste Versuche am Mittelohrmodell.

BACKGROUND: The amount of pressure in the middle ear depends mainly on the function of the Eustachian tube. Currently there are no continuous recording techniques measuring Eustachian tube function in clinical context and under physiological conditions over extended periods of time. In this paper we investigate the suitability of an active optic triangulation method on the basis of a projected laser-point-pattern in measuring tympanic membrane movement during pressure variations in a middle ear model. MATERIAL AND METHODS: For projection we used a green semiconductor laser with an output of 1 mW and a diffractive optical element (DOE). As our measured object we used purple latex-foil (Kimberley-Clark (®)), fixed airtight on the cut-off end of a 2 ml syringe-tube. The movement of the foils was measured by an active optic triangulation method. To simulate pathological variations of the tympanic membrane we prepared the latex-foils in specific ways. One foil was perforated and then covered again (simulating tympanic membrane perforation), another one was partly strengthened by sticking a piece of thick, hard paper to it from the inside (simulating calcification). RESULTS: The test-setup, as well as the appliance of pressure-changes worked fine and measurement of foil movement in all the modified foil surfaces was possible. This shows that it is possible to record foil-movement with this system even in tympanic membranes with pathological variations. CONCLUSIONS: In the course of this study we were able to show that it is possible to assess and record foil movement using a system of optic triangulation and to simulate different tympanic membrane pathologies. This could be used both in ENT medicine, as well as in aviation and diving medicine.

[Acoustic-mechanical trauma during cochleostomy: animal experimental studies]. / Akustisch-mechanisches Trauma während einer Cochleostomie: Tierexperimentelle Untersuchungen.

INTRODUCTION: When performing cochlear implant (CI) surgery in ears with residual hearing, cochlear function should be preserved as far as possible. Besides non-traumatic electrode insertion the acoustic-mechanical trauma of the cochleostomy should be minimized. According to experiences from temporal bone preparations the hypothesis that thorough exposition of the endosteal membrane with the drill prior to opening the cochlea might constitute a bigger acoustic mechanical trauma than direct drilling of the inner ear was examined. These experiments were performed in an animal model. MATERIAL AND METHOD: In 12 guinea pigs the cochlear capsule was exposed by opening the bulla under general anesthesia. In 6 animals the fluid-filled cochlea was exposed by careful unilateral abrasion of the bone, whereas on the other ear cochleostomy was performed by direct penetration drilling into the perilymphatic spaces. Hearing tests were performed before and after drilling by measuring evoked brainstem potentials (brainstem electric response audiometry, BERA). In 8 other guinea pig ears abrasive exposition of the cochlea was performed again by only softly touching the otic capsule with the running burr for 10 s. After a hearing test the drilling maneuver was repeated 4 times collectively. Thereby the inner ear was gradually opened from the surface but not deeper into the cochlear lumen. A total of 4 guinea pig ears treated with a single abrasion of 10 s were used as controls. Brain stem measurements were performed accordingly. RESULTS: Hearing loss was lower after a quick direct and deep penetration of the cochlea in comparison to a longer, less invasive opening of the inner ear. Hearing thresholds ascended depending on the duration of the drilling procedure. CONCLUSION: The results support the hypothesis that prolonged drilling of exposed inner ear structures causes more acoustical damage than a direct cochleostomy with the drill.

Detection of tympanic membrane movement using film patch with integrated strain gauge, assessed by optical coherence tomography: experimental study.

OBJECTIVE: We report an ex vivo and in vivo experimental study of a device designed to measure tympanic membrane movement under normal and pathological conditions, assessed using optical coherence tomography. MATERIALS AND METHODS: We designed two types of flexible, round film patch with integrated strain gauge, to be attached to the tympanic membrane in order to measure tympanic membrane movement. Tympanic membrane attachment was assessed using optical coherence tomography. The devices were tested experimentally using an ex vivo model with varying middle-ear pressure. RESULTS: Optical coherence tomography reliably assessed attachment of the film patch to the tympanic membrane, before and after middle-ear pressure changes. Strain gauge voltage changes were directly proportional to middle-ear pressure recordings, for low pressure changes. Tympanic membrane perforations smaller than 2 mm could be sealed off with the film patch. CONCLUSION: Attachment of the film patch with integrated strain gauge to the tympanic membrane was not ideal. Nevertheless, the strain gauge was able to precisely detect small pressure changes within the middle ear, in this experimental model.

[Tensometry - development of a measurement technique of the tube function in a temporal bone model]. / Tensometrie - Entwicklung eines Langzeitmessverfahrens der Tubenfunktion am Felsenbeinpräparat.

OBJECTIVE: Middle ear pressure depends widely on the function of the eustachian tube. Tube dysfunction is often a trigger for middle ear diseases like chronic otitis media but also for barotrauma. Patients with impaired tubal function should not be exposed to situations with extreme pressure changes. Until today, there is no valid examining method for long-time measuring of the development of middle ear pressure. MATERIAL AND METHODS: The basic idea was to develop a thin flexible film with integrated strain gauges made of platinum and gold, which can be applied directly on the surface of the tympanic membrane. Using these, shifts or distensions of the tympanic membrane in a temporal bone model can be measured and documented. RESULTS: We were able to show that the measuring system was sensitive enough to register pressure variations in the middle ear volume of a temporal bone model. While using a full bridge design of the strain gauge resistors it could be shown that the measuring voltage of the strain gauges were in phase of the pressure measurement curve or according to the positioning in opposite phase. In single resistor mode the measurement were not so positioning depended. Measuring tympanic membrane movement in case of perforation was feasible. CONCLUSIONS: To improve the longtime stability of the strain gauge film the next development step will be to make a new design with Konstantan resistors (CU-Ni-Mn). After a testing period, longtime measurements in clinical studies will follow.

How reliable is visual assessment of the electrically elicited stapedius reflex threshold during cochlear implant surgery, compared with tympanometry?

OBJECTIVES: To assess the reliability of visually assessed thresholds of the electrically elicited stapedius reflex, recorded during cochlear implant surgery, compared with intra-operative tympanometric threshold assessment. Intra-operatively recorded electrically elicited stapedius reflex thresholds vary considerably, and differ from those measured post-operatively by means of impedance changes (i.e. using tympanometry). Thus, any confounding effect of different intra-operative techniques and visual assessment inaccuracies should be excluded. METHODS: Both techniques (i.e. visual observation and tympanometry) were performed intra-operatively in six patients, and threshold values were compared. RESULTS: Recorded electrically elicited stapedius reflex thresholds were very similar for both techniques. Visually assessed thresholds were slightly higher in some cases and lower in others, compared with tympanometric thresholds. DISCUSSION: There was almost no difference between reflex thresholds measured with the two different techniques under the same intra-operative conditions. Therefore, we conclude that differences between intra- and post-operative thresholds are not due to the use of different measuring techniques. The main reason for such differences is probably the influence of intra-operative narcotics on reflex thresholds.

[Time course of microbial colonization of different voice prostheses]. / Die mikrobiologische Oberflächenbesiedlung verschiedener Stimmprothesenarten in der Zeitkinetik.

OBJECTIVE: For the vocal rehabilitation of laryngectomized patients, voice prostheses are actually one of the best known methods. Caused by the surface colonisation with bacteria and fungi the life time of the prostheses is limited to 3-4 months. MATERIAL AND METHODS: In a time period of 127 months we analysed the surface colonisation of 118 voice prostheses. RESULTS: The mean life time of the prostheses was 156 days. In reference to the prosthesis model we also recorded different times of usage (ESKA-Herrmann 141, Provox 2 184 and Provox 1 204 days (p>0.05)). In the microbiological examination the dominating bacteria were S. aureus, Klebsiella sp. and Proteus sp. It was possible to cultivate all these bacteria on every type of prosthesis used in the study. In addition C. albicans, C. glabrata, C. krusei and C. tropicalis were the main fungi on the silicone surface. Thereby a more frequent colonisation with C. krusei on ESKA-Herrmann prostheses was measured, caused by the bigger contact area with saliva on this model (p=0.034). CONCLUSIONS: Because of the similar position and way of function, all types of voice prostheses are colonized by almost the same species of bacteria and fungi. But in dependency of the type an affinity of individual species to special prostheses exist. The knowledge of these individual affinities is necessary for the further development of voice prostheses. Furthermore the diversity of bacteria and fungi species showed a level of saturation on the surface. This is caused by the limited space on the silicone prostheses.

[Tongue fixation system for therapy of sleeping disorders. A feasibility study]. / Implantatgebundene Zungenfixierung zur Therapie schlafbezogener Atmungsstörungen. Eine Machbarkeitsstudie.

INTRODUCTION: Forward displacement of the tongue is a verified principle in the therapy of sleep disorders which prevents the tongue from sinking backwards thus avoiding obstruction of the upper respiratory tract during sleep. In this feasibility study a novel oral appliance which connects to a pin implanted within the tongue was investigated. METHODS: A new tongue positioning system using previously implanted tongue piercings as a pivot was developed. By pulling the tongue forward the oral device prevents airway obstruction. In our study we fitted 10 subjects who already had the tongue pierced with the developed oral device. The subjects underwent two nights of polysomnography with and without using the tongue positioning system. Wearing comfort and side effects were evaluated using a questionnaire. Moderate alcohol consumption was used to provoke snoring or apnea in the subjects. Tongue positioning with and without the device was visualized with oropharyngeal MRI. RESULTS: Subjects did not report any discomfort or side effects wearing the device. Subjects showed only moderate snoring or apnea after alcohol consumption and snoring after alcohol consumption was reduced with the device. The average apnea/hypopnea index (AHI) was 0.8/h without the device. Using the device led to an increase of apnea in the subjects. MRI visualization showed that the device did not keep the upper airway space opened by fixing the tongue. CONCLUSION: The effectiveness of the tongue positioning system should be improved by a modification which should be investigated in patients with preexisting sleep disorders.

[Thermographic investigations during stapedotomy using a CO2 laser]. / Thermografische Untersuchung während der CO2-Laserstapedotomie.

BACKGROUND: Temporary sensorineural hearing losses after CO(2) assisted stapes surgery have been described in literature. Whether thermal effects are the reason for this side effect is still unclear. The specific aim of this research is to demonstrate the thermal spread during CO(2) laser stapedotomy using a high-speed infrared camera. MATERIAL AND METHODS: Thermal depth effects in physiological saline solutions were examined in cochlea models (glass capillary tube, crystal cuvette and temporal bone preparation). Temperature changes and exchange processes after CO(2) laser application were measured using a high-speed infrared camera. Visualization of gas bubbles triggered by vaporisation underneath the stapes footplate after CO(2) shot was achieved with a high-speed camera. The footplate perforations were performed with a scanner system using a micromanipulator (laser power 20 W, 0.6 mm diameter, continuous wave, duration of 40 ms). RESULTS: Homogenous temperature increases of more than 100°C were measured on the surface of the footplate and 0.25 mm within the capillary tube after single shot CO(2) laser stapedotomy. Gas bubbles may cause isolated temperature increases of up to 65 K. These effects were found in depths of up to 2 mm underneath the stapes footplate. CO(2) shots on the saline solutions with parameter used for initial laser application may lead to temperature increases between 20-65 K in depths of 3-6 mm. CONCLUSIONS: CO(2) applications to an opened inner ear with the same laser parameter used for initial shot on the stapes footplate should be avoided.