Influence of backside loading on the floating mass transducer: An in vitro experimental study.

HYPOTHESIS: The vibration of the floating mass transducer (FMT) of a single active middle-ear implant (AMEI) is distinctly influenced by the properties of the material coupled to its back side. BACKGROUND: In round window vibroplasty, the FMT needs to be padded against the surrounding bone opposite from the round window membrane. This represents one factor influencing its performance as a round window driver. Therefore, we examined the effects of different materials linked to the back side of an FMT on its vibration range. METHODS: The back side of an FMT was glued to a silicone cylinder 1.0 mm in diameter and 1.0 mm - 1.5 mm in length and of 40A, 50A or 70A Shore hardness; to cartilage of equivalent size; or to a round window soft coupler (RWSC), all firmly fixed on a steel plate. The vibrations were determined by a laser Doppler vibrometer (LDV) measuring the velocity of the centre point on the front side of the FMT. RESULTS: The materials on the back side of the FMT significantly influenced the vibration range of the FMT. The RWSC and silicone of 40A Shore hardness allowed for the highest detected velocities, while cartilage led to a distinct reduction similarly to 70A silicone. CONCLUSION: The coupling on the back side of an FMT distinctly affects its vibration range. In this regard, the RWSC and silicone of 40A Shore hardness yield the least impairment of vibration. Thus, the RWSC may be a feasible option in round window vibroplasty when additionally connected to the FMT opposite from the round window membrane.

Surgical anatomy of the round window-Implications for cochlear implantation.

BACKGROUND: The round window is an important portal for the application of active hearing aids and cochlear implants. The anatomical and topographical knowledge about the round window region is a prerequisite for successful insertion for a cochlear implant electrode. OBJECTIVE OF REVIEW: To sum up current knowledge about the round window anatomy and to give advice to the cochlear implant surgeon for optimal placement of an electrode. TYPE OF REVIEW: Systematic Medline search. SEARCH STRATEGY: Search term "round window[Title]" with no date restriction. Only publications in the English Language were included. All abstracts were screened for relevance, that is a focus on surgical anatomy of the round window. The search results were supplemented with hand searching of selected reviews and reference lists from included studies. EVALUATION METHOD: Subjective assessment. RESULTS: There is substantial variability in size and shape of the round window. The round window is regarded as the most reliable surgical landmark to safely locate the scala tympani. Factors affecting the optimal trajectory line for atraumatic electrode insertion are anatomy of the round window, the anatomy of the intracochlear hook region and the variable orientation and size of the cochlea's basal turn. CONCLUSIONS: The very close relation to the sensitive inner ear structures necessitates a thorough anatomic knowledge and careful insertion technique, especially when implanting patients with residual hearing. In order to avoid electrode migration between the scalae and to achieve protect the modiolus and the basilar membrane, it is recommended to aim for an electrode insertion vector from postero-superior to antero-inferior.

Reliability of Eustachian tube function measurements in a hypobaric and hyperbaric pressure chamber.

OBJECTIVES: Measurement of the Eustachian tube (ET) function is a challenge. The demand for a precise and meaningful diagnostic tool increases-especially because more and more operative therapies are being offered without objective evidence. The measurement of the ET function by continuous impedance recording in a pressure chamber is an established method, although the reliability of the measurements is still unclear. METHODS: Twenty-five participants (50 ears) were exposed to phases of compression and decompression in a hypo- and hyperbaric pressure chamber. The ET function reflecting parameters-ET opening pressure (ETOP), ET opening duration (ETOD) and ET opening frequency (ETOF)-were determined under exactly the same preconditions three times in a row. The intraclass correlation coefficient (ICC) and Bland and Altman plot were used to assess test-retest reliability. RESULTS: ICCs revealed a high correlation for ETOP and ETOF in phases of decompression (passive equalisation) as well as ETOD and ETOP in phases of compression (active induced equalisation). Very high correlation could be shown for ETOD in decompression and ETOF in compression phases. The Bland and Altman graphs could show that measurements provide results within a 95 % confidence interval in compression and decompression phases. CONCLUSIONS: We conclude that measurements in a pressure chamber are a very valuable tool in terms of estimating the ET opening and closing function. Measurements show some variance comparing participants, but provide reliable results within a 95 % confidence interval in retest. This study is the basis for enabling efficacy measurements of ET treatment modalities.

Position paper on olfactory dysfunction.

Background: Olfactory dysfunction is an increasingly recognised condition, associated with reduced quality of life and major health outcomes such as neurodegeneration and death. However, translational research in this field is limited by heterogeneity in methodological approach, including definitions of impairment, improvement and appropriate assessment techniques. Accordingly, effective treatments for smell loss are limited. In an effort to encourage high quality and comparable work in this field, among others, we propose the following ideas and recommendations. Whilst the full set of recommendations are outlined in the main document, points include the following: • Patients with suspected olfactory loss should undergo a full examination of the head and neck, including rigid nasal endoscopy with small diameter endoscopes. • Subjective olfactory assessment should not be undertaken in isolation, given its poor reliability. • Psychophysical assessment tools used in clinical and research settings should include reliable and validated tests of odour threshold, and/or one of odour identification or discrimination. • Comprehensive chemosensory assessment should include gustatory screening. • Smell training can be helpful in patients with olfactory loss of several aetiologies. Conclusions: We hope the current manuscript will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency and generalisability of work in this field.

[The pressure-equalizing function of the Eustachian tube : Evaluation in a hypo-/hyperbaric pressure chamber]. / Druckausgleichende Funktion der Eustachischen Röhre : Evaluation in einer hypo-/hyperbaren Druckkammer.

BACKGROUND: The Eustachian tube connects the tympanic cavity (cavum tympani) and the nasopharynx, and enables pressure equalization between the middle ear and ambient pressure. Functional pressure compensation is very important for flying and diving in particular, due to non-physiologically large pressure differences. OBJECTIVE: Evaluation of the pressure-equalizing function of the Eustachian tube is still a clinical challenge. This review article evaluates the existing data. METHODS: Based on a selective literature search, different methods for evaluation of tube function are presented and evaluated, with special reference to evaluation of the pressure-equalizing function in a hypo-/hyperbaric pressure chamber. RESULTS: The pressure chamber enables the dynamics of active and passive pressure compensation to be provoked and also permits accurate measurement of pressures in the millibar range. CONCLUSION: A pressure chamber seems to be suitable to evaluate Eustachian tube function and therapeutic approaches to tube dysfunction. Further studies are needed to assess the value of the pressure chamber in combination with other functional tests.

Position paper on olfactory dysfunction.

BACKGROUND: Olfactory dysfunction is an increasingly recognised condition, associated with reduced quality of life and major health outcomes such as neurodegeneration and death. However, translational research in this field is limited by heterogeneity in methodological approach, including definitions of impairment, improvement and appropriate assessment techniques. Accordingly, effective treatments for smell loss are limited. In an effort to encourage high quality and comparable work in this field, among others, we propose the following ideas and recommendations. Whilst the full set of recommendations are outlined in the main document, points include the following: - Patients with suspected olfactory loss should undergo a full examination of the head and neck, including rigid nasal endoscopy with small diameter endoscopes. - Subjective olfactory assessment should not be undertaken in isolation, given its poor reliability. - Psychophysical assessment tools used in clinical and research settings should include reliable and validated tests of odour threshold, and/or one of odour identification or discrimination. - Comprehensive chemosensory assessment should include gustatory screening. - Smell training can be helpful in patients with olfactory loss of several aetiologies. CONCLUSIONS: We hope the current manuscript will encourage clinicians and researchers to adopt a common language, and in so doing, increase the methodological quality, consistency and generalisability of work in this field.

Acoustic effects of a superior semicircular canal dehiscence: a temporal bone study.

A dehiscence of the superior semicircular canal is said to be responsible for a number of specific and unspecific ear symptoms and possible a conductive hearing loss of up to 40 dB. As in vivo a dehiscence would not be opened against air, but is naturally patched with dura and the brain, it was our aim to investigate the effects of an superior semicircular canal dehiscence on the air conduction hearing in fresh human temporal bones with different boundary conditions. At ten fresh human temporal bones, we investigated the transmission of sound energy through the middle and inner ear using a round window microphone and laser Doppler vibrometer for perilymph motions inside the dehiscence. After baseline measurements, the superior semicircular canal was opened. We investigated the change of the transfer function when the canal is opened against air (pressure equivalent water column), against a water column and when it is patched with a layer of dura. Opening the superior semicircular canal resulted in a loss of sound transmission of maximal 10-15 dB only in frequencies below 1 kHz. When covering the dehiscence with a water column, the conductive hearing component was reduced to 6-8 dB. Placing a dura patch on top of the dehiscence resulted in a normalization of the transfer function. If our experiments are consistent with the conditions in vivo, then superior semicircular canal dehiscence does not lead to an extensive and clinically considerable conductive air conduction component.

Intraductal pressure during sialendoscopy.

BACKGROUND: Sialendoscopy can be followed by swelling and infection of the salivary gland. A possible pathomechanism is damage of the deeper salivary duct system by intraductal pressure generated by the irrigation fluid. METHOD: After measuring the physiological intraductal pressures which arise during sialendoscopy, these pressures were simulated in freshly excised salivary glands and the tissue was analysed histologically. RESULTS: Normal intraductal filling pressure during sialendoscopy is 100-250 daPa, and pressure peaks can be up to 2000 daPa during flushing. A filling pressure of more than 400 daPa results in dilatation of the salivary ducts and acinar area. No direct damage to any duct structures could be observed histologically. CONCLUSION: Irrigation fluid should be administered intermittently rather than continuously during sialendoscopy. The intraductal filling pressure should not exceed 400 daPa to minimise the trauma to the salivary duct system and reduce the risk of developing oedema and inflammation.

[Position paper "Chemosensory testing for expert opinion in smell disorders"]. / Positionspapier "Die chemosensorische Testung bei der gutachterlichen Abklärung von Riechstörungen"

Providing expert opinion in the context of smell disorders is often challenging, not only with regard to general aspects of providing an expert opinion but particularly with regard to chemosensory testing. Currently there is no consensus which chemosensory test should be selected and how they should be executed. This positions paper from Committee on Olfaction and Gustation of the German Society of Otorhinolaryngology, Head and Neck Surgery aims to give concrete recommendations for chemosensory testing for providing expert opinion for smell disorders with regard to the selection and execution of these test.

Endoscopic laser-assisted diverticulotomy without versus with wound closure in the treatment of Zenker's diverticulum.

The aim of the present study was to compare the modifications of endoscopic laser-assisted diverticulotomy regarding closure of mucosal wound at the cricopharyngeal bridge. The results of 62 cases after endoscopic laser-assisted diverticulotomy without and with wound closure were retrospectively compared. After laser-assisted transection of the cricopharyngeal bridge, the mucosa wound was left open (OW) in 35 cases (56%), whereas a closure of the mucosa wound (CW) with sutures and fibrin glue was performed in 27 patients (44%). Duration of hospitalization, residual diverticular sac rate and occurrence of complications did not differ significantly between the two groups. Mean surgical time was significantly less in the OW cases. According to these results, it can be assumed that readapting and sealing the wound after transecting the cricopharyngeal bridge does not significantly reduce the complication rate. It does, however, extend the length of surgery and increases the cost of the procedure.

[Acoustic and vestibular effects of superior semicircular canal dehiscence]. / Akustische und vestibuläre Effekte bei einer Dehiszenz des oberen Bogengangs.

A dehiscence of the superior semicircular canal is associated with many middle and inner ear symptoms of varying specificity. Concerning the pathophysiology, the way in which these symptoms are connected to a postulated missing bony layer of the superior semicircular canal remains to be completely clarified. In particular, it is unclear why a bony dehiscence might induce symptoms at all; as shown by recent experimental investigations, the natural in vivo coverage of the superior semicircular canal by dura, cerebrospinal fluid and brain prevents changes in inner ear impedance. Diagnosis of superior semicircular canal dehiscence is currently based on a combination of different tests. While cranial computed tomography (with its limited visual resolution) has proven to be largely unsuitable, ocular vestibular-evoked myogenic potentials (oVEMP) are considered an important component of diagnosis. In addition to symptomatic treatment, isolated cases also present the option of highly invasive surgical intervention. Although the majority of published case reports document positive clinical outcomes for operated patients, these procedures are associated with considerable perioperative risks.

Titanium ball joint total ossicular replacement prosthesis--experimental evaluation and midterm clinical results.

During reconstruction of the ossicular chain, there is a need to address the forces and loads caused by the ambient atmospheric pressure variations and the resulting tympanic membrane movements. It is understood that when a rigid middle ear prosthesis is inserted the malleoincudal joint, a keyfactor in controlling pressure variations in the middle ear space is bypassed. In this paper we describe a modified total titanium ossicular replacement prosthesis with an innovative micro ball joint in the headplate which is designed to compensate for tympanic membrane movements caused by atmospheric pressure variations. The characteristics of this modified prosthesis were examined in temporal bone experiments and compared to the standard titanium total ossicular reconstruction prosthesis. Sound-induced stapes footplate movements were investigated by means of a Laser vibrometer and revealed no significant differences between the two prostheses in vitro. Intraoperatively, the insertion of the modified prosthesis required more delicate handling. The angle between the shaft and the headplate was variable and ranged from 60 to 90° as estimated by the surgeon. Twelve consecutive patients were eligible for clinical evaluation. The pure tone average (PTA) air-bone gap after a mean follow up period of 32 months was 18.8 dB. Furthermore, no extrusion, dislocation or other adverse events were observed. We conclude that the modified total ossicular replacement prosthesis with integrated micro ball joint yields similar volume velocities of the stapes footplate in the laboratory experiments compared to the standard rigid prosthesis. The audiological and morphological results are encouraging and show that the mobile prosthesis headplate adjusting to the level of the tympanic membrane is a further step in the development of a physiological middle ear implant. This article is part of a special issue entitled "MEMRO 2012".

[Generation Y in ENT: leading a young generation of doctors]. / Generation Y in der HNO: Führung einer neuen Generation von Ärzten.

BACKGROUND: The shortage of qualified doctors and nurses has led to a competition between hospitals. Analyzing the circumstances of the competition, nurses and doctors of so-called generation Y are important. These employees are mainly female and have different requirements compared to previous generations. Therefore, knowledge of these requirements will become a critical success factor for hospitals in the future. METHOD: We interviewed medical students in Kiel and Hannover from 2005 to 2011 about the clinical department chosen, the criteria for choosing a specific clinic, and the importance of MD and PhD programs. In addition, we conducted an internet and Medline search for scientific studies on labor shortage, generation Y, and demographics. The data were sorted by main categories and relevance for hospitals. Statistical analyses were performed using descriptive measures. RESULTS: We received 1,097 answers which represents approx. 75% of all students. Sixty-seven percent of the students were female, 33% male. Preferences for departments revealed internal medicine, pediatrics, and anesthesiology as the top three. ENT followed at rank 10. The main criteria for choosing a clinic were working climate, structure and broadness of education, family friendliness, and respect. MD programs were rated 2.6, while PhD programs were rated 3.6. Staff members of Generation Y "live while working" and disagree with hierarchies. Internet and computers are part of their daily routine. CONCLUSION: Employees of Generation Y challenge leadership in hospitals by increasing demands. However, Generation Y can increase professionalization and competitiveness for hospitals significantly.

[The shortage of qualified staff in Germany: a survey on head physicians' expectations of young doctors]. / Fachkräftemangel in Deutschland: Umfrage zu Erwartungen von Chefärzten an junge Mitarbeiter.

BACKGROUND: The shortage of medical specialists in Germany has led to increased competition between hospitals, particularly in the recruitment of young skilled doctors. The quality of training appears to be the critical factor in a clinic's recruiting process. At the same time, the suitability of candidates is decreasing. There is currently no data on the suitability of candidates for otorhinolaryngology, nor are there any forecasts about the labor shortage in this speciality. METHODS: We compiled a questionnaire according to accepted guidelines, which was then sent to 160 ENT departments by email. We asked about the size and location of the department and the number of applicants that were suitable or unsuitable. Finally, we asked about the current availability of staff as well as the requirements set by the head physician. RESULTS: The response rate was 34% (54 questionnaires). Departments received an average of 20 applications per year, of which 36% were unsuitable. Departments received more applications in the new German states than in the old; however, no difference in the quality of candidates was seen. University hospitals receive almost three times more applications than other hospitals. The size of the department correlates with the number of applications and quality of the candidates. Almost 60% of chief physicians expected the lack of qualified staff to worsen in the future. However, 40% of chief physicians of large departments (> 50 beds) expected the situation to improve or remain unchanged. Chief physicians' main expectations of candidates included commitment, independent learning and team spirit. CONCLUSIONS: A broad and structured residency program for new employees is the most important factor in the recruitment of new physicians. Large departments and university hospitals have advantages here. The expectations of head physicians differ from those of young staff in terms of commitment and autonomous learning.

[Prognosis of surgically treated primary parotid gland cancer - an evaluation of 231 cases]. / Zur Prognose chirurgisch therapierter primärer Parotiskarzinome - eine Untersuchung an 231 Fällen.

We present our results on the prognosis of parotid gland cancer with the help of a group of patients who were treated in a standardised manner and received a long term follow-up.We retrospectively analysed the clinicopathological data of 231 patients with a surgically treated primary parotid gland cancer and calculated survival parameters. The mean follow-up time was 52 months.The 5- and 10-year overall survival rate was 74.2% and 66.9%. 70 patients got a locoregional recurrence, 18.6% of those even after more than 5 years. Initial facial nerve palsy was a significant negative prognostic indicator for the disease-free survival. The most frequent histological subtypes could be divided into 3 prognostic groups with significant differences in the survival. The pathological tumour stage was a prognostic indicator for a worse overall and disease-free survival. The pT-stage, the pN-stage and the existence of distant metastases were independent prognostic factors.The group of patients is mainly characterised by the large size, the standardised therapy and the long follow-up time. We could show that the facial nerve palsy is a severe negative prognostic factor. For practical purpose, the classification into 3 histological subgroups seemed to be of great help. This should be considered in patient follow-up. Due to the amount of late recurrences, we propose a follow-up time longer than 5 years. We propose standardized surgery including total parotidectomy in combination with neck dissection.

[Implantable hearing aids]. / Implantierbare Hörgeräte.

Strictly speaking, implantable hearing aids are technical systems that process audiological signals and convey these by direct mechanical stimulation of the ossicular chain or cochlea. They have certain benefits over conventional hearing aids in terms of wearing comfort and general acceptance. As current studies lack convincing audiological results, the indications for implantable hearing aids are primarily of medical or cosmetic nature. To date, three systems are available in Germany: Vibrant Soundbridge®, Carina®, and Esteem®. Because the performance of the different implantable and nonimplantable hearing systems together with various surgical procedures are currently undergoing major changes, audiological indications may also develop in the future.