Bürokratische Zielverschiebung : Negativeffekte von Evaluationen theoretisch rekonstruieren und praktisch meiden

Tut Evaluation Bildungsinstitutionen gut? Eindeutig ist die Antwort auf diese Frage nicht. Vielmehr zeigt sich regelmäßig, wie Evaluationen in einem organisationalen System sogar einen gewissen Schaden anrichten können. Gelegentlich mögen Mängel in der Anlage dafür ursächlich sein: falsche Indikatoren, falsche Prozesse. Wir möchten in diesem Beitrag grundsätzlicher reflektieren und in eine andere Richtung fragen: - Könnte Evaluation als solche nachteilige Auswirkungen haben? Wenn ja: warum und wie? - Was ergibt sich daraus für die Gestaltung von Evaluationen und Qualitätsmanagement? - Gibt es funktionsäquivalente Alternativen

Long-term results and complications following uvulopalatopharyngoplasty in 116 consecutive patients

A modified uvulopalatopharyngoplasty (UPPP) was carried out between January 1992 and December 2003 at the ENT Department of the Inselspital in Bern in 146 patients with habitual or complicated rhonchopathy. The operation consisted of a classical tonsillectomy or residual tonsil resection and additional shortening of the uvula. The natural mucosal fold between the uvula and the upper pole of the tonsils was carefully preserved. A wide opening to the rhinopharynx was created by asymmetric suturing of the glossopalantine and pharyngopalatine arches. A retrospective questionnaire with regard to rhonchopathy, phases of apnea, daytime drowsiness, obstruction of nasal breathing, long-term complications and patient satisfaction was used to evaluate the short-term and long-term effectiveness of the modified UPPP as well as the incidence of adverse side effects. Complete postoperative courses were evaluated in 116 patients. Surgical complications were restricted to one case with postoperative hemorrhage. A velum insufficiency or postoperative rhinopharyngeal stenosis did not occur. Eighty-three patients (72%) confirmed a persistent suppression or substantial improvement of the rhonchopathy. Disappearance or decrease of sleep apnea was confirmed in 12 (63%) out of 19 postoperative polysomnographic follow-up investigations. Long-term complications occurred in a total of 27 (23%) of 116 patients. They were confined to minor problems such as dryness of the mouth (n=12), slight difficulty in swallowing (n=7), discrete speech disturbances (n=1), and slight pharyngeal dysesthesias (n=7) with feeling of a lump in the throat and compulsive clearing of the throat. Eighty-five patients (73%) reported that they were satisfied with the postoperative result even several years after the operation. Looking back, 31 patients (27%) would no longer have the operation performed. The inadequate result of the rhonchopathy was specified as the reason by 21 patients. Ten patients had unpleasant memories of the operation because of intensive postoperative pain. Snoring and apneic phases are suppressed or improved by non-traumatic UPPP in the majority of patients. This effect persisted even years after the operatio

Intracochlear pressure in cadaver heads under bone conduction and intracranial fluid stimulation

Background The frequency dependent contributions of the various bone conduction pathways are poorly understood, especially the fluid pathway. The aim of this work is to measure and investigate sound pressure propagation from the intracranial space to the cochlear fluid. Methods Stimulation was provided sequentially to the bone (BC) or directly to the intracranial contents (hydrodynamic conduction, or HC) in four cadaver heads, where each ear was tested individually, for a total of 8 samples. Intracranial pressure was generated and monitored via commercial hydrophones, while the intracochlear sound pressure (ICSP) levels were monitored via custom-made intracochlear acoustic receivers (ICAR). In parallel, measurements of the 3D motion of the cochlear promontory and stapes were made via 3D Laser Doppler Vibrometer (3D LDV). Results Reliability of the intracochlear sound pressure measurements depends on the immobilization of the ICAR relative to the otic capsule. Regardless of the significant differences in absolute stapes and promontory motion, the ratios between the otic capsule velocity, the stapes volume velocity (relative to the cochlea), and the intracochlear pressure were very similar under BC and HC stimulus. Under HC, the cochlear fluid appears be activated by an osseous pathway, rather than a direct non-osseous pathway from the cerebrospinal fluid (CSF), however, the osseous pathway itself is activated by the CSF pressure. Conclusions Data suggests that the skull bone surrounding the brain and CSF could play a role in the interaction between the two CSF and the cochlea, under both stimulation conditions, at high frequencies, while inertia is dominant factor at low frequencies. Further work should be focused on the investigation of the solid-fluid interaction between the skull bone walls and the intracranial content

Subjective Sound Quality Detection (HISQUI) over Time after Vibrant Soundbridge Implantation

Background: To evaluate the long-term audiological outcomes combined with the Hearing Implant Sound Quality Index (HISQUI) after Vibrant Soundbridge (VSB) implantation. Methods: Prospective recall cohort study of patients who received a VSB in a tertiary academic medical center between 1996 and 2017. Air conduction (AC) and bone conduction (BC), sound field thresholds in aided and unaided conditions, and speech discrimination in noise (Oldenburger sentence test) were measured. Postoperative results were compared with preoperative audiograms. Furthermore, the HISQUI was evaluated. Results: Ten patients (eleven implants) were included, the mean follow up period was nine years. The mean AC threshold preoperatively was between 63 and 70 dB, and the BC was between 38 and 49 dB from 500 to 4000 Hz. In the free-field audiogram, the mean threshold was between 61 and 77 dB unaided vs. between 28 and 52 dB in the aided condition. The average signal to noise ratio (SNR) in the Oldenburger sentence test in the unaided condition was 10 dB ± 6.7 dB vs. 2 dB ± 5.4 dB in the aided condition. Three patients reported a good to very good hearing result, four patients a moderate, and three patients a poor hearing result. There was a significant association between the years of implantation and the HISQUI (p = 0.013), as well as a significant decrease by 14 HISQUI points per 10 dB SPL decline (SE 5.2, p = 0.023). There was a significant difference between the change of BC over the years and the HISQUI, as well as the number of years after implantation and the HISQUI. On average, per dB decrease in BC, the HISQUI decreases by 1.4 points, and every year after implantation the HISQUI decreases by 2.7 points. Conclusions: The aided threshold in free field and speech understanding in noise improved significantly with VSB. An increase over time of BC thresholds was observed as well as a decrease in HISQUI score. This decrease in BC thresholds over time may be due to presbycusis. Therefore, monitoring of these patients over time should be considered to discuss alternative hearing rehabilitation measures in a timely manner

Characterization of Stapes Anatomy: Investigation of Human and Guinea Pig

The accuracy of any stapes model relies on the accuracy of the anatomical information upon which it is based. In many previous models and measurements of the stapes, the shape of the stapes has been considered as symmetric with respect to the long and short axes of the footplate. Therefore, the reference frame has been built based upon this assumption. This study aimed to provide detailed anatomical information on the dimensions of the stapes, including its asymmetries. High-resolution microcomputed tomography data from 53 human stapes and 11 guinea pig stapes were collected, and their anatomical features were analyzed. Global dimensions of the stapes, such as the size of the footplate, height, and volume, were compared between human and guinea pig specimens, and asymmetric features of the stapes were quantitatively examined. Further, dependence of the stapes dimensions on demographic characteristics of the subjects was explored. The height of the stapes relative to the footplate size in the human stapes was found to be larger than the corresponding value in guinea pig. The stapes showed asymmetry of the footplate with respect to the long axis and offset of the stapes head from the centroid of the medial surface of the footplate for both humans and guinea pigs. The medial surface of the footplate was curved, and the longitudinal arches of the medial surface along the long axis of the footplate were shaped differently between humans and guinea pigs. The dimension of the footplate was gender-dependent, with the size greater in men than in wome

Gustatory Function of Patients With and Without Cholesteatoma Undergoing Middle Ear Surgery

Objective: To compare measured and perceived taste function before and after surgery of patients with chronic otitis media with cholesteatoma (OMCC) to patients without cholesteatoma (patients with chronic suppurative otitis media [CSOM] and patients with lateral skull base lesions [LSB]). Methods: This prospective cohort study included 29 patients undergoing surgery for unilateral OMCC. The chorda tympani nerve (CTN) was resected in 8 of these patients. Fourteen patients undergoing surgery for unilateral CSOM and 5 patients undergoing surgery for unilateral LSB (with CTN resection) served as the comparison group. Taste function was measured using taste strips on both sides of the tongue before surgery, 2 weeks postoperatively and 3 months postoperatively. The affected side of the tongue was compared to the unaffected side. A questionnaire on taste perception was completed at each visit. Results: Preoperatively, cholesteatoma patients showed higher taste strip scores than non-cholesteatoma patients, indicating a larger difference between the healthy and affected sides of the tongue. Despite this difference in measured taste function few cholesteatoma patients reported taste alteration before surgery (3/29 [10.3%]). Postoperatively, patients with CTN resection (OMCC patients with CTN resection and LSB patients) showed a decreased measured taste function. Subjectively, only approximately 20% of these patients reported taste alteration 3 months postoperatively. Conclusions: Before surgery, cholesteatoma patients displayed an impaired measured taste function compared to patients without cholesteatoma (CSOM, LSB). Subjectively this was often unnoticed. After surgery, despite removal of the CTN and consequent reduction of measured taste function, few patients reported taste alteration and subjective taste perception was seen to be improving. In regards to middle ear surgery, perceived taste function does not seem to reflect measured gustatory function

Multiphoton imaging for morphometry of the sandwich-beam structure of the human stapedial annular ligament

Background The annular ligament of the human stapes constitutes a compliant connection between the stapes footplate and the peripheral cochlear wall at the oval window. The cross section of the human annular ligament is characterized by a three-layered structure, which resembles a sandwich-shaped composite structure. As accurate and precise descriptions of the middle-ear behavior are constrained by lack of information on the complex geometry of the annular ligament, this study aims to obtain comprehensive geometrical data of the annular ligament via multiphoton imaging. Methods The region of interest containing the stapes and annular ligament was harvested from a fresh-frozen human temporal bone of a 46-years old female. Multiphoton imaging of the unstained sample was performed by detecting the second-harmonic generation of collagen and the autofluorescence of elastin, which are constituents of the annular ligament. The multiphoton scans were conducted on the middle-ear side and cochlear side of the annular ligament to obtain accurate images of the face layers on both sides. The face layers of the annular ligament were manually segmented on both multiphoton scans, and then registered to high-resolution μCT images. Results Multiphoton scans of the annular ligament revealed 1) relatively large thickness of the core layer compared to the face layers, 2) asymmetric geometry of the face layers between the middle-ear side and cochlear side, and variation of their thickness and width along the footplate boundary, 3) divergent relative alignment of the two face layers, and 4) different fiber composition of the face layers along the boundary with a collagen-reinforcement near the anterior pole on the middle-ear side. Conclusion and outlook Multiphoton microscopy is a feasible approach to obtain the detailed three-dimensional features of the human stapedial annular ligament along its full boundary. The detailed description of the sandwich-shaped structures of the annular ligament is expected to contribute to modeling of the human middle ear for precise simulation of middle-ear behavior. Further, established methodology in this study may be applicable to imaging of other middle-ear structures. Keywords Annular ligament Stapes Multiphoton microscopy Two-photon microscopy Face layer Core laye

Complex Stapes Motions in Human Ears

It has been reported that the physiological motion of the stapes in human and several animals in response to acoustic stimulation is mainly piston-like at low frequencies. At higher frequencies, the pattern includes rocking motions around the long and short axes of the footplate in human and animal ears. Measurements of such extended stapes motions are highly sensitive to the exact angulation of the stapes in relation to the measurement devices and to measurement errors. In this study, velocity in a specific direction was measured at multiple points on the footplates of human temporal bones using a Scanning Laser Doppler Vibrometer (SLDV) system, and the elementary components of the stapes motions, which were the piston-like motion and the rocking motions about the short and long axes of the footplate, were calculated from the measurements. The angular position of a laser beam with respect to the stapes and coordinates of the measurement points on the footplate plane were calculated by correlation between the SLDV measurement frame and the footplate-fixed frame, which was obtained from micro-CT images. The ratios of the rocking motions relative to the piston-like motion increased with frequency and reached a maximum around 7kHz. A novel method for quantitatively assessing measurements of complex stapes motions and error boundaries of the motion components is presented. In the frequency range of 0.5 to 8kHz, the magnitudes of the piston-like and two rocking motions were larger than estimated values of the corresponding upper error bound