Marcus Neudert

Experience with vibroplasty couplers at the stapes head and footplate.

Objective To report on experiences with implanting the Vibrant Soundbridge (VSB) coupled to the stapes head using a new Clip-Coupler or to the stapes footplate using a new OW-Coupler (CliP- or OW-Coupler Vibroplasty). Study Design Single subject, repeated measures. Setting Two university hospital ENT departments. Patients Fourteen German-speaking patients from 2 European study sites were implanted with either a CliP-Coupler or OW-Coupler attached to a VSB floating mass transducer (FMT). They were evaluated preoperatively and postoperatively for bone and air conduction thresholds with and without the implant, as well as speech perception tests. Main Outcome Measures Measuring the efficacy and safety of OW- and CliP-Coupler-Vibroplasty as a method to treat mixed hearing loss. Results Bone conduction thresholds remained stable preoperatively and postoperatively. The patients’ average speech perception performances at 65/80 dB (HL) increased from 0.8/13.8% to 63/82%. The pure tone audiograms showed an average improvement in air conduction thresholds after implantation with the VSB of 25 dB at 0.5 kHz to 50 dB at 4 kHz. Conclusion OW- or Clip-Coupler-Vibroplasty using couplers was found to be a straightforward procedure, which produced good results in this group of patients.

Experimental Investigation of Rotational Tomography in Reconstructed Middle Ears with Clinical Implications

A large air-bone-gap after ossiculoplasty may be due to a malpositioned or displaced prosthesis. Rotational tomography (RT) has the potential to provide high-resolution images of implants without artifacts and with less radiation dosage than CT scan. Twenty-seven temporal bone specimens underwent measurements of middle ear transfer function using Laser-Doppler-Vibrometry (LDV) before and after placement of ossicular replacement prostheses (PORPs, TORPs) made of titanium. RT was performed on all specimens. RT allowed 3-dimensional viewing of the temporal bone, accurate localization of implants within the reconstructed middle ear and determination of angles between the inserted prostheses and the tympanic membrane (TM) and/or the malleus handle (MH). Presence or absence of contact between the implant and the TM, malleus or stapes could be clearly visualized. Displaced prostheses were readily identified. The functional LDV-measurements for TORPs showed a trend favoring coupling to the malleus handle, while for PORPs, coupling to the TM was favored. For PORPs, sound transmission was worse with increasing angles between the PORP and stapes superstructure (p<0.05). Following our experimental results RT is an innovative, relevant and useful imaging technique to obtain immediate postoperative feedback after ossicular reconstruction and to precisely determine the position of middle ear implants.

Flat panel CT following stapes prosthesis insertion: an experimental and clinical study

ObjectivesAnatomical information of the middle and inner ear is becoming increasingly important in post-operative evaluation especially after stapesplasty with unsuccessful improvement of the air-bone gap (ABG). So far computed tomography (CT) has been the first choice for detection of reasons for recurrent hearing loss. CT has the disadvantage of metal-induced artefacts after insertion of middle ear implants and of a relatively high irradiation dose.MethodsFlat panel CT (fpCT) was performed in three temporal bone specimen after experimental insertion of different stapes prostheses, aiming to validate the accuracy of fpCT of the middle and inner ear. Additionally, 28 consecutive patients, supplied with different stapes prostheses underwent post-operative fpCT to compare the pre- and post-operative hearing results with the determined prosthesis position in the middle and inner ear.ResultsIn all cases, fpCT showed a statistically significant correlation between hearing improvement and prosthesis position. This technique provided detailed post-operative information of the implant position in patients and temporal bone specimen.ConclusionsThe new imaging technique of fpCT allows the immediate and almost artefact-free evaluation of surgical results following stapesplasty. Further benefits are a lower irradiation dose and higher isovolumetric resolution compared with standard CT.Key Points• Flat panel computed tomography (fpCT) helps otosurgeons design precise stapes protheses• fpCT allows a prediction of the postoperative hearing outcome in patients• fpCT is an adequate imaging technique for immediate postoperative quality control. Postoperative management of patients with prosthesis-related complications is more appropriate

Osseointegration of Titanium Prostheses on the Stapes Footplate

The success of middle ear reconstructive surgery depends on stable coupling between the prosthesis and residual ossicles. To establish a stable fixed point on the stapes footplate for subsequent prosthesis reconstruction, a titanium footplate anchor was coated with osteoinductive substances to induce a controlled osseointegration on the footplate. Various studies have shown that collagen-based matrices with and without bone growth and differentiation factors can induce and enhance bone formation and consequently increase implant stability. The ears of 23 one-year-old Merino sheep (n = 46) were divided into five groups and implanted with a specially designed footplate anchor. The surface of each implant was modified by applying a collagenous matrix (collagen I or II) either with immobilized bone morphogenic protein (BMP-4) or transforming growth factor-ß, respectively, to stimulate osteoblastic activation and differentiation on the stapes footplate with subsequent osseointegration. Polychrome labeling was used to assess new bone formation and remodeling during the study. After study termination on day 84, synchrotron radiation-based computed microtomography and histomorphometry were used to identify bone implant contact. Eight implants showed radiographical and/or histological evidence of integration by newly formed bone. An osseointegration could histologically be proven in two of these eight specimens, and additional ectopic bone formations were seen in another 21 specimens. In all animals, bone turnover on the footplate was proven by polychrome labeling. This study proves the general ability to induce a controlled osseointegration of titanium implants biologically activated with artificial extracellular matrices on their surfaces on the stapes footplate in a mammalian organism.

Clinical investigation of flat panel CT following middle ear reconstruction: a study of 107 patients

ObjectivesAfter middle ear reconstruction using partial or total ossicular replacement prostheses (PORP/TORP), an air–bone gap (ABG) may persist because of prosthesis displacement or malposition. So far, CT of the temporal bone has played the main role in the diagnosis of reasons for postoperative insufficient ABG improvement. Recent experimental and clinical studies have evaluated flat panel CT (fpCT) as an alternative imaging technique that provides images with high isovolumetric resolution, fewer metal-induced artefacts and lower irradiation doses.MethodsOne hundred and seven consecutive patients with chronic otitis media with or without cholesteatoma underwent reconstruction by PORP (n = 52) or TORP (n = 55). All subjects underwent preoperative and postoperative audiometric testing and postoperative fpCT.ResultsStatistical evaluation of all 107 patients as well as the sole sub-assembly groups (PORP or TORP) showed a highly significant correlation between hearing improvement and fpCT-determined prosthesis position. FpCT enables detailed postoperative information on patients with middle ear reconstruction.ConclusionsFpCT is a new imaging technique that provides immediate feedback on surgical results after reconstructive middle ear surgery. Specific parameters evaluated by fpCT may serve as a predictive tool for estimated postoperative hearing improvement. Therefore this imaging technique is suitable for postoperative quality control in reconstructive middle ear surgery.Key Points• Flat panel CT offers advantages with regard to artefacts and radiation dose.• FpCT provides higher isovolumetric resolution of temporal bone and middle ear implants.• FpCT allows prediction of the postoperative hearing outcome in patients.• FpCT is an important tool for immediate postoperative quality control.• FpCT improves postoperative management of patients with complications following ossicular replacement

Cholesteatoma recidivism: comparison of three different surgical techniques.

Objective To compare cholesteatoma recidivism rates after exclusive transcanal technique (ETC), combined transcanal and mastoidal technique (TCM, both subsets of intact canal wall technique, ICW), and canal wall down surgery (CWD). Study Design Retrospective case review and clinical case study Setting Tertiary referral center. Patients 406 cholesteatoma surgeries (2007–2009), 116 ears in clinical re-examination at least 1 year postoperatively. Intervention Sequential cholesteatoma surgery with ETC, TCM, or CWD. Main Outcome Measures Cholesteatoma recidivism, residual and recurrent disease, localization of recidivism, validity of clinical findings. Results Out of 406 patients, ETC was performed in 227 (56%), TCM in 122 (30%), and CWD in 57 (14%) cases. Recidivism rates after ICW (15%) and CWD (16%) were almost similar. Recidivism was more frequent after ETC (11%) than after TCM (25%). Residuals were observed in 2% after ETC, 6.5% after TCM, and 7% after CWD. Incidence of recurrent disease was 9% for ETC, 18% for TCM, and 9% for CWD. Preferred localization of recidivism was the tympanic cavity after ETC (92%) and CWD (56%) and the mastoid cavity after TCM (53%). The clinical re-examination showed no further recidivistic disease. Conclusions Sequential surgery is an effective and successful strategy in cholesteatoma eradication, providing a similar recidivism rate compared to following cholesteatoma retrograde and resection of the posterior canal wall. Lower recidivism after ETC was observed as a consequence of limited disease and the postoperative middle ear status determined the higher rate of recurrence after TCM. Therefore, the restricted visualization of the middle ear during ICW surgery does not increase the rate of recidivism, compared with CWD, as described in other studies. Cholesteatoma recidivism is mainly attributed to the surgeon’s experience that outweighs the chosen strategy.

Sound Transfer of Active Middle Ear Implants

Implantable hearing aids are gaining importance for the treatment of sensorineural hearing loss and also for mixed hearing loss. The various hearing aid systems, combined with different middle ear situations, give rise to a wide range of different reconstructions. This article attempts to summarize the current knowledge concerning the mechanical interaction between active middle ear implants (AMEIs) and the normal or reconstructed middle ear. Some basic characteristics of the different AMEIs are provided in conjunction with the middle ear mechanics. The interaction of AMEIs and middle ear and the influence of various boundary conditions are discussed in more detail.

Medical education in otorhinolaryngology in Germany. Implementation of the new licensing regulations for physicians

BACKGROUND In 2003 new regulations for the licensing of German physicians came into effect. The aim of this study was to survey the present status of realization in German otorhinolaryngology (ORL) university departments. METHODS A questionnaire containing 31 items was sent to all German ORL university departments. RESULTS A total of 31 (86%) ORL departments responded to the questionnaire. Most faculties reacted correctly in the practical realization of the new regulation demands. Regarding the quality of written and practical examinations, some changes have to be considered in order to maintain high quality standards. CONCLUSION The demands of the new licensing regulations have not yet been fully implemented. Therefore, medical education must gain importance in the daily clinical routine. Establishment of nationwide learning objectives and resources pooling for written examinations would be helpful.

A New Intraoperative Real-time Monitoring System for Reconstructive Middle Ear Surgery: An Experimental and Clinical Feasibility Study.

Hypothesis: Electromagnetical excitation of ossicular vibration is suitable for middle ear transmission measurements in the experimental and clinical setting. Thereby, it can be used as a real-time monitoring system for quality control in ossiculoplasty. Background: Positioning and coupling of middle ear prosthesis are a precondition for good postoperative hearing results, but at the same time completely dependent upon the surgeons subjective judgment during surgery. We evaluated an electromagnetically driven measurement system that enables for in vitro and in vivo transmission measurements and thus can be used as a real-time monitoring tool in ossicular reconstruction. Methods: For electromagnetical excitation a magnet was placed on the umbo of the malleus handle and driven by a magnetic field. The induced stapes displacement was picked up by laser Doppler vibrometry on the footplate. Measurements were performed on the intact ossicular chain in five cadaveric temporal bones and during five cochlear implant surgeries. Additionally, two ossiculoplasties were performed under real-time transmission feedback with the monitoring system. Results: Experimentally, the equivalent sound pressure level of the electromagnetic excitation was about 70 to 80 dB which is 10 to 20 dB less than the acoustic stimulation. In the intraoperative setup the generated stapes displacements were about 5 to 20 dB smaller compared with the temporal bone experiments. Applied as real-time feedback system, an improvement in the middle ear transfer function of 4.5 dB in total and 20 dB in partial ossicular reconstruction were achieved. Conclusion: The electromagnetical excitation and measurement system is comparable to the gold standard with acoustical stimulation in both, the experimental setup in temporal bones as well as in vivo. The technical feasibility of the electromagnetical excitation method has been proven and it is shown that it can be used as a real-time monitoring system for ossiculoplasty in the operation room.

Microsurgical Skills Training With a New Tympanoplasty Model: Learning Curve and Motivational Impact

Objectives To evaluate the microsurgical skills training on a tympanoplasty model with regard to the learning curve and the participants’ motivation for a surgical specialty. Study Design Randomized controlled prospective study. Setting Department of Otolaryngology, Head and Neck Surgery, Medical Campus Carl Gustav Carus at the Technische Universität Dresden, Germany. Subjects Thirty randomly chosen fifth-year medical students divided into 2 groups. Interventions Group 2 (n = 16) had to perform an ossicular and tympanic membrane reconstruction on a tympanoplasty model on Days 1, 7, 14, and 21 and Group 1 (n = 14) on Days 1 and 21, while observing the procedure at Days 7 and 14. Six otosurgeons served as gold standard. Attempts and time of prosthesis placement and time for tympanic membrane reconstruction were recorded. Tremor frequency and amplitude were obtained at the same time points. An adjusted study interest questionnaire was used to assess students’ motivation. Results Students in Group 2 showed a significant improvement in all reconstruction parameters over the study period compared with both, baseline measurement on first day and Group 1. However, the obtained learning curve did not reach the experts level. Tremor indices and students’ motivation showed no correlation with the reconstruction parameters, whereas the training itself had a positive impact on students’ interest in the surgical specialty. Conclusion Training with the tympanoplasty model is suitable to acquire first microsurgical motor skills in otolaryngology and to arouse students’ interest in the surgical field and otorhinolaryngology.