Prospective study of the application of a 3D exoscope system (VITOM 3D) in ear surgery compared to conventional surgical microscopes: part I - analysis of objective parameters.

Background: This prospective study compared the application of a 3D exoscope (VITOM 3D) with surgical microscopes (SM) in ear surgery.

Methods: 62 patients were included (exoscope group (E+) n = 31; SM group (E-) n = 31). Procedures included cochlea implantation (nE + = 10, nE- = 10), reconstructive middle ear surgery due to chronic otitis media with (COMwC; nE + = 11, nE- = 11) and without cholesteatoma (COMsC; nE + = 10, nE- = 10).

Influence of the Coupling on the Hearing Outcome After Implantation of an Active Middle Ear Implant: Comparison of the Transmission Behavior in Temporal Bone Experiments With Clinical Data.

Objectives: The active middle ear implant, Vibrant Soundbridge (VSB), can be implanted with a variety of couplers. Hearing outcome after implantation has been investigated in both temporal bone (TB) experiments and patient studies, but the relationship between experimental and clinical data is still weak in the literature. Therefore, experimental data from TB experiments should be compared with patient data in a retrospective study, in which the floating mass transducer is used with couplers of the third generation.

[Coupling of active middle ear implants-biomechanical aspects].

Active middle ear implants or implantable hearing aids are used to treat sensorineural or combined hearing loss. Their coupling to the middle ear structures has a large impact on the success of rehabilitation. Practical issues such as the coupling site, influence of middle ear status, and forward and backward excitation of the inner ear are discussed in the context of biomechanics.

Virtual Quality Control in Middle Ear Surgery: Is Image-guided Tympanoscopy a Valuable Tool for Depicting Borderline Situations?

Hypothesis: Before modern imaging was introduced, revision surgery was the only way to evaluate possible reasons for inadequate improvement in hearing after ossicular replacement during reconstructive middle ear surgery.

Background: The aim of this study was to evaluate freely navigable virtual tympanoscopy using different computed tomographic modalities. We compared cone-beam computed tomography (CBCT), flat panel computed tomography (FPCT), and conventional computed tomography in helical mode (CTH), volume mode (CTV), and ultra high resolution mode (CTD).

[Active hearing implants in chronic otitis media].

In patients with inadequate hearing improvement after tympanoplasty and failure of conventional hearing aid fitting, active hearing implants provide an alternative treatment option. Active middle ear implants function as a vibromechanical bypass of the stiffness and damping effect of a poorly oscillating tympanic membrane and the (reconstructed) ossicular chain. The selection of the hearing system depends on the maximum output levels of the hearing system and the anatomical conditions in mostly multiply operated ears.

Sensor-actuator component for a Floating Mass Transducer-based fully implantable hearing aid.

We propose a novel system based on the Floating Mass Transducer (FMT) to be used as the active component of a fully implantable, Vibrant Soundbridge-like middle ear implant. The new system replaces the external microphone used in the currently available design with an implantable piezoelectric sensor that is inserted into the incudostapedial joint and picks up the vibrations transmitted to the long process of the incus. The FMT is coupled to the round window of the cochlea.

Feasibility Study of a Mechanical Real-Time Feedback System for Optimizing the Sound Transfer in the Reconstructed Middle Ear.

Objective: To evaluate electromechanical excitation as an alternative excitation mode for middle ear transfer function (METF) measurements as well as real-time feedback in prosthetic ossicular reconstruction.

Method: In eight human cadaveric temporal bones, the ossicular chain was excited using acoustic and mechanical (floating mass transducer, FMT) stimulation to determine the METF. After disconnecting the ossicular chain and reconstruction with partial or total prosthesis the METFs were measured again.

Function, Applicability, and Properties of a Novel Flexible Total Ossicular Replacement Prosthesis With a Silicone Coated Ball and Socket Joint.

Hypothesis: A total ossicular replacement prosthesis (TORP) with a silicone coated ball and socket joint (BSJ) is able to compensate pressure changes and therefore provide better sound transmission compared with rigid prostheses.

Background: Dislocation and extrusion are known complications after TORP reconstruction, leading to revisions and recurrent hearing loss. Poor aeration of the middle ear, scar tension, and static pressure variations in conjunction with rigid prosthesis design causes high tension at the implant coupling points.

Impact of Prosthesis Length on Tympanic Membrane's and Annular Ligament's Stiffness and the Resulting Middle Ear Sound Transmission.

Hypothesis: Prosthesis' length creates tension in ossicular reconstructions, which directly effects the middle ear sound transmission.

Background: Relatively long prostheses are often used to stabilize the middle ear reconstruction to prevent dislocation. Thereby, tension on the flexible components such as the tympanic membrane (TM) and the annular ligament (AL) is increased.

Fully implantable hearing aid in the incudostapedial joint gap.

A fully implantable hearing aid is introduced which is a combined sensor-actuator-transducer designed for insertion into the incudostapedial joint gap (ISJ). The active elements each consist of a thin titanium membrane with an applied piezoelectric single crystal. The effectiveness of the operating principle is verified in a temporal bone study.

Hearing outcome after sequential cholesteatoma surgery.

The objective of this study was to assess hearing outcome after sequential cholesteatoma surgery stratified for exclusively transcanal technique (ETC), combined transcanal and transmastoidal technique (TCM) and canal wall down surgery (CWD) and to analyze the impact of ossicular reconstruction technique (partial ossicular replacement prostheses/PORP and total ossicular replacement prostheses/TORP) on hearing outcome. This study is a retrospective case review and clinical case study conducted in a tertiary referral center. Patients who underwent 376 cholesteatoma surgeries (2007-2009) and 92 ears in clinical re-examination at least 12 months postoperatively were included.

Health-related quality of life measurement after cholesteatoma surgery: comparison of three different surgical techniques.

The objective of this study was to compare health-related quality of life (HRQOL) after sequential cholesteatoma surgery including exclusively transcanal technique (ETC), combined transcanal transmastoidal technique (TCM) and canal wall down surgery with obliteration (CWD). It was a clinical case study conducted in a tertiary referral center. 97 patients at least 12 months after cholesteatoma surgery were included.

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.

Influence of the middle ear anatomy on the performance of a membrane sensor in the incudostapedial joint gap.

There is a great demand for implantable microphones for future generations of implantable hearing aids, especially Cochlea Implants. An implantable middle ear microphone based on a piezoelectric membrane sensor for insertion into the incudostapedial gap is investigated. The sensor is designed to measure the sound-induced forces acting on the center of the membrane.

The ostrich middle ear for developing an ideal ossicular replacement prosthesis.

The aim of the study was to investigate the validity of the avian middle ear model for researching the tympanoplasty mechanics. We studied the morphological details, acoustic transmission and quasi-static behavior of the ostrich tympano-ossicular system. The stained specimens of the ostrich middle ear were examined under a light microscope.

New total ossicular replacement prostheses with a resilient joint: experimental data from human temporal bones.

Hypothesis: New flexible total ossicular prostheses with an integrated microjoint can compensate for large static displacements in the reconstructed ossicular chain. When properly designed, they can mimic the function of the joints of the intact chain and ensure good vibration transfer in both straight and bent conditions.

Background: Prosthesis dislocations and extrusions are frequently observed after middle ear surgery.

[Evaluation of the Dresden Tympanoplasty Model (DTM)].

The training of microsurgical motor skills is essentiell for surgical education if the interests of the patient are to be safeguarded. In otosurgery the complex anatomy of the temporal bone and variations necessitate a special training before performing surgery on a patient. We therefore developed and evaluated a simplified middle ear model for acquiring first microsurgical skills in tympanoplasty.

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.

Laser Doppler vibrometry of the middle ear in humans: derivation dependence, variability, and bilateral differences.

Objective: Derivation dependence, inter- and intrasubject/intertest variability, bilateral differences of the eardrum vibration characteristics have been investigated using laser Doppler vibrometry (LDV).

Material And Methods: A total of 31 normally hearing adults were examined. In each subject, both ears were consecutively stimulated by the chirp acoustic stimulus that covered 500-3700-Hz frequencies.

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.

Partial ossicular reconstruction: comparison of three different prostheses in clinical and experimental studies.

Objective: To compare the reconstruction results of a long incus process defect using 3 different partial ossicular replacement prostheses (PORP).

Study Design: Temporal bone experiments and retrospective case review.

Setting: Tertiary referral center.

[A new model for training in tympanoplasty].

Background: Functional simulation of middle ear reconstruction is a valuable tools for training in otosurgery. We introduce a new experimental model which provides a direct acoustic feedback of the functional quality of ossicular chain reconstruction.

Method: In this model the tympanic membrane and the ossicular chain have to be reconstructed for proper sound transmission to an artificial inner ear receptor.