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. Interventions included sequential cholesteatoma surgery with ETC, TCM or CWD; ossiculoplasty with partial and total ossicular replacement prostheses. HRQOL assessed by Chronic Otitis Media Outcome Test 15 including an overall score and three subscores ('ear symptoms', 'hearing function' and 'mental health') as well as a general evaluation of HRQOL and the frequency of physician consultations, audiometric outcome related to HRQOL were the main outcome measures. Patients, who had undergone sequential cholesteatoma surgery, showed moderate restrictions in HRQOL postoperatively. Stratified for the three surgical techniques, patients receiving ETC tended to report lower restrictions in HRQOL. The ETC group offered a significantly lower value in the subscore 'ear symptoms'. The 'hearing function' was attributed to be the most restriction criteria for all techniques. The overall score and all subscores correlated moderately with the postoperative air conduction threshold. The strongest correlation coefficient was achieved for the subscore 'hearing function' (r(s) = 0.49, p < 0.001). Sequential cholesteatoma surgery offers acceptable moderate restrictions in HRQOL postoperatively. Patients receiving canal wall down surgery with obliteration showed equivalent limitations in HRQOL compared to closed techniques (ETC, TCM). The postoperative air conduction threshold was shown not to be a sufficient indicator for HRQOL. Therefore, disease-specific validated and reliable measuring instruments for HRQOL should be transferred from clinical research to clinical practice to provide an individualized postoperative assessment after cholesteatoma surgery.

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. The sound transfer function and quasi-static performance of the ostrich middle ear were evaluated using laser Doppler vibrometry. The application of pressure to the tip of the extracolumella causes a buckling movement of the ossicle between the cartilaginous and bony parts. Histologically, the intracolumellar connection can be identified as a junction zone between bone and hyaline cartilage. Sound conduction through the human middle ear is less effective than it is through the ostrich middle ear. The greatest difference (35 dB) was observed in the low-frequency region. Because the extracolumella bends, the medial displacements of the eardrum were not fully transmitted to the footplate. The amplitude of the ostrich columella footplate quasi-static medial displacements significantly exceeded that of the human footplate in both intact and reconstructed middle ears. The ostrich middle ear is a suitable model for designing total ossicular replacement implants. The main protective mechanism in the ostrich middle ear under quasi-static stress is a buckling movement of the extracolumella. The total ossicular prostheses of the new generation should contain an elastic element that allows an adaptation to greater quasi-static eardrum movements.

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 oneyear-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.

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. Sequential cholesteatoma surgery with ETC, TCM, or CWD; ossiculoplasty with PORP or TORP were the interventions administered. Pre- and postoperative air-bone gap (ABG) and air conduction threshold (AC) for 0.5-3 kHz were the main outcome measures. Overall, the mean preoperative ABG decreased from 25.3 ± 1.3 to 19.8 ± 0.9 dB with a mean ABG closure of 5.4 ± 1.3 dB (p ≤ 0.001). According to surgical technique, the postoperative ABG after CWD 23.5 ± 2.1 was significantly worse compared to ETC (17.3 ± 1.0 dB, p < 0.05) and TCM (19.4 ± 1.3 dB). A significant ABG closure was observed after ETC (6.8 ± 2.0 dB, p < 0.01) and TCM (6.5 ± 2.0 dB, p < 0.01) contrary to CWD (2.1 ± 2.9 dB, p > 0.05). Patients receiving PORP showed a significantly less ABG postoperatively (19.0 ± 0.9 dB, p ≤ 0.05) compared to the TORP group (24.1 ± 2.5 dB). However, a significant hearing gain was assessed after PORP- (4.7 ± 1.6 dB, p ≤ 0.01) and TORP- implantation (10.4 ± 3.7 dB, p ≤ 0.01). Sequential cholesteatoma surgery allowed for an excellent hearing outcome postoperatively. An intact posterior canal wall and a present stapes suprastructure were identified to predict a significantly superior hearing result. In addition to the technical and prosthetic considerations, the audiological outcome was confounded by the attending middle ear pathology.

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.

The titanium prostheses with a resilient joint that were investigated in this study had good sound transfer characteristics under optimal conditions as well as in a compressed state. As a result of joint bending, the implants compensate for the small changes in length of the ossicular chain that occur under varying middle ear pressure. The implants require a stable support at the stapes footplate to function properly.

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.

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.