Safety of high-power short pulse single spot diode laser stapedotomy: an experimental animal study.

BACKGROUND: We present a new method of diode laser stapedoplasty - high-power short-pulse mode with preliminary carbonization of the waveguide and a single spot of laser ablation. AIMS/OBJECTIVE: The aim of our research is the safety evaluation of presented mode 0.98 µm diode laser cochleostomy in guinea pigs. MATERIAL AND METHODS: Guinea pigs (n = 10) received 0.98 µm diode laser cochleostomy on one ear under general anesthesia. The control group was based on untreated ears (n = 10). The assessment of auditory function was performed using the distortion product otoacoustic emission (DPOAE) before and 7 d after surgery. To assess the degree of damage from the laser cochleas were extracted for histological examination. RESULTS: To evaluate the negative impact of laser energy on OHCs and auditory function, we analyzed DPOAE amplitudes for 6400 and 8000 Hz since high frequency. The paired Student's t-test showed no statistically significant difference between the two groups. The histological examination yielded no statistically significant difference in the number of intact OHCs in the two groups. CONCLUSION AND SIGNIFICANCE: Our study confirms that the proposed method of high-power short pulse diode laser stapedotomy is safe for the inner ear. Further prospective and randomized clinical trials are required to evaluate the possible benefits of this method.

Comparing intermediate-term hearing results of NiTiBOND and Nitinol prostheses in stapes surgery.

OBJECTIVE: To statistically analyse the hearing thresholds of two cohorts undergoing stapedotomy for otosclerosis with two different prostheses. METHOD: A retrospective study was conducted comparing NiTiBOND (n = 53) and Nitinol (n = 38) prostheses. RESULTS: Average follow-up duration was 4.1 years for NiTiBOND and 4.4 years for Nitinol prostheses. The post-operative air-bone gap was 10 dB or less, indicating clinical success. The p-values for differences between (1) pre- and post-operative values in the NiTiBOND group, (2) pre- and post-operative values in the Nitinol group, (3) pre-operative values and (4) post-operative values in the two groups were: air-bone gap - p < 0.001, p < 0.001, p = 0.631 and p = 0.647; four-frequency bone conduction threshold - p = 0.076, p = 0.129, p < 0.001 and p = 0.005; four-frequency air conduction threshold - p < 0.001, p < 0.001, p = 0.043 and p = 0.041; three-frequency (1, 2 and 4 kHz) bone conduction threshold pre-operatively - p = 0.639, p = 0.495, p = 0.001 and p = 0.01; and air conduction threshold at 4 kHz: - p < 0.001, p < 0.001, p = 0.03 and p = 0.058. CONCLUSION: Post-operative audiological outcomes for NiTiBOND and Nitinol were comparable.

Robotic Ear Surgery.

Robots under research and development for otology can be classified as collaborative (intervention is constrained by the robot but surgeon directly actuates the end-effector), teleoperated (surgeon remotely controls a tool with modification [eg, tremor reduction] by the robot), or autonomous (surgeon monitors the robot performing a task). Current clinical trials focus on more accurate stapes surgery, minimally invasive access to the cochlea, and less traumatic insertion of cochlear implant electrode arrays. Autonomous approaches to major aspects of surgical interventions (eg, mastoidectomy) will likely be late entries to clinical use, given higher cost of regulatory approval and disruption of existing workflow.

Microdrill in endoscopic stapes surgery: Is it safe?

PURPOSE: To assess the safety of using a microdrill in endoscopic vs microscopic stapes surgery. MATERIALS AND METHODS: A retrospective review of 29 adult ears with otosclerosis who underwent either an endoscopic or microscopic approach to microdrill stapedotomy. PRIMARY OUTCOME: Determine if transcanal endoscopic stapes surgery with the microdrill is as safe as microscopic stapes surgery. Secondary outcome: Bone and air pure-tone averages, air-bone gap, speech discrimination, overall surgical cost, and operative time were measured and analyzed. Complications such as post-operative dysgeusia, vertigo, readmission, revision and hearing loss were noted. RESULTS: 29 patients with otosclerosis were retrospectively reviewed, in total 14 endoscopic and 15 microscopic approaches were included, all performed over one-year period. None of the endoscopic surgeries require conversion to the microscope. No statistically significant audiometric differences between the endoscopic vs microscopic approaches in air pure-tone averages and air-bone gap. There were 82.8% air-bone gap closure to <15 dB with no significant difference in the percent of such closures between the endoscopic (85.7%) and microscopic groups (80%, P = .68). Three prostheses were used: 4.25 mm (17.2%), 4.5 mm (58.6%) and the 4.75 mm (24.1%) smart/eclipse. Endoscopic median operative time was 51 min vs 42 min for microscopic approach (P =.004). CONCLUSIONS: The endoscopic with microdrill approach is criticized to lack depth perception, especially when using a microdrill to perform in stapedotomies. Our study showcases that using the microdrill use produces minimal differences in outcomes, cost, and is a safe modality to stapes surgery in both approaches.

Comparison between Fluoroplastic and Platinum/Titanium Piston in Stapedotomy: A Prospective, Randomized Clinical Study.

OBJECTIVES: The objective of this study was to compare hearing results of fluoroplastic (Teflon) Causse Loop Piston with platinum/titanium (Big Easy) Piston in patients who underwent stapedotomy due to otosclerosis. MATERIALS AND METHODS: In this prospective randomized clinical trial study, Causse Loop Piston prosthesis was used in 76 ears and the Big Easy Piston prosthesis in 72 ears. The main outcomes were preoperative and postoperative pure tone audiometry and air-bone gap (ABG). RESULTS: Postoperative ABG closure was not significantly different between both groups. However, the Causse Loop Piston resulted in a significant improvement of the air conduction (AC) in frequencies of 250, 500, and 1,000 Hz. In addition, the improvement of speech reception threshold (SRT) was significantly higher in Causse Loop Piston group. CONCLUSION: We achieved similar postoperative ABG closure in short-term with both prostheses. However, at low frequencies, AC gain was higher in Causse Loop Piston group. In addition, patients in this group yielded better SRT.

Prospective evaluation of disease-specific quality of life measurements after stapes surgery using Nitinol Head Prostheses.

OBJECTIVES: To analyze health-related quality of life (HRQoL) and audiological results after stapes surgery using a Nitinol Head Prosthesis (NHP). METHODS: Study-Design Prospective longitudinal study. Patients Patients undergoing stapes surgery for otosclerosis and stapes reconstruction with a NHP between January 2018 and December 2018 (n = 48). Intervention Audiological measurements preoperatively and at 6 months follow-up as well as two questionnaires assessing HRQoL, i.e., the Stapes Plasty Outcome Test 25 (SPOT-25) and the Glasgow Benefit Inventory (GBI). Main outcome measures Correlation of pure tone average (4PTA 0.5-3 kHz) with questionnaires assessing HrQOL preoperatively and at follow-up after stapes surgery. RESULTS: Patients showed a significantly reduced air-bone-gap (ABG, 0.5, 1, 2, 3 kHz) at the follow up visit (median: 11.3 dB, IQR 5.0-14.4) compared to the preoperative measurements (median 27.5 dB, IQR 21.9-36.3). Disease-specific HRQoL improved significantly in all scales of the SPOT-25 apart from the subscore "tinnitus". Postoperatively, the subscore "hearing function" correlated well only with the ABG (r = 0.59, p = 0.001). The SPOT-25 and GBI total scores showed a moderate negative correlation (r = - 0.59, p = 0.008). CONCLUSIONS: Stapes surgery leads to significant improvements of hearing and the HRQoL. However, correlations between HRQoL questionnaire scores and the audiometric outcomes were inconclusive, indicating that the use of HRQoL measures for the assessment of stapedotomy outcomes to complement objective outcomes should be encouraged.

Endoscopic stapedotomy: a comparison between 4 mm and 3 mm nasal endoscope.

BACKGROUND: Although, both the microscopic and endoscopic stapes surgery have claimed a parallel audiological outcome, the comparison between two standard endoscopes (4 mm and 3 mm) in endoscopic stapedotomy is not well documented. We have compared the clinical utility and audiological outcomes of the 3 mm and 4 mm rigid nasal endoscopes in the primary endoscopic stapedotomy. MATERIALS AND METHODS: This is a retrospective study conducted in the Department of Otorhinolaryngology between June 2015 and May 2018. Total 46 patients of primary otosclerosis had undergone endoscopic stapedotomy where 3 mm and 4 mm nasal endoscopes have been used in 22 (group A) and 24 patients (group B) respectively. The preoperative, intraoperative and postoperative surgical findings including the hearing outcomes were compared between the two groups. RESULTS: One patient (4.5%) in group A and 6 (25%) patients in group B required canaloplasty (p = 0.00, χ2 test) and 7 (31.18%) patients in group A and 18(75%) in group B had required curettage of the bony canal wall (p = 0.04, χ2 test). There was no significant difference in the air-bone gap between the two groups (p = 0.85). CONCLUSION: Both 3 mm and 4 mm nasal endoscopes can be successfully used in the endoscopic stapedotomy providing a parallel visual field. Although, comparable results can be obtained in preserving the chorda tympani nerve, tympanic membrane, facial nerve, and postoperative giddiness including the audiological outcomes, the requirement of the canaloplasty and curettage of posterior bony canal can be significantly reduced in patients operated with 3 mm nasal endoscope, especially in patients with narrow/over angulated external auditory canal.

Stapes surgery leads to significant improvement in quality of life, independently from the surgical method: evaluation of stapes surgery using different prostheses and different quality of life measurements.

OBJECTIVES: To compare quality-of-life (QoL) measurements with audiological results after stapes surgery with two different prostheses. METHODS: This is a retrospective longitudinal study. All patients required stapes surgery for otosclerosis and ossicular chain reconstruction with either a titanium band prothesis (TBP) or receiving a nitinol head prosthesis (NHP). Intervention was between January 2011 and March 2017 patients received stapes-surgery with either TBP (n = 95) or NHP (n = 50). Audiological measurements at three different time points (preoperatively, early follow up < 3 months, late follow-up > 3 months) were compared and two different QoL-inventories, the Glasgow-Benefit-Inventory (GBI) and the Stapes-Plasty-Outcome-Test-25 (SPOT-25) were investigated postoperatively. The main outcome measures were Pure tone average (PTA) at 0.5, 1, 2, 3 kHz at early and late follow up after stapes surgery were compared and correlated with the subjective benefit on the QoL inventories. The perforation method and the type of surgery were analyzed as potentially influencing factors. RESULTS: All patients showed a significantly reduced air bone gap (ABG 0.5, 1, 2, 3) at the two follow-up visits (visit 2: mean: 13.6 dB, SD 7.7; visit 3: mean: 12.7 dB SD 8.1) compared to preoperative measurements (mean: 28.9 dB, SD 9.9) and subjectively benefitted from stapes surgery (mean GBI score: 21.55; SD 20.60, mean SPOT-25 score: 28.03; SD 18.53). The outcome of the two questionnaires correlated with each other. Neither the hearing-outcome nor the subjective benefit was significantly influenced by the prosthesis, the perforation method or the type of anesthesia. CONCLUSIONS: Both prostheses were safe and led to comparable hearing results as well as to subjective benefits in the Health-related-Quality-of-Life (HrQoL). A combination of the two questionnaires is recommendable for postoperative quality control.

Long-term outcomes of ossiculoplasty using bone cement.

OBJECTIVE: This study aimed to evaluate the long-term results of ossiculoplasty using bone cement. METHOD: Forty patients (24 females and 16 males; mean age: 34.1 ± 11.8 years; range, 9-54 years) with chronic otitis media with perforation but without cholesteatoma who had undergone incudostapedial rebridging ossiculoplasty using bone cement were evaluated retrospectively. Pre-operative and post-operative audiograms were evaluated. Bone conduction, air conduction and air-bone gaps were calculated according to international guidelines. RESULTS: There was a mean reduction in pre-operative and post-operative air conduction (12.30 ± 11.98 dB), and this result was significant (p = 0.0001). There was a mean reduction in pre-operative and post-operative bone conduction (4.30 ± 6.69 dB), and this result was significant (p < 0.0001). The pre-operative air-bone gap was 27.65 dB and decreased to 19.65 dB during follow-up (p = 0.0001). No adverse reactions or complications were observed. CONCLUSION: Bone cement is reliable for the repair of incudostapedial-joint defects.

A Rare Cause of Stapedotomy Failure: When the Depth Marker Becomes a Locking Device: A Report on 2 Cases.

We report 2 cases of stapes surgery failure due to the depth marker groove of the piston of a Big Easy titanium prosthesis getting caught at the edge of the stapedotomy hole. In the first case, the stapedotomy failure, detected peroperatively, was corrected by modifying the angulation of the shaft of the prosthesis. In the second case, the failure occurred after a delay during which scar tissue developed around the depth marker groove, hampering the movement of the prosthesis. The usual postoperative imaging did not detect this complication. The diagnosis was made during revision surgery and the condition was treated by enlarging the hole in the footplate. Alternatively, the use of a piston without a depth marker groove would have resolved the problem. Although a rare event, the possibility of stapes surgery failure due to the depth marker groove should not be overlooked.

Is one of these two techniques: CO2 laser versus microdrill assisted stapedotomy results in better post-operative hearing outcome?

OBJECTIVE: To evaluate hearing results and outcome using two different surgical techniques (microdrill and CO2 Laser fenestration) in the treatment of conductive hearing loss in patients with otosclerosis. STUDY DESIGN: Retrospective audiometric database and chart review from January 2005 until December 2016. SETTING: Two tertiary referral hospitals MATERIALS AND METHODS: Seven-hundred forty-two primary stapedotomy have been reviewed retrospectively in two referral hospitals. This multicenter study compared 424 patients operated for otosclerosis with microdrill technique and 318 patients operated with CO2 laser assisted stapedotomy. Preoperative and postoperative audiological assessment (following the recommendations of the Committee on Hearing and Equilibrium) were compared between the two groups at least 6 weeks and at 1 year or more. Measure of overclosure and hearing damage have been analyzed and compared between the groups. RESULTS: There were no statistically significant differences in demographic data between the two groups and no statistically significant difference in hearing outcome between the two groups. CO2 Laser with 0.4 piston showed slightly better results to close the air-bone gap postoperatively to ≤ 10 dB (84% as compared with the 80% of patients operated with microdrill technique). Patients operated with microdrill technique and 0.6 piston have less damage to hearing at 4 kHz. CONCLUSION: The use of CO2 laser seems associated with better postoperative air-bone gap closure. However, it carries more risk of hearing damage at 4 kHz at it is the case for the microdrill at 1 kHz. In general, postoperative hearing outcome using these two surgical techniques is comparable.

Long-Term Audiometric and Clinical Outcomes Following Stapedectomy With the Shape Memory Nitinol Stapes Prosthesis.

OBJECTIVE: To assess long-term hearing outcomes following stapedectomy using a self-crimping shape memory nitinol prosthesis. The results were compared with those of a group of patients who received a conventional prosthesis. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: All patients who underwent stapedectomy for otosclerosis between July 2001 and November 2008 with a minimum dataset of preoperative, early postoperative (≤2 yr), and late postoperative (≥6 yr) audiometry were included. Fifty-six patients with a nitinol prosthesis and 27 patients with a titanium prosthesis met the inclusion criteria. INTERVENTION: Stapedectomy using a nitinol or conventional prosthesis. MAIN OUTCOME MEASURE(S): Hearing outcomes by audiological assessment. RESULTS: Mean duration of follow up was 9.5 (standard deviation [SD] 1.4) years in the nitinol group and 12.6 (SD 2.1) years in the titanium group. The early and late mean postoperative air-bone gaps (ABGs) were 9.7 and 9.8 dB in the nitinol group and 11.0 and 12.6 dB in the titanium group, respectively. The proportion of patients achieving an ABG less than or equal to 20 dB at early and late follow up was 96% and 96% in the nitinol group and 92% and 86% in the titanium group respectively. CONCLUSIONS: The excellent closure of the ABG achieved at early follow up remains remarkably stable up to 12 years using a self-crimping shape memory nitinol prosthesis. There is no evidence that firm fixation of the hook around the long process of incus has a detrimental effect in the long-term.

Influence of angular positioning of the prosthesis in stapes surgeries with a NiTiBond prosthesis: Investigation in cadaveric temporal bones.

In incus stapedotomy surgeries, the longitudinal direction of the piston prosthesis should ideally be perpendicular to the stapes footplate. However, in reality, some amounts of angular deviation of the prosthesis from the ideal angular position is unavoidable due to anatomical constraints and surgical conditions. This study aims to evaluate the influence of angular positioning of the prosthesis on surgical outcomes in incus stapedotomy and to provide surgical guidelines related to practical tolerance of the angular positioning. In this study, this influence was assessed with a Kurz NiTiBond prosthesis (0.4-mm diameter) and fenestra sizes of 0.5- and 0.6-mm diameter in cadaveric temporal bones (n = 7 including 2 preliminary tests). Angular position of the prosthesis relative to the footplate was modulated by rotating the stapes about the long and short axes of the footplate. At each angular position, the tympanic membrane was acoustically stimulated in the frequency range of 0.2-10 kHz, and motion of the prosthesis was measured using a Laser Doppler vibrometer (LDV). Furthermore, micro-computed tomography (micro-CT) data of the middle-ear ossicles were used for anatomical analysis of angular positioning of the prosthesis. The results showed that changes of angular position of the prosthesis relative to the stapes footplate do not cause significant changes of prosthesis motion until a certain angular position threshold, and sharply attenuate prosthesis motion when the angular position reaches the threshold. The threshold of the angular position, as the tilting angle of the prosthesis from the direction normal to the stapes footplate, was 26.9 ±â€¯2.5° with the fenestration hole of 0.5-mm diameter and 30.6 ±â€¯3.0° with the fenestration hole of 0.6-mm diameter (n = 5, p < 0.01 for difference between the two fenestra sizes). Analysis of the middle-ear anatomy in this study revealed that the tolerances of the angular positions of the prosthesis does not always cover possible positions of prosthesis crimping. This study suggests that if an anterior offset of the stapes head and/or the thickened footplate is suspected, efforts to locate prosthesis crimping closer to the tip of the incus and/or to make a sufficiently large fenestration hole are favorable.

[Diagnostics and Surgical Therapy of Otosclerosis - Part 2: Indication, Surgical Procedure and Postoperative Treatment]. / Diagnostik und operative Therapie der Otosklerose.

After approximately 100 years of development and stepwise improvement, stapes surgery is a succesful strategy of managing hearing loss in otosclerosis, although challanges remain. Contraindications include too poor speech understanding (not enough inner ear reserve), and acute or chronic inflammation of the external ear and middle ear. Stapes surgery in the last hearing ear can today be indicated in exceptional cases, especially if the contralateral ear was supplied with a cochlear implant. In case of simultaneous occurrence of pronounced external auditory canal exostoses, a staged procedure may be useful.The surgical principle is to mechanically replace the fixed stapes with a piston-shaped implant under perforation or partial removal of the stapes footplate. Laser-assisted stapes surgery has proven itself in practice and the laser is used regularly today. In regard to revision surgery the increased risk of hearing loss or deafness and vertigo has to be considered. Revisions are made in the event of complications and persistent or newly occurring conductive components. In the case of insufficient hearing rehabilitation, alternative options should be considered, e. g. the combination of a stapes plastic with an active middle ear implant, or a cochlear implant.

Potential of Robot-Based Surgery for Otosclerosis Surgery.

Otosclerosis surgery is performed through a transcanal approach and requires long, thin instruments with submillimetric precision and precise amplitude of motion. The functional outcomes and complications of otosclerosis surgery depend on the experience of the surgeon. Thus, any technological assistance that can enhance the surgeon's dexterity and rapidly reduce the learning curve could yield an even safer surgical procedure. One of the options is to use robotic assistance to achieve this goal. An overview of different robots designed for otosclerosis surgery is presented focusing on the RobOtol system that we have designed as a multitask platform for ear surgery.

Stapes prosthesis length and hearing outcomes.

OBJECTIVES: First, to determine if prosthesis length plays a role in optimizing successful hearing outcomes in stapedotomy surgery; and second, to determine if patient factors such as height are correlated with prosthesis length. STUDY DESIGN: Retrospective chart review. METHODS: Retrospective chart review of patients undergoing stapedotomy surgeries with adequate follow up. Length of prosthesis, pre-/postoperative audiograms, and follow-up data were obtained. RESULTS: The primary group consisted of 227 cases. The prosthesis length ranged from 3.75 mm to 4.75 mm (median 4.25 mm). The greatest improvement in postoperative air-bone gap (ABG) occurred in the 4.25 mm group, and the least in the 3.75 mm group. Patient height showed a positive, although weak, correlation with prosthesis length. No findings reached statistical significance. CONCLUSION: Accurate measurement of prosthesis length is important for successful postoperative hearing outcomes. There is a positive but not significant correlation between patient height and prosthesis length. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:722-726, 2018.

[The application of stapedoplasty for the treatment of hearing loss in the patients suffering from obliterative otosclerosis]. / Stapedoplastika v lechenii tugoukhosti u bol'nykh obliteriruiushchim otosklerozom.

This article presents the results of analysis of the data obtained during the examination and the surgical treatment of the patients presenting with the obliterative form of otosclerosis and suffering from hearing impairment with special reference to the intraoperative findings, technical aspects of stapedoplasty, and its effectiveness. A total of 14 patients (17 ears) were recruited for the participation in the present study including 10 women at the mean age of 38.8±6.2 years and 4 men (mean age 44.8±3.9 years). The duration of the hearing loss in the period preceding the surgical treatment in 7 (50%) patients was more than 8 years. According to the results of tonal threshold audiometry (TTA), the mean bone conduction (BC) threshold for conductive hearing loss in the frequency range from 0.5 to 4.0 kHz was 24.9±8.1 dB with the mean bone air gap (BAG) equaling 38±5.1 dB. Computed tomography (CT) of the temporal bones revealed grade 1 obliterative otosclerosis in 4 patients, grade II of the same condition in 6 patients, and grade III in 7 ones. These findings were confirmed intraoperatively. In 15 cases, stapedostomy was carried out with the use of the non-contact CO2 laser-based system, in the remaining cases a microdrill was employed. Five patients underwent laser-assisted piston stapedoplasty while in 11 others the stapes prosthesis was placed on the autovein. One patient was treated by the same method with the use of the autocartilaginous prosthesis. The functionally acceptable results within 1 year after the surgical intervention were obtained in all the treated patients with the mean bone air gap equaling 13.2±3.4 dB. The best outcome (the reduction of the BC threshold and BAG by 7 dB and 25.9 db on the average respectively within 1 year after surgery was achieved in the patients with grade III obliterative otosclerosis.

A comparative study of MED-EL FMT attachment to the long process of the incus in intact middle ears and its attachment to disarticulated stapes head.

The Vibrant Soundbridge© (VSB) active middle-ear implant provides an effective treatment for mild-to-severe sensorineural hearing loss in the case of normal middle ear anatomy and mixed hearing loss in middle ear malformation. The VSB floating mass transducer (FMT), with proper couplers, can be installed on various structures of the ossicular chain, e.g., the short and long process of the incus, the stapes head, and the stapes footplate. A long process (LP) coupler is most commonly used for FMT attachment to the long process of the incus with intact ossicular chain, while CliP and Bell couplers are two standardized and reliable methods for FMT attachment to the stapes head with missing incus and malleus. However, the difference and relationship of the vibration properties among these three FMT couplers remain unclear. In the present study, the stapes footplate velocity responses of the LP, CliP, and Bell couplers have been investigated in eight fresh temporal bones (TBs) to evaluate the vibration properties of these three couplers. Normal and reconstructed middle ear transfer functions (METFs) were determined from laser Doppler vibrometer (LDV) measurements. A mastoidectomy and a posterior tympanotomy were performed to expose the ossicular chain. The METFs of the normal middle ear and middle ear with LP-FMT-coupler were compared under acoustic stimulation, thus the mass effect of the FMT with LP coupler was evaluated. Additional comparisons were made between the stapes footplate vibrations of the LP-FMT-coupler (with the intact ossicular chain at the long process of the incus), CliP-FMT-coupler and Bell-FMT-coupler on the stapes head (after incus and malleus removed) under active electromechanical stimulation. After the installation of CliP-FMT-coupler and Bell-FMT-coupler to the middle ear, the average velocity amplitude of the stapes footplate, comparing to the LP-FMT-coupler, was about 15 dB higher between 1 and 6 kHz, and 10 dB lower at about 0.5 kHz. Quantitatively, there was no significant difference between the CliP-FMT-coupler and Bell-FMT-coupler. According to our study, installation of CliP-FMT-coupler or Bell-FMT-coupler on the stapes head provides considerable improvement of the middle ear mechanical and functional responses, comparing with the LP-FMT-coupler in the temporal bone experiments. Moreover, the installation of the Bell-FMT-coupler to the stapes head produces essentially the same footplate velocity responses in comparison to the CliP-FMT-coupler.

[Destruction of microsurgical devices by sterilisation]. / Schädigung von mikrochirurgischen Instrumenten durch Aufbereitung in einer Zentralsterilisation.

Hospital facilities issue numerous risk announcements on corrosion, deformation or premature wearout of medical devices every year. As there is yet little data on the impact of reprocessing on the quality and durability of microsurgical instruments, this paper aims at evaluating the effects of the reprocessing on microsurgical instruments. Material and Methods 22 brand new microsurgical instruments for stapes surgery were being reprocessed 30 times without being used for surgery or other purposes in the interim time. After each reprocessing the instruments were examined macroscopicly and microscopicly. The results were portrayed in a photo documentation and analysed on that basis. Results Almost all devices showed mechanical damage caused by the reprocessing procedure. The increasing deterioration was often associated with missing protective caps. Furthermore contaminations and stains were apparent in several cases. Conclusions The findings illustrate that careful handling of delicate surgical devices during reprocessing is vital. They also highlight problems of protective caps. As an alternative going forward it should be considered to store microsurgical instruments statically in special racks.

New chamber stapes prosthesis - A preliminary assessment of the functioning of the prototype.

Piston-stapedotomy is the most common method for hearing restoration in patients with otosclerosis. In this study, we have experimentally examined a prototype of a new chamber stapes prosthesis. The prototype was implanted in a human cadaver temporal bone. The round window vibrations before and after implantation were measured for the acoustic signal (90 dB SPL, 0.8-8 kHz) in the external auditory canal. In comparison with a 0.4-mm piston prosthesis, the chamber prosthesis induced significantly higher vibration of the round window, especially for frequencies above 1.5 kHz. Based on the results, it can be surmised that stapedotomy with a chamber stapes prosthesis could provide better hearing results in comparison with the piston-stapedotomy.