The TORP-PORP: A Tympanoplasty Technique for Isolated Defects of the Stapes Suprastructure.

OBJECTIVE: Investigating the outcomes of a surgical approach to treat isolated defects of the stapes suprastructure, using a modified total ossicular replacement prosthesis (TORP) prosthesis as a PORP between the footplate and the incus, effectively creating a TORP-PORP configuration. PATIENTS: Eleven patients (mean age, 37.2 years; 36% male and 64% female) between the years 2007 and 2022. INTERVENTIONS: Therapeutic (ossiculoplasty). MAIN OUTCOME MEASURES: Hearing gain (in dB) in air conduction thresholds at 0.5, 1, 2, 3, and 4 kHz, stability of bone conduction, revision rate. RESULTS: Significant improvement in air conduction between the preoperative and the postoperative cohorts (p = 0.002) with a mean postoperative hearing level of 30.00 ± 5.25 dB. The bone conduction remained stable. We encountered no perioperative complications, and there were no revisions surgery. CONCLUSIONS: The described ossiculoplasty procedure is a safe and effective approach to treat isolated defects of the stapes suprastructure.

Performance of personalised prosthesis under static pressure: Numerical analysis and experimental validation.

This study investigates the performance of personalised middle ear prostheses under static pressure through a combined approach of numerical analysis and experimental validation. The sound transmission performances of both normal and reconstructed middle ears undergo changes under high positive or negative pressure within the middle ear cavity. This pressure fluctuation has the potential to result in prosthesis displacement/extrusion in patients. To optimise the design of middle ear prostheses, it is crucial to consider various factors, including the condition of the middle ear cavity in which the prosthesis is placed. The integration of computational modelling techniques with non-invasive imaging modalities has demonstrated significant promise and distinct prospects in middle ear surgery. In this study, we assessed the efficacy of Finite Element (FE) analysis in modelling the responses of both normal and reconstructed middle ears to elevated static pressure within the ear canal. The FE model underwent validation using experimental data derived from human cadaveric temporal bones before progressing to subsequent investigations. Afterwards, we assessed stapes and umbo displacements in the reconstructed middle ear under static pressure, with either a columella-type prosthesis or a prosthetic incus, closely resembling a healthy incus. Results indicated the superior performance of the prosthetic incus in terms of both sound transmission to the inner ear and stress distribution patterns on the TM, potentially lowering the risk of prosthesis displacement/extrusion. This study underscores the potential of computational analysis in middle ear surgery, encompassing aspects such as prosthesis design, predicting outcomes in ossicular chain reconstruction (OCR), and mitigating experimental costs.

Predictive Factors and Audiometric Outcome Comparison Between Titanium Prosthesis and Autologous Incus in Traumatic Ossicular Injury.

OBJECTIVES: To investigate the etiology and ossicular pathology of traumatic ossicular injury in Taiwan and examine the hearing outcomes and predictive factors between the titanium prosthesis and autologous incus groups. METHODS: We retrospectively analyzed patients with traumatic ossicular injury from 2011 to 2020 in Taiwan. Patients were divided into the titanium or autologous group according to the surgical materials used. The audiometric outcomes and predictive factors of ossiculoplasty were analyzed between groups. RESULTS: Twenty patients with ossicular chain discontinuity were enrolled (8 in the titanium group and 12 in the autologous group). The postoperative hearing threshold (26.6 ± 8.9 dB) and air-bone gap (10.3 ± 5.6 dB) improved significantly compared with the preoperative hearing threshold (50.7 ± 13.3 dB) and air-bone gap (29.9 ± 11.0 dB). The improvements in the hearing threshold and air-bone gap were not significantly different between the titanium and autologous groups. Our patients presented an improvement in hearing restoration with 65% closure of the air-bone gap in 0 to 10 dB range and 30% in 11 to 20 dB range, without sensorineural hearing loss during surgery. Univariate regression analysis revealed that vertigo, benign paroxysmal positional vertigo, and temporal bone fracture may serve as negative factors influencing the air-bone gap gain. CONCLUSIONS: Ossiculoplasty with both titanium prosthesis and autologous materials demonstrated favorable hearing recovery in traumatic ossicular injury. Vertigo, benign paroxysmal positional vertigo, and temporal bone fracture may serve as negative predictive factors of the hearing benefit after surgery.

Reconstructive ossiculoplasty options in primary cholesteatoma surgeries with an intact stapes.

PURPOSE: In primary cholesteatoma patients, incus destruction with an intact and mobile stapes is a frequent finding. Different techniques have been described to restore the ossicular chain, including incus interposition, stapes augmentation and type III tympanoplasty. Controversy about postoperative hearing results in open versus closed surgical techniques exist. METHODS: We performed a retrospective analysis of clinical, surgical and audiometric data of patients with primary cholesteatoma surgery operated between 2010 and 2020, and a mobile stapes and one-stage ossicular reconstruction. Pre- and post-operative audiograms were compared for the different surgical groups, mainly focusing on postoperative air-bone gap. Mastoid pneumatization and ventilation was also considered. RESULTS: The mean postoperative air-bone gap (0.5-4 kHz) of the 126 included patients was 20 dB. Hearing after type III tympanoplasty (26 dB) was worse than incus interposition (19 dB) and stapes augmentation (20 dB). Hearing after an open (23 dB) versus closed (19 dB) surgical technique was significantly different. No improvement in air-bone gap was observed for the higher frequencies. CONCLUSION: A residual postoperative air-bone gap should be considered after primary cholesteatoma surgery with intact and mobile stapes. Incus interposition in closed cavity operation is the optimal situation, but open cavity surgery should not be avoided because of hearing. Extent of the disease is prioritized and poorer ventilation before and after surgery may affect postoperative hearing.

Comparison of dislocation rates of Teflon and Titanium stapes prostheses: a retrospective survival analysis on 855 patients.

BACKGROUND: Stapes prosthesis dislocation is the first cause of revision stapes surgery. To our knowledge, there is no data about stability of the incus attachment of manual crimped prosthesis of different materials. This study aimed to compare the dislocation incidence between titanium and fluoroplastic stapes prostheses. METHOD: A monocentric retrospective cohort study was conducted between January 2013 and June 2022 in a tertiary-care center. All patients that underwent a primary stapes surgery with manually crimped fluoroplastic or titanium prostheses were included. Prosthesis dislocation from the incus was identified intraoperatively or with CT scan. The incidence of stapedial prosthesis dislocation over time was estimated using the Kalbfleisch and Prentice survival analysis method. Other indications for revision surgery prior to prosthesis dislocation were considered as competing events. Differences in the cumulative incidence functions between the fluoroplastic group and the titanium group was assessed using the Gray's test. RESULTS: Eight hundred and fifty-five patients underwent primary stapes surgery during the study period. Fluoroplastic prosthesis was used in 758 (88.7%) cases and titanium prosthesis in 97 (11.3%) cases. Median follow-up was 51.7 months (28.4-80.1). Dislocation was observed in 23 (3.0%) patients with fluoroplastic prosthesis and none (0.0%) in the titanium group. The probability of prosthesis dislocation at two years after surgery was 3.5% in the Teflon group and 0.0% in the Titanium group. No significant difference was found in the cumulative incidence of prosthesis dislocation between the fluoroplastic group and the titanium group (p = 0.12). CONCLUSIONS: Despite lack of statistical power, our results suggest a trend in a more stable incus attachment of manually crimped titanium stapes prosthesis compared to fluoroplastic over time. Further prospective randomized studies could be valuable to assess our findings.

Assessment of the ability of the radiological incudo-stapedial angle to predict the stapedotomy technique type: a prospective case-series study.

PURPOSE: This study aimed to propose a radiological classification of the incudo-stapedial angle by preoperative high-resolution computed tomography (HRCT) images and to highlight its importance for predicting the use of reversal-steps stapedotomy (RSS) rather than the traditional non-reversal technique. METHODS: We included 83 candidates for stapedotomy operation. Two physicians measured the radiological incudo-stapedial joint angle in the preoperative HRCT. According to this measurement, the radiological incudo-stapedial joint was classified into three types: obtuse, right, and acute. In addition, this radiological classification was correlated with the intraoperative use of the stapedotomy technique, either reversal or non-reversal. RESULTS: The RSS technique was used in forty-two (97.7%) cases with an obtuse angle and twenty-six (89.7%) with a right angle. At the same time, the traditional non-reversal technique was used in all patients with an acute angle. The three groups differed significantly regarding the method used for stapedotomy (P value < 0.001). Moreover, Spearman's correlation coefficient revealed a significant correlation between the used technique and the radiological type of the incudo-stapedial angle (P value < 0.001). CONCLUSIONS: This prospective study proposed a preoperative radiological classification of the incudo-stapedial angle. This classification was significantly correlated with the type of stapedotomy technique. The RSS technique was feasible in most cases with an obtuse and right radiological incudo-stapedial angle. In contrast, the non-reversal method was used in all patients with an acute radiological incudo-stapedial angle. This radiological classification could predict the choice for the stapedotomy technique with an accuracy of 95.18%, a sensitivity of 73.33%, and a specificity of 100%.

Can the unmodified incus be used for a simpler, more cost-effective functional ossicular chain reconstruction? A retrospective clinical study.

OBJECTIVE: To evaluate patients' hearing outcomes after ossicular chain reconstruction using unmodified autologous incus. METHODS: A single-centred, retrospective study of patients who underwent incus interposition between June 2010 and October 2017 was conducted at a Dutch secondary referral centre. This paper describes a chart review of patients who presented with erosion of the long process of the incus due to atelectasis or cholesteatoma who were treated with an unmodified incus interposition. The main outcome measures were: post-operative air-bone gap and level of air-bone gap closure. RESULTS: Thirty-three ears of 32 patients were included. Follow-up duration ranged from six weeks to seven years. A mean post-operative air-bone gap under 25 dB was considered successful; this was achieved in 25 patients (76 per cent), 20 (91 per cent) in the partial ossicular reconstruction prosthesis group and 5 (45 per cent) in the total ossicular reconstruction prosthesis group. This difference was statistically significant (p = 0.007). CONCLUSION: Successful preservation and improvement of hearing was observed in most patients. As expected, the closure rate in the partial ossicular reconstruction prosthesis group was better. Longer follow-up studies with larger case numbers are needed to assess whether further reconstruction techniques are necessary.

Isolated Traumatic Dislocation of the Malleus into the External Auditory Canal.

We report a rare case of isolated malleus dislocation into the external auditory canal with lateralized intact tympanic membrane following a head trauma. The patient was a 63-year-old woman who presented at the outpatient department of our institute with hearing loss of 10 years' duration after a bicycle accident. During physical examination of the patient, total dislocation of the malleus-like bony structure into the external auditory canal on the right side was observed. In the computed tomography scan, an isolated malleus dislocation with intact incus-stapes articulation was identified. The patient was successfully treated with endoscopic exploratory tympanotomy and partial ossicular replacement prosthesis. The isolated malleus dislocation can rarely occur after trauma. A careful diagnostic step through history, physical examination, and temporal bone computed tomography scan are needed to confirm this rare condition.

Creation of an incus recess for a middle-ear microphone using a drill or laser ablation: a comparison of equivalent noise level and middle ear transfer function.

PURPOSE: Studies have assessed the trauma and change in hearing function from the use of otological drills on the ossicular chain, but not the effects of partial laser ablation of the incus. A study of the effectiveness of a novel middle-ear microphone for a cochlear implant, which required an incus recess for the microphone balltip, provided an opportunity to compare methods and inform a feasibility study of the microphone with patients. METHODS: We used laser Doppler vibrometry with an insert earphone and probe microphone in 23 ears from 14 fresh-frozen cadavers to measure the equivalent noise level at the tympanic membrane that would have led to the same stapes velocity as the creation of the incus recess. RESULTS: Drilling on the incus with a diamond burr created peak noise levels equivalent to 125.1-155.0 dB SPL at the tympanic membrane, whilst using the laser generated equivalent noise levels barely above the baseline level. The change in middle ear transfer function following drilling showed greater variability at high frequencies, but the change was not statistically significant in the three frequency bands tested. CONCLUSIONS: Whilst drilling resulted in substantially higher equivalent noise, we considered that the recess created by laser ablation was more likely to lead to movement of the microphone balltip, and therefore decrease performance or result in malfunction over time. For patients with greatly reduced residual hearing, the greater consistency from drilling the incus recess may outweigh the potential benefits of hearing preservation with laser ablation.

Endoscopic transcanal management of incus long process defects: rebridging with bone cement versus incus interposition.

OBJECTIVES: to compare hearing outcomes between endoscopic transcanal rebridging with bone cement and endoscopic transcanal incus interposition in patients with incus long process defects secondary to chronic suppurative otitis media (inactive mucosal type). METHODS: This retrospective study was performed on 83 ears of 83 consecutive patients with incus long process defects secondary to chronic suppurative otitis media (inactive mucosal type). According to the extent of incus long process erosion and subsequent ossiculoplasty technique, patients were divided into 2 groups. Patients in group 1 had erosion involving up to two thirds of the length of the incus long process and underwent endoscopic transcanal rebridging with bone cement. Patients in group 2 had erosion involving more than two thirds of the length of the incus long process and underwent endoscopic transcanal incus interposition. RESULTS: Hearing gain (mean ± standard deviation) was 21.39 ± 2.15 dB in group 1 and 19.71 ± 6.12 dB in group 2. A significantly greater hearing gain was achieved in bone cement group than in incus interposition group (P value < 0.001). Successful hearing outcome (post-operative air bone gap closure within 20 dB) was achieved in 81.6% and 71.1% of patients of group 1 and group 2 respectively. CONCLUSION: Endoscopic transcanal rebridging with bone cement offers greater hearing gain than endoscopic transcanal incus interposition. The two techniques remain reliable and cost-effective techniques in management of patients with incus long process defects. The main limitation of this study was the short follow-up period. Further studies with relatively long-term follow-up are strongly recommended.

Long-Term Hearing Results of Endoskeletal Ossicular Reconstruction in Chronic Ears Using Titanium Prostheses Having a Helical Coil: Part 1-Kraus K-Helix Crown, Incus to Stapes.

OBJECTIVES: 1) To assess long-term hearing results after endoskeletal ossicular chain reconstruction (eOCR) using the titanium Kraus K-Helix Crown prosthesis, implanted incus to stapes, with glass-ionomer cement (GIC) in chronic ears and 2) to determine safety of the prosthesis and cement. STUDY DESIGN: Prospective, nonrandomized, sequential, single center, single surgeon. SETTING: Private practice, ambulatory surgical center. PATIENTS: N = 15 males (42%) and 21 females (58%). Mean age was 40.4 years (range, 6-81 years); 38 ears (22 right ears [58%] and 16 left ears [42%]). INTERVENTIONS: eOCR in chronic ears. Comprehensive preoperative and postoperative hearing measurements were performed for up to 9 years. MAIN OUTCOME MEASURES: Postoperative hearing results at 1 year showed statistically significant improvement as compared with preoperative hearing. Long-term hearing results remained stable and showed no statistically significant change over 9 years. RESULTS: Estimated mean pure-tone air conduction average improved by 14.5 dB (95% confidence interval = 10.3-18.7). Estimated mean speech reception thresholds improved by 15.5 dB (10.8-20.2). Word recognition scores improved by -2.2% (-5.3 to 1.0). The estimated mean postoperative air-bone gap was 10.5 dB (7.2-13.8). The estimated mean calculated air-bone gap was 11.3 dB (8.0-14.5). The estimated mean change in high-tone bone conduction (HTBC) average was +3.5 dB (0.9-6.0). Two prostheses extruded (5%). No patients experienced any unanticipated serious adverse effects or events. CONCLUSION: eOCR using the K-Helix Crown prosthesis, incus to stapes, and GIC can significantly improve hearing at 1 year and maintain stable hearing over 9 years. Both prosthesis and cement are safe.

Measurement of Incus and Stapes Velocity Following Sound Stimulus in the Setting of Incudostapedial Joint Separation and Reconstruction.

OBJECTIVE: Understand the biophysical property changes of incudostapedial joint (ISJ) separation and ossicular hydroxyapatite application on middle ear function. STUDY DESIGN: Basic science. SETTING: Cadaveric temporal bone research laboratory. SUBJECTS AND METHODS: A complete mastoidectomy was performed on five human temporal bones. A Laser Doppler Vibrometer was utilized to obtain velocity transfer function measurements of the incus and stapes across a range of frequencies in response to an acoustic stimulus. Under binocular microscopy the ISJ was separated and subsequently repaired with bone cement. Measurements were taken prior to ISJ separation, following joint separation, 30 to 60 min postrepair of the joint, and again 24 to 48 h postrepair of the joint. RESULTS: The stapes measurements taken from the intact ossicular chain and from the chains repaired with bone cement demonstrated a similar distribution of measurements. The ISJ separation showed dramatically reduced velocity transfer function stapes measurements but increased incus velocity transfer function measurements. In the early and delayed repaired chains, the mean velocity of the incus and stapes velocity peaked between 1.5 and 2 kHz, matching intact maximal velocity. Pure tone average at 0.5, 1, 2, and 3 kHz demonstrated no change in reconstructed stapes velocity at 24 to 48 h. CONCLUSIONS: Isolated ISJ separation in fresh frozen and thawed temporal bones produces stapes velocity transfer function changes that corresponds with the clinically experienced conductive hearing loss. Repair with bone cement produced similar velocity curves to the intact ISJ curve with excellent recovery across mid-frequencies. This model would be useful for future ossicular mechanical studies.

Revision Stapes Surgery: Hearing Symptoms and Associations With Intraoperative Findings and Outcomes.

OBJECTIVE: Stapes surgery for otosclerosis occasionally requires revision due to recurrent or persistent conductive hearing loss (CHL). This study examines outcomes after revision stapes surgery. STUDY DESIGN: Retrospective review. SETTING: Single tertiary neurotology center. METHODS: Patients undergoing revision stapes surgery for otosclerosis from 2008 to 2017 were reviewed. Postoperative air-bone gaps (ABGs) were the primary outcome measure. RESULTS: During the study period, 150 patients underwent revision stapes surgery. One hundred patients (67%) had gradually progressive recurrent CHL; 16 (11%), sudden recurrent CHL; 13 (9%), persistent CHL; and 21 (14%), no CHL. For 129 patients with CHL, the mean ABG improved from 23.7 to 9.3 dB (P < .0005). The most common intraoperative findings for these patients were prosthesis displacement with incus necrosis (38%) or without it (43%), normal anatomy with seemingly good prosthesis placement (6%), and abundant scar tissue (6%). Patients with recurrent hearing loss achieved lower mean ABGs than patients with persistent hearing loss (8.8 vs 13.2 dB, P = .02). There were no associations between onset pattern of CHL or intraoperative findings and hearing outcomes (P > .05). Four patients (2.7%) developed sensorineural hearing loss after revision, defined as an increase in bone conduction pure tone average ≥15 dB, all of whom had previous replacement of a malpositioned prosthesis. CONCLUSIONS: Revision stapes surgery confers significant improvement in hearing for patients with persistent and recurrent CHL, although patients with persistent CHL after initial surgery see less improvement with revision.

The posterior ligament of the incus ("white dot"): A reliable surgical landmark for the facial recess.

OBJECTIVE: There is a void in the literature describing reliable surgical landmarks that aid in the dissection of the facial recess in the absence of skeletonizing the mastoid segment of the facial nerve. The posterior ligament of the incus is a readily distinguishable "white dot" along the incus buttress that has been used to guide dissection in a safe and efficient manner. The goal of our study is to describe a surgical approach that utilizes this surgical landmark to drill the facial recess and to take anatomical measurements demonstrating the safety and reliability of this approach. MATERIALS AND METHODS: After cortical mastoidectomies were performed in 10 cadaveric temporal bones, the white dot was identified at the junction of short process of the incus and the incus buttress. Using the white dot for anatomical reference, a 2 mm diamond drill bit was used to open the facial recess without first identifying the facial nerve or chorda tympani nerve. After photographs were taken, the facial and chorda tympani nerves were definitively identified and skeletonized to delineate the confines of the facial recess. Photographs were once again acquired in a consistent manner for comparison. Finally, calibrated anatomic measurements were acquired from the 10 distinct image sets. RESULTS: The facial recess was successfully drilled in 10 temporal bones using the posterior ligament as a surgical landmark without injury to the chorda tympani or facial nerve. The median angle taken from the axis of the short process of the incus to the facial nerve - chorda tympani junction was 139.2° (IQR 136.8-141). At the widest point in the facial recess, median distances anterior and posterior to an imaginary line connecting the white dot to the facial nerve - chorda tympani junction were 1.6 mm (IQR 1.5-1.7) and 1.6 mm (IQR 1.6-1.7; p = 0.57), indicating at this point, the white dot reference reliably bisects the facial recess width. Similarly, at the level of the round window niche, median anterior and posterior distances from an imaginary line connecting the white dot to the facial nerve - chorda tympani junction were 1.1 mm (IQR 1.1-1.3) and 1.3 mm (IQR 1.1-1.7; p = 0.07), respectively, once again demonstrating the white dot reliably bisecting the facial recess. CONCLUSIONS: The white dot, representing the posterior ligament of the incus, is a reliable surgical landmark that aids in safe and efficient drilling of the facial recess without first skeletonizing the facial nerve.

The aetiology of ossicular chain defects in congenital cholesteatoma.

OBJECTIVE: The aim of the present study was to perform a retrospective review of the lesion sites in congenital middle-ear cholesteatoma and any accompanying ossicular defects, as well as to explore the possible aetiology of congenital middle-ear cholesteatoma associated with such ossicular chain defects. METHOD: The clinical characteristics and pathogenic mechanisms of ossicular chain defects were investigated in 10 patients with early-stage congenital middle-ear cholesteatoma confirmed by surgery, from August 2011 to February 2019. RESULTS: Monofocal cholesteatoma was located in the anterosuperior quadrant in 3 cases and in the posterosuperior quadrant in 7 cases; all 10 cases showed an absence of the long crus of incus, and 8 cases showed a complete or partial absence of stapes superstructure. The lesions were confined to the vestibular window and the stapes region and had no contact with the long crus of the incus or stapes in nine cases. None of the 10 patients had any recurrence of cholesteatoma. CONCLUSION: Although cholesteatoma can cause erosion of ossicles, the present cases suggest that residual epithelium of the cholesteatoma may coexist with ossicular malformations. Therefore, the aetiology of the clinical characteristics in these patients may derive from residual epithelial hinderance of ossicle development.

Device failure caused by the dissociation of floating mass transducer in Vibrant SoundBridge®.

BACKGROUND: Vibrant SoundBridge® (VSB), a semi-implantable middle ear device, is one of the treatment options for patients with mild-to-severe sensorineural hearing loss or mixed hearing loss. Herein, we report delayed device failure after VSB surgery in two patients. CASE PRESENTATION: In both cases, a revision surgery was performed for the removal of the device; dissociation of the floating mass transducer (FMT) and coupler was noticed in one patient, and dissociation of the FMT-coupler complex from the short process of the incus in the other. In Case 1, the vibration-like sounds disappeared after the surgery. In Case 2, wearing bilateral hearing aids improved hearing after removal surgery, but complaints regarding speech discrimination persisted. Both cases show the importance of not loosening the connectivity between the FMT, coupler, and short process of the incus during VSB surgery. CONCLUSIONS: To our knowledge, there has been no report of dissociation from the short process of the incus or the dissociation between an FMT and the coupler.

The role of malleostapedotomy in intra-operative incus injury: A review of 2 cases.

Malleostapedotomy (MS) is an evolving otology procedure that involves attaching prosthesis to the malleus on one end and the stapes footplate on the other end. It has multiple indications and requires skills and experience. We present 2 cases operated in our center (King Abdullah Ear Specialist Center, Riyadh, Saudi Arabia) in which intraoperative incus injury occurred, and MS was used to reconstruct the ossicular chain with good postoperative outcomes and patient satisfaction. As the procedure was surgically difficult and time consuming, many otologists prefer not to do it. Nevertheless, we believe that all surgeons dealing with stapes surgery should be familiar and gain confidence in performing MS considering that intraoperative incus dislocation is a complication that can happen even with great caution.

Performance Evaluation of Coupling Variants for an Active Middle Ear Implant Actuator: Output, Conductive Losses, and Stability of Coupling With Ambient Pressure Changes.

INTRODUCTION: This study aims to investigate the performance of an active middle ear implant actuator for various coupling configurations. Actuator output and conductive losses were measured, and the stability of coupling was evaluated by challenging the link between actuator and ossicles through pressure events in magnitudes that occur in daily life. METHODS: Actuator coupling efficiency and the occurrence of conductive losses were measured in 10 temporal bones through laser Doppler vibrometry on the stapes footplate for various coupling types (incus short process with and without laser hole, incus long process, stapes head). To test the stability of coupling, actuator output was measured before and after daily-life pressure events that were simulated; Valsalva maneuvers (500 cycles of -40 to +60 hPa) and jumping into a swimming pool and diving 3 m deep (a step change of 300 hPa). RESULTS: Actuator output was similarly high for all types of coupling to the incus (short process and long process) and most efficient for coupling to the stapes head. Conductive losses occurred in two temporal bones (TBs) for short process coupling but for seven TBs for coupling to the incus long process. All coupling types were stable and did not lose efficiency after pressure events in the low-frequency range (<1 kHz). Losses in output of 13 to 24 dB were observed in one TB at frequencies from 3 to 6 kHz. CONCLUSION: Actuator output was similarly high for all types of coupling to the incus but coupling to the incus long process led to a higher occurrence of conductive losses. All three coupling configurations connected the actuator securely to the ossicular chain, under variations of barometric pressure that can be expected in daily life.

The Effect of the Status of the Ossicular Chain and Choice of Graft Material on Hearing Outcomes in Pediatric Cholesteatoma Surgery.

OBJECTIVE: Compare hearing benefit of incus preservation in primary cholesteatoma surgery versus cartilage-myringostapediopexy. METHODS: Prospective cohort study in a tertiary referral center. Tympanoplasty utilizing cartilage or other grafts, with or without intact incus was performed in 195 ears (187 children) with intact stapes. Outcome measures were pre and post-operative four-tone air conduction (AC) threshold (0.5, 1, 2, 4 kHz) and proportion with normal hearing (AC ≤ 30 dB HL) at 12 months. RESULTS: Ears with intact ossicles had better post-operative AC thresholds than those with incus eroded or removed (median 20 dB HL vs. 30 dB HL, Mann-Whitney P < .001). The normal hearing rate was 81/106 (74%) with intact incus and 46/89 (52%) without (Fisher's exact P = .001). Ears without intact incus and a cartilage-myringostapediopexy had better post-operative thresholds than those with a non-cartilage graft (28.8 dB HL vs. 36.3 dB HL, Mann-Whitney P = .005). Of ears without intact incus, 37/59 (63%) with a cartilage-myringostapediopexy and 9/30 (30%) with a non-cartilage graft had normal hearing post-operatively (Fisher's exact P = .007). By preserving the incus in 12 ears, 1 more ear would have normal hearing than with incus removal plus cartilage-myringostapediopexy (NNT = 12 (CI 3.6-); Fisher's exact = 0.1). CONCLUSION: Preserving an intact ossicular chain conveys a small but significant hearing benefit in cholesteatoma surgery, the magnitude of which should be considered before deciding to remove the intact incus. Cartilage-myringostapediopexy provides a significant gain in hearing when the incus is absent, even without a partial ossicular replacement prosthesis.