Anatomical Variations of the Epitympanum and the Usable Space for Middle Ear Implants Analyzed With CT-assisted Imaging Using a Tablet-based Software.

OBJECTIVE: To evaluate interindividual anatomical variations of the epitympanum and the usable space for implantation of active middle ear implants (AMEI) as well as the usefulness of a tablet-based software to assess individual anatomy on computed tomography (CT) scans. PATIENTS: CT scans of 126 patients, scheduled for cochlea implantation (50.8% men; 0.6-90.0 yr) without middle ear malformations or previous middle ear surgery and with slice thickness ≤0.7 mm were analyzed. MAIN OUTCOME MEASURES: Since no standardized measurements to assess the size of the epitympanum are available, relevant distances were defined according to anatomical landmarks. Three independent raters measured these distances using a tablet-based software. Interrater correlation was computed to evaluate the quality of the measurement process. Descriptive data were analyzed for validation and for evaluation of interindividual anatomical variations. Influence of age and sex on the taken measurements was assessed. RESULTS: No relevant correlation between age or sex and the anatomy of the epitympanum was found. Interrater correlation ranged from Spearman's ρ = 0.3-0.9 and there were significant differences between individual rater results for various combinations. Descriptive data revealed high interindividual anatomical variance of the epitympanum, especially regarding the distance between incus and skull base. CONCLUSION: The reported descriptive data regarding the anatomy of the epitympanum emphasizes the importance of preoperative planning, especially since the height of the epitympanum showed great interindividual variance potentially limiting implantation of AMEIs. The herein used tablet-based software seems to be convenient for preoperative assessment of individual anatomy in the hand of otosurgeons.

Combination of Direct Oval Window Vibroplasty With Customized Partial Ossicular Replacement Prosthesis (PORP): A Novel Reconstruction Technique to Rehabilitate Mixed Hearing Loss.

OBJECTIVE: Hearing rehabilitation with an active middle ear implant (AMEI) in patients with mixed hearing loss (MHL) after multiple ear surgeries is surgically challenging and requires individual solutions in some cases. Our objective was to introduce a feasible novel technique for direct oval window vibroplasty (OW vibroplasty) using a partial ossicular replacement prosthesis (PORP) to ensure stability and enable active and passive sound transmission. DESIGN: Four patients with MHL following multiple middle ear surgeries and indication for an AMEI received direct OW vibroplasty in combination with a customized PORP between the enwrapped actuator and reconstructed tympanic membrane (TM). RESULTS: Postoperative bone conduction was stable in all patients. All patients benefitted from the AMEI in combination with PORP with a mean functional gain of 31.5 ±â€Š17.0 dB. Mean aided postoperative pure tone average was 27.3 ±â€Š2.6 dB. Speech discrimination in quiet at 65 dB with the German Language Freiburg Monosyllabic Test improved for all patients to 68.8 ±â€Š6.3% and in noise with the German Language Oldenburger Sentence Test to -10.4 ±â€Š3.3 dB SNR. No complications were observed. CONCLUSIONS: This novel technique of direct OW vibroplasty extends the portfolio of reconstructive middle ear procedures by combining an intraoperatively customized "off-the-shelf" PORP as a coupler between floating mass transducer (FMT) and a cartilage TM. We found satisfying functional hearing results. Benefits of the reported technique comprise 1) stabilization and optimized coupling of the reconstruction, 2) possibility of passive sound transmission, 3) general feasibility due to great availability of a regular PORP, and 4) flexibility in bridging of large gaps between TM and actuator.

Stapes and Stapes Revision Surgery: Preoperative Air-Bone Gap Is a Prognostic Marker.

OBJECTIVE: Stapes surgery is considered an effective treatment in otosclerosis, but controversy remains regarding predictors of surgical outcome. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary referral center. PATIENTS: One hundred sixty three cases of stapes surgery between 2012 and 2019 were reviewed. MAIN OUTCOME MEASURES: Primary outcome measures were relative hearing improvement (relHI), defined as preoperative minus postoperative air conduction divided by preoperative air-bone gap (ABG), as well as relative ABG closure (relABGc), defined as preoperative ABG minus postoperative ABG divided by preoperative ABG. Univariate and multivariate linear regression analyses were performed to determine independent predictors for these outcomes. RESULTS: Higher preoperative bone conduction (BC) and primary surgery (compared with revision) were independently associated with increased relHI (p = 0.001 and p = 0.004, respectively). Lower preoperative BC, higher preoperative ABG, primary surgery, and age were independently associated with increased relABGc (p = 0.0030, p < 0.001, p = 0.0214, and p = 0.0099, respectively). Sex did not predict surgical outcome. In patients with less than 20 dB preoperative ABG, likelihood of negative relABGc was increased (compared with 20-30 dB or >30 dB preoperative ABG, p = 0.0292, Fisher's exact test). This tendency was not significant for relHI (p = 0.074). CONCLUSIONS: Our findings demonstrate that calculating HI and ABGc in relation to preoperative ABG can reliably predict outcomes of stapes surgery. Both primary and revision stapes surgery are effective treatment options, but relative improvement is higher in primary cases. Preoperative BC, preoperative ABG, and age predict surgical outcomes as well. Otosclerosis patients with low preoperative ABG, especially less than 20 dB, should be counseled and selected cautiously regarding stapes surgery.