Erosion of the long process of the incus in revision stapes surgery: malleovestibular prosthesis or incus reconstruction with hydroxyapatite bone cement?

OBJECTIVE: To study hearing outcome in revision stapedotomy cases where extensive erosion of the long process of the incus was observed in a consecutive series where a malleovestibular prosthesis was used versus a consecutive series where hydroxyapatite (HA) bone cement was used to rebuild the eroded long process of the incus and integrate the prosthesis. PATIENTS: Twenty revision cases of surgically treated otosclerosis where extensive incus erosion was observed during revision surgery. INTERVENTION: In the earlier consecutive series, 10 cases were treated with malleovestibular prostheses. In the later consecutive series, 10 cases were treated with HA bone cement to rebuild the incus-prosthesis interface. MAIN OUTCOME MEASURES: Air-bone gap, bone-conduction thresholds, and air-conduction thresholds were evaluated preoperatively and at 1 to 3 months. Last audiometry available also was reported (median, 12 mo). Pure-tone averages were calculated according to the guidelines of the Committee on Hearing and Equilibrium for the evaluation of conductive hearing loss. Raw data were displayed in an Amsterdam Hearing Evaluation Plot. RESULTS: Six male patients and 14 female patients were included. Age varied from 34 to 75 years (median, 53 yr). The median postoperative air-bone gap at last follow-up audiometry was 15.6 in the malleovestibular prosthesis group and 13.1 dB in the HA bone cement group. No short-term or intermediate-term adverse reactions or unsuspected bone conduction deteriorations were seen. CONCLUSION: HA bone cement can be successfully used to reconstruct the long process of the incus in case of extensive erosion of the long process. Intermediate-term hearing outcome is comparable to the outcome of a series of similar cases treated with malleovestibular prostheses. Because the placement of a malleovestibular prosthesis is technically more difficult and presents a high risk to the inner ear, we think HA bone cement can be a useful alternative in these difficult cases.

Systematic review of the literature on nitinol prostheses in surgery for otosclerosis: assessment of the adequacy of statistical power.

OBJECTIVE: To perform a systematic review of observational studies reporting hearing outcome in primary stapes surgery where a heat-crimping prosthesis was used. DATA SOURCES: Medline, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, TRIP database, Clinical Trials Registry, ISI Web of Knowledge, and Web of Science. The search was performed on January 1, 2010, including articles published ahead of print. No language restrictions. STUDY SELECTION: Inclusion criteria for qualitative synthesis were a population of otosclerosis patients, intervention being primary stapes surgery with a nickel titanium alloy (Nitinol) heat-crimping prosthesis, and hearing outcome. Inclusion criteria for quantitative analysis: application of audiometry guidelines of the American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium for evaluation of conductive hearing loss. DATA EXTRACTION: Strategy and reporting based on Cochrane, Quality of Reporting of Meta-analyses, and Meta-analysis of Observational Studies in Epidemiology statements. A bias assessment tool was developed according to Cochrane guidelines. DATA SYNTHESIS: A quantitative synthesis was performed, but because of the heterogeneity in postoperative follow-up periods and outcome measures reported, we were not able to pool these data. A sample size analysis was performed to indicate the sample needed to demonstrate a statistically significant difference in hearing outcome between both interventions. Hearing outcome superiority of the Nitinol heat-crimping prosthesis over manually crimping prosthesis types was not demonstrated. CONCLUSION: Superiority could probably not be demonstrated because of insufficient sample size. Research addressing technical improvements in stapes surgery should agree on a base sample size able to detect the smallest difference that is clinically important or accept the null hypothesis. With data gathered in the Common Otology Database as basis, a sample size of at least 413 patients is needed in both the intervention and the control group. Other clinical outcome measures also should be explored.