Ossicular Chain Reconstruction With Titanium Prostheses: A Systematic Review and Meta-Analysis.

OBJECTIVES: This review sought to establish expectations for hearing improvement with specifically titanium partial (PORP) and total ossicular replacement prostheses (TORP) to give surgeons an acceptable goal for postoperative hearing results and to counsel patients on their expected results. DATABASES REVIEWED: MEDLINE/PubMed, EMBASE, and Cochrane Library. METHODS: A systematic review of the literature was performed per the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Three databases (MEDLINE/PubMed, EMBASE, Cochrane library) were searched using relevant key search terms to identify studies evaluating outcomes of titanium prostheses. A title/abstract and full article review was then done, and the results from the remaining studies were analyzed with Review Manager 5.4 Software to perform a meta-analysis using a random-effects model. RESULTS: Forty articles were analyzed after full article review based on the inclusion and exclusion criteria. For PORPs, the average improvement in air-bone gap (ABG) and pure-tone average were 12.1 and 13.5 dB, respectively. For TORPs, the average improvements in ABG and pure-tone average were 16.7 and 17.0 dB, respectively. Preoperatively, the average ABG was 7.0 dB better for PORP than TORP patients, and postoperatively, the ABG improved an average of 4.9 dB more for the PORP cohort. Seventy percent of PORPs and 57% of TORPs subjects had a postoperative ABG less than 20 dB. CONCLUSIONS: Overall, reconstruction of the ossicular chain with titanium prostheses reliably improves patients' hearing outcomes, and this study gives relevant information for counseling patients preoperatively on realistic hearing outcomes.

MRI Screening in Vestibular Schwannoma: A Deep Learning-based Analysis of Clinical and Audiometric Data.

Objective: To find a more objective method of assessing which patients should be screened for a vestibular schwannoma (VS) with magnetic resonance imaging (MRI) using a deep-learning algorithm to assess clinical and audiometric data. Materials and Methods: Clinical and audiometric data were collected for 592 patients who received an audiogram between January 2015 and 2020 at Duke University Health Center with and without VS confirmed by MRI. These data were analyzed using a deep learning-based analysis to determine if the need for MRI screening could be assessed more objectively with adequate sensitivity and specificity. Results: Patients with VS showed slightly elevated, but not statistically significant, mean thresholds compared to those without. Tinnitus, gradual hearing loss, and aural fullness were more common in patients with VS. Of these, only the presence of tinnitus was statistically significant. Several machine learning algorithms were used to incorporate and model the collected clinical and audiometric data, but none were able to distinguish ears with and without confirmed VS. When tumor size was taken into account the analysis was still unable to distinguish a difference. Conclusions: Using audiometric and clinical data, deep learning-based analyses failed to produce an adequately sensitive and specific model for the detection of patients with VS. This suggests that a specific pattern of audiometric asymmetry and clinical symptoms may not necessarily be predictive of the presence/absence of VS to a level that clinicians would be comfortable forgoing an MRI.

Intratonsillar abscess: A not-so-rare clinical entity.

OBJECTIVE: To report the prevalence of intratonsillar abscess in the pediatric population at our institution and demonstrate that intratonsillar abscess is a more commonly encountered diagnosis than previously reported. METHODS: A retrospective chart review was performed that included patients presenting to our pediatric tertiary referral academic emergency department from January 1, 2014 to December 31, 2014 diagnosed with intratonsillar abscess on computed tomography. RESULTS: In the year 2014, 22 children were diagnosed with intratonsillar abscess by radiological criteria. The majority of patients (82%) required no surgical intervention and were successfully treated with antibiotics and supportive measures. All patients recovered from the infection uneventfully, and there were no treatment complications recorded. CONCLUSION: Even in recent literature, intratonsillar abscess is described as a rare entity, with few cases reported. In our experience, CT imaging demonstrating the presence of intratonsillar abscess is more common than previously described. Regardless of treatment method, in our experience children with intratonsillar abscess do well clinically.

Comparing Cancellous Bone Volume of the Manubrium to Iliac Crest in Fresh Cadavers.

Objective The iliac crest is the gold standard for cancellous bone grafting. This site is distant from head and neck reconstruction and may lead to significant postoperative morbidity. We propose an alternative harvest site within the head and neck with potentially less mobility deficits, the manubrium. Study Design Fresh-frozen cadaveric study. Setting Gross anatomy laboratory. Subjects and Methods Access to 18 cadavers was granted from the Medical Education and Research Institute in Memphis, Tennessee. The anterior iliac crests were exposed and H-type osteotomies performed. The manubrium was accessed through a substernal notch incision and a cortical window created through the anterior manubrium. Cancellous bone was harvested from these sites. Cadaveric demographics and noncompressed and compressed volumes were recorded with statistical comparisons. Results The population was predominantly male (12/18) with a mean age of 69.6 (95% confidence interval [CI], 64.0-75.3) years. The mean body mass index was 22.9 (95% CI, 18.8-27.1) kg/m2 with no sex propensity. Uncompressed volumes did not vary, ranging from 6.4 to 7.5 mL. Compressed volumes (mL) for the right iliac crest (4.3; 95% CI, 3.0-5.6), left iliac crest (3.5; 95% CI, 2.7-4.2), and manubrium (2.4; 95% CI, 1.8-3.0) varied (1-way analysis of variance: F(2, 51) = 4.63; P < .02). Furthermore, there was correlation between compressed volumes taken from either area ( r = 0.58; P < .02). Conclusions The manubrium can be used for cancellous bone grafting. This site affords a proximity to the head and neck rather than the distant iliac crest but with slightly lower yields. Potential applications include reconstructing small mandibular defects, mandible nonunion, or alveolar bone grafting.

Examining the impact of acetylene on N-fixation and the active sediment microbial community.

Here we examined the impact of a commonly employed method used to measure nitrogen fixation, the acetylene reduction assay (ARA), on a marine sediment community. Historically, the ARA technique has been broadly employed for its ease of use, in spite of numerous known artifacts. To gauge the severity of these effects in a natural environment, we employed high-throughput 16S rRNA gene sequencing to detect differences in acetylene-treated sediments vs. non-treated control sediments after a 7 h incubation. Within this short time period, significant differences were seen across all activity of microbes identified in the sediment, implying that the changes induced by acetylene occur quickly. The results have important implications for our understanding of marine nitrogen budgets. Moreover, because the ARA technique has been widely used in terrestrial and freshwater habitats, these results may be applicable to other ecosystems.