An Implantable Piezofilm Middle Ear Microphone: Performance in Human Cadaveric Temporal Bones.

PURPOSE: One of the major reasons that totally implantable cochlear microphones are not readily available is the lack of good implantable microphones. An implantable microphone has the potential to provide a range of benefits over external microphones for cochlear implant users including the filtering ability of the outer ear, cosmetics, and usability in all situations. This paper presents results from experiments in human cadaveric ears of a piezofilm microphone concept under development as a possible component of a future implantable microphone system for use with cochlear implants. This microphone is referred to here as a drum microphone (DrumMic) that senses the robust and predictable motion of the umbo, the tip of the malleus. METHODS: The performance was measured by five DrumMics inserted in four different human cadaveric temporal bones. Sensitivity, linearity, bandwidth, and equivalent input noise were measured during these experiments using a sound stimulus and measurement setup. RESULTS: The sensitivity of the DrumMics was found to be tightly clustered across different microphones and ears despite differences in umbo and middle ear anatomy. The DrumMics were shown to behave linearly across a large dynamic range (46 dB SPL to 100 dB SPL) across a wide bandwidth (100 Hz to 8 kHz). The equivalent input noise (over a bandwidth of 0.1-10 kHz) of the DrumMic and amplifier referenced to the ear canal was measured to be about 54 dB SPL in the temporal bone experiment and estimated to be 46 dB SPL after accounting for the pressure gain of the outer ear. CONCLUSION: The results demonstrate that the DrumMic behaves robustly across ears and fabrication. The equivalent input noise performance (related to the lowest level of sound measurable) was shown to approach that of commercial hearing aid microphones. To advance this demonstration of the DrumMic concept to a future prototype implantable in humans, work on encapsulation, biocompatibility, and connectorization will be required.

Middle Fossa Decompression for Recurrent Facial Palsy: Prevalence and Surgical Outcomes.

OBJECTIVE: To investigate the surgical outcomes in patients treated for recurrent facial nerve palsy (RFP) at a quaternary facial nerve referral center. METHODS: A retrospective chart review was performed on 132 patients with RFP who presented to our institution's facial nerve clinic from 2001 to 2021. Records were analyzed for etiology of palsy, facial nerve function, and recurrence rates. Pre- and post-operative audiometric outcomes were also assessed in surgically managed patients. RESULTS: 6.8% of RFP patients underwent surgical decompression. For patients who did not undergo surgery, the House-Brackmann (HB) score was 2.9 ± 1.3 (SD) at the initial clinic visit, and 2.4 ± 1.3 (SD) at the last clinic visit. This difference was significantly different (p = 0.01, t-test). For surgical patients, the pre-operative HB score was 2.9 ± 0.9 (SD) and post-operative HB score was 1.8 ± 0.6 (SD), which were significantly different (p = 0.01, t-test). The number of facial palsy episodes also decreased pre- and post-operatively from 3.5 ± 0.8 (SD) to 0.2 ± 0.4 (SD) episodes, which were significantly different (p < 0,001, t-test). Audiometric outcomes were not significantly different pre- and post-surgery (p = 0.31, t-test for PTA; p = 0.34, t-test for WRS). CONCLUSION: Facial nerve decompression for RFP patients with incomplete functional recovery may be an effective treatment for decreasing the frequency and severity of facial palsy episodes. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:1222-1227, 2023.

The UmboMic: A PVDF Cantilever Microphone.

Objective: We present the "UmboMic," a prototype piezoelectric cantilever microphone designed for future use with totally-implantable cochlear implants. Methods: The UmboMic sensor is made from polyvinylidene difluoride (PVDF) because of its low Young's modulus and biocompatibility. The sensor is designed to fit in the middle ear and measure the motion of the underside of the eardrum at the umbo. To maximize its performance, we developed a low noise charge amplifier in tandem with the UmboMic sensor. This paper presents the performance of the UmboMic sensor and amplifier in fresh cadaveric human temporal bones. Results: When tested in human temporal bones, the UmboMic apparatus achieves an equivalent input noise of 32.3 dB SPL over the frequency range 100 Hz to 7 kHz, good linearity, and a flat frequency response to within 10 dB from about 100 Hz to 6 kHz. Conclusion: These results demonstrate the feasibility of a PVDF-based microphone when paired with a low-noise amplifier. The reported UmboMic apparatus is comparable in performance to a conventional hearing aid microphone. Significance: The proof-of-concept UmboMic apparatus is a promising step towards creating a totally-implantable cochlear implant. A completely internal system would enhance the quality of life of cochlear implant users.

Voluntary Field Recall of Advanced Bionics HiRes Cochlear Implants: A Single-Institution Experience.

OBJECTIVES: In 2020, Advanced Bionics (AB) announced a recall of two cochlear implant (CI) models, the "HiRes Ultra" and "HiRes Ultra 3D", because of reports of hearing degradation. The present study examines clinical parameters and patient features in cases of device failure and evaluates outcomes after reimplantation. MATERIALS AND METHODS: A series of 52 patients implanted with the recalled devices experienced suspected device failure and subsequently underwent revision CI placement at a tertiary academic medical center between December 2019 and November 2021. RESULTS: Consonant-nucleus-consonant scores and individual phonemes increased significantly between patients' preoperative evaluation and primary cochlear implantation. Performance declined significantly before revision and recovered after revision CI placement. Similarly, pure-tone average thresholds improved between preoperative and primary CI, fell before revision surgery, and were corrected with revision implantation. As a group, patients reached their peak hearing performance significantly faster after revision CI (mean ± standard deviation, 53.4 ± 51.8 d) compared with their primary CI (mean ± standard deviation, 260.6 ± 245.9 d). Electrical field imaging performed by AB and device impedance measurements were found to be abnormal in the basally positioned electrodes (electrodes 9-16). CONCLUSION: Hearing performance degradation is significant in AB Ultra device failures and seems to be linked to the basal-most electrodes in the array. Revision outcomes have been robust, necessitating continued monitoring of affected patients and support for reimplantation procedures. LEVEL OF EVIDENCE: IV.

Feeding Tube Placement Following Transoral Robotic Surgery for Oropharyngeal Squamous Cell Carcinoma.

OBJECTIVE: To identify factors that may predict the need for feeding tubes in patients undergoing transoral robotic surgery (TORS) in the perioperative setting. STUDY DESIGN: Retrospective chart review. SETTING: Academic tertiary center. METHODS: A retrospective series of patients undergoing TORS for oropharyngeal squamous cell carcinoma (OPSCC) was identified between October 2016 and November 2019 at a single tertiary academic center. Patient data were gathered, such as frailty information, tumor characteristics, and treatment, including need for adjuvant therapy. Multiple logistic regression was performed to identify factors associated with feeding tube placement following TORS. RESULTS: A total of 138 patients were included in the study. The mean age was 60.2 years (range, 37-88 years) and 81.9% were male. Overall 82.9% of patients had human papilloma virus-associated tumors, while 28.3% were current or former smokers with a smoking history ≥10 pack-years. Eleven patients (8.0%) had a nasogastric or gastrostomy tube placed at some point during their treatment. Five patients (3.6%) had feeding tubes placed perioperatively (<4 weeks after TORS), of which 3 were nasogastric tubes. Six patients (4.3%) had feeding tubes placed in the periadjuvant treatment setting for multifactorial reasons; 5 of which were gastrostomy tubes. Only 1 patient (0.7%) was gastrostomy dependent 1 year after surgery. Multiple logistic regression did not demonstrate any significant predictive variables affecting perioperative feeding tube placement following TORS for OPSCC. CONCLUSIONS: Feeding tubes are seldom required after TORS for early-stage OPSCC. With appropriate multidisciplinary planning and care, patients may reliably avoid the need for feeding tube placement following TORS for OPSCC.

Impact of surgical margins on local control in patients undergoing single-modality transoral robotic surgery for HPV-related oropharyngeal squamous cell carcinoma.

BACKGROUND: The impact of close surgical margins on oncologic outcomes in HPV-related oropharyngeal squamous cell carcinoma (HPV + OPSCC) is unclear. METHODS: Retrospective case series including patients undergoing single modality transoral robotic surgery (TORS) for HPV + OPSCC at three academic medical centers from 2010 to 2019. Outcomes were compared between patients with close surgical margins (<1 mm or requiring re-resection) and clear margins using the Kaplan-Meier method. RESULTS: Ninety-nine patients were included (median follow-up 21 months, range 6-121). Final margins were close in 22 (22.2%) patients, clear in 75 (75.8%), and positive in two (2.0%). Eight patients (8.1%) recurred, including two local recurrences (2.0%). Four patients died during the study period (4.0%). Local control (p = 0.470), disease-free survival (p = 0.513), and overall survival (p = 0.064) did not differ between patients with close and clear margins. CONCLUSIONS: Patients with close surgical margins after TORS for HPV + OPSCC without concurrent indications for adjuvant therapy may be considered for observation alone.

An Implantable Umbo Microphone For Fully-Implantable Assistive Hearing Devices.

This paper presents an implantable microphone for sensing the displacement of the umbo, the end of the malleus where it attaches to the center tip of the cone-shaped tympanic membrane. The sensor comprises a piezoelectric polyvinylidene fluoride (PVDF) film with copper-nickel electrodes suspended across a brass cylinder. The cylinder is oriented so that the umbo pushes on the film center, causing a static and acoustically-driven dynamic film displacement. An amplifier filters the resulting piezoelectric charge to produce an output signal. The sensor enables the full implantation of assistive hearing devices, which can restore hearing without inhibiting the user's lifestyle, while enabling better sound localization in noisy environments.

Opioid Usage and Prescribing Predictors Following Transoral Robotic Surgery for Oropharyngeal Cancer.

OBJECTIVE/HYPOTHESIS: Pain management following transoral robotic surgery (TORS) varies widely. We aim to quantify opioid usage following TORS for oropharyngeal squamous cell carcinoma (OPSCC) and identify prescribing predictors. STUDY DESIGN: Retrospective cohort study. METHODS: A consecutive series of 138 patients undergoing TORS for OPSCC were reviewed from 2016 to 2019. Opioid usage (standardized to morphine milligram equivalents [MME]) was gathered for 12 months post-surgery via prescribing record cross-check with the Massachusetts Prescription Awareness Tool. RESULTS: Of 138 OPSCC TORS patients, 92.8% were human papillomavirus (HPV) positive. Adjuvant therapy included radiation (XRT;67.4%) and chemoradiation (cXRT;6.5%). Total MME usage from start of treatment averaged 1395.7 MMEs with 76.4% receiving three prescriptions or less. Categorical analysis showed age <65, male sex, overweight BMI, lower frailty, former smokers, HPV+, higher T stage, and BOT subsite to be associated with increased MMEs. Adjuvant therapy significantly increased MMEs (TORS+XRT:1646.2; TORS+cXRT:2385.0; TORS alone:554.7 [P < .001]) and 12-month opioid prescription totals (TORS+XRT:3.2; TORS+cXRT:5.5; TORS alone:1.6 [P < .001]). Adjuvant therapy increased time to taper (total MME in TORS alone versus TORS+XRT/cXRT: 0 to 3 months:428.2 versus 845.5, 4 to 6 months:46.8 versus 541.8, 7 to 9 months:12.4 versus 178.6, 10 to 12 months:11.0 versus 4.4,[P < .001]). Positive predictors of opioid prescribing at the 4- to 6-month and 4- to 12-month intervals included adjuvant therapy (odds ratio [OR]:5.56 and 4.51) and mFI-5 score ≥3 (OR:36.67 and 31.94). Following TORS at 6-, 9-, and 12-month, 15.7%, 6.6%, and 4.1% were still using opioids. CONCLUSIONS: In OPSCC treated with TORS, opioid use tapers faster for surgery alone versus with adjuvant therapy. Opioid prescribing risks include adjuvant therapy and higher frailty index. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1888-E1894, 2021.

Optimal timing of endoscopic sinus surgery for odontogenic sinusitis.

OBJECTIVES: Odontogenic sinusitis (ODS) is more common than historically reported, and management recommendations are limited in the literature. Although ODS case series have shown successful outcomes with dental treatment and endoscopic sinus surgery (ESS), no studies have considered the optimal timing of these treatments. The purpose of this study was to analyze times to ODS resolution after primary dental treatment and ESS based on symptom, 22-item sinonasal outcome test (SNOT-22), and endoscopic outcomes. STUDY DESIGN: Prospective cohort study. METHODS: Thirty-seven symptomatic ODS patients who failed medical management were offered primary dental treatment or ESS. Eleven patients selected primary dental treatment, and 26 patients selected ESS. The following variables were collected prospectively at every office visit before and after dental treatment or ESS: SNOT-22, presence or absence of cardinal sinusitis symptoms, and presence or absence of middle meatal endoscopy findings (edema, polyps, purulence). Times to resolution of these clinical variables were analyzed with t test, chi-square test, Fisher exact test, McNemar test, and Kaplan-Meier survival analysis. RESULTS: Patients in the dental treatment and ESS groups showed no significant differences in preoperative sinusitis disease burdens based on symptoms, SNOT-22, endoscopy, and computed tomography. The ESS group experienced faster and more significant improvement in nearly all symptom, SNOT-22, and endoscopic outcomes. CONCLUSIONS: For symptomatic ODS, primary ESS resulted in faster resolution of SNOT-22, sinusitis symptoms, and endoscopic findings in ODS patients compared with primary dental treatment. ESS can be considered first-line therapy for symptomatic ODS, followed by dental treatment when necessary. LEVEL OF EVIDENCE: 2b Laryngoscope, 129:1976-1983, 2019.

Using Radiolabeled 3'-Deoxy-3'-18F-Fluorothymidine with PET to Monitor the Effect of Dexamethasone on Non-Small Cell Lung Cancer.

Non-small cell lung cancer (NSCLC) is a leading cause of cancer mortality in the United States, and pemetrexed-based therapies are regularly used to treat nonsquamous NSCLC. Despite widespread use, pemetrexed has a modest effect on progression-free survival, with varying efficacy between individuals. Recent work has indicated that dexamethasone, given to prevent pemetrexed toxicity, is able to protect a subset of NSCLC cells from pemetrexed cytotoxicity by temporarily suppressing the S phase of the cell cycle. Therefore, dexamethasone might block treatment efficacy in a subpopulation of patients and might be contributing to the variable response to pemetrexed. Methods: Differences in retention of the experimental PET tracer 3'-deoxy-3'-fluorothymidine (FLT) were used to monitor S-phase suppression by dexamethasone in NSCLC cell models, animals with tumor xenografts, and patients with advanced cancer. Results: Significant reductions in tracer uptake were observed after 24 h of dexamethasone treatment in NSCLC cell lines and xenograft models expressing high levels of glucocorticoid receptor α, coincident with pemetrexed resistance visualized by attenuation of the flare effect associated with pemetrexed activity. Two of 4 patients imaged in a pilot study with 18F-FLT PET after dexamethasone treatment demonstrated reductions in tracer uptake from baseline, with a variable response between individual tumor lesions. Conclusion:18F-FLT PET represents a useful method for the noninvasive monitoring of dexamethasone-mediated S-phase suppression in NSCLC and might provide a way to individualize chemotherapy in patients receiving pemetrexed-based regimens.

Effects of capecitabine treatment on the uptake of thymidine analogs using exploratory PET imaging agents: 18F-FAU, 18F-FMAU, and 18F-FLT.

BACKGROUND: A principal goal for the use of positron emission tomography (PET) in oncology is for real-time evaluation of tumor response to chemotherapy. Given that many contemporary anti-neoplastic agents function by impairing cellular proliferation, it is of interest to develop imaging modalities to monitor these pathways. Here we examined the effect of capecitabine on the uptake of thymidine analogs used with PET: 3'-deoxy-3'-[18F]fluorothymidine (18F-FLT), 1-(2'-deoxy-2'-[18F]fluoro-ß-D-arabinofuranosyl) thymidine (18F-FMAU), and 1-(2'-deoxy-2'-[18F]fluoro-ß-D-arabinofuranosyl) uracil (18F-FAU) in patients with advanced cancer. METHODS: Fifteen patients were imaged, five with each imaging agent. Patients had been previously diagnosed with breast, colorectal, gastric, and esophageal cancers and had not received therapy for at least 4 weeks prior to the first scan, and had not been treated with any prior fluoropyrimidines. Subjects were imaged within a week before the start of capecitabine and on the second day of treatment, after the third dose of capecitabine. Tracer uptake was quantified by mean standard uptake value (SUVmean) and using kinetic analysis. RESULTS: Patients imaged with 18F-FLT showed variable changes in retention and two patients exhibited an increase in SUVmean of 172.3 and 89.9 %, while the other patients had changes ranging from +19.4 to -25.4 %. The average change in 18F-FMAU retention was 0.2 % (range -24.4 to 23.1) and 18F-FAU was -10.2 % (range -40.3 to 19.2). Observed changes correlated strongly with SUVmax but not kinetic measurements. CONCLUSIONS: This pilot study demonstrates that patients treated with capecitabine can produce a marked increase in 18F-FLT retention in some patients, which will require further study to determine if this flare is predictive of therapeutic response. 18F-FAU and 18F-FMAU showed little change, on average, after treatment.

Integrating Dynamic Positron Emission Tomography and Conventional Pharmacokinetic Studies to Delineate Plasma and Tumor Pharmacokinetics of FAU, a Prodrug Bioactivated by Thymidylate Synthase.

FAU, a pyrimidine nucleotide analogue, is a prodrug bioactivated by intracellular thymidylate synthase to form FMAU, which is incorporated into DNA, causing cell death. This study presents a model-based approach to integrating dynamic positron emission tomography (PET) and conventional plasma pharmacokinetic studies to characterize the plasma and tissue pharmacokinetics of FAU and FMAU. Twelve cancer patients were enrolled into a phase 1 study, where conventional plasma pharmacokinetic evaluation of therapeutic FAU (50-1600 mg/m2 ) and dynamic PET assessment of 18 F-FAU were performed. A parent-metabolite population pharmacokinetic model was developed to simultaneously fit PET-derived tissue data and conventional plasma pharmacokinetic data. The developed model enabled separation of PET-derived total tissue concentrations into the parent drug and metabolite components. The model provides quantitative, mechanistic insights into the bioactivation of FAU and retention of FMAU in normal and tumor tissues and has potential utility to predict tumor responsiveness to FAU treatment.

pH required to kill Enterococcus faecalis in vitro.

Enterococcus faecalis tolerates highly alkaline environments, yet the exact pH required for killing E. faecalis is not known. This study tests growth at 0.5 increments from pH 9.5 to 12. Twelve culture tubes were used in each group. Positive growth was measured using turbidity, a visual scale, and a spectrophotometer. At 24 h, growth was observed in all tubes at pH 9.5 and 10. At 48 h, all pH 10.5 tubes showed growth. At 72 h, six of the pH 11 tubes showed growth. After 7 days, five of the remaining pH 11 tubes were positive. No growth occurred in any of the pH 11.5 or pH 12 tubes. Apparently, pH 10.5 to 11.0 retards growth of E. faecalis, whereas no tubes showed growth at pH 11.5 or greater.