Comprehensive Analysis of Adverse Events Associated With Hypoglossal Nerve Stimulators: Insights From the MAUDE Database.

OBJECTIVE: This study aims to examine the adverse events associated with hypoglossal nerve stimulator (HNS) implantation for treating obstructive sleep apnea (OSA), drawing data from the Manufacturer and User Facility Device Experience (MAUDE) database. We aim to provide a comprehensive and updated account of these adverse events. STUDY DESIGN: Retrospective analysis. SETTING: MAUDE Database review. METHODS: A retrospective analysis was performed on the MAUDE database to collect all HNS-related reports from May 2014 to December 2023. Variables collected included date of event, event description, nature of event, iatrogenic injuries, required interventions, and, if available, root causes. Each event description was analyzed to classify the adverse event, the postevent intervention, and device model number. RESULTS: Out of 1178 reports fulfilling the inclusion criteria, 1312 adverse events were identified. Common adverse events included infection (24.0%), pain (19.7%), and hematoma/seroma (10.2%). Approximately 83.1% of these adverse events necessitated medical and/or surgical intervention. The most frequent procedures included explantation (29.4%) and device repositioning (15.8%). Pneumothorax was reported in 50 cases, with 41 (82.0%) requiring a chest tube to be inserted. Three adverse events described overstimulation in the setting of magnetic resonance imaging (MRI) despite the implantation of MRI-compatible second-generation internal pulse generators. CONCLUSION: While HNS implantation has been established as a reliable intervention for OSA in cases of continuous positive airway pressure failure or intolerance, this study highlights several perioperative and postoperative difficulties and complications. Understanding these challenges is essential for refining surgical practices and enhancing patient consent processes, ultimately aiming to improve therapeutic outcomes.

Are There Hidden Adverse Events in Hypoglossal Nerve Stimulation: Comparing Social Media and a Federal Database.

OBJECTIVE: Hypoglossal nerve stimulation (HNS) can be an effective treatment for moderate to severe obstructive sleep apnea (OSA) in positive airway pressure (PAP) intolerant patients. To better understand patient experiences with HNS therapy, we explored reported events from HNS-related Facebook groups and the Manufacturer and User Facility Device Experience (MAUDE) database. METHODS: A retrospective analysis of HNS-related Facebook posts from three groups pertaining to HNS therapy, from October 1, 2022 to October 1, 2023, was performed. Posts were analyzed for patient-reported adverse events. Concurrently, the MAUDE database was reviewed for HNS-related events during the same timeframe. RESULTS: From 737 Facebook posts, 132 (17.55%) adverse events were identified. Adverse events included pain (34.85%), stimulation discomfort (14.39%), lip weakness (6.82%) and issues related to lead tethering or tight leads around the neck (3.79%). Analysis of the MAUDE database found 428 adverse events, including pain (24.07%), lip weakness (0.44%), and lead tethering (1.64%). CONCLUSION: Facebook group members reported higher rates of lip weakness and lead tethering than recorded in the MAUDE database. These findings illustrate how diverse data sources, such as social media, can enhance our understanding of patient experiences and identify gaps in patient education with HNS therapy. LEVEL OF EVIDENCE: NA Laryngoscope, 2024.

Mitigating Infection Risk in Upper Airway Stimulation.

OBJECTIVE: This study aims to define the incidence of infection with upper airway stimulation (UAS) devices requiring explantation in a single academic center and identify factors that may influence the risk of infection. METHODS: A database of patients who underwent UAS at a single tertiary referral academic center from 2017 to 2021 was retrospectively reviewed to identify patients who developed surgical site infections, with and without subsequent explantation. Additional data for cases complicated by infection was extracted from the electronic medical record (EMR) and included: demographic information, medical history, complications and management, and overall outcomes. In March 2021, 2 modifications to infection control protocols were implemented: double skin preparation with Betadine and chlorhexidine, and MRSA decolonization. Statistical analysis was performed to compare infectious risk before and after these protocol changes. RESULTS: In the study period, 215 patients underwent UAS in the specified time period and 3 cases (1.4%) of postoperative infections were identified, all of which required explantation. The infection rate did not significantly change after modifications to the surgical prep protocol (P = .52). CONCLUSIONS: While no significant difference in infection risk was noted after modifying infection control protocols, additional longer-term study is warranted to elucidate effective infection reduction strategies.

Respiratory Sensing Lead Malfunction in Upper Airway Stimulation: A Single Institution Report.

OBJECTIVES: Upper airway stimulation (UAS) is an effective treatment for patients with obstructive sleep apnea. The device consists of a stimulating electrode, an internal pulse generator, and a respiratory sensing lead. The purpose of this study is to characterize the incidence of sensing lead malfunction necessitating revision surgery in a high-volume center in conjunction with a review of the FDA Manufacturer and User Facility Device Experience (MAUDE) database reports on adverse events associated with the sensing lead component. METHODS: Patients age ≥18 implanted with the device were reviewed between July 2017 and June 2022. Those determined to have sensing lead malfunction were analyzed. The FDA MAUDE database was reviewed for reports associated with "Inspire Model 4323 Respiratory" and "Inspire Model 4340 Respiratory" between January 2014 and September 2022. RESULTS: One hundred ninety patients underwent UAS at our institution during the study period and four (2.1%) patients were found to have sensing lead malfunction. Analysis of the MAUDE database revealed 122 reports of adverse events associated with the sensing lead component, with 72% (88/122) of these requiring revision surgery. The most frequently reported adverse event was sensing lead tip separation from lead body, noted in 46% of these reports (56/122). CONCLUSION: The functionality of the sensing lead component is vital to the integrity of the UAS device and is measurable through waveform analysis. To provide optimal care after device implantation, it is essential to have a comprehensive understanding of the scenarios in which this component fails, the incidence of such events, and appropriate management. LEVEL OF EVIDENCE: 4 Laryngoscope, 134:1479-1484, 2024.

Should lateral wall collapse be a contraindication for hypoglossal nerve stimulation?

OBJECTIVE: The purpose of this study is to examine how lateral wall collapse affects treatment outcomes for hypoglossal nerve stimulation (HNS) patients. METHODS: Patients (n = 111) queried from a single surgeon's database of HNS cases were divided into groups based on their degree of oropharyngeal lateral wall collapse noted on drug-induced sleep endoscopy (DISE): Complete, Partial, None. For each group, apnea hypopnea index (AHI) reduction, Epworth Sleepiness Scale (ESS) score, stimulation voltage, average nightly usage, need for alternate device configuration/awake sleep endoscopy, and rate of surgical success were collected. Patients with Complete collapse were compared to those with Partial/None via Student's t-tests and Pearson's Chi-square test. RESULTS: Of the 111 eligible patients, 45 had complete, 30 partial, and 36 had no lateral oropharyngeal wall collapse. There were no statistically significant differences found between the Complete and Partial/None groups in terms of age, BMI, sex, AHI (pre and post-op), ESS (pre and post-op), voltage, alternate device configuration, or nightly adherence. Notably, a significantly greater number of the Partial/None group had surgical success (84.84 % vs 66.67 %, p = 0.024). CONCLUSIONS: Patients with Partial/None oropharyngeal collapse were significantly more likely than patients with Complete lateral wall collapse to see surgical success. There are many factors to weigh when assessing a patient's surgical candidacy, it is clear that complete lateral wall collapse at the level of the oropharynx is a negative predictor for success in HNS.

Hyoid Suspension With UPPP for the Treatment of Obstructive Sleep Apnea.

This retrospective evaluation of surgical outcomes for hyomandibular suspension when performed with uvulopalatopharyngoplasty (UPPP) for the treatment of obstructive sleep apnea (OSA). Thirty-nine patients with moderate-to-severe OSA were treated with hyoid myotomy and suspension and uvulopalatopharyngoplasty. Patients underwent hyoid advancement and suspension to the mandible (Encore System) with either staged or concurrent UPPP. The primary outcome was a successful surgical result, defined as an apnea hypopnea index (AHI) lower than 20, and a 50% or greater decline in AHI on postoperative polysomnography. Successful surgical results were achieved in 30 (76.9%) out of 39 patients. The mean preoperative AHI improved 69.2% from 49.9 ± 25.6 to 15.4 ± 14.9 (P < .001) postoperatively. All patients reported clinical improvement of symptoms. There were 4 wound complications and one infection requiring removal of hardware. For patients with multilevel obstructive sleep apnea, hyoid advancement and suspension to the mandible appears efficacious when performed in conjunction with uvulopalatopharyngoplasty.

Comparison of readmission and complication rates between traditional sleep surgery and hypoglossal nerve stimulation.

Objective: This study aims to compare readmission and complication rates between hypoglossal nerve stimulation (HNS) and traditional sleep surgery (TSS) in the 90-day postoperative period using a federated electronic health record (EHR) database. Methods: We queried TriNetX, a global federated health research network providing access to EHR data from approximately 70 million patients in 49 large health care organizations to identify individuals who underwent either HNS or TSS for obstructive sleep apnea (OSA) from April 2014 to March 2021. Propensity scores based on demographics and obesity were used to balance groups. We compared the frequency of readmission/representation and surgical-related complication rates between cohorts. Results: After propensity score matching of HNS versus palatal surgery (n = 1014 in each cohort) and HNS versus multilevel surgery (n = 374 in each cohort), we found palatal and multilevel surgery had a significantly higher risk of readmission versus HNS. (12% vs. 4%, p < .0001). Palatal surgery complication rate was also higher than HNS (21% vs. 2%, p < .0001). Multi-level surgery results were similarly higher (22% vs. 3%, p < .001). The most common diagnoses at ER readmission for TSS were procedural complications and pain, while common diagnoses for HNS readmission were general complaints such as malaise and headache. Conclusions: Hypoglossal nerve stimulation has lower risk of readmission and postoperative complications than traditional sleep surgery as demonstrated in a large research network database analysis. Level of Evidence: 3.

Pneumothorax during upper airway stimulation: Does experience make a difference?

OBJECTIVES: Upper airway stimulation is a treatment option for select patients with obstructive sleep apnea. Pneumothorax may occur with UAS implantation during placement of the respiratory sensor. This study aims to evaluate the incidence of pneumothorax during UAS device placement. We hypothesize that sleep surgeons with high implantation volumes experience lower rates of pneumothorax compared to the general population of surgeons. METHODS: We also aim to describe management of pneumothorax when it does occur. The incidence of pneumothorax during UAS implantation among the general population of surgeons was assessed using the TriNetX Research Network. Additionally, a select group of Otolaryngologist sleep surgeons with a high UAS implantation volume were surveyed regarding experiences with UAS related pneumothoraces. RESULTS: 8 pneumothoraces occurred among 3823 UAS procedures in the surveyed otolaryngologist sleep surgeon population. 4 required chest tube insertion. Among the general population cohort, 42 of 1233 patients developed pneumothorax after UAS implantation. The rates of pneumothorax between the otolaryngologist sleep surgeon cohort and general population of surgeons cohort were 0.21 % and 3.4 % respectively (p < 0.00001). CONCLUSION: Pneumothorax rarely occurs during UAS implantation. Surgeons with higher implantation volumes showed a lower incidence of pneumothorax. Pneumothorax management is dependent on patient stability, perioperative setting, and degree of injury. The use of needle decompression, chest tube placement, and suture placement also vary with clinical scenario.

Post-operative Complication Rate Comparison Between Airway Surgery and Upper Airway Stimulation Using NSQIP and ADHERE.

OBJECTIVE: Postoperative complication rates were compared between obstructive sleep apnea surgery (OSAS) and hypoglossal nerve upper airway stimulation (UAS). STUDY DESIGN: Cohort. SETTING: Multi-institutional international databases. METHODS: OSAS data were collected from the NSQIP database (2014; American College of Surgeons National Surgery Quality Improvement Program). UAS data were obtained from the ADHERE registry (Adherence and Outcome of Upper Airway Stimulation for OSA International Registry; 2016-December 2019). ADHERE comorbidities and complications were categorized to match NSQIP definitions. A chi-square test was used for proportion P values. RESULTS: There were 1623 UAS procedures in ADHERE and 310 in NSQIP. The UAS group was older than the OSAS group (mean ± SD, 60 ± 11 vs 42 ± 13 years) but similarly male (75% vs 77%) and overweight (body mass index, 29 ± 4 vs 29 ± 3 kg/m2). There was a higher proportion of hypertension, diabetes, and heart disease in the UAS cohort. Palatopharyngoplasty was the most common surgical procedure (71%), followed by tonsillectomy (25%). UAS operative time was longer (132 ± 47 vs 54 ± 33 minutes). Postoperative length of stay was not normally distributed, as 71% of UAS stays were <1 day as opposed to 40% of OSA stays (P < .0001). Thirty-day return to the operating room related to the procedure was 0.1% for UAS and 4.8% for OSAS (P < .0001). Surgical site infections were 0.13% for UAS and 0.9% for OSAS (P = .046). CONCLUSION: The UAS cohort was older and more likely to have comorbid hypertension, diabetes, and heart disease. Despite baseline differences, the postoperative complication rate was lower with UAS than with OSAS.

Clinical Characteristics of Older Adults Seeking Hypoglossal Nerve Stimulation for the Treatment of Obstructive Sleep Apnea.

OBJECTIVES: Obstructive sleep apnea (OSA) is a common sleep disorder with numerous clinical correlates. Although effective treatments abound, patient acceptance and adherence is low. Hypoglossal nerve stimulation (HNS) is a surgical treatment alternative for the treatment of OSA; however, the demographic and clinical characteristics of individuals seeking HNS are not well categorized. This study sought to determine the clinical characteristics of older adults seeking HNS for the treatment of OSA. METHODS: Self-report questionnaires were administered to all patients older than 50 years seeking a HNS consultation at a large university medical center. Questionnaires included validated National Institutes of Health Patient-Reported Outcomes Measurement Information System (NIH PROMIS) measures of physical functioning, sleep-related impairment, cognitive abilities, depression, anxiety, and anger along with the Information extracted from electronic medical records included age, sex, race, and apnea-hypopnea index (AHI). RESULTS: Patients included 113 adults (mean age 63.30 years, 57% male, 79% white) with severe OSA (AHI = 33.91, standard deviation = 20.63). Overall, 88% of patients reported elevated insomnia symptoms, 30% reported mild difficulty with physical functioning, and 36% indicated that they had experienced moderate-severe daytime impairments attributed to poor sleep. Additionally, we found 28% of sampled individuals reported moderate-severe depressive symptomology, over 19% reported moderate-severe anxiety, and over 17% reported moderate to severe anger issues. Approximately, 38% of the sample reported moderate to severe cognitive difficulties. CONCLUSIONS: The aim of the study was to better understand the clinical characteristics of older patients with OSA seeking HNS treatment. Utilizing NIH PROMIS questionnaires, we identified unique clinical and psychosocial correlates in this sample, which included higher rates of insomnia symptoms, physical dysfunction, cognitive deficits, and depressive symptoms than the general population. Future studies will be needed to investigate these relationships more thoroughly and throughout the course of the treatment.

Successful endovascular management of venous sinus thrombosis complicating trans-labyrinthine removal of vestibular schwanomma.

Cerebral venous sinus thrombosis (CVST) is a rare complication of surgical treatment of vestibular schwanomma. We present a rare case of extensive venous sinus thrombosis after trans-labyrinthine approach that was refractory to systemic anti-coagulation. Mechanical aspiration thrombectomy was utilized to re-canalize the venous sinuses and resulted in successful resolution of neurological symptoms. Indications of utilizing endovascular approaches are discussed that will enable skull base surgeons to address this uncommon yet potentially fatal complication.

Pulsed electric field (PEF) as an intensification pretreatment for greener solvent lipid extraction from microalgae.

Microalgae, with their high lipid content, are a promising feedstock for renewable fuels. Traditionally, human and environmentally toxic solvents have been used to extract these lipids, diminishing the sustainability of this process. Herein, pulsed electric field technology was utilized as a process intensification strategy to enhance lipid extraction from Ankistrodesmus falcatus wet biomass using the green solvent, ethyl acetate. The extraction efficiency for ethyl acetate without PEF was lower (83-88%) than chloroform. In addition, the ethyl acetate exhibited a 2-h induction period, while the chloroform showed no time dependence. Utilizing PEF technology resulted in 90% of the cells being lysed and a significant enhancement in the rate of lipid recovery using ethyl acetate. The increase in lipid recovery was due to the presence of the electric field and not due to temperature effects. The PEF technology uses less energy than other PEF systems reported in the literature.

Balloon dilation for recurrent stenosis after pediatric laryngotracheoplasty.

OBJECTIVES: We assessed the safety and efficacy of balloon dilation as treatment for recurrent stenosis after pediatric laryngotracheoplasty. METHODS: We studied a retrospective case series at an academic tertiary care children's hospital. We included all patients under the age of 18 years with subglottic or tracheal stenosis treated at our institution with balloon dilation between June 2007 and April 2009. The records were analyzed for patient demographics, presenting symptoms, surgical technique, and airway description. The outcome measures were airway diameter, postoperative symptoms, tracheotomy status, and complications. RESULTS: Ten patients (9 with subglottic stenosis and 1 with tracheal stenosis) underwent 20 balloon dilation procedures without complication. The average age at the time of the procedure was 17 months (range, 3 months to 9 years). The patient presenting symptoms were stridor in 7 cases and tracheotomy in 3 cases. Vascular balloons (diameter range, 6 to 12 mm; length, 20 mm) were inflated to 10 to 12 cm H2O pressure for an average of 40 seconds (range, 10 to 120 seconds). Each procedure consisted of 1 to 3 dilation cycles. The immediate postdilation airway area increased by an average factor of 4.9 (range, 1.9 to 9). Six patients had repeat procedures with an average interval between dilations of 67 days (range, 6 to 337 days). Stridor was eliminated or greatly improved in all patients on the first postoperative day; 7 patients sustained this benefit, with an average follow-up time of 10 months (range, 4 to 23 months). Six of the 10 patients had undergone previous laryngeal reconstruction (age range, 3 months to 4 years). Of these 6, 3 have no tracheotomy, with a mean follow-up of 12.5 months. The 3 children who benefited the least from dilation were noted to have more diffuse and chronic inflammation of the larynx in comparison to the responders. CONCLUSIONS: This case series suggests that balloon dilation is a relatively safe and effective procedure. It may be particularly well suited to recent stenosis after laryngotracheal reconstruction.