Device-related outcomes following hypoglossal nerve stimulator implantation.

STUDY OBJECTIVES: Hypoglossal nerve stimulation (HGNS) has been widely used to treat obstructive sleep apnea in selected patients. Here we evaluate rates of revision and explant related to HGNS implantation and assess types of adverse events contributing to revision and explant. METHODS: Post-market surveillance data for HGNS implanted between January 1, 2018 and March 31, 2022, were collected. Event rates and risk were calculated using the post-market surveillance event counts and sales volume over the same period. Indications were categorized for analysis. Descriptive statistics were reported and freedom from explant or revision curves were grouped by year of implantation. RESULTS: Of the 20,881 HGNS implants assessed, rates of explant and revision within the first year were 0.723% and 1.542%, respectively. The most common indication for explant was infection (0.378%) and for revision was surgical correction (0.680%). Of the 5,820 devices with three-year post-implantation data, the rate of explant was 2.680% and of revision was 3.557%. During this same interval, elective removal (1.478%) was the most common indication, and for revisions, surgical correction (1.134%). CONCLUSIONS: The efficacy of HGNS is comparable in the real world setting to published clinical trial data. Rates of explant and revision are low, supporting a satisfactory safety profile for this technology.

Hypoglossal Nerve Stimulation and Cardiovascular Outcomes for Patients With Obstructive Sleep Apnea: A Randomized Clinical Trial.

Importance: Sham-controlled trials are needed to characterize the effect of hypoglossal nerve stimulation (HGNS) therapy on cardiovascular end points in patients with moderate-severe obstructive sleep apnea (OSA). Objective: To determine the effect of therapeutic levels of HGNS, compared to sham levels, on blood pressure, sympathetic activity, and vascular function. Design, Setting, and Participants: This double-blind, sham-controlled, randomized crossover therapy trial was conducted from 2018 to 2022 at 3 separate academic medical centers. Adult patients with OSA who already had an HGNS device implanted and were adherent and clinically optimized to HGNS therapy were included. Participants who had fallen asleep while driving within 1 year prior to HGNS implantation were excluded from the trial. Data analysis was performed from January to September 2022. Interventions: Participants underwent a 4-week period of active HGNS therapy and a 4-week period of sham HGNS therapy in a randomized order. Each 4-week period concluded with collection of 24-hour ambulatory blood pressure monitoring (ABPM), pre-ejection period (PEP), and flow-mediated dilation (FMD) values. Main Outcomes and Measures: The change in mean 24-hour systolic blood pressure was the primary outcome, with other ABPM end points exploratory, and PEP and FMD were cosecondary end points. Results: Participants (n = 60) were older (mean [SD] age, 67.3 [9.9] years), overweight (mean [SD] body mass index, calculated as weight in kilograms divided by height in meters squared, 28.7 [4.6]), predominantly male (38 [63%]), and had severe OSA at baseline (mean [SD] apnea-hypopnea index, 33.1 [14.9] events/h). There were no differences observed between active and sham therapy in 24-hour systolic blood pressure (mean change on active therapy, -0.18 [95% CI, -2.21 to 1.84] mm Hg), PEP (mean change on active therapy, 0.11 [95% CI, -5.43 to 5.66] milliseconds), or FMD (mean change on active therapy, -0.17% [95% CI, -1.88% to 1.54%]). Larger differences between active and sham therapy were observed in a per-protocol analysis set (n = 20) defined as experiencing at least a 50% reduction in apnea-hypopnea index between sham and active treatment. Conclusions and Relevance: In this sham-controlled HGNS randomized clinical trial, mean 24-hour systolic blood pressure and other cardiovascular measures were not significantly different between sham and active HGNS therapy. Several methodologic lessons can be gleaned to inform future HGNS randomized clinical trials. Trial Registration: ClinicalTrials.gov Identifier: NCT03359096.

Evaluating ChatGPT responses on obstructive sleep apnea for patient education.

STUDY OBJECTIVES: We evaluated the quality of ChatGPT responses to questions on obstructive sleep apnea for patient education and assessed how prompting the chatbot influences correctness, estimated grade level, and references of answers. METHODS: ChatGPT was queried 4 times with 24 identical questions. Queries differed by initial prompting: no prompting, patient-friendly prompting, physician-level prompting, and prompting for statistics/references. Answers were scored on a hierarchical scale: incorrect, partially correct, correct, correct with either statistic or referenced citation ("correct+"), or correct with both a statistic and citation ("perfect"). Flesch-Kincaid grade level and citation publication years were recorded for answers. Proportions of responses at incremental score thresholds were compared by prompt type using chi-squared analysis. The relationship between prompt type and grade level was assessed using analysis of variance. RESULTS: Across all prompts (n = 96 questions), 69 answers (71.9%) were at least correct. Proportions of responses that were at least partially correct (P = .387) or correct (P = .453) did not differ by prompt; responses that were at least correct+ (P < .001) or perfect (P < .001) did. Statistics/references prompting provided 74/77 (96.1%) references. Responses from patient-friendly prompting had a lower mean grade level (12.45 ± 2.32) than no prompting (14.15 ± 1.59), physician-level prompting (14.27 ± 2.09), and statistics/references prompting (15.00 ± 2.26) (P < .0001). CONCLUSIONS: ChatGPT overall provides appropriate answers to most questions on obstructive sleep apnea regardless of prompting. While prompting decreases response grade level, all responses remained above accepted recommendations for presenting medical information to patients. Given ChatGPT's rapid implementation, sleep experts may seek to further scrutinize its medical literacy and utility for patients. CITATION: Campbell DJ, Estephan LE, Mastrolonardo EV, Amin DR, Huntley CT, Boon MS. Evaluating ChatGPT responses on obstructive sleep apnea for patient education. J Clin Sleep Med. 2023;19(12):1989-1995.

A systematic approach to the evaluation and management of obstructive sleep apnea: The Jefferson Protocol.

Obstructive sleep apnea (OSA) has become increasingly prevalent in the United States. While continuous positive airway pressure (CPAP) therapy remains the gold standard for treatment, surgical intervention can enhance compliance and improve outcomes for those intolerant of CPAP. Since the majority of OSA patients have multilevel obstruction, it is critical that otolaryngologists understand each patient's pattern and anatomic level of obstruction before solidifying a treatment plan. This publication serves as a comprehensive review of evaluation, characterization, and management of OSA. Further, the authors outline their departmental algorithm for identifying ideal surgical candidates and tailoring corresponding surgical interventions.

Straws Don't Suck: Are Straws Dangerous after Endoscopic Skull Base Surgery?

Objective Patients undergoing endoscopic endonasal surgery have historically been restricted from using straws postoperatively, due to the concern that this activity generates negative pressure. The objective of this study is to evaluate the pressure dynamics in the sinonasal cavity associated with the use of a straw. Methods Intracranial pressure catheters were placed in the nasal cavity of 20 healthy individuals. Pressure measurements were then recorded while participants drank liquids of different viscosities from a cup and from a straw. Measurements were recorded with and without subjects occluding their nose to simulate postoperative nasal obstruction. Results The average pressure in the nasal cavity while drinking water from a cup was -0.86 cmH 2 O, from a straw was -1.09 cmH 2 O, and while occluding the nose and using a straw was -0.81 cmH 2 O. The average pressure in the nasal cavity while drinking a milkshake from a cup was -0.98 cmH 2 O, from a straw was -1.88 cmH 2 O, and while occluding the nose and using a straw was -1.37 cmH 2 O. There was no statistically significant difference in pressure measurements when comparing either task or consistency ( p > 0.05). Conclusion Straw use is not associated with the generation of significant negative pressure in the nasal cavity. The pressure generated when drinking from a straw is not significantly different from that of drinking from a cup. This data suggest that straw use may be safe for patients following endoscopic skull base surgery, but further investigation is warranted.

Tolerance of Continuous Positive Airway Pressure After Sinonasal Surgery.

OBJECTIVES/HYPOTHESIS: For patients with obstructive sleep apnea (OSA) undergoing sinonasal surgery, there is a lack of consensus on the risk and appropriate postoperative use of continuous positive airway pressure (CPAP). The aim of this study was to assess the tolerability of restarting CPAP on postoperative day one. STUDY DESIGN: Prospective cohort study. METHODS: A prospective study on patients with OSA on CPAP who required a septoplasty/turbinectomy and/or functional endoscopic sinus surgery (FESS) was performed. Data from the memory card of a patient's CPAP machine and subjective information were obtained on the day of surgery and at scheduled follow-up visits. All subjects were instructed to restart CPAP on the first postoperative night. RESULTS: A total of 14 patients were analyzed; nine underwent FESS and five had a septoplasty/turbinectomy. There were no postoperative complications encountered. The only significant change in the first postoperative week was a reduction in the percentage of nights used over 4 hours (P < .05). By the third postoperative visit, average 22-item Sino-Nasal Outcome Test, Nasal Obstruction Symptom Evaluation, and CPAP tolerance scores improved from preoperative values. CPAP pressures, residual apnea-hypopnea index, and number of hours and mean percentage of nights used remained stable throughout the study period. CONCLUSIONS: Both quality-of-life and CPAP outcomes improved or remained the same when restarting CPAP immediately postoperatively. Combined with a lack of significant complications, this study suggests that CPAP is well-tolerated when restarted the day after a septoplasty/turbinectomy or FESS. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1013-E1018, 2021.

3D printed temporal bone as a tool for otologic surgery simulation.

PURPOSE: In this face validity study, we discuss the fabrication and utility of an affordable, computed tomography (CT)-based, anatomy-accurate, 3-dimensional (3D) printed temporal bone models for junior otolaryngology resident training. MATERIALS AND METHODS: After IRB exemption, patient CT scans were anonymized and downloaded as Digital Imaging and Communications in Medicine (DICOM) files to prepare for conversion. These files were converted to stereolithography format for 3D printing. Important soft tissue structures were identified and labeled to be printed in a separate color than bone. Models were printed using a desktop 3D printer (Ultimaker 3 Extended, Ultimaker BV, Netherlands) and polylactic acid (PLA) filament. 10 junior residents with no previous drilling experience participated in the study. Each resident was asked to drill a simple mastoidectomy on both a cadaveric and 3D printed temporal bone. Following their experience, they were asked to complete a Likert questionnaire. RESULTS: The final result was an anatomically accurate (XYZ accuracy = 12.5, 12.5, 5 µm) 3D model of a temporal bone that was deemed to be appropriate in tactile feedback using the surgical drill. The total cost of the material required to fabricate the model was approximately $1.50. Participants found the 3D models overall to be similar to cadaveric temporal bones, particularly in overall value and safety. CONCLUSIONS: 3D printed temporal bone models can be used as an affordable and inexhaustible alternative, or supplement, to traditional cadaveric surgical simulation.

Qualitative Assessment of the Effect of Continuous Positive Airway Pressure on the Nasal Cavity.

BACKGROUND: For patients with obstructive sleep apnea (OSA), there is a lack of knowledge regarding the impact of continuous positive airway pressure (CPAP) on the nasal cavity. There is a significant need for evidence-based recommendations regarding the appropriate use of CPAP following endoscopic sinus and skull base surgery. OBJECTIVE: The goal of this study is to translate a previously developed cadaveric model for evaluating CPAP pressures in the sinonasal cavity by showing safety in vivo and quantifying the effect of positive pressurized air flow on the nasal cavity of healthy individuals where physiologic effects are at play. METHODS: A previously validated cadaveric model using intracranial sensor catheters has proved to be a reliable technique for measuring sinonasal pressures. These sensors were placed in the nasal cavity of 18 healthy individuals. Pressure within the nose was recorded at increasing levels of CPAP. RESULTS: Overall, nasal cavity pressure was on average 85% of delivered CPAP. The amount of pressure delivered to the nasal cavity increased as the CPAP increased. The percentage of CPAP delivered was 77% for 5 cmH2O and increased to 89% at 20 cmH2O. There was a significant difference in mean intranasal pressures between all the levels of CPAP except 5 cmH2O and 8 cmH2O (P < .001). CONCLUSION: On average, only 85% of the pressure delivered by CPAP is transmitted to the nasal cavity. Higher CPAP pressures delivered a greater percentage of pressurized air to the nasal cavity floor. Our results are comparable to the cadaver model, which demonstrated similar pressure delivery even in the absence of anatomic factors such as lung compliance, nasal secretions, and edema. This study demonstrates the safety of using sensors in the human nasal cavity. This technology can also be utilized to evaluate the resiliency of various repair techniques for endoscopic skull base surgery with CPAP administration.

Dysfunctional hypoglossal nerve stimulator after electrical cardioversion: A case series.

OBJECTIVES/HYPOTHESIS: Upper airway stimulation has demonstrated marked improvements in apnea-hypopnea index, oxygen desaturation index, and quality-of-life measures in patients with moderate to severe obstructive sleep apnea (OSA) who cannot tolerate continuous positive airway pressure. Cardiac arrhythmias are common in patients with OSA and can require electrical cardioversion. We describe the first four reported cases of hypoglossal nerve stimulator (HGNS) dysfunction after electrical cardioversion and illustrate our operative approach to device troubleshooting and repair. STUDY DESIGN: Retrospective case series. METHODS: A retrospective review of 201 HGNS implantations performed at two academic institutions revealed four cases of HGNS device dysfunction after electrical cardioversion requiring surgical revision. Preoperative and postoperative device performance metrics and electrical cardioversion specifications were retrospectively assessed and compiled for this case series. The senior authors (R.J.S., M.S.B.) detail operative planning and approach for HGNS implantable pulse generator (IPG) replacement. RESULTS: At least two patients with HGNS device dysfunction had received cardioversion via anterolateral electrode pad placement. Three patients had received multiple shocks. All four patients experienced a change in device functionality or complete cessation of functionality after electrocardioversion. Operatively, each patient required replacement of the IPG, with subsequent intraoperative interrogation revealing proper device functionality. CONCLUSION: Counseling for patients with HGNS undergoing external electrical cardioversion should include possible device damage and need for operative replacement. Anteroposterior electrode pad placement should be considered for patients with HGNS who require electrocardioversion. Operative replacement of an HGNS system damaged by electrocardioversion begins with IPG replacement and intraoperative device interrogation. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:1949-1953, 2019.