Disparities in polysomnography referral in a high-risk cardiac population.

PURPOSE: Obstructive sleep apnea (OSA) is associated with metabolic, cardiovascular, and cerebrovascular comorbidities. Appropriate diagnosis and treatment of OSA might mitigate these comorbidities. This retrospective review sought to assess the impact of sex, age, race, ethnicity, and insurance status on polysomnography (PSG) referral rates. METHODS: An institutional STOP-Bang database of 299,320 patients was filtered for patients admitted to the hospital with an acute cardiac diagnosis between 2015-2020. A cohort of 4,735 patients were risk stratified by STOP-Bang (SB) score and correlations were made between PSG referrals and demographic and clinical variables (sex, age, race, ethnicity, and insurance status). RESULTS: Of the 25.3% of the cohort with high SB scores (5-8) only 21.3% were referred for PSG. Age and female sex were negatively associated with sleep study referrals (p < 0.001). No correlation was found between sleep study referral rates and race or ethnicity. No correlation was found between sleep study referrals and insurance provider. Admitting cardiac diagnosis significantly influenced sleep study referrals with diagnoses of arrhythmias and myocardial infarction being associated with an increased rate of PSG referrals compared to heart failure patients (p < 0.002). CONCLUSIONS: Our study found no significant correlation between PSG referral rates and race, ethnicity, or insurance provider. However, we found low overall rates of PSG referral, with negative correlations between older age and female sex and a high-risk cardiac population. This represents a substantial missed opportunity to identify patients at risk for OSA, obtain a diagnosis, and provider adequate treatment.

OSA Upper Airways Surgery: A Targeted Approach.

Obstructive sleep apnea syndrome (OSA) is a multi-factorial disorder, with quite complex endotypes, consisting of anatomical and non-anatomical pathophysiological factors. Continuous positive airway pressure (CPAP) is recognized as the first-line standard treatment for OSA, whereas upper airway (UA) surgery is often recommended for treating OSA patients who have refused or cannot tolerate CPAP. The main results achievable by the surgery are UA expansion, and/or stabilization, and/or removal of the obstructive tissue to different UA levels. The site and pattern of UA collapse identification is of upmost importance in selecting the customized surgical procedure to perform, as well as the identification of the relation between anatomical and non-anatomical factors in each patient. Medical history, sleep studies, clinical examination, UA endoscopy in awake and drug-induced sedation, and imaging help the otorhinolaryngologist in selecting the surgical candidate, identifying OSA patients with mild UA collapsibility or tissue UA obstruction, which allow achievement of the best surgical outcomes. Literature data reported that the latest palatal surgical procedures, such as expansion sphincter palatoplasty or barbed reposition palatoplasty, which achieve soft palatal and lateral pharyngeal wall remodeling and stiffening, improved the Apnea Hypopnea Index, but the outcome analyses are still limited by methodological bias and the limited number of patients' in each study. Otherwise, the latest literature data have also demonstrated the role of UA surgery in the improvement of non-anatomical factors, confirming that a multidisciplinary and multimodality diagnostic and therapeutical approach to OSA patients could allow the best selection of customized treatment options and outcomes.

Upper-airway stimulation for obstructive sleep apnea.

BACKGROUND: Obstructive sleep apnea is associated with considerable health risks. Although continuous positive airway pressure (CPAP) can mitigate these risks, effectiveness can be reduced by inadequate adherence to treatment. We evaluated the clinical safety and effectiveness of upper-airway stimulation at 12 months for the treatment of moderate-to-severe obstructive sleep apnea. METHODS: Using a multicenter, prospective, single-group, cohort design, we surgically implanted an upper-airway stimulation device in patients with obstructive sleep apnea who had difficulty either accepting or adhering to CPAP therapy. The primary outcome measures were the apnea-hypopnea index (AHI; the number of apnea or hypopnea events per hour, with a score of ≥15 indicating moderate-to-severe apnea) and the oxygen desaturation index (ODI; the number of times per hour of sleep that the blood oxygen level drops by ≥4 percentage points from baseline). Secondary outcome measures were the Epworth Sleepiness Scale, the Functional Outcomes of Sleep Questionnaire (FOSQ), and the percentage of sleep time with the oxygen saturation less than 90%. Consecutive participants with a response were included in a randomized, controlled therapy-withdrawal trial. RESULTS: The study included 126 participants; 83% were men. The mean age was 54.5 years, and the mean body-mass index (the weight in kilograms divided by the square of the height in meters) was 28.4. The median AHI score at 12 months decreased 68%, from 29.3 events per hour to 9.0 events per hour (P<0.001); the ODI score decreased 70%, from 25.4 events per hour to 7.4 events per hour (P<0.001). Secondary outcome measures showed a reduction in the effects of sleep apnea and improved quality of life. In the randomized phase, the mean AHI score did not differ significantly from the 12-month score in the nonrandomized phase among the 23 participants in the therapy-maintenance group (8.9 and 7.2 events per hour, respectively); the AHI score was significantly higher (indicating more severe apnea) among the 23 participants in the therapy-withdrawal group (25.8 vs. 7.6 events per hour, P<0.001). The ODI results followed a similar pattern. The rate of procedure-related serious adverse events was less than 2%. CONCLUSIONS: In this uncontrolled cohort study, upper-airway stimulation led to significant improvements in objective and subjective measurements of the severity of obstructive sleep apnea. (Funded by Inspire Medical Systems; STAR ClinicalTrials.gov number, NCT01161420.).

Expansion sphincter pharyngoplasty for the treatment of OSA: a systemic review and meta-analysis.

This study seeks to determine the success rates of the expansion sphincter pharyngoplasty and its variants on the treatment of obstructive sleep apnea (OSA). Systematic review and meta-analysis. Two independent searches of MEDLINE, Google Scholar, Cochrane Library and Evidence Based Medicine Reviews to identify publications relevant to OSA and expansion pharyngoplasty. All relevant studies published before 31 March 2015 were included. Five studies were included in the systematic review and meta-analysis. The numbers of patients in each paper ranged from 10 to 85 (total = 155), and mean age ranged from 8 to 56 years. Substantial and consistent improvement in PSG outcomes were observed post-expansion pharyngoplasty patients, with or without multilevel surgery groups. The results showed that the expansion pharyngoplasty technique has significantly lower AHI than control group [Standardised mean difference -7.32, 95 %CI (-11.11, -3.52), p = 0.0002]; however, substantial heterogeneity between these studies were observed. The mean pre-operative AHI (in the five papers) improved from 40.0 ± 12.6 to 8.3 ± 5.2 post-operatively. The overall pro-rated pooled success rate for all the patients was 86.3 %. The expansion pharyngoplasty is effective in the management of patients with OSA.

Impact of posture and CPAP on nasal airflow.

Obstructive sleep apnea (OSA) patients who use continuous positive airway pressure (CPAP) often complain of nasal dryness and nasal obstruction as side effects of CPAP. The physiological mechanisms by which CPAP may cause nasal dryness and nasal obstruction remain poorly understood. It has been hypothesized that CPAP interferes with the nasal cycle, abolishing the resting phase of the cycle and leading to nasal dryness. We performed rhinomanometry measurements in 31 OSA patients sitting, laid supine, and supine after 10 min of CPAP at 10 cmH2O. A posture change from sitting to supine led to more symmetric airflow partitioning between the left and right nostrils in the supine position. CPAP did not have a significant impact on nasal resistance, unilateral airflows, or airflow partitioning. Our results suggest that airflow partitioning becomes more symmetric immediately after changing to a supine position, while CPAP had no effect on nasal airflow, thus preserving the nearly symmetric airflow partitioning achieved after the posture change.

Palate shape is associated with Unilateral Hypoglossal Nerve Stimulation Outcomes.

OBJECTIVE: The aim was to determine the potential association between palate shape and unilateral hypoglossal nerve stimulation (HNS) outcomes. METHODS: Preoperative drug-induced sleep endoscopy (DISE) videos were reviewed and scored by 3 blinded reviewers to determine airway narrowing at the hard-soft palate junction (HP), soft palate genu, and inferior velum, as described by Woodson (2014). Scoring was as follows: 1-open airway, 2-narrow, 3-severe narrowing. Overall palate shape (oblique, intermediate, or vertical) was determined based on prior criteria. Successful surgical treatment was defined by the HNS titration polysomnogram as a reduction of ≥50% in the apnea-hypopnea index (AHI) to <15 events/h. RESULTS: Of 332 adults, the majority was male (77%) with an average BMI of 29.2 ± 3.6 kg/m2 . Overall success rate was 73%. Success rate was lower in patients with vertical palate shape compared with the other shapes (56% vs. 75%, p = 0.029). HP score 3 compared with scores 2 and 1 was associated with lower success rates (60% vs. 76%, p = 0.028), but genu and velum scores were not associated with outcomes. Patients with both HP score 3 and complete oropharyngeal lateral wall-related obstruction had notably worse outcomes (22% vs. 74%, p = 0.026). HP score 3 (OR 0.45, 95%CI 0.22-0.92) and vertical palate shape (OR 0.33, 95%CI 0.15-0.78) were independently associated with lower odds of surgical response after adjustment for DISE findings, age, gender, and BMI. CONCLUSION: Vertical palate shape and narrowing at the hard-soft palate junction are independently associated with lower HNS surgical success rates. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:981-986, 2024.

Palate Shape, Drug-Induced Sleep Endoscopy Findings, and Obstructive Sleep Apnea Pharyngeal Surgery Outcomes.

OBJECTIVE: Pharyngeal surgery is a treatment option for patients with obstructive sleep apnea (OSA) unable to tolerate positive pressure therapy. This study aims to determine the association between palate shape as described by Woodson and pharyngeal surgical outcomes. STUDY DESIGN: Exploratory analysis of retrospective cohort. SETTING: Multicenter. METHODS: Three blinded reviewers assessed palate shape using drug-induced sleep endoscopy (DISE) videos from a previously-assembled cohort of adults undergoing pharyngeal surgery. Palate shape scores were examined for association with surgical outcomes with univariate and multivariate analyses. Multivariate analyses included adjustment for consensus DISE findings determined previously. RESULTS: Two hundred nine study subjects were included from 13 centers. Age was 53.7 ± 11.5 years, body mass index (BMI) was 30.3 ± 5.0 kg/m2, and 21% were female. In isolated soft palate surgery, greater GenuAP narrowing was associated with lesser odds of surgical response, whereas greater GenuLW narrowing was associated with greater odds of surgical response. These findings largely persisted after adjustment for key DISE findings, age, gender, OSA severity, BMI, and tonsil size. Other palate-shape findings were not clearly associated with surgical outcomes, although some palate-shape findings demonstrated trends toward an association with outcomes (P < .10). CONCLUSION: Greater GenuAP narrowing and GenuLW narrowing were associated with lesser and greater, respectively, odds of surgical response after isolated soft palate surgery. Palate shape and other palate shape level scores were not clearly associated with surgical outcomes. Larger studies may determine more precisely the association between palate shape and pharyngeal surgery outcomes.

Mandibular advancement reduces pharyngeal collapsibility by enlarging the airway rather than affecting velopharyngeal compliance.

Mandibular advancement devices (MADs) are frequently prescribed for obstructive sleep apnea (OSA) patients, but approximately one third of patients experience no therapeutic benefit. Understanding the mechanisms by which MADs prevent pharyngeal collapse may help optimize MAD therapy. This study quantified the relative contributions of changes in airspace cross-sectional area (CSA) versus changes in velopharyngeal compliance in determining MAD efficacy. Sixteen patients with moderate to severe OSA (mean apnea-hypopnea index of 32 ± 15 events/h) underwent measurements of the velopharyngeal closing pressure (PCLOSE ) during drug induced sedated endoscopy (DISE) via stepwise reductions in nasal mask pressure and recording of the intraluminal pressure with a catheter. Airspace CSA was estimated from video endoscopy. Pharyngeal compliance was defined as the slope of the area-pressure relationship of the velopharyngeal airspace. MAD therapy reduced PCLOSE from a median of 0.5 cmH2 O pre-advancement to a median of -2.6 cmH2 O post-advancement (p = 0.0009), increased the minimal CSA at the velopharynx by approximately 20 mm2 (p = 0.0067), but did not have a statistically significant effect on velopharyngeal compliance (p = 0.23). PCLOSE had a strong correlation with CSA but did not correlate with velopharyngeal compliance. Our results suggest that MADs reduce velopharyngeal collapsibility by increasing airway size as opposed to affecting velopharyngeal compliance. This contradicts the speculation of previous literature that the effectiveness of MADs is partially due to a reduction in velopharyngeal compliance resulting from stretching of the soft palate. These findings suggest that quantification of velopharyngeal CSA pre- and post-MAD advancement has potential as a biomarker to predict the success of MAD therapy.

Anatomical determinants of upper airway collapsibility in obstructive sleep apnea: A systematic review and meta-analysis.

Upper airway (UA) collapsibility is one of the key factors that determine the severity of obstructive sleep apnea (OSA). Interventions for OSA are aimed at reducing UA collapsibility, but selecting the optimal alternative intervention for patients who fail CPAP is challenging because currently no validated method predicts how anatomical changes affect UA collapsibility. The gold standard objective measure of UA collapsibility is the pharyngeal critical pressure (Pcrit). A systematic literature review and meta-analysis were performed to identify the anatomical factors with the strongest correlation with Pcrit. A search using the PRISMA methodology was performed on PubMed for English language scientific papers that correlated Pcrit to anatomic variables and OSA severity as measured by the apnea-hypopnea index (AHI). A total of 29 papers that matched eligibility criteria were included in the quantitative synthesis. The meta-analysis suggested that AHI has only a moderate correlation with Pcrit (estimated Pearson correlation coefficient r = 0.46). The meta-analysis identified four key anatomical variables associated with UA collapsibility, namely hyoid position (r = 0.53), tongue volume (r = 0.51), pharyngeal length (r = 0.50), and waist circumference (r = 0.49). In the future, biomechanical models that quantify the relative importance of these anatomical factors in determining UA collapsibility may help identify the optimal intervention for each patient. Many anatomical and structural factors such as airspace cross-sectional areas, epiglottic collapse, and palatal prolapse have inadequate data and require further research.

The prevalence of sleep problems in emergency medical technicians.

PURPOSE: To investigate the prevalence, demographic, and work associations of self-reported sleep complaints in US emergency medical technicians (EMTs) METHODS: The mailed 2005 Longitudinal Emergency Medical Technician Attributes and Demographics Study (LEADS) questionnaire was distributed to selected EMTs that included 35 sleep-related questions. Questions were adapted from previously validated sleep medicine surveys, including the Epworth Sleepiness Scale (ESS), and were used to estimate the prevalence of different sleep problems. These sleep problems were analyzed in relation to demographic, health, satisfaction, and workplace characteristics. Responses of individuals who were not working as EMTs were used as a comparison group. RESULTS: Sleep problems in working EMTs were more prevalent than in a comparison group. Seventy percent of working EMTs had at least one sleep problem. The most common sleep problem was a risk of long sleep onset disorder (50%). EMTs with tiredness-related work difficulties were more than 50% as likely to report this problem. The prevalence of excessive daytime sleepiness (ESS > 10) was 36%; 6% of the EMTs had an ESS > 16. EMTs reporting tiredness-related work difficulties were more than twice as likely to have ESS scores >10 and more than three times as likely to ESS scores >16. Symptom-defined risk of sleep apnea was present in 5%. Risks of sleep onset and maintenance disorder problems were more prevalent among those who worked longer shifts and had longer work weeks and were associated with poorer job satisfaction and poorer health. CONCLUSIONS: Severe sleep problems and severe sleepiness at a level that may contribute to health and job issues are common in US EMTs. Although breathing disorders are common, behaviorally related sleep issues are more prevalent. These data support an increased focus on sleep onset and maintenance disorders.

A Pharyngoplasty with a Dorsal Palatal Flap Expansion: The Evaluation of a Modified Surgical Treatment Method for Obstructive Sleep Apnea Syndrome-A Preliminary Report.

Surgical techniques for obstructive sleep apnea syndrome (OSAS) constantly evolve. This study aims to assess the effectiveness and safety of a new surgical approach for an OSAS pharyngoplasty with a dorsal palatal flap expansion (PDPFEx). A total of 21 participants (mean age 49.9; mean BMI 32.5) underwent a type III sleep study, an endoscopy of the upper airways, a filled medical history, a visual analog scale for snoring loudness, an Epworth Sleepiness Scale, and a Short Form Health Survey-36 questionnaire. A follow-up re-evaluation was performed 11 ± 4.9 months post-operatively. The study group (4 with moderate, 17 with severe OSAS) showed an improvement in all measured sleep study characteristics (p < 0.05), apnea-hypopnea index (pre-median 45.7 to 29.3 post-operatively, p = 0.009, r = 0.394), oxygen desaturation index (pre-median 47.7 and 23.3 post-operatively, p = 0.0005, r = 0.812), mean oxygen saturation (median 92% pre-operatively and median 94% post-operatively, p = 0.0002, r = 0.812), lowest oxygen saturation (p = 0.0001, r = 0.540) and time of sleep spent with blood oxygen saturation less than 90% (p = 0.0001, r = 0.485). The most commonly reported complications were throat dryness (11 patients) and minor difficulties in swallowing (5 patients transient, 3 patients constant). We conclude that a PDPFEx is a promising new surgical method; however, further controlled studies are needed to demonstrate its safety and efficacy for OSAS treatment in adults.

Effect of tube length on the buckling pressure of collapsible tubes.

BACKGROUND: The higher incidence of obstructive sleep apnea (OSA) in men than in women has been attributed to the upper airway being longer in men. The Starling resistor is the paradigm biomechanical model of upper airway collapse in OSA where a collapsible tube (representing the pharynx) is located between two rigid tubes (representing the nasal cavity and trachea). While the Starling resistor has been extensively studied due to its relevance to many physiological phenomena, the effect of tube length on tube collapsibility has not been quantified yet. METHODS: Finite element analysis of a 3-dimensional collapsible tube subjected to a transmural pressure was performed in ANSYS Workbench. The numerical methods were validated with in vitro experiments in a silicone tube whose modulus of elasticity (361 ± 28 kPa) and dimensions (length = 100 mm, diameter = 22.2 mm, and wall thickness = 1.59 mm) were selected so that tube compliance was similar to pharyngeal compliance in humans during sleep. The buckling pressure (transmural pressure at which the tube collapses) was quantified in tubes of three different diameters (10 mm, 16 mm, and 22.2 mm) and ten length-to-diameter ratios (L/D = 4 to 13), while keeping the wall-thickness-to-radius ratio constant at 0.143. RESULTS: The absolute value of the buckling pressure decreased from 4.7 to 3.3 cmH2O (461-324 Pa) when L/D increased from 4 to 13. The buckling pressure was nearly independent from tube length for L/D >10. CONCLUSIONS: Our finding that longer tubes are more collapsible than shorter tubes is consistent with the higher incidence of obstructive sleep apnea in males than females.

Drug-Induced Sleep Endoscopy and Hypoglossal Nerve Stimulation Outcomes: A Multicenter Cohort Study.

OBJECTIVES/HYPOTHESIS: To determine the association between findings of blinded reviews of preoperative drug-induced sleep endoscopy (DISE) and outcomes of hypoglossal nerve stimulation (HNS) for obstructive sleep apnea (OSA). STUDY DESIGN: Cohort study. METHODS: A retrospective, multicenter cohort study of 343 adults who underwent treatment of OSA with HNS from 10 academic medical centers was performed. Preoperative DISE videos were scored by four blinded reviewers using the VOTE Classification and evaluation of a possible primary structure contributing to airway obstruction. Consensus DISE findings were examined for an association with surgical outcomes based on therapy titration polysomnogram (tPSG). Treatment response was defined by a decrease of ≥50% in the apnea-hypopnea index (AHI) to <15 events/hour. RESULTS: Study participants (76% male, 60.4 ± 11.0 years old) had a body mass index of 29.2 ± 3.6 kg/m2 . AHI decreased (35.6 ± 15.2 to 11.0 ± 14.1 events/hour; P < .001) on the tPSG, with a 72.6% response rate. Complete palate obstruction (vs. none) was associated with the greatest difference in AHI improvement (-26.8 ± 14.9 vs. -19.2 ± 12.8, P = .02). Complete (vs. partial/none) tongue-related obstruction was associated with increased odds of treatment response (78% vs. 68%, P = .043). Complete (vs. partial/none) oropharyngeal lateral wall-related obstruction was associated with lower odds of surgical response (58% vs. 74%, P = .042). CONCLUSIONS: The DISE finding of primary tongue contribution to airway obstruction was associated with better outcomes, whereas the opposite was true for the oropharyngeal lateral walls. This study suggests that the role for DISE in counseling candidates for HNS extends beyond solely for excluding complete concentric collapse related to the velum. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:1676-1682, 2021.

Non-pressure therapies for obstructive sleep apnea: surgery and oral appliances.

The first-line treatment of obstructive sleep apnea (OSA) is positive airway pressure (PAP). If PAP fails to adequately treat the OSA, oral appliances that enlarge the airway (mandibular advancement devices primarily, or the tongue retaining device if the patient has no dentition) are the next line of therapy. The third-line treatment of OSA is surgery. Surgeries that have been used to treat OSA include septoplasty, tonsillectomy adenoidectomy, uvulopalatopharyngoplasty, mandibular advancement procedures, tongue reduction surgery, hyoid bone suspension, maxillofacial surgery, and bariatric procedures. There are scant data to support or compare the various procedures.

A New Metric for Precision Medicine: PAP and Hypoglossal Neurostimulation.

CITATION: Jacobowitz O, Woodson BT. A new metric for precision medicine: PAP and hypoglossal neurostimulation. J Clin Sleep Med. 2019;15(8):1079-1080.

Palatal anatomy for sleep apnea surgery.

The goal of this review is to advance the understanding of the muscular and soft tissue palatal anatomy as it relates to palatal surgery for sleep apnea and the phenotypic variations that generate the shape and collapsibility of the retropalatal airway. Anatomically, the soft palate has both a proximal and distal segments separated by the palatal genu. The proximal palatal segment has a variable angle from the hard palate (ie, alpha angle) determined by the position and length of the levator veli palatini muscle. The palatopharyngeus muscle (PP) is a major defining element of the palate and lateral pharyngeal wall and forms the medial wall of the lateral palatal space. It is composed of two divisions: the longitudinal palatopharyngeus fasciculi which acts to elevate the pharynx and depress the soft palate and the transverse palatopharyngeus fascicle (Passavant's ridge) which function is a nasopharyngeal sphincter. The lateral palatal space incorporates the supra-tonsilar fat, and is bounded by muscles that determine the structure of the palate and associated lateral pharyngeal walls. Understanding of palatal muscles and pharyngeal airway phenotypes provides insight into the steps and mechanisms of pharyngoplasty procedures. LEVEL OF EVIDENCE: N/A.

Airflow limitation in a collapsible model of the human pharynx: physical mechanisms studied with fluid-structure interaction simulations and experiments.

The classical Starling Resistor model has been the paradigm of airway collapse in obstructive sleep apnea (OSA) for the last 30 years. Its theoretical framework is grounded on the wave-speed flow limitation (WSFL) theory. Recent observations of negative effort dependence in OSA patients violate the predictions of the WSFL theory. Fluid-structure interaction (FSI) simulations are emerging as a technique to quantify how the biomechanical properties of the upper airway determine the shape of the pressure-flow curve. This study aimed to test two predictions of the WSFL theory, namely (1) the pressure profile upstream from the choke point becomes independent of downstream pressure during flow limitation and (2) the maximum flowrate in a collapsible tube is VImax=A3/2(ρdA/dP)-1/2 , where ρ is air density and A and P are the cross-sectional area and pressure at the choke point respectively. FSI simulations were performed in a model of the human upper airway with a collapsible pharynx whose wall thickness varied from 2 to 8 mm and modulus of elasticity ranged from 2 to 30 kPa. Experimental measurements in an airway replica with a silicone pharynx validated the numerical methods. Good agreement was found between our FSI simulations and the WSFL theory. Other key findings include: (1) the pressure-flow curve is independent of breathing effort (downstream pressure vs. time profile); (2) the shape of the pressure-flow curve reflects the airway biomechanical properties, so that VImax is a surrogate measure of pharyngeal compliance.

Defining common outcome metrics used in obstructive sleep apnea.

Sleep-disordered breathing a spectrum that ranges from snoring through disorder of increased airway resistance, to overt sleep apnea affects many clinical disease outcomes. Traditionally, disease outcomes have been measured by polysomnography, with the most common metric being the apnea hypopnea index (AHI). Multiple other clinical metrics are commonly used to assess the severity and impact of disease on important outcomes of obstructive sleep apnea (OSA). These allow assessment of sleepiness, quality of life, performance, and medical, especially cardiovascular outcomes. Currently the available metrics only partially explain the associated disease outcomes in different patients. This review highlights the available clinical, physiological and biomarker metrics in measuring OSA and associated co-morbidities and defines treatment goals.

Palate implants for obstructive sleep apnea: multi-institution, randomized, placebo-controlled study.

OBJECTIVE: To determine efficacy of Pillar palate implants for mild to moderate obstructive sleep apnea (OSA) syndrome. DESIGN: Multi-institution, randomized, double-blind, placebo-controlled study. METHODS: One hundred patients with mild to moderate OSA and suspected retropalatal obstruction were randomly assigned treatment with three palatal implants or sham placebo. RESULTS: Final apnea-hypopnea index (AHI) increased for both groups at 3 months, correlating with increased percentage of supine sleep but was less in the implant group (P = 0.05). A clinically meaningful reduction in AHI (> or =50% reduction to <20) was more common in the implant group (26% vs 10%, P = 0.05). Significant differences were noted for changes in lowest oxyhemoglobin saturation (P = 0.007) and Functional Outcomes of Sleep Questionnaire (P = 0.05). Improvement in Epworth Sleepiness Score did not differ from that of sham (P = 0.62). Partial implant extrusion occurred in two patients (4%). CONCLUSION: Palate implants for mild to moderate obstructive sleep apnea demonstrated efficacy over placebo for several important outcomes measures with minimal morbidity, but overall effectiveness remains limited. Further study is needed.

Technical tips during implantation of selective upper airway stimulation.

OBJECTIVE: Selective upper airway stimulation is now well-established in the United States and in several European countries, with more than 1,000 patients implanted since U.S. Food and Drug Administration approval in April 2014. The authors herein, all head and neck surgeons, account for approximately one of every five implants completed to date. Several of the authors also provide comprehensive longitudinal care of their patients as dual-specialty sleep medicine physicians. STUDY DESIGN: Multi-center, retrospective clinical analysis. METHODS: More than 300 implants have been evaluated and reviewed in five different implant centers (Germany, United States). RESULTS: This analysis shares tips and techniques from the collective experiences with more than 300 implants, which can help newer implanters learn vicariously both for standard practices in executing routine implants through activation and, importantly, for working through more challenging encounters with anatomy, special patient phenotypes, system testing, and troubleshooting. CONCLUSION: These tips should help new implanters handle most of the situations arising during implantation and avoid common pitfalls. Laryngoscope, 128:756-762, 2018.