Patient selection for upper airway stimulation: is concentric collapse in sleep endoscopy predictable?

Surgical failure guided by DISE in patients with obstructive sleep apnea: a systematic review and meta-analysis

OBJECTIVES

The failure rate and risk factors of upper airway surgery with drug induced sleep endoscopy (DISE) remain unknown in the treatment of obstructive sleep apnea (OSA). This review aims to analyze the failure rate of upper airway surgery with DISE and identify obstruction sites for surgical failure.

METHODS

A systematic review was conducted using PubMed, Embase, Web of Science, and Google Scholar until May 20th, 2023. We included studies that used DISE to assess obstructive sites before upper airway surgery and reported surgical failure rates and outcomes in patients with OSA.

RESULTS

25 studies with a total of 1522 patients were included in the systematic review and meta-analysis. Upper airway surgery guided by DISE had a relatively low failure rate of 37% (95% CI 0.31-0.44) in the random effects model (I2 = 85.97%, P < 0.001). According to the velum, oropharynx, tongue base, and epiglottis (VOTE) scoring system, major risk factors for surgical failure included circumferential collapse at the velum, lateral wall collapse and small tonsils at the oropharynx, anterior-posterior lingual collapse and complete collapse at the tongue base. High body mass index and large preoperative apnea hypopnea index were also risk factors for OSA surgical failure.

CONCLUSIONS

Upper airway surgery guided by DISE in patients with OSA had a low failure rate of 37%. DISE can identify obstruction sites associated with surgical failure and guide single-level and multi-level surgeries.

[Velopalatal coupling in sleep endoscopy: collapse-pattern based analysis of simulated airway opening]

OBJECTIVE

Drug-induced sleep endoscopy (DISE) is an established diagnostic procedure to assess the upper airway in patients with obstructive sleep apnea. During DISE airway opening is regularly simulated by various maneuvers. One of them is mandibular advancement by the modified jaw-thrust maneuver (MJTM).

MATERIAL AND METHODS

All DISE examinations evaluated by VOTE classification in the last 15 months were included. The effect of MJTM on anatomical levels was analyzed retrospectively. Frequency and type of collapse at the anatomic levels were recorded. Apnea-hypopnea index (AHI), body mass index (BMI), Epworth Sleepiness Scale (ESS) were determined.

RESULTS

61 patients were included (f=13, m=48, 54.3±12.9 y, ESS 11±5.5, AHI 30.2±19/h, BMI 29.7±4.5 kg/m2). A correlation of r=0.30 was found between AHI and BMI (p=0.02). At velum level, concentric collapse was detected in 16.4%, anterior-posterior (a.p.) collapse in 70.5%, and lateral collapse in 11.5%. A resolution of the collapse using the MJTM was observed in 75.5% of patients. However, in the presence of concentric collapse, opening was evident in 33.3% of cases in contrast to 86.5% in patients with a.p. collapse. Base of tongue collapse was resolved in 98.0% of the cases.

CONCLUSION

A correlation between the success of the MJTM on airway opening at the velum level and the pattern of palatal collapse was found. In therapies aimed at mandibular advancement, e.g. hypoglossal nerve stimulation, an effect on velopalatal airway opening has relevance, so optimization of preoperative diagnosis is of particular importance.

Supine Pharyngeal Width Is Associated With Complete Concentric Palatal Collapse During Drug-Induced Sleep Endoscopy and Hypoglossal Nerve Stimulator Outcomes

OBJECTIVE

Hypoglossal nerve stimulation (HNS) implantation in the US requires preoperative drug-induced sleep endoscopy (DISE) screening for complete concentric palatal collapse (CCC) to establish treatment candidacy. We hypothesized that supine pharyngeal width (SPW) in awake patients is associated with CCC and HNS therapy outcomes.

METHODS

Adults with moderate to severe obstructive sleep apnea underwent awake measurement of SPW followed by DISE screening for CCC. Eligible patients electing for HNS implantation underwent postoperative polysomnography per standard of care.

RESULTS

SPW was measured in 73 patients. For SPW >20 mm, the positive likelihood ratio for absence of CCC was 6.67 with pre- and post-test odds of 6.3 and 42.0, respectively. Postoperative PSG data were available from 31 of 44 (70.5%) patients subsequently implanted with HNS. Patients with SPW >20 mm had a greater rate of HNS response than those with SPW ≤20 (62 vs 30%; P < .05). Only SPW and BMI were significantly associated with CCC and HNS response in regression models.

CONCLUSION

In a retrospective cohort study, SPW was significantly associated with CCC and postoperative apnea-hypopnea index following HNS implantation. SPW may be a viable screening tool for HNS candidacy.

Guidelines of the French Society of ENT (SFORL): Drug-induced sleep endoscopy in adult obstructive sleep apnea syndrome

OBJECTIVES

To determine the indications, anesthesiological and surgical procedure and interest of drug-induced sleep endoscopy in the treatment of adult obstructive sleep apnea syndrome.

DESIGN

A redactional committee of 17 experts was set up. Conflicts of interest were disclosed and followed up throughout the process of drawing up the guidelines. The work received no funding from any firm dealing in health products (drugs or devices). The GRADE (Grading of Recommendations Assessment, Development and Evaluation) method was applied to assess the quality of the data on which the guidelines were founded. It was stressed that strong recommendations should not be made on the basis of poor-quality or insufficient data.

METHODS

The committee studied 29 questions on 5 topics: indications and contraindications, anesthetic technique, surgical technique, interpretation and reporting of results, and management guided by results.

RESULTS

Expert review and application of the GRADE method led to 30 guidelines: 10 with high level of evidence (Grade 1+ or 1-), 19 with low level (GRADE 2+ or 2-) and 1 expert opinion.

CONCLUSION

Experts fully agreed on the strong guidelines formalizing the indications and modalities of drug-induced sleep endoscopy for adult obstructive sleep apnea syndrome.

Critical closing pressure (Pcrit) of the pharyngeal airway during routine drug-induced sleep endoscopy: feasibility and protocol

In obstructive sleep apnea (OSA), there are various pathophysiological factors affecting the upper airway during sleep. Two prominent factors contributing to OSA are site and pattern of upper airway collapse and degree of pharyngeal collapsibility. In a clinical setting, drug-induced sleep endoscopy (DISE) is used to visualize the structures of the upper airway. Critical closing pressure (Pcrit) is the gold standard measure of pharyngeal collapsibility. This prospective clinical study aimed to investigate the feasibility and protocol of Pcrit measurements during DISE. Thirteen patients with OSA were included. Pcrit was calculated using peak inspiratory airflow and inspiratory ventilation. The proposed protocol was successful in Pcrit measurement during DISE in all subjects [median[Q1;Q3] Pcrit for “peak inspiratory method” (n = 12): −0.84[−2.07;0.69] cmH₂O, “ventilation method” (n = 13): −1.32[2.32;0.47] cmH₂O], highlighting the feasibility of the approach. There was no significant difference (P = 0.67) between calculated Pcrit with either of the calculation methods, indicating high reliability. Correlation analysis showed Pcrit as an independent parameter of any of the anthropometric or polysomnographic parameters. The ventilation method proved to be more successful in assessment of Pcrit in subjects with epiglottic collapse (e.g., with high negative effort dependence). Subjects with palatal complete concentric collapse during DISE had a wide Pcrit range ([−2.86;2.51]cmH₂O), suggesting no close correlation between Pcrit and this DISE pattern (P = 0.38). Incorporation of Pcrit measurements into DISE assessments is feasible and may yield valuable additional information for OSA management. Combining Pcrit and DISE provides information on both the site and degree of upper airway collapse and the degree of pharyngeal collapsibility.

NEW & NOTEWORTHY The protocol of this study was successful in concomitant measurement of Pcrit during routine clinical endoscopy. Comparison of two calculation methods for Pcrit showed that the inspiratory ventilation method was more successful in assessment of Pcrit in subjects with epiglottic collapse who have high negative effort dependence. Subjects with palatal complete concentric collapse during DISE had a wide Pcrit range and did not have a greater Pcrit than patients in other site of collapse categories.

Hypoglossal Nerve Stimulation Therapy

Hypoglossal nerve stimulation (HNS) has been shown to be a safe alternative in the treatment of moderate-to-severe obstructive sleep apnea (OSA). A recent meta-analysis of 12 studies by Costantino et al. indicated the surgical success rates at 55-75%, a reduction of the apnea hypopnea index (AHI) of 18 events/h, and a reduction of the Epworth Sleepiness Scale (ESS) of 2.9-5.3. After animal studies in the 1970s, the first trial on humans to decrease upper airway resistance by transcutaneous electrical stimulation of the genioglossus was reported in 1989. A separate stimulation of protruding and retracting muscles was realized in 1995 by fine-wire electrodes that were placed into the tongue transoral. Over the next years, several companies developed implantable devices for hypoglossal stimulation in OSA. Initially, devices were developed that used unilateral stimulation of the hypoglossal nerve. In 2014, a device for unilateral respiratory frequency-controlled hypoglossal stimulation finally received FDA approval after a successful phase III trial. In recent years, a device for bilateral breath rate-independent stimulation of the hypoglossal nerve has been added to these approaches as a new development. Accordingly, hypoglossal nerve stimulation, on the one hand, is now an established tool for patients with OSA when standard treatments are not satisfactory. Beyond that, hypoglossal stimulation is undergoing a continuous and impressive development like hardly any other field of surgical therapy for OSA.

Improving outcomes of hypoglossal nerve stimulation therapy: current practice, future directions and research gaps. Proceedings of the 2019 International Sleep Surgery Society Research Forum

Hypoglossal nerve stimulation (HGNS) has evolved as a novel and effective therapy for patients with moderate-to-severe obstructive sleep apnea (OSA). Despite positive published outcomes of HGNS, there exist uncertainties regarding proper patient selection, surgical technique, and the reporting of outcomes and individual factors that impact therapy effectiveness. According to current guidelines, this therapy is indicated for select patients, and recommendations are based on the Stimulation Therapy for Apnea Reduction (STAR) trial. Ongoing research and physician experiences continuously improve methods to optimize the therapy. An understanding of the way in which airway anatomy, OSA phenotypes, individual health status, psychological conditions and comorbid sleep disorders influence the effectiveness of HGNS is essential to improve outcomes and expand therapy indications. This manuscript presents discussions on current evidence, future directions, and research gaps for HGNS therapy from the 10th International Surgical Sleep Society expert research panel.

Concentric vs Anteroposterior-Laterolateral Collapse of the Soft Palate in Patients With Obstructive Sleep Apnea

The presence of complete concentric collapse of the soft palate (CCCp) during drug-induced sleep endoscopy (DISE) has important therapeutic consequences. However, CCCp may present in various, sometimes doubtful, ways due to the complex anatomy of the upper airway. Herein, we aimed to characterize these doubtful variants by reviewing the DISE recordings of patients with obstructive sleep apnea (n = 332). We observed in some individuals that the soft palate collapsed in an anteroposterior-laterolateral (AP-LL) way, producing a polygonal shape that was distinct from CCCp. Patients with this collapse pattern (n = 29) had a smaller neck circumference and less severe obstructive sleep apnea than patients with CCCp (n = 68). The majority of patients with AP-LL collapse (n = 19) were originally diagnosed with CCCp. Based on these findings, AP-LL collapse of the soft palate might represent a distinct DISE phenotype that is easily confounded with CCCp.

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.

Effect of body weight on upper airway findings and treatment outcome in children with obstructive sleep apnea

OBJECTIVE/BACKGROUND

Surgical interventions for obstructive sleep apnea (OSA) are less effective in obese than in normal-weight children. However, the mechanisms that underpin this relationship are not fully understood. Therefore, this study aimed to explore how body weight influences upper airway collapse and treatment outcome in children with OSA.

METHODS

We conducted a retrospective analysis of prospectively collected data on polysomnography, drug-induced sleep endoscopy (DISE), and treatment outcome in otherwise healthy children with OSA. Associations between body mass index (BMI) z-score and upper airway collapse during DISE were assessed using logistic regression modelling. Treatment success was defined as obstructive apnea-hypopnea index (oAHI) < 5 events/hour and cure as oAHI < 2 events/hour with obstructive apnea index < 1 event/hour.

RESULTS

A total of 139 children were included [median (Q1─Q3); age 4.5 (3.1─8.4) years; BMI z-score 0.3 (-0.8 to 1.4); oAHI 10.8 (6.8─18.0) events/hour]. Twenty-five of them were overweight and 21 were obese. After adjusting for age and history of upper airway surgery, BMI z-score was significantly correlated with circumferential upper airway collapse during DISE (odds ratio 1.67; 95% confidence interval 1.12─2.65; P = 0.011). Outcome of DISE-directed treatment was similar in normal-weight (success: 91.4%; cure: 78.5%), overweight (success: 88.0%; cure: 80.0%), and obese (success: 90.5%; cure: 76.5%) children. Children with circumferential collapse responded better to continuous positive airway pressure than to (adeno)tonsillectomy.

CONCLUSION

Increasing body weight is associated with circumferential upper airway collapse during DISE and, accordingly, may require treatment strategies other than (adeno)tonsillectomy.

Electrical stimulation of the whole hypoglossal nerve in patients with obstructive sleep apnea

PURPOSE

Electrical stimulation of the whole hypoglossal nerve (HGp-ES) has been demonstrated to enlarge the pharynx and improve pharyngeal stability and patency to airflow in all animals studied, but not in humans. The present study was undertaken to better understand the effect of HGp-ES on the human pharynx.

METHODS

Eight patients with obstructive sleep apnea who had implanted stimulators with electrodes positioned proximally on the main truck of the hypoglossus were studied under propofol sedation. Pharyngoscopy and air flow measurements at multiple levels of continuous positive airway pressure (CPAP) were performed before and during Hgp-ES.

RESULTS

HGp-ES that activates both tongue protrusors and retractors narrowed the pharyngeal lumen at the site of collapse (velopharynx in all subjects) from 1.38 ± 0.79 to 0.75 ± 0.44 cm2, p < 0.05 (measured at mid-range of CPAP levels) and lowered airflow (from 8.88 ± 2.08 to 6.69 ± 3.51 l/min, p < 0.05). Changes in critical pressure (Pcrit) and velopharyngeal compliance were not significant, but oropharyngeal compliance decreased (from 0.43 ± 0.18 to 0.32 ± 0.13 cm2/cmH2O, p < 0.05). No correlation was found between the pattern of change in luminal shape (determined as the ratio of a-p vs. lateral diameter when lowering CPAP) or changes in cross-sectional area and airflow during Hgp-ES.

CONCLUSIONS

Our findings indicate that human retractors dominate when stimulated together with the protrusors during HGp-ES. While co-activation of retractors may be beneficial, it should be limited. We speculate that exercises that augment protrusor force may improve the response to hypoglossal stimulation. The exclusion of patients with concentric pharyngeal obstruction should be re-evaluated.

Phenotypic Labelling Using Drug-Induced Sleep Endoscopy Improves Patient Selection for Mandibular Advancement Device Outcome: A Prospective Study

STUDY OBJECTIVES

Mandibular advancement device (MAD) outcome varies between patients. We hypothesized that upper airway collapse sites, patterns, and degrees assessed during baseline drug-induced sleep endoscopy (DISE) affect MAD outcome.

METHODS

One hundred patients with obstructive sleep apnea (OSA) were included and underwent baseline type 1 polysomnography. MAD was fitted intraorally at fixed 75% maximal protrusion. A total of 72 patients completed 3-month follow-up polysomnography and baseline DISE. Response was defined as apnea-hypopnea index (AHI) reduction ≥ 50%, deterioration as AHI increases during MAD treatment compared to baseline.

RESULTS

Adjusting for baseline AHI and body mass index, patients with tongue base collapse showed 3.69 higher odds (1.27-10.73; P = .0128) for response. Complete concentric collapse at the level of the palate (5.32 [1.21-23.28]; P = .0234) and complete laterolateral oropharyngeal collapse (6.62 [1.14-38.34]; P = .0330) related to deterioration. Results for tongue base collapse and complete concentric collapse at the level of the palate were confirmed in the moderate to severe OSA subgroup. Applying these results to this selected subgroup increased response rate with 54% and decreased deterioration rate with 53%. These results were confirmed using other response and deterioration definitions.

CONCLUSIONS

Three baseline DISE phenotypes identified during drug-induced sleep were significantly related to MAD treatment outcome: one beneficial, tongue base collapse, and two adverse, complete concentric collapse at the level of the palate and complete laterolateral oropharyngeal collapse. If confirmed in future prospective studies, these results could guide patient selection for MAD outcome.

CLINICAL TRIAL REGISTRATION

This prospective clinical trial (PROMAD) was registered on Clinicaltrials.gov with identifier: NCT01532050.

CITATION

Op de Beeck S, Dieltjens M, Verbruggen AE, Vroegop AV, Wouters K, Hamans E, Willemen M, Verbraecken J, De Backer WA, Van de Heyning PH, Braem MJ, Vanderveken OM. Phenotypic labelling using drug-induced sleep endoscopy improves patient selection for mandibular advancement device outcome: a prospective study. J Clin Sleep Med. 2019;15(8):1089-1099.

Drug-induced sleep endoscopy while administering CPAP therapy in patients with CPAP failure

Study objectives

To study the pattern of upper airway collapse in patients with CPAP failure by performing DISE while administering CPAP therapy and to determine the reason for CPAP failure accordingly.

Methods

This observational retrospective study comprised 30 patients diagnosed with OSA and CPAP failure, who underwent DISE while administering CPAP therapy. During DISE, the upper airway was assessed with and without CPAP therapy using the VOTE classification. Additionally, a jaw thrust maneuver was performed, in order to mimic the effect of an additional mandibular advancement device (MAD) in combination with CPAP therapy. Consequently, the outcome of DISE was translated into a clinically relevant categorization.

Results

Eleven patients (37%) had a persistent anteroposterior (AP) collapse, including a collapse at velum, tongue base, or epiglottis level and multilevel collapse. Eight patients (27%) had a floppy epiglottis. Five patients (17%) had a persistent complete concentric collapse (CCC) and three patients had a persistent laryngeal collapse (10%). In three patients (10%), no airway collapse was found after CPAP administration.

Conclusions

Based on the results of the reported study, in most cases, the potential cause of CPAP failure can be determined by this new diagnostic method. Consequently, suggestions can be made for additional therapy.

Palatopharyngoplasty Resolves Concentric Collapse in Patients Ineligible for Upper Airway Stimulation

OBJECTIVE

To determine if a modified tissue-preserving palatopharyngoplasty could convert retropalatal concentric collapse to anteroposterior or lateral patterns of collapse on drug-induced sleep endoscopy (DISE) in patients who are not candidates for upper airway stimulation due to complete circumferential collapse at the velum.

METHODS

A prospective, nonconsecutive, single-blinded cohort study was performed by two sleep surgeons at a tertiary care center from 2015 to 2018. Inclusion criteria included adults > 18 years of age with a diagnosis of obstructive sleep apnea with an Apnea-Hypopnea Index (AHI) > 15, a body mass index (BMI) < 32, and < 25% central apneas on polysomnography. Twelve patients with complete circumferential collapse underwent a modified palatopharyngoplasty. Postoperatively, a repeat sleep study was performed. A repeat DISE was recommended for those with incomplete surgical response (clinically and/or AHI).

RESULTS

Twelve patients with complete circumferential collapse were eligible for the study. Mean BMI was 30.5. Mean preoperative AHI was 54.0 events per hour. Following a modified palatopharyngoplasty, the mean AHI was reduced to 33.1 events per hour, and 100% (12 of 12) of the patients converted from a pattern of complete circumferential collapse to either no collapse at the level of the velum (3) or an anteroposterior pattern of collapse (9).

CONCLUSION

We demonstrate that a modified palatopharyngoplasty can successfully convert collapse patterns in patients with complete circumferential collapse. Further studies are required to determine the outcome of these patients following upper airway stimulation implantation.

LEVEL OF EVIDENCE

1B Laryngoscope, 2020.

Hypoglossal Nerve Stimulation in the Treatment of Obstructive Sleep Apnea: Patient Selection and New Perspectives

Hypoglossal nerve stimulation (HNS) is an increasingly widespread OSA treatment. It is a non-anatomical modifying surgery able to achieve an adequate objective and subjective result with a reasonable complication rate. HNS exploits the neurostimulation to reduce upper airway collapsibility providing a multilevel upper airway improvement within a single procedure. Proper patient selection has a fundamental role in determining an adequate long-term clinical outcome. All patient candidates for HNS undergo a standard comprehensive sleep medicine assessment and upper airway surgical examination. Several features should be assessed preoperatively in order to predict patients' response to HNS treatment. In particular, the assessment of OSA severity, BMI > 32 Kg/m², collapse pattern during drug-induced sleep endoscopy (DISE), and many other parameters, is central for a good patient selection and customization of OSA treatment. HNS is indeed one of the most promising tools in the widespread context of personalized sleep medicine. HNS is an adjustable medical device that could be titrated in order to improve HNS effectiveness, maintaining patient comfort. Moreover, HNS provides the opportunity for patients to play an active role in their own care, with a potential improvement in therapy adherence and efficacy. This review summarizes the current evidence in patient selection for HNS, highlighting the reasons behind the optimistic future of this OSA treatment in the context of personalized medicine.

Outcomes of Hypoglossal Nerve Upper Airway Stimulation among Patients with Isolated Retropalatal Collapse

Objective

To examine whether patients with isolated retropalatal collapse perform as well as others following implantation with an upper airway stimulation (UAS) device.

Study Design

Retrospective review.

Setting

Single-institution tertiary academic care medical center.

Subjects and Methods

Following drug-induced sleep endoscopy, subjects who met inclusion criteria for implantation with a UAS device received an implant per industry standard. Subjects with isolated retropalatal collapse were compared with those having other patterns of collapse. Outcome measures included apnea-hypopnea index (AHI) and nadir oxyhemoglobin saturation (NOS).

Results

Ninety-one patients were implanted during the duration of the study, and 82 met inclusion criteria for analysis. Twenty-five had isolated retropalatal collapse, while the remaining 57 had other patterns of collapse on drug-induced sleep endoscopy. For all patients, mean preoperative AHI and NOS were 38.7 (95% CI, 35.0-42.4) and 78% (95% CI, 75%-80%), respectively; these improved postoperatively to 4.5 (95% CI, 2.3-6.6) and 91% (95% CI, 91%-92%). There was no significant preoperative difference between groups with regard to demographics, AHI, or NOS. Group comparison showed postoperative AHI to be 5.7 (95% CI, 0.57-10.8) for patients with isolated retropalatal collapse and 3.9 (95% CI, 1.7-6.1) for other patients ( P = .888). Postoperative NOS was 92% (95% CI, 90%-94%) among patients with isolated retropalatal collapse and 91% (95% CI, 90%-92%) for others ( P = .402).

Conclusions

All patients showed significant improvement following implantation with UAS. Patients with isolated retropalatal collapse showed similar improvement to other types of collapse with regard to AHI and NOS.

Complete concentric collapse at the soft palate in sleep endoscopy: what change is possible after UPPP in patients with CPAP failure?

PURPOSE

The aim of this work was to assess whether uvulopalatopharyngoplasty in patients with failure for positive airway pressure not only reduces the degree of obstructive sleep apnea but also to determine as well if it changes the collapse pattern of the soft palate and thereby fulfills the qualifications for implementing upper airway stimulation (UAS) as an adjunctive solution.

METHOD

Fifteen patients with intolerance for positive airway pressure were included in this retrospective cohort study. Polygraphy and drug-induced sleep endoscopy were used in order to evaluate the reduction of the apnea-hypopnea index (AHI), as well as the change of collapse pattern at the soft palate level before and about 3 months after uvulopalatopharyngoplasty and tonsillectomy (TE-UPPP).

RESULTS

In 93% of the patients, a postoperative change of the initially complete concentric palatal collapse pattern could be found during drug-induced sleep endoscopy. In one patient, no obstruction at all was seen at the soft palatal level. Only one patient still presented with a complete concentric collapse at velum level. AHI decreased from mean 34.7 events per hour to 20.2/h and oxygen desaturation index from 25.3 events per hour to 16.1/h.

CONCLUSION

Patients seeking for positive airway pressure alternatives could not only benefit from reduction of AHI by TE-UPPP postoperatively; additionally, by changing the collapse pattern at the soft palate, they might also fulfill criteria for upper airway stimulation (UAS) in case of persistent OSA of at least moderate degree.

Computed Tomography Characterization and Comparison With Polysomnography for Obstructive Sleep Apnea Evaluation

PURPOSE

We hypothesized that computed tomography (CT) combined with portable polysomnography (PSG) might better visualize anatomic data related to obstructive sleep apnea (OSA). The present study evaluated the CT findings during OSA and assessed their associations with the PSG data and patient characteristics.

PATIENTS AND METHODS

We designed a prospective cross-sectional study of patients with OSA. The patients underwent scanning during the awake state and apneic episodes. Associations of the predictor variables (ie, PSG data, respiratory disturbance index [RDI]), patient characteristics (body mass index [BMI], neck circumference [NC], and waist circumference [WC]), and outcome variables (ie, CT findings during apneic episodes) were assessed using logistic regression analysis. The CT findings during apneic episodes were categorized regarding the level of obstruction, single level (retropalatal [RP] or retroglossal [RG]) or multilevel (mixed RP and RG), degree of obstruction (partial or complete), and pattern of collapse (complete concentric collapse [CCC] or other patterns).

RESULTS

A total of 58 adult patients with OSA were scanned. The mean ± standard deviation for the RDI, BMI, NC, and WC were 41.6 ± 28.55, 27.80 ± 5.43 kg/m², 38.3 ± 4.3 cm, and 93.8 ± 13.6 cm, respectively. No variables distinguished between the presence of single- and multilevel airway obstruction in the present study. A high RDI (≥30) was associated with the presence of complete obstruction and CCC (odds ratio 6.33, 95% confidence interval 1.55 to 25.90; and odds ratio 3.77, 95% confidence interval 1.02 to 13.91, respectively) compared with those with a lesser RDI.

CONCLUSIONS

An increased RDI appears to be an important variable for predicting the presence of complete obstruction and CCC during OSA. Scanning during apneic episodes, using low-dose volumetric CT combined with portable PSG provided better anatomic and pathologic findings of OSA than did scans performed during the awake state.

Insights since FDA Approval of Hypoglossal Nerve Stimulation for the Treatment of Obstructive Sleep Apnea

Purpose

The literature on hypoglossal nerve stimulation (HNS) for the treatment of moderate-to-severe obstructive sleep apnea (OSA) was reviewed from 2014, the time of FDA approval for the Inspire Systems device, to 2017 for themes that might be useful conceptually and practically in the consideration of this new non-anatomic surgical therapy.

Recent Findings

there are now further follow-up articles since the 12-month results for Apnea Reduction (STAR) trial of the Inspire device, and post-approval publications which report similar and/0r improved AHI outcomes. Other emerging themes include drug-induced sedation endoscopy (DISE) as a tool in assessment of eligibility and a more detailed understanding of mechanisms for an HNS effects.

Summary

The post-STAR literature provides guidelines for an integrated coordination of medicine and surgery to appropriately screen and manage patients.

Outcome after one year of upper airway stimulation for obstructive sleep apnea in a multicenter German post-market study

OBJECTIVE/HYPOTHESIS

Upper airway stimulation (UAS) of the hypoglossal nerve has been implemented in the routine clinical practice for patients with moderate-to-severe obstructive sleep apnea (OSA) who could not adhere to continuous positive airway pressure. This study reports objective and patient-reported outcome after 12 months of implantation.

STUDY DESIGN

Multicenter prospective single-arm study.

METHODS

Consecutive patients who received the UAS system (Inspire Medical Systems, Inc., Minneapolis, Minnesota, Maple Grove, MN, U.S.A.) were enrolled in three German centers. Key study exclusion criteria included body mass index > 35 kg/m² , apnea-hypopnea index (AHI) < 15 or > 65, or complete concentric collapse at the soft palate during sedated endoscopy. Data collection at 6- and 12-month visit include home sleep test and patient-reported outcome measures.

RESULTS

Among the total of 60 participants, the median AHI reduced from 28.6 to 9.5 from baseline to 12 months. Patient-reported outcome measured in Epworth Sleepiness Scale and Functional Outcomes of Sleep Questionnaire both improved significantly from baseline to 12 months. The average usage time was 39.1 ± 14.9 hours per week among all participants based on recordings by the implanted device. One patient requested a removal of the device for cosmetic and other personal reasons and was completed without sequelae.

CONCLUSION

This study supported that UAS is a safe and effective treatment option for patients with OSA in routine clinical practice.

LEVEL OF EVIDENCE

4. Laryngoscope, 128:509-515, 2018.

[Drug-induced sedation endoscopy-quo vadis? : Review and outlook]

BACKGROUND

Drug-induced sedation endoscopy (DISE) is a diagnostic procedure which allows evaluation of the collapsibility of the upper airway. According to expert opinion, it is possible to imitate nocturnal collapsibility and perform a realistic investigation of the site of obstruction and vibration. This should enable sufficient and precise therapeutic advice to be given solely on the basis of clinical assessment.

OBJECTIVE

The current publication critically evaluates the present state of development of DISE and its potential indications.

MATERIALS AND METHODS

A PubMed literature research was performed using "sleep" and "endoscopy" or "DISE" as keywords. Relevant publications were evaluated.

RESULTS

The present publication provides a historical summary of the available publications and relates these to other methods for examining obstructive sleep apnea. The present state of DISE in terms of drugs applied, grading systems, and validity is evaluated. Indications for DISE are described and critically discussed on the basis of literature data.

CONCLUSION

DISE provides deep insights into the genesis of obstructions of the upper airway and snoring. Although its value for diagnosis and treatment of sleep-disordered breathing could not yet be demonstrated for all non-CPAP (continuous positive airway pressure) therapies, DISE could identify predictive parameters some methods. Further potential indications for DISE might be predictive examinations for mandibular advancement devices and respiration-synchronous neurostimulation of the hypoglossal nerve. DISE will thus remain a valuable diagnostic tool for obstructive sleep apnea and rhonchopathy.

Outcomes of Upper Airway Stimulation for Obstructive Sleep Apnea in a Multicenter German Postmarket Study

Objective Selective stimulation of the hypoglossal nerve is a new surgical therapy for obstructive sleep apnea, with proven efficacy in well-designed clinical trials. The aim of the study is to obtain additional safety and efficacy data on the use of selective upper airway stimulation during daily clinical routine. Study Design Prospective single-arm study. Setting Three tertiary hospitals in Germany (Munich, Mannheim, Lübeck). Subjects and Methods A multicenter prospective single-arm study under a common implant and follow-up protocol took place in 3 German centers (Mannheim, Munich, Lübeck). Every patient who received an implant of selective upper airway stimulation was included in this trial (apnea-hypopnea index ≥15/h and ≤65/h and body mass index <35 kg/m²). Before and 6 months after surgery, a 2-night home sleep test was performed. Data regarding the safety and efficacy were collected. Results From July 2014 through October 2015, 60 patients were included. Every subject reported improvement in sleep and daytime symptoms. The average usage time of the system was 42.9 ± 11.9 h/wk. The median apnea-hypopnea index was significantly reduced at 6 months from 28.6/h to 8.3/h. No patient required surgical revision of the implanted system. Conclusion Selective upper airway stimulation is a safe and effective therapy for patients with obstructive sleep apnea and represents a powerful option for its surgical treatment.

Hypoglossal nerve stimulation for obstructive sleep apnea: A review of the literature

Objective

To review the indications and clinical evidence supporting hypoglossal nerve stimulation (HNS) therapy for the treatment of moderate-to-severe obstructive sleep apnea (OSA).

Methods

Peer reviewed literature on hypoglossal nerve stimulation therapy for obstructive sleep apnea from 2001 to 2016.

Results

The only currently FDA-approved HNS device for the treatment of moderate-to-severe OSA is produced by Inspire Medical Systems, which recently published its 36-month outcomes data from its Stimulation Therapy for Apnea Reduction (STAR) trial. HNS therapy is currently indicated for moderate-to-severe OSA patients who are CPAP-intolerant, have a body mass index <32, apnea-hypopnea index <50, and without a concentric pattern of upper airway collapse on sleep endoscopy.

Conclusions

Data from the STAR trial suggests that a subset of OSA patients can achieve a significant therapeutic response from hypoglossal nerve stimulation. However, these results may be limited in their generalizability to the broader OSA population.

Sonographic evaluation of tongue motions during upper airway stimulation for obstructive sleep apnea-a pilot study

INTRODUCTION

The objective was to evaluate the feasibility of sonographic evaluation of functional tongue motion as a tool to evaluate postoperative outcomes in human subjects using breathing-synchronized stimulation of the hypoglossal nerve-a novel therapy option for patients with obstructive sleep apnea (OSA).

MATERIAL AND METHODS

Sixteen patients with OSA (n = 16, age 60.4 ± 10.2, BMI 28.7 ± 2.4, AHI 35.0 ± 11.8) underwent sonographic evaluation of tongue motion after initiation of therapy with the Inspire II Upper Airway Stimulation system. Sonographic examination was performed in four different planes (A = floor of the mouth frontal, B = base of the tongue horizontal, C = floor of the mouth parallel to mandible, and D = floor of the mouth median sagittal) in an attempt to visualize tongue surface, tongue and hyoid motion, and the distance of protrusion.

RESULTS

Identification of the tongue surface was achieved in all cases in planes B, C, and D and 81 % of patients in plane A. Tongue motion was evident on the right (implant) side in 63 % in plane A and 75 % in plane B. Distance of protrusion was measured in plane B at 1.04 cm (±0.51), in plane C at 1.08 cm (±0.47), and in plane D at 0.96 cm (±0.45). Hyoid protrusion was measured in plane C or D and was 0.57 cm (±0.39). Significant correlations among the three planes were observed, but there was no correlation to the reduction of apnea-hypopnea index.

CONCLUSION

The results indicate feasibility of sonography to identify tongue and hyoid motions during upper airway stimulation. Useful sonographic planes and landmarks, which allow visualization of dynamic effects of upper airway stimulation, could be established. The evaluation of the tongue in a horizontal (B) and in a sagittal plane (D) appears to be superior to the other investigated planes. The approximate tongue protrusion needed to generate a significant reduction of AHI and ODI was 1 cm.