Long-Term Generator Replacement Experience in Hypoglossal Nerve Stimulator Therapy Recipients With CPAP-Intolerant Obstructive Sleep Apnea

OBJECTIVE

In the last decade, hypoglossal nerve stimulation (HNS) has emerged as a therapeutic alternative for patients with obstructive sleep apnea. The original clinical trial cohorts are entering the phase of expected battery depletion (8-12 years). This study aimed to examine the surgical experience with implantable pulse generator (IPG) replacements and the associated long-term therapy outcomes.

STUDY DESIGN

Retrospective analysis of patients from the original clinical trial databases (STAR, German post-market) who were followed in the ongoing ADHERE registry.

SETTING

International multicenter HNS registry.

METHODS

The ADHERE registry and clinical trial databases were cross-referenced to identify the serial numbers of IPGs that were replaced. Data collection included demographics, apnea-hypopnea index (AHI), therapy use, operative times, and adverse events.

RESULTS

Fourteen patients underwent IPG replacement 8.3 ± 1.1 years after their initial implantation. Body mass index was unchanged between the original implant and IPG replacement (29 ± 4 vs 28 ± 2 kg/m2 , p = .50). The mean IPG replacement operative time was shorter than the original implant (63 ± 50 vs 154 ± 58 minutes, p < .002); however, 2 patients required stimulation lead replacement which significantly increased operative time. For patients with available AHI and adherence data, the mean change in AHI from baseline to latest follow-up (8.7 ± 1.1 years after de novo implant) was -50.06%, and the mean therapy use was 7.2 hours/night.

CONCLUSION

IPG replacement surgery was associated with low complications and shorter operative time. For patients with available outcomes data, adherence and efficacy remained stable after 9 years of follow-up.

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.

Sleep medicine in otolaryngology units: an international survey

PURPOSE

No study to date has described the overall landscape of sleep disorders management and training in otolaryngology departments of different countries. The aim of our study was to investigate and compare settings, diagnostic and therapeutic approaches and training programmes.

METHODS

An international online survey was developed with the collaboration of the YO-IFOS (Young Otolaryngologists-International Federation of Otorhinolaryngological Societies) to assess the current practice of otolaryngologists in the management of sleep disorders. The survey also included a session dedicated to training.

RESULTS

A total of 126 otolaryngologists completed the survey. The larger part of responses was collected from Central/South America and Europe. The majority of responders from South/Central America (97%) declared to be certified as sleep specialist while 49% of Europeans stated the opposite. Of responders 83% perform a drug-induced sleep endoscopy (DISE) before planning a possible surgical intervention. Soft palate and base of tongue interventions were the most common procedure, respectively performed in 94% and 79% of the cases. Residents were allowed to perform soft palate surgery in 77% of the cases. Upper airway stimulation (26% vs 10%), trans-oral robotic surgery (36% vs 11%) and radiofrequency of the base of the tongue (58% vs 25%) were preferred more frequently by European responders. The highest caseloads of soft palate surgery and bi-maxillary advancement were registered in the academic institutions.

CONCLUSION

Significant concordance and few interesting divergences in diagnosis and treatment of sleep disorders were observed between nationalities and types of institution. Economic resources might have played a significant role in the therapeutic choice. Trainees' lack of exposure to certain interventions and to a sufficient caseload appeared to be the main burden to overcome.

Surgery for obstructive sleep apnea: sleep endoscopy determinants of outcome

OBJECTIVES/HYPOTHESIS

Although drug-induced sleep endoscopy is often employed to determine the site of obstruction in patients with obstructive sleep apnea (OSA) who will undergo upper airway surgery, it remains unknown whether its findings are associated with surgical outcome. This study tested the hypothesis that drug-induced sleep endoscopy variables can predict the outcome of upper airway surgery in OSA patients.

STUDY DESIGN

Case series retrospective analysis.

METHODS

Forty-nine OSA patients (41 male; mean apnea-hypopnea index [AHI] 30.9 ± 18.5 events/hour) underwent propofol-induced sleep endoscopy followed by upper airway surgery (palatal surgery, and/or radiofrequency ablation of the tongue base, and/or hyoid suspension) and subsequently a follow-up polysomnography to assess surgical outcome.

RESULTS

Twenty-three patients (47%) were responders, and twenty-nine were nonresponders (53%). Nonresponders had a higher occurrence of complete or partial circumferential collapse at velum and complete antero-posterior collapse at tongue base or epiglottis in comparison with responders. Multivariate logistic regression analysis revealed that among baseline clinical and polysomnographic characteristics (e.g., AHI, body mass index) and sleep endoscopy findings, the presence of complete circumferential collapse at velum, and of complete antero-posterior collapse at tongue base were the only independent predictors of upper airway surgery failure.

CONCLUSIONS

Drug-induced sleep endoscopy can be used to predict higher likelihood of response to upper airway surgery in OSA.

Reliable Calculation of the Efficacy of Nonsurgical and Surgical Treatment of Obstructive Sleep Apnea

Objective: The effectiveness of CPAP compliance criteria can be questioned, just as the effectiveness of surgical success criteria has often been questioned. The aim of the study was to measure the effectiveness of compliant CPAP use.

Method: Using mathematical function formulas, the effect on the AHI of various treatment modalities and their respective compliance and success criteria were calculated.

Results: The more severe the AHI, the more percentage of total sleep time (TST) CPAP must be used to significantly reduce the AHI. Patients with moderate OSA reduce the AHI by 33.3% to 48.3% when using CPAP 4 h/ night (AHI 0-5, respectively). The required nightly percentage use rises as one reduces the AHI target to smaller than 5. CPAP must be used 66.67% to 83.33% per night to reduce the AHI below 5 (AHI of 0 while using CPAP).

Conclusion: Using a mean AHI in CPAP therapy is more realistic than using arbitrary compliance rates, which, in fact, hide insufficient reductions in AHI.

One Hundred Consecutive Patients Undergoing Drug Induced Sleep Endoscopy (DISE): Results and Evaluation

Objective: Document the results of 100 consecutive DISE and investigate associations between PSG and DISE findings.

Method: Between June and August 2010, 100 consecutive patients, eligible for sleep surgery or MRA underwent a PSG and DISE. DISE findings were reported using the VOTE classification system; site, degree of airway narrowing, and configuration of obstruction were reported. Associations were analyzed between PSG results, patient characteristics and DISE findings.

Results: 82% suffered from OSA, 52% from positional OSA. 75% were found to have a multi-level obstruction, which was associated with a higher AHI value, as was a complete collapse and a tongue base collapse. A tongue base collapse or epiglottal collapse was associated with positional OSA. And lastly, a complete concentric collapse was associated with an increased BMI.

Conclusion: PSG is mandatory in the diagnostic work-up of OSA; DISE a valid addition. The results of this small scale study help us understand the pathogenesis of OSA and the various associations between PSG outcomes and DISE results, as well as assisting the sleep surgeon to tailor surgery for the patient.

OSAS and Bariatric Surgery: Incidence of OSAS in the Bariatric Surgery Population

Objective: Obesity is a significant risk factor for OSA. The benefits of bariatric surgery (BS) are increasingly reported, but concern about the safety is also heightened. With the aim to prevent OSA related complications of BS, we were interested to see which percentage of patients undergoing BS in our clinic have OSA.

Method: The prospective, multidisciplinary, single-center, observational study enrolled 289 consecutive patients eligible for BS from June 2009 until June 2010. Irrespective of history or clinical findings, all patients on the waiting list for BS visited our ENT out-patient clinic and underwent a full night polysomnography, unless performed previously.

Results: A total of 69.9% fulfilled the criteria for OSA (mean BMI: 44.2 ± SD 6.4). A total of 40.4% of the patients met the criteria for severe OSA. A mere 13.3% of the patients were aware with OSA before being placed on the waiting list for BS. Increased neck circumference, BMI, or ESS were found to be insufficient predictors of OSA presence on linear stepwise regression and ROC curve.

Conclusion: In this large patient series, 69.9% of patients undergoing BS meet the criteria for OSA. Increased neck circumference, BMI, or ESS are insufficient predictors of OSA presence. Polysomnography is an essential component of the preoperative workup of patients undergoing BS. When OSA is found, specific perioperative measures are indicated.