Soft Palate Implants for the Treatment of Mild to Moderate Obstructive Sleep Apnea

International Consensus Statement on Obstructive Sleep Apnea

BACKGROUND

Evaluation and interpretation of the literature on obstructive sleep apnea (OSA) allows for consolidation and determination of the key factors important for clinical management of the adult OSA patient. Toward this goal, an international collaborative of multidisciplinary experts in sleep apnea evaluation and treatment have produced the International Consensus statement on Obstructive Sleep Apnea (ICS:OSA).

METHODS

Using previously defined methodology, focal topics in OSA were assigned as literature review (LR), evidence-based review (EBR), or evidence-based review with recommendations (EBR-R) formats. Each topic incorporated the available and relevant evidence which was summarized and graded on study quality. Each topic and section underwent iterative review and the ICS:OSA was created and reviewed by all authors for consensus.

RESULTS

The ICS:OSA addresses OSA syndrome definitions, pathophysiology, epidemiology, risk factors for disease, screening methods, diagnostic testing types, multiple treatment modalities, and effects of OSA treatment on multiple OSA-associated comorbidities. Specific focus on outcomes with positive airway pressure (PAP) and surgical treatments were evaluated.

CONCLUSION

This review of the literature consolidates the available knowledge and identifies the limitations of the current evidence on OSA. This effort aims to create a resource for OSA evidence-based practice and identify future research needs. Knowledge gaps and research opportunities include improving the metrics of OSA disease, determining the optimal OSA screening paradigms, developing strategies for PAP adherence and longitudinal care, enhancing selection of PAP alternatives and surgery, understanding health risk outcomes, and translating evidence into individualized approaches to therapy.

Computational fluid-structure interaction analysis of flapping uvula on aerodynamics and pharyngeal vibration in a pediatric airway

The uvula flapping is one of the most distinctive features of snoring and is critical in affecting airway aerodynamics and vibrations. This study aimed to elucidate the mechanism of pharyngeal vibration and pressure fluctuation due to uvula flapping employing fluid-structure interaction simulations. The followings are the methodology part: we constructed an anatomically accurate pediatric pharynx model and put attention on the oropharynx region where the greatest level of upper airway compliance was reported to occur. The uvula was assumed to be a rigid body with specific flapping frequencies to guarantee proper boundary conditions with as little complexity as possible. The airway tissue was considered to have a uniform thickness. It was found that the flapping frequency had a more significant effect on the airway vibration than the flapping amplitude, as the flapping uvula influenced the pharyngeal aerodynamics by altering the jet flow from the mouth. Breathing only through the mouth could amplify the effect of flapping uvula on aerodynamic changes and result in more significant oropharynx vibration.

Distance to Specialist Medical Care and Diagnosis of Obstructive Sleep Apnea in Rural Saskatchewan

Obstructive sleep apnea (OSA) is the most common sleep-disordered breathing condition. Patients with OSA symptoms are often not diagnosed clinically, which is a concern, given the health and safety risks associated with unmanaged OSA. The availability of fewer practicing medical specialists combined with longer travel distances to access health care services results in barriers to diagnosis and treatment in rural communities. This study aimed to (1) determine whether the proportion of adults reporting OSA symptoms in the absence of a sleep apnea diagnosis in rural populations varied by travel distance to specialist medical care and (2) assess whether any distance-related patterns were attributable to differences in the frequency of diagnosis among adults who likely required this specialist medical care. We used a cross-sectional epidemiologic study design, augmented by analysis of follow-up survey data. Our study base included adults who completed a 2010 baseline questionnaire for the Saskatchewan Rural Health Study. Follow-up occurred until 2015. 6525 adults from 3731 households constituted our sample. Statistical models used log-binomial regression. Rural adults who reported the largest travel distances (≥250 km) to specialist medical care were 1.17 (95% CI: 1.07, 1.29) times more likely to report OSA symptoms in the absence of a sleep apnea diagnosis than those who reported the smallest (<100 km; referent) distances. However, the proportion of sleep apnea diagnoses was low and unaffected by reported travel distance among adults who likely required this specialist medical care. Our findings suggest factors other than travel distance may be contributing to the low sleep apnea diagnostic rate. This remains important as undiagnosed and untreated OSA has serious implications on the health of people and populations, but effective treatments are available. Health care access barriers to the diagnosis and treatment of OSA require evaluation to inform health care planning and delivery.

Palatal implant surgery effectiveness in treatment of obstructive sleep apnea: A numerical method with 3D patient-specific geometries

Obstructive sleep apnea (OSA) affects a large percentage of the population and is increasingly recognized as a major global health problem. One surgical procedure for OSA is to implant polyethylene (PET) material into the soft palate, but its efficacy remains to be discussed. In this study, we provide input to this topic based on numerical simulations. Three 3 dimensional (3D) soft palate finite element models including mouth-close and mouth-open cases were created based on three patient-specific computed tomography (CT) images. A simplified material modeling approach with the Neo-Hookean material model was applied, and nonlinear geometry was accounted for. Young's modulus for the implant material was obtained from uniaxial tests, and the PET implant pillars were inserted to the 3D soft palate model. With the finite element model, we designed different surgical schemes and investigated their efficacy with respect to avoiding the soft palate collapse. Several pillar schemes were tested, including different placement directions, different placement positions, different settings for the radius and the array parameters of the implant pillars, and different Young's moduli for the pillars. Based on our simulation results, the longitudinal-direction implant surgery improved the stiffness of the soft palate to a small degree, and implanting in the transverse direction was evaluated to be a good choice for improving the existing surgical scheme. In addition, the Young's modulus of the polyethylene material implants has an influence on the reinforcement efficacy of the soft palate.

Extended follow-up of palatal implants for OSA treatment

Objective

Evaluate long-term safety and outcomes of palatal implants for patients with mild to moderate obstructive sleep apnea (OSA).

Study Design and Setting

Continuation of a prospective case series of patients with palatal implants. Polysomnography, daytime sleepiness, and snoring intensity were measured at baseline, 90 days, and extended follow-up.

Results

Twenty-two (42%) patients from the previous study were followed for a median of 435.5 days. Thirteen were classified as responders, based on their 90-day evaluation. 76.9% of initial responders maintained improvements in apnea-hypopnea index (AHI), daytime sleepiness, and snoring at extended follow-up. Nine patients were initial nonresponders for AHI and daytime sleepiness and remained unchanged at extended follow-up. However, snoring for these nine patients initially improved, and the improvement continued through extended follow-up.

Conclusion

Initial response or nonresponse to palatal implants remains stable over an extended period. The generalizability of these results is unknown because of significant loss to follow-up.

Significance

Study results report safety and beneficial long-term outcomes of palatal implants for mild to moderate OSA treatment in selected patients.

Reconsidering first-line treatment for obstructive sleep apnea: a systematic review of the literature

BACKGROUND

Continuous positive airway pressure (CPAP) is typically recommended as first line therapy for obstructive sleep apnea, but the adherence rate of CPAP is problematic. This study's objective was to systematically review the literature relating to CPAP as first line therapy for OSA and compare it to surgical literature on the same topic.

METHODS

A systematic review was conducted according to PRISMA guidelines, examining Medline-Ovid, Embase, and Pubmed databases. The primary search objective was to identify all papers reporting the results of (1) randomized clinical trials (RCT) of CPAP for the treatment of adults with OSA; and (2) both randomized and non-randomized clinical trials and case series on the surgical treatment of OSA in adults. A PhD-level biostatistician first screened papers, and then those that met study criteria were retrieved and analyzed using standardized forms for each author. The primary outcomes were adherence rates of CPAP.

RESULTS

A total of 82 controlled clinical trials for CPAP and 69 controlled and non-controlled surgery trials were identified for analysis. Variation in CPAP use within reported RCT trials were identified, and the majority of patients in the studies would eventually be considered non-adherent to CPAP.

CONCLUSIONS

When considering the numerous patient-related factors that come into play when CPAP is prescribed, the concept of CPAP as gold-standard therapy for OSA should be reconsidered. In many cases surgery can provide a better overall outcome. This study's results suggest that certain patients with OSA may be managed more effectively with surgery than CPAP, without confounding issues of treatment adherence.

A novel palatal implant surgery combined with uvulopalatopharyngoplasty and inferior turbinate radiofrequency for the treatment of moderate to severe obstructive sleep apnea: a pilot study

The efficacy of Pillar implant system for the treatment of obstructive sleep apnea-hypopnea syndrome (OSAHS) is limited. The aim of this study is to explore a new type of soft palatal surgery for the treatment of adult OSAHS, and describe the subjective and objective results of this new surgery combined with uvulopharyngoplasty and inferior turbinate radiofrequency, and assess its safety and feasibility. Pre-operative preparation and risk assessment were conducted following the guidelines for uvulopalatopharyngoplasty surgery. At the follow-up visits 6 and 12 months after surgery, polysomnography and video laryngoscope examination were performed, and the snoring visual analog scale (VAS) and Epworth Sleepiness Scale (ESS) were used to assess the success of the treatment. The median apnea-hypopnea index (AHI) was 16.0 at 6 months and 20.9 at 12 months after the operation. The pre-operative median LSaO2, 74.0, was significantly increased to 82 at 6 months and 80 at 12 months after the operation. VAS was significantly decreased from the pre-operative median of 8.0 to 3.0 and 3.0 at 6 and 12 months after the operation, respectively. ESS was significantly decreased from the pre-operative median of 10.0 to 5.0 and 6.0 at 6 and 12 months after the operation, respectively. The soft palate support surgery is less invasive and has a mild postoperative reaction, few complications and adverse reactions, and good graft safety. Its short-term efficacy is good in patients with moderate to severe OSAHS and velopharyngeal obstruction.

Comparative effects of snoring sound between two minimally invasive surgeries in the treatment of snoring: a randomized controlled trial

Background

Minimally invasive surgeries of the soft palate have emerged as a less-invasive treatment for habitual snoring. To date, there is only limited information available comparing the effects of snoring sound between different minimally invasive surgeries in the treatment of habitual snoring.

Objective

To compare the efficacy of palatal implant and radiofrequency surgery, in the reduction of snoring through subjective evaluation of snoring and objective snoring sound analysis.

Patients and Method

Thirty patients with habitual snoring due to palatal obstruction (apnea-hypopnea index ≤15, body max index ≤30) were prospectively enrolled and randomized to undergo a single session of palatal implant or temperature-controlled radiofrequency surgery of the soft palate under local anesthesia. Snoring was primarily evaluated by the patient with a 10 cm visual analogue scale (VAS) at baseline and at a 3-month follow-up visit and the change in VAS was the primary outcome. Moreover, life qualities, measured by snore outcomes survey, and full-night snoring sounds, analyzed by a sound analytic program (Snore Map), were also investigated at the same time.

Results

Twenty-eight patients completed the study; 14 received palatal implant surgery and 14 underwent radiofrequency surgery. The VAS and snore outcomes survey scores were significantly improved in both groups. However, the good response (postoperative VAS ≤3 or postoperative VAS ≤5 plus snore outcomes survey score ≥60) rate of the palatal implant group was significantly higher than that of the radiofrequency group (79% vs. 29%, P = 0.021). The maximal loudness of low-frequency (40–300 Hz) snores was reduced significantly in the palatal implant group. In addition, the snoring index was significantly reduced in the radiofrequency group.

Conclusions

Both palatal implants and a single-stage radiofrequency surgery improve subjective snoring outcomes, but palatal implants have a greater effect on most measures of subjective and objective snoring. Multi-stage radiofrequency surgery was not tested.

Trial Registration

ClinicalTrials.gov NCT01955083

The surgical treatment of sleep-related upper airway obstruction

BACKGROUND

Obstructive sleep apnea (OSA) is a very common disorder among adults: the prevalence of mild OSA is 20%, and that of moderate or severe OSA is 6% to 7%. Simple snoring is even more common. Conservative treatments such as nocturnal ventilation therapy and oral appliances are successful as long as the patient actually uses them, but they do not eliminate the underlying obstruction of the upper airway.

METHOD

The relevant literature up to 2008 on the surgical treatment of OSA was selectively reviewed.

RESULTS

Five types of surgical treatment for OSA are available, each for its own indications: optimization of the nasal airway to support nasal ventilation therapy, (adeno-)tonsillectomy as first-line treatment for OSA in children, minimally invasive surgery for simple snoring and mild OSA, invasive surgery as first- and second-line treatment for mild OSA, and invasive multilevel surgery as second-line treatment of moderate to severe OSA that remains refractory to ventilation therapy.

CONCLUSION

Surgical treatment for OSA is appropriate for specific indications as a complement to the established conservative treatment methods.

Long-term results of palatal implants for obstructive sleep apnea

Successful results of palatal implants in the treatment of obstructive sleep apnea (OSA) have been reported in the short term; however, there are limited data in the long-term results. The aim of this study was to evaluate the long-term results and to determine factors that predicted the responders in patients undergoing palatal implants in the treatment of OSA. A study was undertaken on 92 OSA patients. Palatal implants were conducted to stiffen the soft palate and data were analyzed. Patients tolerated the procedure well. They were examined between 26 and 32 months after the operation (mean 28.9 ± 4.8). Age range was 25-65 years (38.4 ± 10.5) and BMI was 27.3 ± 2.4 kg/m. The mean preoperative ESS score was 12.3 ± 2.6 and long-term ESS was 7.9 ± 1.8 (p < 0.001). The mean VAS for snoring in the baseline was 8.2 ± 1.2 and long-term VAS was 3.8 ± 2.3 (p < 0.001). The mean preoperative LSAT and long-term LSAT were 87.4 ± 6.7 and 89.2 ± 4.8%, respectively (p < 0.01). The mean AHI decreased from 21.7 ± 6.8 to 10.8 ± 4.8 (p < 0.001). Forty-eight (52.2%) patients had long-term surgical response. Responders had significantly lower preoperative BMI, AHI, and MMP level than non-responders. Implant extrusion occurred in seven patients (7.6%) and palatal abscess in one patient (1.1%). Bleeding and airway obstruction were not encountered. Palatal implants in carefully selected patients suffering from mild OSA, give fairly good long-term results and have a low complication rate.

Surgical options for the treatment of obstructive sleep apnea

Obstructive sleep apnea (OSA) is a prevalent condition characterized by repetitive airway obstruction during sleep with associated increased morbidity and mortality. Although CPAP is the preferred treatment, poor compliance is common. Patients intolerant of conventional OSA medical treatment may benefit from surgical therapy to alleviate pharyngeal obstruction. Case series suggest that maxillomandibular advancement has the highest surgical efficacy (86%) and cure rate (43%). Soft palate surgical techniques are less successful, with uvulopalatopharyngoplasty having an OSA surgical success rate of 50% and cure rate of 16%. Further research is needed to more thoroughly assess clinical outcomes (eg, quality of life, morbidity), better identify key preoperative patient and clinical characteristics that predict success, and confirm long-term effectiveness of surgical modalities to treat OSA.

Effects of soft palate implants on acoustic characteristics of voice and articulation

OBJECTIVE

To evaluate the effects of soft palate implants on voice and articulation.

STUDY DESIGN

Prospective case series.

METHODS

Male subjects (n=23) diagnosed with mild obstructive sleep apnea and/or habitual snoring underwent acoustic analysis with the Multidimensional Voice Program (Kay Multi-Speech Model 3700 Advanced Version; Kay Elemetrics [KayPentax], Lincoln Park, NJ) before and 8 weeks after insertion of palatal implants to determine the effects of soft palate implants on voice and articulation. Sustained vowels (/a/e/u/o/i/) and phonetically balanced carrier sentences were used for acoustic analyses. Parameters measured were fundamental frequency (F0), jitter, shimmer, noise-to-harmonics ratio, Voice Turbulence Index, Soft Phonation Index, degree of voiceless, degree of voice breaks and peak amplitude variation, first formant (F1) and second formant (F2) frequencies, and voice onset time (VOT). F1 and F2 for each vowel were determined using linear predictive analysis on a spectrogram. VOT was measured for the palatal consonant /k/ and the dental consonant /t/ on a wideband spectrogram from a carrier sentence segment that contained a syllable with a stop consonant.

RESULTS

No statistically significant difference was detected in F0, F1, F2, or other MDVP parameters before and after implantation. Average VOT values measured for /t/ were not significantly different. On the other hand, average VOT values of /k/ were found to be significantly shorter.

CONCLUSIONS

Implant insertion had no significant effect on MDVP parameters, F0, F1, or F2. On the other hand, articulation as a function of velar region seemed to be affected because VOT values of velar /k/ were changed.

[Guideline: Treatment of obstructive sleep apnea in adults]

The current guideline discusses conservative and surgical therapy of obstructive sleep apnea (OSA) in adults from the perspective of the ear, nose and throat specialist. The revised guideline was commissioned by the German Society of Ear-Nose-Throat, Head-Neck Surgery (DG HNO KHC) and compiled by the DG HNO KHC's Working Group on Sleep Medicine. The guideline was based on a formal consensus procedure according to the guidelines set out by the German Association of Scientific Medical Societies (AWMF) in the form of a"S2e guideline". Research of the literature available on the subject up to and including December 2008 forms the basis for the recommendations. Evaluation of the publications found was made according to the recommendations of the Oxford Centre for Evidence-Based Medicine (OCEBM). This yielded a recommendation grade, whereby grade A represents highly evidence-based studies and grade D those with a low evidence base.

Effectiveness of Pillar palatal implants for snoring management

Objective: Determine patient factors associated with the success and complications of using the Pillar palatal implants for snoring management.

Study Design: Retrospective series of 79 consecutive adult patients receiving Pillar implants for snoring management between January 2005 and December 2007. Multiple regression analysis was used to determine factors associated with initial and final bed partner satisfaction with the snoring result, and factors associated with Pillar-related complications.

Results: A total of 64 of 79 (81%) bed partners reported snoring improvement in patients after initial Pillar implantation; however, only 31 (39%) were satisfied with the level of reduction. Following secondary procedures, the number of satisfied bed partners improved to 52 (66%). Factors associated with final bed partner satisfaction included lower initial apnea-hypopnea index (AHI) ( P = 0.029), Friedman tongue position I or II ( P = 0.008), and shorter follow-up time ( P = 0.001). Sixteen patients (20%) experienced procedure-related complications. Factors associated with Pillar complications included female gender ( P = 0.001) and placement under general anesthesia ( P = 0.009).

Conclusions: Initial AHI values and tongue position scores are important determinants of final snoring success. Pillar implants placed in women and under general anesthesia may have a higher risk of poor placement and extrusion.

[Update on surgery for obstructive sleep apnea syndrome]

Several indications for surgery for obstructive sleep apnea (OSA) have been clarified within the past 3 years. In pediatric OSA, adenotonsillectomy and tonsillotomy are the most common treatments and are highly effective. In adults, nasal surgery facilitates--and sometimes enables--nasally applied continuous positive airway pressure (CPAP) treatment. Today, minimally invasive treatment options for mild OSA are established. Furthermore, several invasive surgical techniques have proven to be efficient in the treatment of mild to moderate OSA. Above an apnea-hypopnea index of 30, surgery should be done only as secondary treatment in cases of CPAP failure or noncompliance. Special forms of OSA, such as laryngeal OSA and supine OSA, must be kept in mind.

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.

One-year results: palatal implants for the treatment of obstructive sleep apnea

OBJECTIVE

To evaluate long-term effectiveness of palatal implants for treatment of mild to moderate obstructive sleep apnea (OSA).

STUDY DESIGN

A prospective study of 26 referred patients with a pretreatment apnea-hypopnea index (AHI) of 10 to 30 and a body mass index of < or =30, representing an extended follow-up of a subset of 41 patients enrolled in previous short-term trials.

RESULTS

Twenty-one of 26 patients (80.8%) experienced a decrease in AHI. Fifteen of 26 patients (57.7%) had a follow-up AHI <10 at 1 year, whereas 13 patients (50%) had a 50% or greater reduction to an AHI <10 at 1 year. Mean AHI was reduced from 16.5 +/- 4.5 at baseline to 12.5 +/- 10.5 at 3 months (P < 0.014) and to 12.3 +/- 12.7 at 1 year (P < 0.019).

CONCLUSIONS

Patients initially responding to palatal implants with improved AHI maintained improvement through long-term follow-up at 1 year.