Effect of Han-uvulopalatopharyngoplasty on flow-mediated dilatation in patients with moderate or severe obstructive sleep apnea syndrome

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.

Long-term outcomes of pharyngoplasty for Obstructive Sleep Apnea Syndrome

<b>Introduction: </b> Pharyngoplasty techniques for the treatment of obstructive sleep apnea syndrome (OSAS) have evolved, which improved the understanding of the anatomy, patient selection, and adoption of functional approaches. </br></br> <b>Aim:</b> To analyze long-term results of pharyngoplasty in OSAS patients. </br></br> <b>Material and methods:</b> Between 2007 and 2021, a total of 234 adult patients with OSAS who had previously failed positive airway pressure (PAP) therapy underwent sleep surgery. Of this group, 75 patients met the criteria of a minimum 5-year follow-up. To date, 25 patients completed the follow-up study protocol, including the medical history, visual analog scale (VAS) for snoring loudness, body mass index (BMI), endoscopy of the upper airways, type III sleep study, and standardized questionnaires including Epworth Sleepiness Scale (ESS) and EQ-5D-5L Euro – Quality of Life Questionnaire. </br></br> <b>Results:</b> The average period of follow-up was 96.80 ± 30.20 months. The mean age of participants was 54.6 ± 14.02 and the mean BMI 30.28 ± 2.74. Patients underwent uvulopalatopharyngoplasty (n = 21) and expansion sphincterpharyngoplasty (n = 4) between 2008–2015. A long-term improvement in sleep parameters was observed for the mean AHI (29.84 ± 20.06before and 19.45 ± 18.53 after surgery, p = 0.0294), and the median VAS (8.13 before and 3.78 after surgery), mean oxygen saturation during sleep 94,5% (IQR 93.0–95.25), and the median ESS score was 6.17 ± 4.57. The majority of patients reported subjective long-term improvement in sleep quality and a reduction of snoring. </br></br> <b>Conclusions:</b> In OSAS patients who failed PAP therapy, pharyngoplasty may provide a long-term improvement in upper airway obstruction during sleep.

Obstructive sleep apnoea syndrome and endothelial function: potential impact of different treatment strategies-meta-analysis of prospective studies

PURPOSE

Previous studies have shown an association between obstructive sleep apnoea syndrome (OSAS) and cardiovascular events. Whether this association is mediated by an impairment of endothelial function, which is itself a driver of elevated cardiovascular risk, has yet to be clarified, as it is the eventual protective role of several OSAS treatments. The aim of our meta-analysis is to evaluate the effect of various OSAS treatments on endothelial function calculated by means of flow-mediated dilatation (FMD).

METHODS

We conducted a meta-analysis of prospective studies including patients affected by mild to severe OSAS treated with continuous positive airway pressure (CPAP), surgery, oral appliance and medical treatments. FMD was measured before and after treatment RESULTS: After pooling results from different treatment strategies, OSAS treatment showed a positive impact on endothelial function (Mean Difference [MD] = 2.58; 95% CI 1.95-3.20; p < 0.00001).

CONCLUSIONS

Our study supports the hypothesis that several modalities of treatment for OSAS positively impact endothelial function. Whether this effect also associates with an improvement of clinical outcomes remains to be ascertained.

Computational fluid dynamics analysis of H-uvulopalatopharyngoplasty in obstructive sleep apnea syndrome

PURPOSE

To explore the impact of H-uvulopalatopharyngoplasty (H-UPPP) in obstructive sleep apnea syndrome (OSAS) and gain insights into the potential mechanism underlying improvement by H-UPPP.

METHODS

In a cohort of 11 OSAS patients, computational fluid dynamics (CFD) models of the upper airway were obtained using commercial software from computed tomography (CT) datasets before and after H-UPPP. Morphological and numerical parameters were respectively computed and compared during the peak tidal inspiratory flow. The correlations among polysomnography endpoints, airway dimensions, and pre- and post-operative airflow properties were analyzed with Spearman's rank correlation.

RESULTS

The preoperative minimum cross-sectional area was significantly increased by 89.56% (p < .05), with a positive correlation to the apnea hypoapnea index (AHI) (r = 0.974). However, the capacity of all pharyngeal regions was not significantly altered (p > .05). Following H-UPPP, we observed a significant increase in pressure and reduction of velocity (p < .05) in the previously constricted areas. The change in pressure and velocity were significantly correlated with AHI (r = 0.922 and r = 0.946, respectively). In addition, the pressure drop in the constricted area, oropharynx, and hypopharynx were also significantly decreased (p < .05).

CONCLUSIONS

H-UPPP is capable of expanding the constricted region of the velopharynx and can decrease the airway resistance which will in turn decrease the workload necessary for breathing and facilitate inspiration.

Which place of pharmacological approaches beyond continuous positive airway pressure to treat vascular disease related to obstructive sleep apnea?

Obstructive sleep apnea (OSA) is characterized by recurrent episodes of partial or complete upper airway obstruction, occurring during sleep, leading to chronic intermittent hypoxia (IH), which harms the cardiovascular system. OSA is associated with both functional and structural vascular alterations that contribute to an increased prevalence of fatal and non-fatal cardiovascular events. OSA is a heterogeneous disease with respect to the severity of hypoxia, the presence of daytime symptoms, obesity, and cardiovascular comorbidities. Various clusters of OSA phenotypes have been described leading to more highly personalized treatment. The aim of this review is to describe the various therapeutic strategies including continuous positive airway pressure (CPAP), oral appliances, surgery, weight loss, and especially pharmacological interventions that have been evaluated to reduce vascular alterations in both OSA patients and preclinical animal models. Conventional therapies, predominantly CPAP, have a limited impact on vascular alterations in the presence of co-morbidities. A better knowledge of pharmacological therapies targeting IH-induced vascular alterations will facilitate the use of combined therapies and is crucial for designing clinical trials in well-defined OSA phenotypes.

Surgical Treatment of OSA on Cardiovascular Outcomes: A Systematic Review

BACKGROUND

OSA is an increasingly prevalent clinical problem with significant effects on quality of life and cardiovascular risk. Surgical therapy represents an important treatment for those unable to use positive airway pressure. This systematic review examines the available cardiovascular risk reduction data for the surgical treatment of OSA.

METHODS

A comprehensive literature search was performed. Articles were included if they met the following criteria: (1) the sample population consisted of adults (age ≥ 18 years); (2) OSA was diagnosed according to a sleep study; (3) surgical intervention was performed for OSA; and (4) one or more physical or biochemical cardiovascular and/or cerebrovascular variables was measured preoperatively and at ≥ 14 days postoperatively.

RESULTS

Thirty-three articles were included. The majority of studies were case series and cohort studies (42% and 44%, respectively), with wide-ranging follow-up periods (4 weeks-9 years) and sample sizes (range, 6-10,339; median, 34). The following classes of surgical intervention were examined: pharyngeal surgery (n = 23), tracheostomy (n = 6), maxillomandibular advancement (n = 3), and hypoglossal nerve stimulation (n = 1). In total, 19 outcome measures were assessed. Tracheostomy was most consistently associated with improvement in cardiovascular end points. Pharyngeal surgeries (eg, uvulopalatopharyngoplasty) were variably associated with improvement in cardiovascular end points.

CONCLUSIONS

The published literature examining cardiovascular end points following surgical treatment of OSA is limited and generally of poor quality. However, available data from mainly small and observational studies suggest that surgical treatment of OSA may provide improvement in some cardiovascular end points. Larger, randomized, and prospective trials with more rigorous study designs are needed.

TRIAL REGISTRY

PROSPERO International Prospective Register of Systemic Reviews (PROSPERO 42016040120).

Patients with Obstructive Sleep Apnea Display Decreased Flow-Mediated Dilatation: Evidence from a Meta-Analysis

Background

Endothelial dysfunction, which can be measured by flow-mediated dilatation (FMD), is an early clinical marker of atherosclerosis, which is considered to be the main cause of the observed cardiovascular complications in obstructive sleep apnea (OSA) patients. The association between OSA and endothelial dysfunction has been reported in a number of studies; however, the findings are not entirely consistent. Our aim was to meta-analytically synthesize the existing evidence to explore the association between OSA and endothelial dysfunction.

Material/Methods

Data from PubMed, EMBASE, the Cochrane library, and Google Scholar for all trials that investigated the relationship between endothelial dysfunction and OSA were systematically reviewed. The minimum inclusion criteria for the studies were reporting of the Apnea-Hypopnea Index (AHI) and FMD measurements (as an indicator of endothelial dysfunction) for both OSA and control groups. Data from case-control studies that met the inclusion criteria were extracted.

Results

Twenty-eight studies comprising a total of 1496 OSA patients and 1135 controls were included in the meta-analysis. A random-effects model was used. The weighted mean difference in the FMD measurements was −3.07 and the 95% confidence interval was −3.71 to −2.43 (P<0.01). Meta-regression analysis showed that age, sex, body mass index (BMI), blood pressure, glucose, high-density lipoprotein (HDL) cholesterol, and low-density lipoprotein (LDL) cholesterol did not explain the heterogeneity.

Conclusions

This meta-analysis showed that patients with OSA have decreased FMD, which may contribute to the development of atherosclerosis.

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.