The Combination of Anatomy and Genioglossus Activity in Predicting the Outcomes of Velopharyngeal Surgery

Postoperative Apnea-Hypopnea Index Prediction of Velopharyngeal Surgery Based on Machine Learning

Objective

To investigate machine learning-based regression models to predict the postoperative apnea-hypopnea index (AHI) for evaluating the outcome of velopharyngeal surgery in adult obstructive sleep apnea (OSA) subjects.

Study Design

A single-center, retrospective, cohort study.

Setting

Sleep medical center.

Methods

All subjects with OSA who underwent velopharyngeal surgery followed for 3 to 6 months were enrolled in this study. Demographic, polysomnographic, and anatomical variables were analyzed. Compared with traditional stepwise linear regression (LR) algorithm, machine learning algorithms including artificial neural network (ANN), support vector regression, K-nearest neighbor, random forest, and extreme gradient boosting were utilized to establish the regression model. Surgical success was defined as a ≥50% reduction in AHI to a final AHI of <20 events/h.

Results

A total of 152 OSA adult patients (median [interquartile range] age = 40 [35, 48] years, male/female = 136/16) were included in this study. The ANN model achieved the highest performance with a coefficient of determination (R 2) of 0.23 ± 0.05, a root mean square error of AHI of 10.71 ± 1.01 events/h, an accuracy for outcomes classification of 81.3% ± 1.2% and an area under the receiver operating characteristic of 74.6% ± 1.9%, whereas for LR model, they were 0.094 ± 0.06, 11.61 ± 0.76 events/h, 71.7% ± 1.5% and 68.8% ± 2.9%, respectively.

Conclusion

The machine learning-based model exhibited excellent performance for predicting postoperative AHI, which is helpful in guiding patient selections and improving surgery outcomes.

Predictors of Success of Pharyngeal Surgery in the Treatment of Obstructive Sleep Apnea: A Narrative Review

(1) Background: This narrative review aims to explore the predictors of success for pharyngeal surgery in the treatment of obstructive sleep apnea (OSA). An extensive literature search was conducted, identifying relevant studies published up to June 2023, utilizing various databases and key search terms related to OSA, surgical interventions, and predictors of success. The review encompasses both retrospective and prospective studies, case series, and cohort studies to provide a broad understanding of the topic; (2) Methods: Review of English scientific literature on phenotypes of OSA related to predictors of success of pharyngeal surgery; (3) Results: Of 75 articles, 21 were included, in these the following were determined to be factors for surgical success: body mass index (BMI) (8 articles), apnea/hypopnea index (AHI) (8 articles), cephalometry (8 articles), palatine tonsil size (7 articles), Modified Mallampati score (2 articles), genioglossus electromyography (2 articles), Friedman score or upper airway anatomy (3 articles), nasopharyngolaryngoscopy (2 articles), drug-induced sleep endoscopy (DISE) (1 article), oral cavity anatomy (1 article) and oxygen desaturation index (ODI) (1 article); (4) Conclusions: The lack of standardized protocols for the indication of pharyngeal surgery is a reality, however identifying known predictors of surgical success may facilitate homogenizing indications.

Representation of Race and Sex in Sleep Surgery Studies

OBJECTIVE

Obstructive sleep apnea (OSA) is a highly prevalent disorder with many treatment modalities, including surgical intervention. While OSA is known to be more prevalent in males and Black Americans, the representation of race and sex in sleep surgery studies is unknown. The aim of this systematic review is to assess the race and sex demographics represented in sleep surgery studies relative to known OSA demographics.

DATA SOURCES

PubMed, MEDLINE, and OVID databases.

REVIEW METHODS

A systematic review was conducted to identify studies published between 2016 and 2020 that investigated sleep outcomes following nonnasal surgical intervention for OSA in adults. Pooled racial, ethnic, and sex data of the enrolled subjects in selected studies were analyzed.

RESULTS

The 148 included studies comprised 13,078 patients. Of the 137 studies that reported sex, 84.0% of participants were male, exceeding the population prevalence of OSA in males, which is estimated at 66%. Only 13 studies reported racial/ethnic demographic data. Of these, 87.8% of patients were White. Out of 30 studies of primarily American patients, only 4 reported race demographic data, with an average of 82.8% White participants.

CONCLUSION

There is a racial/ethnic and sex inclusion bias among sleep surgery studies. Future studies should better document the demographics of enrolled participants as well as recruit participants who better represent the demographics of adults with OSA in the general population.

Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment

INTRODUCTION

This systematic review provides supporting evidence for the accompanying clinical practice guideline on the referral of adults with obstructive sleep apnea (OSA) for surgical consultation.

METHODS

The American Academy of Sleep Medicine commissioned a task force of experts in sleep medicine. A systematic review was conducted to identify studies that compared the use of upper airway sleep apnea surgery or bariatric surgery to no treatment as well as studies that reported on patient-important and physiologic outcomes pre- and postoperatively. Statistical analyses were performed to determine the clinical significance of using surgery to treat obstructive sleep apnea in adults. Finally, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) process was used to assess the evidence for making recommendations.

RESULTS

The literature search resulted in 274 studies that provided data suitable for statistical analyses. The analyses demonstrated that surgery as a rescue therapy results in a clinically significant reduction in excessive sleepiness, snoring, blood pressure (BP), apnea-hypopnea index (AHI), respiratory disturbance index (RDI), and oxygen desaturation index (ODI); an increase in lowest oxygen saturation (LSAT) and sleep quality; and an improvement in quality of life in adults with OSA who are intolerant or unaccepting of positive airway pressure (PAP) therapy. The analyses demonstrated that surgery as an adjunctive therapy results in a clinically significant reduction in optimal PAP pressure and improvement in PAP adherence in adults with OSA who are intolerant or unaccepting of PAP due to side effects associated with high pressure requirements. The analyses also demonstrated that surgery as an initial treatment results in a clinically significant reduction in AHI/RDI, sleepiness, snoring, BP, and ODI and an increase in LSAT in adults with OSA and major anatomical obstruction. Analysis of bariatric surgery data showed a clinically significant reduction in BP, AHI/RDI, sleepiness, snoring, optimal PAP level, BMI, and ODI and an increase in LSAT in adults with OSA and obesity. Analyses of very limited evidence suggested that upper airway surgery does not result in a clinically significant increase in risk of serious persistent adverse events and suggested that bariatric surgery may result in a clinically significant risk of iron malabsorption that may be managed with iron supplements. The task force provided a detailed summary of the evidence along with the quality of evidence, the balance of benefits and harms, patient values and preferences, and resource use considerations.

CITATION

Kent D, Stanley J, Aurora RN, et al. Referral of adults with obstructive sleep apnea for surgical consultation: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2021;17(12):2507-2531.

Short-term postoperative CPAP may improve the outcomes of velopharyngeal surgery for obstructive sleep apnea

PURPOSE

To evaluate the effects of short-term postoperative continuous positive airway pressure (CPAP) on the outcomes of velopharyngeal surgery for obstructive sleep apnea (OSA).

MATERIALS AND METHODS

This study included 119 OSA patients who underwent velopharyngeal surgery. Based on the results of postoperative pulse oximetry, the patients were divided into 3 groups: intervention, control, and observation. Patients with oxygen desaturation index (ODI) > 10 and lowest SpO₂ < 90% were randomly assigned to the CPAP intervention group and non-CPAP control. Patients with ODI ≤10 or lowest SpO₂ ≥ 90% were assigned to the non-CPAP observation group. Patients in the intervention group completed at least 3 months of CPAP treatment. Postoperative polysomnography data were compared to assess the difference of prognosis between the three groups.

RESULTS

Baseline data showed no significant differences between the three groups except the observational group showed a significantly larger tonsil size relative to the intervention and control groups. However, there was no significant difference in terms of tonsil size between the control and intervention groups. The surgical success rate of the intervention group was 80.65%, whereas it was 55.17% in the control group, with significant difference. The success rate of the observation group was 85.71% which was significantly different from that of the control group, but not the intervention group.

CONCLUSION

Short-term postoperative CPAP treatment may improve the outcomes of velopharyngeal surgery for OSA in patients who have respiratory events related hypoxia after surgery. Further studies are necessary for the underlying mechanisms.

The Role of Genioglossus Activity in Predicting Uvulopalatopharyngoplasty Outcomes

OBJECTIVE

The aim of this study was to evaluate the association between genioglossus activity during sleep onset and the outcome of uvulopalatopharyngoplasty (UPPP) in patients with obstructive sleep apnea.

STUDY DESIGN

Case series with planned data collection.

SETTING

Sleep medical center.

SUBJECTS AND METHODS

Forty-four patients with obstructive sleep apnea underwent overnight polysomnography with synchronous genioglossus electromyography (GGEMG) with intraoral electrodes. In addition, all patients underwent revised UPPP with uvula preservation and were followed up with polysomnography at least 3 months after surgery.

RESULTS

Twenty-five patients (56.8%) were responders. Multiple regression analysis revealed that increasing tonsil size (odds ratio [OR], 0.086; P = .038) and higher sleep-onset GGEMG (OR, 0.664; P = .04) were significant predictors for surgical success. The area under the receiver operating characteristic curve was 0.942 (OR, 0.040; P < .001) for those predictors, 0.884 for GGEMG, and 0.848 for tonsil size. Moreover, all patients were divided into 4 groups according to tonsil size and sleep-onset GGEMG. The success rate of patients with tonsil size III or IV and sleep-onset GGEMG >11.20% (maximal GGEMG) was optimal (92.9%, 13 of 14), while the success rate of patients with tonsil size I or II and sleep-onset GGEMG ≤11.20% was 0% (0 of 10).

CONCLUSIONS

Sleep-onset GGEMG and tonsil size are both important in deciding outcomes of UPPP. Patients with tonsil size III or IV and higher sleep onset may be more suitable candidates for UPPP because of the higher probability of surgical success.

Five-Year Objective and Subjective Outcomes of Velopharyngeal Surgery for Patients with Obstructive Sleep Apnea

OBJECTIVE

To assess the long-term effects of velopharyngeal surgery on objective and subjective symptoms in patients with obstructive sleep apnea (OSA).

STUDY DESIGN

Prospective cohort study.

SETTING

University medical center.

SUBJECTS AND METHODS

Eighty-six patients with OSA underwent velopharyngeal surgery, which consisted of revised uvulopalatopharyngoplasty with uvula preservation, with or without concomitant transpalatal advancement pharyngoplasty. The results from polysomnography and the Epworth Sleep Scale after 6 months and 5 years were compared with baseline. Baseline variables were compared between responders and nonresponders.

RESULTS

Sixty-three patients were successfully followed up at the end of study. The surgical success rate after 6 months and 5 years was 66.67% (42 of 63) and 60.32% (38 of 63), respectively, with no significant difference (P = .459). The apnea-hypopnea index and Epworth Sleep Scale dramatically decreased from baseline after 6 months and 5 years in responders and nonresponders (P < .001 for all). As compared with nonresponders, the responders exhibited larger tonsil size, higher nocturnal lowest oxygen desaturation, lower CT90 (percentage of time with oxygen saturation <90%), and shorter MH (vertical distance between the lower edge of the mandible and hyoid in the midsagittal plane of computed tomography). Tonsil size and CT90 showed significant predictive value for surgery success (P < .001 for both).

CONCLUSION

Velopharyngeal surgery was effective in improving nocturnal respiration and excessive daytime sleepiness in patients with OSA at 6-month and 5-year follow-up. Tonsil size and CT90 could be predictors for surgery responders.

Analysis of the myoelectric characteristics of genioglossus in REM sleep and its improvement by CPAP treatment in OSA patients

OBJECTIVES

To reveal the characteristics of genioglossus (GG) activation in moderate and severe obstructive sleep apnea (OSA) patients during rapid eye movement (REM) sleep compared with non-rapid eye movement (NREM) sleep and to determine whether continuous positive airway pressure (CPAP) could improve GG activation in OSA patients during sleep.

METHODS

All subjects underwent polysomnography (PSG) with synchronous GG electromyography (GGEMG) recording with intra-oral surface electrodes at baseline on the first night. Only those subjects diagnosed with moderate and severe OSA were included and were manually titrated with CPAP to achieve a therapeutic pressure (Pt) with GGEMG recording on the second night.

RESULTS

Nine OSA patients and six normal controls were analyzed in this study. The tonic GGEMG was higher in OSA patients during wakefulness (p = 0.003) and NREM sleep (p = 0.015), but it was not higher in REM sleep (p = 0.862). The average phasic activity of OSA patients was significantly higher in all stages, including wakefulness (p = 0.007), NREM sleep (p = 0.005), and REM sleep (p = 0.021). The peak phasic GGEMG was not different in wakefulness compared with normal controls (p = 0.240), but it was higher in OSA patients in NREM sleep (p = 0.001) and REM sleep (p = 0.021), and it was significantly reduced by using CPAP during sleep (NREM sleep: p = 0.027; REM sleep: p = 0.001).

CONCLUSIONS

Our results demonstrate that GG activation during NREM and REM sleep is associated with component differences. The tonic component of GGEMG exhibited less of a compensatory increase compared with the phasic component in REM sleep, suggesting that it may be one of the pathological mechanisms of UA collapsibility in REM sleep. In addition, treatment with CPAP can normalize GGEMG activity and mostly reduced the peak phasic GGEMG during sleep.

Long-term Efficacy of Uvulopalatopharyngoplasty among Adult Patients with Obstructive Sleep Apnea: A Systematic Review and Meta-analysis

OBJECTIVES

To evaluate the long-term efficacy and potential predictors of uvulopalatopharyngoplasty (UPPP) among adult patients with obstructive sleep apnea (OSA).

DATA SOURCES

A systematic search was conducted through PubMed/Medline, Embase, Web of Science, and the Cochrane Library until December 2018.

REVIEW METHODS

Full-text articles were selected that studied adult patients who underwent single-level UPPP or its modification for OSA and had a long-term follow-up (at least 34 months) with objective sleep study results. Studies that had no objective outcomes or performed other surgical procedures for OSA were excluded.

RESULTS

Of 2600 studies, 11 were included. Meta-analysis comparing long-term post- and preoperative outcomes showed significant improvements, with an 15.4 event/h (46.1%) decrease of apnea-hypopnea index. Compared with the short-term outcomes (3-12 months), the long-term outcomes were less effective, with apnea-hypopnea index increasing 12.3 events/h (63.8%) and the surgical response decreasing from 67.3% to 44.35%. Subanalysis of individual patient data showed significant correlations of baseline body mass index, lowest arterial oxygen saturation, and proportion of sleep time with oxygen saturation <90% with long-term surgical response.

CONCLUSIONS

Despite the surgical efficacy decreasing over time, UPPP and its modification are an effective surgical method for adult OSA in both the short term and the long term after the surgery. Baseline body mass index, lowest arterial oxygen saturation, and proportion of sleep time with oxygen saturation <90% were potentially predictive for long-term surgical response. Case-control studies of the long-term surgical effect of OSA are needed.