Updated Nasal Surgery for Obstructive Sleep Apnea

Clinical Practice Guideline: Clinical Efficacy of Nasal Surgery in the Treatment of Obstructive Sleep Apnea

Obstructive sleep apnea (OSA) is a common disorder characterized by upper airway obstruction during sleep. To reduce the morbidity of OSA, sleep specialists have explored various methods of managing the condition, including manifold positive airway pressure (PAP) techniques and surgical procedures. Nasal obstruction can cause significant discomfort during sleep, and it is likely that improving nasal obstruction would enhance the quality of life and PAP compliance of OSA patients. Many reliable studies have offered evidence to support this assumption. However, few comprehensive guidelines for managing OSA through nasal surgery encompass all this evidence. In order to address this gap, the Korean Society of Otorhinolaryngology-Head and Neck Surgery (KORL-HNS) and the Korean Society of Sleep and Breathing designated a guideline development group (GDG) to develop recommendations for nasal surgery in OSA patients. Several databases, including OVID Medline, Embase, the Cochrane Library, and KoreaMed, were searched to identify all relevant papers using a predefined search strategy. The types of nasal surgery included septoplasty, turbinate surgery, nasal valve surgery, septorhinoplasty, and endoscopic sinus surgery. When insufficient evidence was found, the GDG sought expert opinions and attempted to fill the evidence gap. Evidence-based recommendations for practice were ranked according to the American College of Physicians' grading system. The GDG developed 10 key action statements with supporting text to support them. Three statements are ranked as strong recommendations, three are only recommendations, and four can be considered options. The GDG hopes that this clinical practice guideline will help physicians make optimal decisions when caring for OSA patients. Conversely, the statements in this guideline are not intended to limit or restrict physicians' care based on their experience and assessment of individual patients.

The Role of Isolated Nasal Surgery in Obstructive Sleep Apnea Therapy-A Systematic Review

Nasal obstruction is believed to play a significant role in the pathophysiology and management of obstructive sleep apnea (OSA). However, controversy remains about the ability of isolated nasal surgery to improve OSA. The objective of this systematic review is to give an updated overview of the literature on whether isolated nasal surgery can improve OSA subjectively (Epworth Sleepiness Scale (ESS)) and/or objectively (polysomnography (PSG)). Methods: A systematic review was performed searching the electronic databases PubMed, Embase.com (accessed on 20 June 2022) Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Trials (CENTRAL) up to 20 June 2022. Eligible studies were reviewed for methodological quality using the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Results: Twenty-one studies met the inclusion criteria. The majority of the included studies reported no significant reduction in the apnea-hypopnea index (AHI) after isolated nasal surgery in patients with OSA. The meta-analysis suggests that the AHI slightly decreases after nasal surgery. The ESS was significantly lower after nasal surgery in eighteen studies. Conclusion: Based on the present analysis of objective outcomes, isolated nasal surgery did not improve the AHI significantly in the majority of the studies. The meta-analysis suggests a slight decrease in AHI after nasal surgery, but this reduction is not clinically relevant in terms of treatment success. Isolated nasal surgery should therefore not be recommended as a first-line treatment for OSA. Because of high study heterogeneity, these results should be interpreted with caution. Isolated nasal surgery can possibly improve OSA subjectively. Perhaps only OSA patients with complaints of nasal obstruction or OSA patients experiencing difficulty with continuous positive airway pressure (CPAP) compliance would benefit from isolated nasal surgery.

Aerodynamics Analysis of the Impact of Nasal Surgery on Patients with Obstructive Sleep Apnea and Nasal Obstruction

OBJECTIVE

The purpose of this study was to evaluate the effects of nasal surgery on airflow characteristics in patients with obstructive sleep apnea (OSA) by comparing the alterations of airflow characteristics within the nasal and palatopharyngeal cavities.

METHODS

Thirty patients with OSA and nasal obstruction who underwent nasal surgery were enrolled. A pre- and postoperative 3-dimensional model was constructed, and alterations of airflow characteristics were assessed using the method of computational fluid dynamics. The other subjective and objective clinical indices were also assessed.

RESULTS

By comparison with the preoperative value, all postoperative subjective symptoms statistically improved (p < 0.05), while the Apnea-Hypopnea Index (AHI) changed little (p = 0.492); the postoperative airflow velocity and pressure in both nasal and palatopharyngeal cavities, nasal and palatopharyngeal pressure differences, and total upper airway resistance statistically decreased (all p < 0.01). A significant difference was derived for correlation between the alteration of simulation metrics with subjective improvements (p < 0.05), except with the AHI (p > 0.05).

CONCLUSION

Nasal surgery can decrease the total resistance of the upper airway and increase the nasal airflow volume and subjective sleep quality in patients with OSA and nasal obstruction. The altered airflow characteristics might contribute to the postoperative reduction of pharyngeal collapse in a subset of OSA patients.

Adult sleep apnea and tonsil hypertrophy: should pharyngoplasty be associated with tonsillectomy?

PURPOSE

Velopharyngoplasty and palatine tonsillectomy are at the very heart of the surgical treatment of obstructive sleep apnea syndrome (OSAS) care. In cases of major tonsil hypertrophy, we evaluated the relevance of associating soft palate surgery with palatine tonsillectomy, independent of the soft palate length.

METHODS

We conducted a retrospective single-center study in OSAS patients with grade III or IV tonsils treated with tonsillectomy. Preoperative assessment included an upper airway examination performed while the patient was awake, a polysomnography and a drug-induced sedation endoscopy (DISE). Surgical efficacy was assessed on postoperative polysomnography. Success was considered when the postoperative apnea-hypopnea index (AHI) was less than 20 events/h with a 50% reduction. We compared palatine tonsillectomy efficacy alone (group A) and associated with soft palate surgery (group B).

RESULTS

We analyzed 33 patients who had undergone surgery between December 2006 and May 2018. Their preoperative mean BMI and mean AHI were 27.3 ± 7.5 kg/m² and 38.6 ± 21.4 events/h, respectively. The two groups (A, n = 18 and B, n = 15) were clinically comparable. The success rate was 72.2% in group A and 60% in group B. There was no statistically significant difference between the two groups (p > 0.1).

CONCLUSIONS

According to this study, in our institution, in cases of major tonsillar hypertrophy, simultaneous soft palate surgery had no significant impact on the success rate, regardless of soft palate length. Associating soft palate surgery with palatine tonsillectomy does not seem mandatory to increase the success rate.

LEVEL OF EVIDENCE

III. Retrospective comparative study.

Analyses of aerodynamic characteristics of the oropharynx applying CBCT: obstructive sleep apnea patients versus control subjects

OBJECTIVES

To determine the most relevant aerodynamic characteristic of the oropharynx related to the collapse of the upper airway in obstructive sleep apnea (OSA) patients; and to determine the correlation between the most relevant aerodynamic characteristic(s) of the oropharynx and anatomical characteristics of the oropharynx in OSA patients.

METHODS

31 mild to moderate OSA patients (mean ± SD age = 43.5 ± 9.7 years) and 13 control subjects (mean ± SD age = 48.5 ± 16.2 years) were included in this prospective study. The diagnosis of OSA patients was based on an overnight polysomnographic recording. To exclude the presence of OSA in the control subjects, they were asked to fill out a validated questionnaire to determine the risk of OSA. NewTom5G cone beam CT (CBCT) scans were obtained from both OSA patients and control subjects. Computational models of the oropharynx were reconstructed based on CBCT images. The aerodynamic characteristics of the oropharynx were calculated based on these computational models. Pearson correlation analysis was used to analyse the correlation between the most relevant aerodynamic characteristic(s) and anatomical characteristics of the oropharynx in OSA patients.

RESULTS

Compared with controls, the airway resistance during expiration (R_ex) of the OSA patients was significantly higher (p = 0.04). There was a significant negative correlation between R_ex and the minimum cross-sectional area (CSA_min) of the oropharynx (r = -0.41, p = 0.02), and between R_ex and the volume of the oropharynx (r = -0.48, p = 0.01) in OSA patients. After excluding an outlier, there is only significant correlation between R_ex and the CSA_min of the oropharynx (r = -0.45, p = 0.01).

CONCLUSIONS

Within the limitations of this study, we concluded that the most relevant aerodynamic characteristic of the oropharynx in the collapse of the upper airway in OSA patients is R_ex. Therefore, the repetitive collapse of the upper airway in OSA patients may be explained by a high R_ex, which is related to the CSA_min of the oropharynx.