Hypopharyngeal airway surgery

Strategies in the clinical diagnosis and surgical treatment of OSAHS with multilevel obstruction

OBJECTIVE

To examine the safety and effectiveness of individualized treatment strategies that include three principles (security, top-down and priority) for patients with obstructive sleep apnoea hypopnea syndrome (OSAHS) and multilevel obstruction who decline therapy with continuous positive airway pressure (CPAP).

METHODS

Patients with OSAHS and upper airway obstruction who were diagnosed with multilevel obstruction were included in this retrospective study. Patients were evaluated for the degree of obstruction in each level. Three principles were followed in planning the appropriate intervention level and measures to reduce perioperative risks. Polysomnography indices and Epworth sleepiness scores were used to evaluate the efficacy of surgery and improvement in patients' sleepiness at ≥3 months post-surgery.

RESULTS

Among 51 patients with OSAHS and multilevel obstruction, three were treated with CPAP, 41 were treated with nasopharyngeal surgery, and seven were treated with oropharyngeal surgery. No severe complications were reported. Following surgery, apnoea hypopnea index and Epworth sleepiness scores were significantly reduced, and the lowest oxygen saturation level was significantly increased.

CONCLUSION

The three-principle strategy was safe and effective in planning surgical treatments for patients with OSAHS and multilevel obstruction.

The effect of geniglossal advancement on airway flow using a computational flow dynamics model

OBJECTIVES/HYPOTHESIS

Obstructive sleep apnea (OSA) is a sleep disorder caused by partial or complete collapse of the pharyngeal airway. Genioglossal advancement (GGA) is a well-tolerated surgical procedure intended to address hypopharyngeal collapse, yet there are few studies that monitor changes in airflow dynamics at this site. Computation fluid dynamics (CFD) utilizes airflow simulation to predict changes in airflow after anatomic manipulation.

STUDY DESIGN

We investigated the change in volume and airflow dynamics of the pharyngeal airway after GGA in a cadaveric model.

METHODS

We performed serial GGA from 1 mm (control) to 3, 7, and 9 mm on a lightly preserved cadaver. After each intervention, we performed high-resolution computed tomography scans, reconstructed the pharyngeal airway, and quantified airspace volume and CFD analysis with both laminar and large eddy simulation models.

RESULTS

Airway volume increased with linear GGA. In both CFD simulation models, velocity increased and pressure decreased after 9-mm advancement secondary to increased airway diameter and less abrupt changes in airway geometry.

CONCLUSIONS

These results suggest that GGA may be effective in increasing airway volume and flow to address hypopharyngeal obstruction in OSA.

Obstructive sleep apnea syndrome (OSAS). Review of the literature

Obstructive sleep apnea and hypopnea syndrome is characterized by repeated airway collapse during sleep. The literature describes multiple causes of the disease. The main cause is a reduction of the expansion forces of the pharyngeal dilator muscles, as in situations of genioglossal muscle dysfunction, and discoordination between the inspiratory activity of the muscle and respiratory effort, which play an important role in progression of the disease. Other described causes are soft tissue disorders, such as macroglossia or tonsillar hypertrophy, and skeletal structural alterations such as micrognathia and retrognathia. The syndrome is also more frequent in obese people, where the accumulation of fat in the neck region produces narrowing of the pharyngeal airway, thereby diminishing the passage of air. This review focuses on the pathogenesis, epidemiology, main features and diagnosis of the disease, and on its main forms of treatment.

Lateral oropharyngeal wall and supraglottic airway collapse associated with failure in sleep apnea surgery

OBJECTIVES/HYPOTHESIS

To identify patterns of airway collapse during preoperative drug-induced sleep endoscopy (DISE) as predictors of surgical failure following multilevel airway surgery for patients with obstructive sleep apnea-hypopnea syndrome (OSAHS).

STUDY DESIGN

Retrospective clinical chart review.

METHODS

Medical records of patients who underwent site-specific surgical modification of the upper airway for treatment of OSHAS were reviewed. Patients were included in this study if they had a preoperative airway evaluation with DISE as well as preoperative and postoperative polysomnography. Airway obstruction on DISE was described according to airway level, severity, and axis of collapse. Severe airway obstruction was defined as >75% collapse on endoscopy. Surgical success was described as a postoperative apnea-hypopnea index (AHI) of <20 and a >50% decrease in preoperative AHI.

RESULTS

A total of 34 patients were included in this study. The overall surgical success rate was 56%. Surgical success (n = 19) and surgical failure (n = 15) patients were similar with regard to age, gender, body mass index, preoperative AHI, Friedman stage, adenotonsillar grades, and surgical management. DISE findings in the surgical failure group demonstrated greater incidence of severe lateral oropharyngeal wall collapse (73.3% vs. 36.8%, P = .037) and severe supraglottic collapse (93.3% vs. 63.2%, P = .046) as compared to the surgical success group.

CONCLUSIONS

The presence of severe lateral pharyngeal wall and/or supraglottic collapse on preoperative DISE is associated with OSAHS surgical failure. The identification of this failure-prone collapse pattern may be useful in preoperative patient counseling as well as in directing an individualized and customized approach to the treatment of OSHAS.