Patient selection for upper airway stimulation: is concentric collapse in sleep endoscopy predictable?

Purpose: Upper airway stimulation is an effective treatment option for obstructive sleep apnea after failure of positive airway pressure (PAP) therapy. To ensure a therapeutic effect, closed-loop hypoglossal nerve implants require the absence of palatal complete concentric collapse during sleep endoscopy. The frequency and potential predictors of this exclusion criterion are unknown. Methods: Over a 2-year period, 74 consecutive patients with sleep apnea who sought PAP alternatives were evaluated with sleep endoscopy using propofol. The influence of sleep apnea severity and anthropometric characteristics as predictors of sleep endoscopy results was investigated. Results: One-fifth of all patients showed a concentric collapse. Gender and age did not predict the presence of concentric collapse, but higher body mass and apnea hypopnea index values were predictive (p = 0.011; e.g., 0.026). The most commonly used body mass index values for upper airway stimulation indications demonstrated acceptable specificity (BMI 32 kg/m² 0.71, 95 % confidence interval = 0.57, 0.82; e.g., 35 kg/m² 0.81, 95 % confidence interval = 0.69, 0.90). Despite the association with overweight, a significant number of severely overweight patients had no concentric palatal collapse. Conclusions: Concentric collapse is a somewhat common condition encountered in sleep endoscopy evaluations of PAP alternatives, and cannot be sustainably predicted with anthropometric or sleep assessments. Sleep surgeons should be aware of the possibility of concentric collapse, especially in candidates who are more overweight and have severe sleep apnea. Sleep endoscopy can be useful for providing information about continuous positive airway pressure (CPAP) alternatives or to motivate patient adherence to treatment.