UVULOPALATOPHARYNGOPLASTY IN OBSTRUCTIVE APNEA - VALUE OF PREOPERATIVE LOCALIZATION OF SITE OF UPPER AIRWAY NARROWING DURING SLEEP

We hypothesized that those obstructive sleep apnea (OSA) patients with upper airway collapse during sleep within the transpalatal airway would have a more favorable response to uvulopalatopharyngoplasty (UPP) than those patients with obstruction within the hypopharyngeal airway. We tested this hypothesis in seven OSA patients with transpalatal and seven with hypopharyngeal obstruction undergoing UPP. Preoperatively the apnea/hypopnea index (AHI) was different between palatal and hypopharyngeal obstructors, 37.8 +/- 6.0 (+/- SEM) and 63.9 +/- 6.3, respectively (p < 0.05), but the apnea-associated arterial oxygen desaturation and the lowest sleep saturation level were not different between the two groups. Postoperatively the AHI was 17.6 +/- 7.2 in the palatal obstructors and 40.3 +/- 15.6 in the hypopharyngeal obstructors (both p < 0.05 from preoperative AHI). The palatal obstructors had a significant decrease in the percentage of sleep time spent apneic and the hypopharyngeal obstructors had a significant decrease in the hypopnea, but not apnea, time following surgery. The palatal obstructors had a significantly higher postoperative arterial oxygen saturation than the hypopharyngeal obstructors. Two hypopharyngeal obstructors worsened postoperatively. In addition we found that regardless of the site of the obstruction preoperatively, all obstructions occurred at the level of the palate postoperatively. We conclude that patients with preoperative transpalatal obstruction had diminution in obstructive apneas and those with hypopharyngeal obstruction had diminution in hypopneas but not apneas. Oxygenation was better postoperatively in the palatal obstructors, and none worsened postoperatively. These results suggest that identification of the site of upper airway obstruction in OSA may be beneficial. We anticipate that these findings will lead to further study of the benefit of obstruction site identification and the role of this principle in designing specific operative approaches to OSA at different pharyngeal sites.