Polysomnographic endotypes of successful multilevel upper airway surgery for obstructive sleep apnea

Multilevel upper airway surgery is effective for some patients with obstructive sleep apnea (OSA), but predicting the response to surgery remains a challenge. The underlying endotypes of OSA include upper airway collapsibility, muscle compensation, loop gain, and the arousal threshold. This study aimed to explore the effect of surgery on polysomnography (PSG)-derived OSA endotypes and establish a surgical response prediction model.

Our study included 54 Chinese patients with OSA who underwent multilevel upper airway surgery. Participants underwent PSG before and after surgery with a median follow-up time of 6.5 months. Using AHIBaseline/AHIpost-surgery ≥ 2 and AHIpost-surgery < 10 events/h as criteria, participants were classified as surgery responders and non-responders. The surgical success rate was 26%. These endotypic traits were derived from a standard PSG data by validated methods.

The surgery altered both anatomical and non-anatomical endotypic traits, including increased Vpassive (baseline vs post-surgery: 51.5 [18.7-84.2] vs 86.8 [67.4-93.7] %Veupnea, p < .001), decreased loop gain (baseline vs post-surgery: 0.7 [0.7-0.8] vs 0.6 [0.5-0.6]; p < .001), and a higher arousal threshold (baseline vs post-surgery: 202.9 [183.7-222.0] vs 160.7 [143.9-177.4] %Veupnea; p < .001). However, it did not significantly affect muscle compensation. Fully adjusted logistic regression analyses indicated that a favorable response to surgery was independently associated with a lower LG (OR [CI 95%], 0.1 [0.0-0.5], p = .032). In patients with improved muscle compensation or a more collapsible airway (lower Vpassive), a lower loop gain was more strongly indicative of success. However, when muscle compensation was lower or collapsibility was less severe (higher Vpassive), a lower loop gain was less predictive of success.

This study demonstrated that multilevel upper airway surgery altered both anatomical and non-anatomical endotypes in Chinese patients with OSA. An endotype based regression model may meaningfully predict surgical success.