The relationship between the duration of obstructive respiratory events and outcomes of multilevel upper airway surgery in patients with obstructive sleep apnea.

We aimed to examine whether the duration of respiratory events and related oximetric values are associated with outcomes of multilevel upper airway surgery in patients with moderate-severe obstructive sleep apnea (OSA). The records of patients with a preoperative apnea-hypopnea index (AHI) >15 events/h, who underwent uvulopharyngopalatoplasty plus tongue base suspension with or without septoplasty between 2012 and 2014, were reviewed retrospectively. If the postoperative 6th month AHI was <20 events/h with at least a 50 % reduction from preoperative rates, the outcome of surgery was regarded as successful, otherwise, as failure. To calculate factors predictive of surgical outcomes, a receiver operating characteristic (ROC) analysis was performed. Logistic regression analyses were utilized to obtain the Odds ratio (OR) and 95 % confidential interval (CI). In total, 82 patients were enrolled in the study. Sixty-one patients (74.4 %) met the success criteria. The mean obstructive apnea duration (OAD) was the sole variable with a significant and satisfactory area under the curve (AUC) value [AUC (95 % CI) = 0.719 (0.597-0.842), p = 0.003]. The cutoff value was found to be 26.75 s with 71.4 % sensitivity, 72.1 % specificity, 88.0 % positive predictive value, and 46.9 % negative predictive value. Univariate analysis revealed an association between surgical failure and mean OAD > 26.75 s, total apnea duration, lowest SaO2, mean SaO2, mean O2 desaturation, and oxygen desaturation index, although only mean OAD > 26.75 s remained to be an independent predictor for unfavorable outcome after adjustment for other confounders in multivariate analysis [OR (95 % CI) = 3.92 (1.08-14.17), p = 0.041]. The current study suggests that OSA patients having longer OAD are in the risk of having surgical failure.