The potential effects of obesity on predicting outcomes of velopharyngeal surgery for obstructive sleep apnea

Purpose To explore the outcome associated factors of velopharyngeal surgery for treating obstructive sleep apnea (OSA) and the effects of obesity. Methods A total of 175 adult OSA patients who underwent velopharyngeal surgery, including the revised uvulopalatopharyngoplasty with uvula preservation (H-UPPP) alone or the combination of H-UPPP and transpalatal advancement pharyngoplasty, were retrospectively studied. The pre-operative information of these patients, including physical examination, polysomnography (PSG), and upper airway CT, were collected for analysis. Post-operative PSG used for evaluation of surgical outcomes were all done 3–6 months after surgery. Results The overall AHI decreased significantly from 59.7 ± 18.8 events/h to 22.1 ± 18.8 events/h after surgery ( P < 0.001), and there were 104 responders (59.4%). Tonsil size, the percentage of time with oxygen saturation below 90% (CT90), the vertical distance between the lower margin of the mandible and the lower margin of the hyoid (MH), and surgical methods were independently associated with treatment outcomes. The independent associated factors for surgical success were large tonsil size and combined surgical methods in non-obese patients (BMI < 27.5 kg/m 2 ) and were large tonsil size, short MH, and low CT90 in obese patients (BMI ≥ 27.5 kg/m 2 ), respectively. Conclusions Although BMI is not directly associated with surgical outcomes of velopharyngeal procedures, the outcomes associated factors in obese and non-obese OSA patients were not entirely the same. Obesity should be taken into accounts in pre-operative patient selection of such surgery.