Study on the structural changes of pharyngeal cavity after bariatric surgery in obese patients with obstructive sleep apnea

Abstract

Objective:To study whether and how bariatric surgery changes the structure of the pharyngeal cavity in obese patients with obstructive sleep apnea（OSA）. Methods:Forty-two patients who underwent laparoscopic sleeve gastrectomy were recruited. Morphological indicators（BMI, neck and waist circumference）, PSG and acoustic pharyngometry indicators were evaluated pre-operatively and 3, 6, and 12 months post-operatively. Results:All indicators including morphology, pharyngeal cavity structure and OSA severity changed significantly after surgery. Among them, BMI, neck circumference, waist circumference and AHI value were significantly reduced（P<0.001）, while pharyngeal cavity volume, pharynx volume, oropharyngeal junction area, glottis area and LSaO2 increased significantly（P<0.001）. The results of multiple comparisons showed that BMI, neck and waist circumference decreased significantly in the first 6 months, and no further decline occurred during 6 to 12 months postoperatively. The decrease in AHI and LSaO2 mainly occurred within the first 3 months postoperatively, while there was no statistically significant difference in these two indicatiors between 3 months vs. 6 months, 6 months vs. 12 months postoperatively. The area of the oropharyngeal junction increased significantly within 0 to 3 months after surgery, while the volume of the pharyngeal cavity and the area of the glottis increased at 6 months and 12 months after surgery. Conclusion:Bariatric surgery can significantly reduce body weight and reduce fat accumulation in the neck. It can also enlarge the volume and cross-sectional area of the pharyngeal cavity, and improve upper airway obstruction, therefore reduce the symptoms of sleep apnea in obese patients with OSA to a certain extent.