Volume of parapharyngeal fat pad in obstructive sleep apnea syndrome: prognostic role for multilevel sleep surgery.

STUDY OBJECTIVES: To evaluate the prognostic role of volume of parapharyngeal fat pad (VPPFP) after multilevel sleep surgery in patients with obstructive sleep apnea syndrome. METHODS: This retrospective cohort study was conducted in 50 patients with moderate to severe obstructive sleep apnea syndrome who underwent polysomnography (preoperative and postoperative 6 months) and preoperative facial computed tomography with multilevel sleep surgery between May 2010 and February 2019. All patients had failed or refused positive airway pressure treatment. RESULTS: Of the 50 patients with moderate to severe obstructive sleep apnea syndrome who underwent multilevel sleep surgery, 46 were male (92.0%) with mean ± standard deviation age of 41.2 ± 12.5 years. On the preoperative polysomnography, mean ± standard deviation of apnea-hypopnea index and CT90 (cumulative percentage of time spent at oxygen saturation less than 90%) were 43.4 ± 19.3 events/h and 5.6 ± 9.6%, respectively. The average VPPFP measured by facial computed tomography scan was 4.9 ± 1.9 cm3. Multiple linear regression analysis showed that VPPFP was significantly correlated (R2 = 0.38) with age (ß = 0.05; 95% confidence interval [CI], 0.01-0.09) and body mass index (ß = 0.31; 95% CI, 0.16-0.45). Surgical success rate was 38%, and VPPFP higher than 5.1 cm3 was significantly associated with surgical failure after covariate adjustment (P = .01; odds ratio = 0.09; 95% CI, 0.02-0.48). Postoperative apnea-hypopnea index was positively correlated (R2 = 0.40) with CT90 (ß = 1.33; 95% CI, 0.74-1.92) and VPPFP (ß = 3.52; 95% CI, 0.30-6.74). CONCLUSIONS: VPPFP correlated with age and body mass index, and high VPPFP and CT90 were associated with high postoperative apnea-hypopnea index. VPPFP larger than 5.1 cm3 was a possible risk factor for surgical failure, which may inform a decision on multilevel sleep surgery as salvage therapy for positive airway pressure treatment. CITATION: Kim BK, Park SI, Hong SD, Jung YG, Kim HY. Volume of parapharyngeal fat pad in obstructive sleep apnea syndrome: prognostic role for multilevel sleep surgery. J Clin Sleep Med. 2022;18(12):2819-2828.