Response to Singh: "Volumetric MRI analysis of multilevel upper airway surgery effects on pharyngeal structure"

Swallowing biomechanics before and following multi-level upper airway surgery for obstructive sleep apnea

STUDY OBJECTIVES

The effect of contemporary multi-level upper airway surgery for obstructive sleep apnea on swallowing is unclear. This study assessed the biomechanical swallowing function in participants with obstructive sleep apnea pre- and post-modified uvulopalatopharyngoplasty and coblation channeling of the tongue.

METHODS

In this prospective, longitudinal study, adults diagnosed with moderate-severe obstructive sleep apnea who underwent modified uvulopalatopharyngoplasty and coblation channeling of the tongue surgery had swallowing biomechanics assessed using high-resolution pharyngeal manometry and analyzed with swallowgateway.com. Symptomatic swallowing difficulty was evaluated using the Sydney Swallow Questionnaire (≥ 234). General linear mixed-model analysis was conducted to evaluate the difference pre- and post-modified uvulopalatopharyngoplasty and coblation channeling of the tongue. Data are presented as mean [95% confidence intervals].

RESULTS

High-resolution pharyngeal manometry assessments were conducted in 10 participants (7 men; median age 50 [interquartile range 36-65]) preoperatively and repeated postoperatively at 9 months [interquartile range 6-13]. Self-reported dysphagia was unchanged following surgery (Sydney Swallow Questionnaire =149 [53, 447] to 168 [54, 247]; P = .093). High-resolution pharyngeal manometry outcomes indicated reduced mesopharyngeal pressures (148 [135, 161] to 124 [112, 137] mm Hg s cm; P = .011), reduced hypopharyngeal pressures (113 [101, 125] to 93 [84, 102] mm Hg s cm; P = 0.011), and reduced upper esophageal sphincter relaxation pressure (5 [4, 6] to 2 [1,3] mm Hg; P = 0.001) but no change to velopharyngeal pressures (135 [123, 147] to 137 [117, 157] mm Hg s cm; P = .850) postsurgery.

CONCLUSIONS

Modified uvulopalatopharyngoplasty may have less implications on the swallow mechanism than previously suspected. In contrast, the reduction in mesopharyngeal contractile pressures associated with coblation channeling of the tongue, although within normal limits, may affect bolus propulsion. Biomechanical alterations were insufficient to worsen self-reported swallowing function.

CITATION

Schar MS, Omari TI, Woods CW, et al. Swallowing biomechanics before and following multi-level upper airway surgery for obstructive sleep apnea. J Clin Sleep Med. 2022;18(4):1167-1176.