Effects of Obstruction Length and Height on Predicting Velopharyngeal Surgery Outcome in Obstructive Sleep Apnea

Abstract

Objectives:

Measure obstruction length and height using drug-induced sleep endoscopy (DISE) in obstructive sleep apnea syndrome (OSA) patients and to evaluate their effects on predicting velopharyngeal surgery.

Methods:

A single institution, prospective, nonrandomized trial of DISE in a consecutive group of patients undergoing velopharyngeal surgical procedure, which consisted of revised uvulopalatopharyngoplasty with uvula preservation and transpalatal advancement pharyngoplasty between July 1, 2012, and June 30, 2013. Eighty patients with OSA diagnosed by polysomnography were evaluated by DISE using dexmedetomidine before surgery. Obstruction length (defined as the distance from the most superior point of the collapse to the most inferior point of the collapse) and obstruction height (the distance from the posterior border of the nasal septum to the most proximal point of the collapse) were measured.

Results:

Out of 80 subjects studied, the mean obstruction length and obstruction height was 1.6 ± 0.8 (range was 0.4-3.8) cm, and 3.4 ± 1.0 (range was 1.1-5.0) cm, respectively. The obstruction length had correlations with body mass index (BMI), CT90, and lowest oxygen saturation (r = 0.247, 0.302, and –0.297, respectively, P < .05). Forty-three patients had postoperative polysomnography a ≥3 months. Preprocedure mean apnea hypopnea index (AHI) was 57.2 ± 17.3 per hour. Postoperative AHI was 22.7 ± 20.1 per hour. Twenty-six patients (60.5%) were responders, and seventeen were nonresponders (39.5%). Multivariate logistic regression analysis revealed that obstruction length and height were the only independent predictors of upper airway surgery failure.

Conclusions:

Obstruction length and height can be accurately measured while apnea occurs during the patient’s drug-induced sleep. They are useful to help predict outcome to upper airway surgery in OSA.