Changes of sleep-disordered breathing after laryngeal surgery in patients with bilateral vocal fold paralysis

Snoring is the most obvious symptom of sleep-disordered breathing (SDB). Vibratory sound usually originates from the pharynx; however, in some circumstances, the narrowing of glottic structures can also cause nighttime breathing noise. This clinical study investigated the role of laryngeal obstruction in patients with SDB. Nine female patients with paralysis of bilateral vocal folds were enrolled in this study. All the patients received unilateral laser arytenoidectomy as the only treatment. Nocturnal polysomnography (PSG) was performed at baseline and 6 months after the operation. Parameters of PSG including the respiratory disturbance index (RDI) and snoring index (SI) were recorded, as well as the subjective Epworth Sleepiness Scale (ESS). Before surgery, six patients (66.6%) were identified as having obstructive sleep apnea (OSA, RDI>5). After the operation, the SI improved significantly (P=0.02). The RDI (P=0.07) and ESS (P=0.11) showed no significant improvement. The success rate of surgery in OSA patients was 66% (4/6) according to the criteria of a greater than 50% reduction of the preoperative RDI and less than 20 events per hour. The mechanism, outcomes and causes of failure are discussed in this unusual larynx-related SDB.