SLEEP-APNEA FOLLOWING A PHARYNGEAL FLAP - A FEARED COMPLICATION

Pharyngeal flaps are often used to correct velopharyngeal insufficiency. They produce a permanent partial obstruction of the velopharyngeal space. Respiratory obstruction and obstructive sleep apnea have been reported following this surgery. We undertook a study to find out the incidence of sleep apnea associated with pharyngeal flap surgery. Forty-one children (aged 2 to 22 years) admitted for a pharyngeal flap underwent a polysomnographic recording prior to their surgery. One child with Steinert's disease showed some episodes of obstructive apnea, and the surgery was canceled. Forty children underwent pharyngeal flap surgery, and polysomnography with continuous arterial saturation was repeated following surgery. Postoperative polysomnograms were normal in 26 patients (65 percent) and abnormal in 14 patients (35 percent). Among the 14 abnormal patients, we found 6 with obstructive apneas, 6 with central apneas; and 2 with both central and obstructive apneas. Ten of the 14 abnormal patients were restudied in the following months. Eight children had normal recordings, while 2 had central apneas. The 4 patients who declined a follow-up recording had no clinical symptoms of respiratory difficulty when sleeping. Of the 2 children with abnormal recordings on long-term follow-up, 1 is asymptomatic, while the second has persistent snoring, nocturnal awakening, sweating, and daytime lethargy. A section of his flap has been recommended. Independent analysis of arterial oxygen saturation revealed that the percentage of time with a saturation of less than 90 percent identifies patients with clinically significant apneas. Our data show that significant sleep apneas following pharyngeal flaps may not be as frequent or permanent as previously reported. Long-term follow-up studies in 10 children showed only 2 children with persistent central apneas. The preoperative polysomnograms were found to be of little value except in high-risk patients. The percentage of sleep time with an arterial saturation lower than 90 percent can detect subjects with significantly disordered breathing.