SLEEP-APNEA FOLLOWING A PHARYNGEAL FLAP - A FEARED COMPLICATION

Pharyngeal flaps are often used to correct velopharyngeal insufficienc y. They produce a permanent partial obstruction of the velopharyngeal space. Respiratory obstruction and obstructive sleep apnea have been r eported following this surgery. We undertook a study to find out the i ncidence of sleep apnea associated with pharyngeal flap surgery. Forty -one children (aged 2 to 22 years) admitted for a pharyngeal flap unde rwent a polysomnographic recording prior to their surgery. One child w ith Steinert's disease showed some episodes of obstructive apnea, and the surgery was canceled. Forty children underwent pharyngeal flap sur gery, and polysomnography with continuous arterial saturation was repe ated 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. Eigh t children had normal recordings, while 2 had central apneas. The 4 pa tients 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 le thargy. A section of his flap has been recommended. Independent analys is of arterial oxygen saturation revealed that the percentage of time with a saturation of less than 90 percent identifies patients with cli nically significant apneas. Our data show that significant sleep apnea s following pharyngeal flaps may not be as frequent or permanent as pr eviously reported. Long-term follow-up studies in 10 children showed o nly 2 children with persistent central apneas. The preoperative polyso mnograms 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 .