The role of lateral pharyngeal wall movement in pharyngeal flap surgery.
A total of 202 patients with pharyngeal flaps were assessed with nasopharyngoscopy and multiview fluoroscopy to determine the role of lateral pharyngeal wall movement postoperatively. Variations in the construction of flaps resulted in three categories: namely, a long narrow flap with a high insertion, a short broad flap with a low insertion, and an intermediate-size flap that is inserted in a position somewhere between the first two. It was found that in all cases where there was no evidence of velopharyngeal insufficiency, the sole determiner of velopharyngeal closure was the medical excursion of the lateral pharyngeal walls to the sides of the flap. In flap failures, the causes for velopharyngeal insufficiency were inappropriate degree, level, and symmetry of the lateral pharyngeal wall motion. The success of pharyngeal flap surgery depends largely on the preoperative assessment of the velopharyngeal mechanism and the choice of a type of pharyngeal flap that will best assist closure of the velopharyngeal port during speech.