Single Blinded Randomized Controlled Trial Comparing Muscular Pharyngeal Flap to Mucosal/Submucosal Pharyngeal Flap Surgical Technique for the Treatment of Velopharyngeal Dysfunction

Velopharyngeal dysfunction (VPD) results from failure of the airway to close and separate the oropharynx and nasopharynx during speech, eating and drinking as a result of insufficiency of the velum (soft palate) (1). VPD leads to a number of symptoms including difficulty with articulation, nasal regurgitation and excess nasal air emissions. VPD can often be treated through speech language therapy alone, however when refractory to this treatment surgical correction of problematic anatomy is indicated (2). The current surgery of choice at this center is a pedicled, posterior wall pharyngeal flap. During this procedure a small flap comprised of mucosa, submucosa and superior pharyngeal constrictor muscle is pedicled via surgical dissection and attached anteriorly to the inadequate soft palate. This creates an incomplete midline obstruction at the level of the velum allowing for a dynamic valve which can be closed through the medial constriction of the pharyngeal muscles during speech and eating/drinking. While this surgery has a high success rate there can be a high degree of post operative pain and sub-optimal lateral wall motion (2). It is hypothesized that the suboptimal lateral wall motion post-operatively is due to intentional segmentation of the superior constrictor muscle during the operation. Due to the necessary de-innervation of the pedicled pharyngeal flap there is evidence that the muscle atrophies and the bulk it initially adds to the flap is lost over time. Despite this, patients typically have good long-term outcomes with a pharyngeal flap (3,4). For these reasons it has been postulated that a successful surgery could be carried out using a pharyngeal flap comprised only of mucosa and submucosa, sparing the superior constrictor muscle. By sparing the superior constrictor muscle the investigators hope to achieve a decrease in post operative pain, complications and improved lateral wall motion while maintaining the effectiveness of the flap and symptomatic improvement. This novel surgical approach to treating VPD was shown to be effective and safe in animal trial (2). The major concern of the mucosal/submucosal flap procedure was that the flap would atrophy and fail without the inclusion of the muscular portion. However, results of the animal study comparing the standard pharyngeal flap to the experimental flap, indicated that at 12 weeks post-operation, bulk loss in the muscosa/submucosa group was not significantly greater than bulk loss in the muscular flap group.