Correction of Velopharyngeal Dysfunction by Double-Opposing Z-Plasty
Michael C. Kao, Kathleen C.Y. Sie
○ Patients with velopharyngeal insufficiency and sagittal orientation of the levator veli palatini musculature are candidates for double-opposing Z-plasty.
○ Sagittal orientation of the levator veli palatini musculature is seen in patients with submucous cleft palate and in some patients with previously repaired cleft palate.
○ The orientation of the levator veli palatini can be ascertained on intraoral examination and confirmed on nasendoscopy during speech production.
○ Double-opposing Z-plasty is most likely to resolve velopharyngeal insufficiency in patients with small velopharyngeal gaps on preoperative nasendoscopy.
○ Double-opposing Z-plasty is unlikely to cause obstructive sleep symptoms.
Establishing velopharyngeal function is the primary purpose of repairing clefts of the palate. Regardless of the surgical technique, velopharyngeal dysfunction (VPD) may occur after cleft palate repair. Surgical options to treat VPD include palatoplasty, sphincter pharyngoplasty, pharyngeal wall augmentation, and pharyngeal flap.1–4 The surgical recommendations for any particular patient are based on the degree of VPD, the status of the palate and velopharyngeal port, and surgeon preference. The goal of these interventions is to optimize velopharyngeal closure during speech without compromising the upper airway.
Although surgical management of VPD is largely related to surgeon preference, the concept of tailoring the procedure to a patient’s needs is appealing. For patients with sagittal orientation of the levator veli palatini (LVP) muscles, such as those with submucous cleft palate or previously repaired cleft palate, surgical procedures to reposition the LVP into a transverse orientation may improve palatal function.
Fig. 58-1 A, Preoperative abnormal insertion of the levator. B, Postoperative reorientation of the levator in a transverse direction.
Leonard Furlow5 described a technique for repair of cleft palate that incorporates a Z-plasty on the nasal surface of the velum and an opposing Z-plasty on the oral surface of the muscular palate. Originally described for repair of cleft palate, the double-opposing Z-plasty has also been used to correct VPD.5–7 It offers specific advantages by repositioning the LVP muscles transversely with velar Z-plasties, resulting in reorientation of the LVP musculature and palatal lengthening (Fig. 58-1). D’Antonio et al8 showed that realignment of the levator musculature with double-opposing Z-plasty improved palate motion, lengthened the palate, and thickened the middle of the soft palate.
Furthermore, the likelihood of postoperative obstructive sleep apnea is very low after double-opposing Z-plasty, which makes it particularly well suited for patients with VPD and sagittal orientation of the LVP.9
ANATOMY AND PHYSIOLOGY
Velopharyngeal closure is necessary for normal speech production. VPD is characterized by hypernasal resonance and nasal air emission, which can compromise speech intelligibility. VPD is often associated with cleft palate, previously repaired cleft palate, or submucous cleft palate. Less commonly, it may be acquired after adenoidectomy or result from progressive neuromuscular disease.
In patients with unrepaired clefts of the palate, the LVP fibers lay in the sagittal position, with abnormal insertion onto the posterior margin of the hard palate.10,11 In patients with previously repaired clefts of the palate, who may have had a straight-line palate repair or incomplete intravelar veloplasty (IVVP), persistent sagittal orientation of the LVP may compromise palate elevation.
Intuitively, restoring the physiologic orientation of the LVP to treat VPD in patients with a sagittally oriented LVP is desirable.12,13 Chen et al7 and others have shown favorable outcomes (97% to 100%) when using the double-opposing Z-plasty in patients with sagittal LVP and small velopharyngeal gaps on fluoroscopy. When reviewing a large series of patients with a sagittally oriented LVP, VPD, and a range of preoperative gap sizes, Perkins et al9 demonstrated that the likelihood of resolution of VPD after double-opposing Z-plasty was related to gap size. Specifically, patients with a gap larger than 50% were less likely to have resolution of VPD after double-opposing Z-plasty than patients with smaller gaps.
Diagnosis of VPD should include perceptual evaluation by a speech-language pathologist, who generates a speech differential diagnosis. Patients with velopharyngeal mislearning or other speech disorders, such as childhood apraxia, should receive speech therapy. Patients with velopharyngeal insufficiency or inadequacy (VPI) should have an instrumental assessment with nasendoscopy (Fig. 58-2). The endoscopic finding of a notch on the dorsal aspect of the velum during speech production confirms the sagittal orientation of the LVP9 (see Fig. 58-2, A). In some patients with previously repaired cleft palate, extensive scarring of the muscular palate may obscure the characteristic notch (see Fig. 58-2, B). In contrast, the endoscopic appearance of an anatomically normal muscular palate is characterized by a central bulging of the palate (see Fig. 58-2, C).
On intraoral examination during phonation or gagging, the sagittal orientation of the LVP results in a vaulted V-shaped pattern of velar elevation, in contrast to the normal transverse elevation of the velum. This physical finding is very similar to that seen in patients with submucous clefts of the palate, because the physiology and orientation of the LVP is similar. This vaulted V-shaped pattern of velar elevation is the intraoral finding that corresponds to the notching on the dorsal aspect of the velum seen on nasendoscopy.
The orientation of the LVP, the gap size as a percent of velopharyngeal area at rest, presence of Passavants ridge, and aberrant pulsations are evaluated on endoscopy.14 The Golding-Kushner scale is applied to the endoscopic examination to describe the degree of lateral wall and palatal movement during speech production relative to rest.15 Velopharyngeal gap larger than 50% is defined as large, 20% to 50% is considered moderate, and smaller than 20% is classified as small.
The basal view of multiview videofluoroscopy may be helpful in demonstrating the dorsal notch. However, the basal view is the most difficult view to obtain. For this reason, we reserve multiview fluoroscopy for patients with VPD and transverse orientation of the LVP.
In our protocol, patients with sagittal LVP muscles, VPI, and small or medium gaps (smaller than 50%) are treated with a double-opposing Z-plasty.