Indications

The indications for surgery for VPD include those patients who have failed correction of their VPI with speech therapy or for whom speech therapy is felt likely to be inadequate. They must be making attempts at verbal communication and be motivated to participate in therapy after surgery. The patient must be deemed medically safe for surgery under general anesthesia on the airway. In children with complex medical problems or history of cardiac anomalies, clearance by their cardiologist or primary care physician is necessary prior to surgery.

Key Aspects of the Consent Process

Risks associated with surgery for VPD must be discussed, including bleeding, infection, and risks of general anesthesia or airway complications. Risks of palatal fistula, or dehiscence of a pharyngeal flap or sphincter pharyngoplasty, are specific to each procedure. Furthermore, all patients and their parents must understand the possibility for incomplete correction of their speech dysfunction and possible need for additional surgical procedures if the primary procedure is insufficient or inadequate. Finally, all VPD procedures that narrow the VP port may increase the risk of developing obstructive sleep apnea (OSA). Development of OSA after surgery may require additional treatments or even revision of the surgery to improve the breathing concerns.

After surgery, most surgeons employ specific dietary restrictions such as a liquid or soft diet for several weeks postoperatively to allow for healing to take place and prevent the risk of dehiscence. Parents must also understand the importance of initiating or returning to speech therapy after the healing time to address any mislearning or articulation concerns and optimize resonance in these patients. In some patients, speech and resonance may continue to improve with speech therapy over the next several years [22, 23].

Equipment

A Dingman mouth gag is used for exposure of the palate and oropharynx. The Hurd elevator can be used to palpate the palate, evaluate the palatal anatomy, and evaluate the adenoid pad along the posterior pharyngeal wall. Good-quality and well-positioned overhead lighting may be used, or a headlight and loupe magnification are helpful to optimize intraoral visualization. Anesthetic solution with epinephrine is typically infiltrated into the tissues prior to incision to help with hemostasis. Standard palatal surgical instruments may be used including long toothed and smooth forceps, long needle drivers, tenotomy dissecting scissors, periosteal elevators, and needle-tip bovie electrocautery. #11, #12, or #15 scalpel blades may be used per surgeon preference. For sphincter pharyngoplasty and posterior pharyngeal flap, often a 12F red rubber catheter is helpful for lifting the uvula and posterior soft palate out of the palatal plane to achieve proper positioning of the flaps. 4-0 Vicryl or chromic sutures are typically used, per the surgeon preference.

Approach 1: Palatal Lengthening

Palatal lengthening is often the first choice for correction of VPI when there is active sphincter movement and a relatively small gap of 5 mm or less. Approaches to lengthen the palate vary. Options include a hard palate pushback (Fig. 41.2) or lengthening of the soft palate with the addition of buccal myomucosal flaps at the junction of the hard and soft palate (Fig. 41.3) [24, 25]. When an overt or occult submucous cleft palate is present, palatal lengthening with a Furlow palatoplasty is often the procedure of choice. This procedure has the advantage of lengthening the palate, narrowing the velopharyngeal sphincter, and creating a functional muscular sling containing the levator veli palatini muscles. Furlow palatoplasty is the author’s preferred approach and is described in more detail here.

Furlow palatoplasty includes the creation of two oral and two nasal flaps for a double opposing Z-plasty on each mucosal surface. The anteriorly based flaps on each surface are mucosa-only flaps, and the posteriorly based flaps are myomucosal flaps containing the levator veli palatini muscle, as well as the palatoglossus and palatopharyngeus muscles. Bilateral velar relaxing incisions may be used if necessary to allow for complete release and retropositioning of the flaps. In the non-cleft palate, these incisions are less commonly needed. These relaxing incisions are drawn in the crease formed between the junction of the vertically oriented cheek side walls and the horizontal velar shelves. They may extend from the hard palate around the maxillary tuberosity toward the retromolar trigone of the mandible as needed.

The Z-plasty is then marked at four key points: the junction of the hard and soft palate, the base of the uvula, and the hamulus on each side. In Fig. 41.4, a left-sided posteriorly based oral myomucosal flap and a right-sided anteriorly based oral mucosal flap of between 60 and 90° are marked. The incisions are made through the oral mucosa. The left-sided posteriorly based oral myomucosal flap is then elevated off of the nasal lining. Any abnormal muscle attachments are freed from the posterior edge of the hard palate and tensor veli palatini aponeurosis anteriorly and from the superior pharyngeal constrictor laterally. Releasing these attachments allows the flap to be rotated posteriorly and medially without tension. The right-sided anteriorly based oral mucosal only flap is elevated off of the underlying palatal muscle, which is left attached to the nasal lining (Fig. 41.5a).

After the oral flaps are elevated, the nasal flaps are marked and divided. Here the Z-plasty is designed in the opposite configuration, with a left-sided anteriorly based nasal mucosal flap and a right-sided posteriorly based nasal myomucosal flap. Any muscle on the right side is again freed from its abnormal attachments to the posterior edge of the hard palate, tensor aponeurosis, and superior constrictors. The nasal lining is divided and this flap carries the muscle posteriorly. The left-sided nasal mucosa lining flap is incised, and the right-sided flap can then be inset posteriorly and medially to begin the nasal lining repair of the Z-plasty (Fig. 41.5b). After complete closure of the nasal lining, the oral lining is repaired, mobilizing the left-sided myomucosal flap posteriorly to overlap the muscle of the soft palate to create a functional levator veli palatini muscular sling (Fig. 41.4b, c). Note the change in direction of the flaps after closure with lengthening of the palate. After the palate is well healed, it has increased length and normalized muscular position to reach the posterior pharyngeal wall.

Approach 2: Sphincter Pharyngoplasty

Sphincter pharyngoplasty functions to reduce the transverse diameter of the VP port by medializing the lateral walls. This leaves a smaller central VP port and also augments the posterior wall of the pharynx at the point of velar contact. On nasendoscopy or videofluoroscopy, evidence of poor lateral wall movement with coronal closure pattern is considered a good indication for sphincter pharyngoplasty. Sphincter pharyngoplasty requires a mobile velum and normal levator orientation to achieve closure in the smaller VP port. Often this procedure may be performed in combination with Furlow palatoplasty to optimize palatal function either in a staged or simultaneous operation [26].

Superiorly based myomucosal flaps are created from the palatopharyngeus muscles of the posterior tonsillar pillar (Fig. 41.6). A key element of this procedure is anchoring these flaps at the appropriate height along the posterior wall of the oropharynx to optimize velar contact. Often this point is slightly above the tubercle of the first cervical vertebra (C1) which can be identified by palpation. After marking these flaps and the transverse incision, the tissues are infiltrated with epinephrine containing solution. The posterior tonsillar pillar flaps are incised and mobilized superiorly, incorporating the palatopharyngeus muscle with its overlying mucosa. A transverse incision is made in the mucosa of the posterior pharyngeal wall. Care is taken to avoid complete transection of the posterior muscle to decrease the risk of inferior migration of the flaps. The myomucosal flaps on both sides are then rotated 90° and anchored to the posterior pharyngeal wall mucosa. The muscle flaps are typically overlapped in a Z pattern to create optimal tightness with a sphincter effect. Finally, the lateral pharyngeal wall donor sites are closed. Postoperatively, if the patient has either persistent VPI or hyponasality and OSA, the limbs of the sphincter may be taken down and either loosened or tighten to adjust the size of the VP port.

Approach 3: Pharyngeal Flap

A pharyngeal flap is commonly performed in patients with a large central gap and/or poor velar mobility or hypotonia. In general, many feel this surgery is optimal in the presence of good lateral wall movement. Some surgeons suggest that a coronal closure pattern is better treated with sphincter pharyngoplasty; however others recommend a wide pharyngeal flap in patients with large gap coronal closure VPI, such as patients with 22q11.2 deletion [27]. This procedure creates a static bridge of tissue extending from the posterior wall of the oropharynx to the velum. A pharyngeal flap therefore creates permanent passive obturation centrally with two lateral ports for nasal airflow and dynamic closure.

The pharyngeal flap may be superiorly or inferiorly based; however superiorly based pharyngeal flaps are most common (Fig. 41.7). The flap is marked with the base at the tubercle of C1 or optimal point of VP contact. The width of the flap may vary depending on lateral pharyngeal wall movement, with wider flaps used when this movement is poor or in the setting of hypotonia. Often the width is between 1/3 and 2/3 of the total width of the pharynx. The flap length is also relative to need, but is typically around 3 cm in length. This flap is infiltrated with epinephrine-containing solution prior to being incised. The incision travels through the palatopharyngeus and superior constrictor muscles, leaving the prevertebral fascia intact. This myomucosal flap is then mobilized completely to its superior extent to prevent any tension on the inset. The donor site muscle and mucosa are closed in a single layer.

The soft palate is split down the middle to allow for inset of the posterior pharyngeal flap. A key element is insetting the flap at the level of the palatal plane to minimize inferior displacement and recurrence of VPI. There are several variations on flap inset. The Hogan modification involves the creation of nasal palatal flaps based along the free edge of the palate to help line the muscular surface of the pharyngeal flap. The flap is inset with multiple sutures to position the flap anteriorly as well as laterally to set the size of the lateral ports. The oral and nasal palatal flaps are then closed over the raw surface of the flap on the lingual side.

Risks of this surgery include hyponasality and obstructive sleep apnea. While OSA may occur in up to 38% of patients in the early postoperative period [28], this resolves by 6 months in most patients to a rate of <10% [28–30]. The lateral ports may become scarred or stenotic, increasing the likelihood of OSA or respiratory difficulties. Alternatively, the pharyngeal flap may become tubularized with contractile scarring, leading to narrowing of the flap and suboptimal obturation with persistent VPI. Finally, the flap may dehisce and fall either early in the healing process or late in response to trauma to the area.

Approach 4: Augmentation Pharyngoplasty

Augmentation pharyngoplasty is another option for treatment of minimal VPI or in patients in whom pharyngeal flap or sphincter pharyngoplasty may be contraindicated due to comorbidities. Most commonly, this approach is felt to benefit patients with a small central gap of less than 3–4 mm or with touch closure of the VP port on nasopharyngoscopy or videofluoroscopy. Some authors have suggested this may be appropriate for those children with VPI after adenoidectomy. Multiple different substances have been described for use in augmentation pharyngoplasty including silicone, cartilage, collagen, fat, fascia, acellular dermal matrix (ADM), and calcium hydroxyapatite (CAHA) [31, 32]. Depending on the substance used, risks may include infection, extrusion, absorption, or migration of the substance. Fat and CAHA appear to be most widely studied for this purpose [31–36].

In terms of the location of injection, various sites have been described. In the posterior pharyngeal wall, the substance is ideally placed into the retropharyngeal space just deep to the superior constrictor muscle and superficial to the pharyngobasilar fascia. Fat is typically over-injected by 30–50% to offset anticipated fat resorption. With any substance, multiple injections may be necessary to achieve adequate impact on VP closure. Other authors advocate targeting fat grafting to the uvula to allow for improved closure when touch closure is present [33]. Some studies have evaluated injection in the posterior pharyngeal wall, soft palate, and pharyngeal arches [34].

Augmentation pharyngoplasty demonstrates safety and success in the literature [31, 32], but the indications remain limited. All studies to date contain relatively small numbers of patients, are retrospective in nature, and have limited follow-up. The necessary volume needed for injection varies from a mean of 5–6 ml of fat in some studies to 11–13 ml in others. Injection sites vary between centers, and the technique lacks consensus on indications. Outcomes may vary depending on the indication, with some suggesting fat grafting may be better as a secondary procedure for VPI following another primary treatment [37]. Long-term data on the use of this approach in children is lacking at present. Fat hypertrophy may increase the risk of OSA as children age and gain weight. In one reported case of fat hypertrophy, the patient subsequently required two debulking procedures [38]. Finally, in children with 22q11 deletion, the surgeon must be aware of the abnormal course of the carotid arteries in the pharyngeal space to ensure intra-arterial injection is avoided as a potentially devastating complication. An unpublished report of MCA infarct due to presumed fat embolism has been reported, and autologous fat grafting has other known risks in the head and neck including blindness and cerebrovascular accident [31]. Avoidance of injection into the lateral pharyngeal walls has been recommended to minimize the risk of intravascular fat injection.

Comparison of Surgical Approaches

In general, the literature on the use of these different surgical approaches for the treatment of VPI is diverse, without consistent conclusions, and lacks high-level evidence to support one procedure over any other in terms of indications or speech outcomes [39]. In general, Furlow palatoplasty is thought to be less likely to lead to nasopharyngeal obstruction or OSA. No consensus exists regarding the increased risk of OSA between sphincter pharyngoplasty or pharyngeal flap. The majority of studies on VPI in children are on patients with cleft palate, and this population may fundamentally differ from patients with non-cleft VPI as discussed in this chapter. Nasopharyngoscopy or videofluoroscopy to evaluate closure pattern has been traditionally used to help determine the appropriate surgical approach. Some authors have recently called this into question, suggesting that coronal closure patterns traditionally thought to be best treated with sphincter pharyngoplasty may actually be better treated with pharyngeal flap [27].