1
Introduction
The uvulopalatopharyngoplasty (UPPP), as described by Fujita in 1981, marked a breakthrough for the evolving field of sleep surgery. However, the procedure’s limited success and cure of obstructive sleep apnea/hypopnea syndrome (OSAHS) resulted in the need to develop modifications of UPPP. Nevertheless, its role as part of a comprehensive treatment plan remains solidly accepted in most situations in which the palate, with or without the tonsils, is contributing to airway turbulence and obstruction. Palatal surgery traditionally seeks to widen the airway, reducing obstruction of the tongue base, retropalatal, and lateral dimensions. This is accomplished through two components: (1) the palatoplasty component, which involves palatal shortening with closure of mucosal incisions; and (2) the pharyngoplasty component, which is composed of a classic tonsillectomy with pharyngeal closure. These goals, however, are not always achieved with classic UPPP.
Persistent retropalatal obstruction after traditional UPPP has remained a limiting factor to UPPP success. Surgical success is found to be variable, with an estimated success rate of 40%. This may be attributed to a narrow palatal arch with a decreased diameter of the oropharyngeal inlet due to a forward approximation of the posterior palatal mucosa. The resulting new shape of the free edge of the palate is triangular rather than square. Further contraction of the wound occurs due to scarring secondary to the resection of the posterior tonsillar pillars, and additional narrowing is caused, which further affects long-term results ( Fig. 35.1 ).
Patients who previously underwent tonsillectomy are particularly poor candidates for classic UPPP due to scarring or absence of the posterior pillar from the previous tonsillectomy. These patients have an already narrowed space between the soft palate and the posterior pharyngeal wall and often do not have any redundant pharyngeal folds. Important modifications of the classic UPPP proposed by Fairbanks (described in Chapter 34 ), in which the posterior pillar is advanced lateral cephalad to widen the retropalatal space, are, hence, not possible. It is well known that when UPPP fails, the severity of obstruction may actually worsen.
Consequently, selection criteria are implemented to identify the patients with a higher likelihood of cure after UPPP. A staging system introduced by Friedman et al. identified that patients with anatomic stage I disease (Friedman tongue position [FTP] I and II) with large tonsils have better than an 80% chance of success, whereas patients with stage II and III disease (FTP III and IV) are less-than-ideal candidates and should therefore undergo a combined procedure that addresses both the palate and the hypopharynx.
The zetapalatopharyngoplasty (ZPP) was first described as a modification of the UPPP in patients with absent tonsils and a more aggressive technique for patients with stage II and III disease. This includes all patients who have had previous tonsillectomy, as well as patients with small tonsils and those with unfavorable tongue positions. Subsequently, multiple modifications have been reported. A modification useful for revision UPPP is presented in Chapter 67 . The modified ZPP changes the direction of closure tension lines. By suturing the flaps of the soft palate and uvula laterally, the line of healing and contracture is lateral rather than medial ( Fig. 35.2 ). Furthermore, a benefit of using ZPP to correct patients with failed previous UPPP is the potential to correct nasopharyngeal stenosis, which often is not addressed with other surgical techniques for UPPP correction.
The ZPP aims, as does the UPPP, to widen the space between the palate and the posterior pharyngeal wall, between the palate and the tongue base, and to either maintain or even widen the lateral dimensions of the pharynx. However, the ZPP procedure seeks to correct the problem of narrowed lateral dimensions that can be caused by contracture of the wound in UPPP. The ZPP, a double Z-plasty applied to the palate, changes scar contraction tension lines to an anterolateral vector and widens the anteroposterior and lateral oropharyngeal air spaces at the level of the palate. By splitting the soft palate and retracting it anterolaterally, an effective anterolateral pull is created, which actually continues to widen the airway as healing and contracture occur.
None of the palatal musculature is resected, in spite of the aggressive palatal shortening, thereby addressing and minimizing the risk for permanent velopharyngeal insufficiency (VPI). This procedure is performed with adjunctive tongue base reduction by radiofrequency (TBRF), which addresses the hypopharyngeal airway.
2
Patient Selection
As with all surgical treatment of OSAHS, patients should first be recommended to a trial of conservative measures, including lifestyle changes, continuous positive airway pressure (CPAP), and oral appliances. All surgical patients should have a documented history of intolerance to or noncompliance with these methods of treatment. As with any other surgical procedure, adequate medical clearance and informed consent should be obtained.
Patient anatomy should be carefully considered when selecting a potential ZPP patient. All patients should have noted obstruction at the soft palate, as determined by fiber-optic examination before the procedure. Patients with and without tonsils can both be considered. Because the ZPP procedure significantly widens the retropalatal space, it should be reserved for significantly symptomatic patients with diagnosed moderate to severe OSAHS. Friedman anatomic staging should also be considered. Patients with stage II and III disease have historically responded poorly to UPPP, but are candidates for ZPP. Stage II is defined as having FTP I or II with tonsil grade 0, 1, or 2 and FTP III or IV with tonsil grade 3 or 4. Stage III is a combination of FTP III or IV with tonsil grades 0, 1, or 2. Patients with stage II and III disease should all have a body mass index <40 kg/m 2 (see Chapter 15 ). Patients who have previously undergone conservative palatal surgery such as a classical UPPP may also be candidates for ZPP.
3
Surgical Technique
Candidates eligible to undergo a modified UPP technique can be divided into patients with intact tonsils and patients status posttonsillectomy. The revision UPPP technique is outlined in Chapter 67 .
The main goals of ZPP are the removal of the anterior mucosa only and the splitting of the soft palate in the midline. The key features are cutting of the palatoglossus muscle, cutting the palatopharyngeus muscle and suturing it to the lateral palate, and sewing the posterior palatal mucosa to the anterior resection margin. This results in retraction of the midline anterolaterally and widening of the retropharyngeal area.
For patients who have tonsils, tonsillectomy is first performed with cold steel ( Fig. 35.3 ). Two butterfly-patterned adjacent flaps are outlined on the palate ( Fig. 35.4 ). The anterior midline margin should be marked halfway between the free edge of the palate and uvula and the hard palate. The distal margin will be made up of the free edge of the soft palate and uvula. The flaps should extend laterally to the most lateral extent of the palate. After marking the flaps, only the mucosa on the anterior aspect of the two flaps is removed to expose the palatal musculature ( Fig. 35.5 ). Next, the palatoglossus muscle is transected bilaterally ( Fig. 35.6 ). The palatopharyngeus muscle is transected bilaterally, approximately two-thirds of the way down from the palate ( Fig. 35.7 ). It is then mobilized and sutured to the lateral palatal musculature along with the palatoglossus muscle ( Fig. 35.8 ). The soft palate and uvula are then split in the midline ( Fig. 35.9 ). The uvular flaps and soft palate are reflected laterally over the soft palate ( Fig. 35.10 ). This allows for lateral expansion. Meticulous two-layered closure follows, bringing the midline to the anterolateral margin of the palate. Primary closure of the submucosal layer is done with 2-0 Vicryl, allowing for a tension-free closure of the mucosal layer with 3-0 chromic suture ( Figs. 35.11 and 35.12 ). The end result should see 3 to 4 cm of distance between the posterior pharynx and palate. Fig. 35.13 illustrates the widening of the nasopharynx after the midline palatoplasty. The lateral dimension of the palate is usually increased to approximately 4 cm.
