Chapter 29 Uvulopalatopharyngoplasty
Although the surgical armamentarium for snoring and obstructive sleep apnea (OSA) has, in the last several years, expanded significantly to include many procedures, uvulopalatopharyngoplasty (UPPP) still remains the most widely performed operation for these conditions. The procedure was first introduced by Fujita in 1981 and is designed to enlarge the airway lumen at the level of the velopharynx and decrease the collapsibility of the pharyngeal walls.
A large number of UPPP procedures were performed in the 1980s, because with the exception of tracheostomy, UPPP was the only available treatment for OSA during that period. This provided adequate material for an accurate assessment of the efficacy of the operation in both selected and unselected patients. Although UPPP enjoyed success in reducing snoring, it had unpredictable results in curing apnea. The success rate of the procedure in unselected OSA patients was only 20–25%. Uvulopalatopharyngoplasty results continued to be unpredictable even after careful selection of candidates, although its success rate increased to 50–60% in groups of selected patients. Further investigation of the upper airway mechanics of obstruction revealed that the pharynx of OSA patients collapses in more than one site. This realization offered some understanding of the limitations of the isolated UPPP procedure in curing OSA and the concept of multilevel airway surgery was born. Uvu-lopalatopharyngoplasty nowadays is frequently performed in conjunction with other airway procedures in multi- or single-stage fashion. The original technique has also undergone many modifications in order to comply with anatomical variations of the velopharynx and minimize morbidity.
Theoretically patients who have airway collapse at the level of the velopharynx should respond well to UPPP. However, so far, identification of the site of collapse has proven to be a difficult task. Furthermore, even patients whose site of collapse is documented to be in the velopharynx may have poor response to the UPPP. Fiberoptic and manometric studies have shown that many patients who failed UPPP continue to have obstruction at the level of the velopharynx, although it is speculated that increased resistance due to narrowing (without obstruction) at the base of tongue level causes the more collapsible velopharynx to obstruct. There is a plethora of methods to evaluate the airway in OSA patients, but the efficacy of most of them in predicting UPPP success is limited. It would be beyond the scope of this chapter to elaborate on methods of airway evaluation. From a practical view point, information obtained by physical examination (PE), awake fiberoptic endoscopy and cephalometric analysis is quite valuable and these three methods are utilized by majority of otolaryngologists for preoperative airway evaluation.
There are no widely accepted standardized methods or algorithms and frequently surgeons utilize their own judgment in interpreting such indices for patient selection. General points by which UPPP candidates can be identified are seen in Table 29.1. It should be pointed out that when UPPP is performed as part of a multilevel approach, most of these criteria are not relevant.
|Posterior nasal spine to uvula tip distance
Posterior airway space
Mandibular plane to hyoid distance
Friedman tongue position
Absence of retrognathia
Absence of retroglossia
Absence of hypopharyngeal narrowing
Absence of lateral pharyngeal wall bulging
Absence of morbid obesity
Absence of sagittal orientation of airway
I or II
Obviously there is only a small fraction of OSA patients that can satisfy all the aforementioned selection criteria. Friedman et al., using a standardized method of airway evaluation based on assessment of palatal position and tonsillar size, found that only 23.5% of OSA patients were considered acceptable UPPP candidates. This fact emphasizes the concept that if surgical correction of OSA is deemed necessary, the vast majority of patients will require a multi-level approach to their airway. It would be incorrect for one to utilize rigid criteria and a ‘cook book’ approach for patient selection. Instead the process should be individualized and the surgeon should implement her/his judgment keeping always in mind that additional surgery may be necessary.
In general patients with large tonsils, elongated uvula and palatal redundancy position who do not have hypopharyngeal narrowing or tongue enlargement and are not extremely obese will be advised to have UPPP (Figs 29.1 and 29.2). Because of its relative simplicity and low morbidity UPPP is usually performed as part of a multilevel approach in many patients, even if there is no overt evidence of velopharyngeal pathology.
Uvulopalatopharyngoplasty is an evolving procedure and has undergone many modifications since its introduction primarily in order to comply with the variability of the pharyngeal anatomy and physiology and to reduce morbidity. Generally emphasis is placed on maximal tissue removal from the lateral pharyngeal walls and conservative resection of the palate and uvula. In a technique called palatal advancement with pharyngoplasty proposed by Woodson, the soft palate is elevated by advancing it towards the hard palate in order to totally preserve its functionality. The Z-palatoplasty technique has been designed for individuals without tonsillar hypertrophy and elongated palate. Another modification proposed by Pirsig describes complete preservation of the palatoglossus, palatopharyngeus and uvularis muscles thus leaving all velar muscles intact. I have used the technique described here in the last few years for the majority of patients undergoing the operation. Some of the reported modifications are utilized on an individual basis.
The procedure is performed under general anesthesia. The anesthesiology staff should be alerted about the diagnosis and the likelihood of difficult intubation. If deemed necessary fiberoptically aided awake intubation is carried out. Administration of narcotics should be kept to a minimum because of the likelihood of airway obstruction and depressed respiratory drive post extubation. Dexametasone and a broad-spectrum antibiotic are administered IV preoperatively.
Following orotracheal intubation and deep muscle relaxation, the mouth gag is positioned. This routinely provides adequate visualization and exposure. Local infiltration with epinephrine solution is not performed. In the past the amount of palate to be resected was determined by gently pushing the palate to the posterior pharyngeal wall and marking on its ventral surface the point where the palate met the posterior pharyngeal wall. Currently soft palate resection is conservative and is determined by gently curving the anterior pillar incision towards the base of the uvula, leaving only 5–10 mm of soft palate to be resected. The incision is marked with electrical cautery on the most lateral aspect of the anterior pillar in order to maximally resect this structure and the underlying palatoglossus muscle. The incision is then gently curved towards the base of the uvula and is continued in an identical fashion onto the opposite side (Fig. 29.3).