Uvulopalatopharyn­goplasty: Analysis of Failure

1

Introduction

Sleep-disordered breathing (SDB) encompasses a spectrum of conditions, including socially unacceptable snoring (SUS) and obstructive sleep apnea syndrome (OSAS). Whereas SUS is mostly debilitating in social circumstances, OSAS and its complications pose a major health problem for society. Increased awareness has led to the development of various treatment modalities to combat both these diseases, of which uvulopalatopharyngoplasty (UPPP) is, without a doubt, the most widely used surgical intervention.

UPPP was first performed in 1964 by Ikematsu, but modified and formally introduced as a surgical treatment for OSAS in 1981 by Fujita.

Now a quarter century later, it is time to do an accounting. Has UPPP lived up to its initial expectations? At this point numerous studies have been performed estimating the outcome of UPPP in both the short and long term. Unfortunately, UPPP as the sole (surgical) management is not as uniformly successful as initially hoped. Growing understanding of the multifactorial and multilevel pathophysiology of OSAS has raised discussions as to whether the widespread application of UPPP continues to be justifiable or whether UPPP should be offered only to well-selected patients. This chapter aims to review the current knowledge on factors especially associated with negative UPPP outcome and discuss various ways of selecting patients for UPPP.

2

Patient Selection

The first step in the process of patient selection is diagnosing the severity of the condition. This starts with a thorough history from the patient and possible partner, as well as general ear/nose/throat (ENT) examination. Body mass index (BMI) and neck circumference are noted at this stage, too. The severity of disease is important only to determine if the patient is a candidate for surgery or whether the patient should undergo nonsurgical minimally invasive techniques. Severity will not be a guide to determine the type of surgery. The location of the obstruction will determine the correct surgical procedure.

The next step in the workup of suspected OSAS patients is a polysomnogram (PSG). This objective tool allows qualitative and quantitative measurements such as differentiation between SUS and OSAS and evaluation of the degree of disease severity. There are four levels of polysomnographic testing, of which level I is the most elaborate, including recordings such as an electroencephalogram, registration of eye movements, submental electromyogram, registration of thoracic and abdominal respiratory movement, limb movements, oxygen saturation, and the intensity of snoring—all recorded in a clinical setting for the duration of at least 6 hours. The other levels are less extensive and are not performed in a clinical setting. Events recorded during the PSG and most commonly used to estimate severity and treatment outcome are the Apnea Index (AI), Apnea/Hypopnea Index (AHI), Respiratory Distress Index (RDI), Respiratory Arousal Index, Respiratory Effort Related Arousals, and Oxygen Desaturation Index (ODI). Recently the American Academy of Sleep Medicine (AASM) formulated recommendations for clinical and research definitions of PSG studies.

A subjective measuring tool is the Epworth Sleepiness Scale, a questionnaire regarding hypersomnia. It was originally designed as an easy, noninvasive tool to distinguish SUS from OSAS. Although practical in use, it has been shown to have a low predictive value, and it cannot show the severity of the disease.

After assessment of the severity of the disease by PSG, it is of equal importance to determine the level of obstruction(s) in the upper airway.

Mallampati et al. developed the Mallampati clinical scoring system in the mid-1980s to predict difficulty in tracheal intubation based on the ability to visualize the faucial pillars, soft palate, and uvula base. The Mallampati score has been modified by Friedman et al., who studied the value of this type of assessment in patients with obstructive sleep apnea.

Friedman modified the original Mallampati score in the following ways:

• 1.

  Anesthesiologists assess the palate by asking the patient to protrude their tongue. The tongue position during sleep is not protruded, so we ask the patient only to open their mouth and not protrude their tongue.

• 2.

  Mallampati had three positions, and Friedman expanded to four positions and, most recently, has expanded it to five positions.

• 3.

  It really describes the position of the tongue more than the palate. The analysis, as used to assess OSAS, is therefore called the Friedman tongue position (see Chapter 16 ).

The Friedman staging system represents a clinical, anatomic staging system, independent of disease severity. Friedman et al. found patients classified with stage 1 disease had an 80.6% chance of successful cure with UPPP as opposed to success rates of 38% and 8% in stage 2 and stage 3, respectively. The major advantage of this system is its easy use in various settings and its ability to predict which patients are most likely to fail (stage 3).

Sleep(naso)endoscopy (sedated endoscopy) is another way of determining the levels of obstruction during induced sleep. This approach attempts to simulate the natural situation during snoring. Although this is a relatively time-consuming and costly method, it is also the best option for topical preoperative dynamic diagnostic workup for an ENT practice.

Despite reports that each method is capable of good preoperative workup, it is intriguing that the correlation between Friedman tongue position (or Friedman staging system) and findings with sleep endoscopy is low.

The importance of determining the level of obstruction or collapsibility of the pharynx is increasingly recognized. Globally one way of describing the level of pharynx anatomy involves the subdivision into retropalatal and retrolingual obstruction. This has led to the following, much applied, preoperative classification: type 1 refers to collapse at the retropalatal level, type 2 indicates collapse at both retropalatal and retrolingual levels, and type 3 means collapse at the retrolingual area.

3

Outline of Procedure

UPPP targets obstructions at the oropharyngeal level by removing and tightening excess pharyngeal tissue and shortening an elongated uvula and soft palate. These interventions are often combined with tonsillectomy to increase the oropharyngeal lumen (see Chapter 29 ).

4

Postoperative Complications

There are roughly three major groups of complications regarding UPPP:

• 1.

  Perioperative complications, such as edema and hemorrhage, can lead to life-threatening situations in an already compromised upper airway. Kezirian et al. investigated the perioperative mortality rate of UPPP in a large prospective cohort study and found a 30-day mortality rate of 0.2%, mostly due to unsuccessful upper airway management.

• 2.

  Short-term complications may comprise transient velopharyngeal incompetence apparent by wound dehiscence, hemorrhage, wound infection, mild nasal regurgitation, and in some cases hypernasal speech. In addition, severe postoperative pain and poor intake can contribute to overall morbidity.

• 3.

  Long-term complications include pharyngeal discomfort, dryness and tightness, postnasal secretions, dysphagia, prolonged angina, inability to initiate swallowing, speech and taste disturbances and numbness of the tongue, permanent velopharyngeal incompetence, and nasopharyngeal stenosis (NPS).

In addition, there have been reports that tolerance to nasal continuous positive airway pressure was diminished after UPPP, which compounds treatment failure because other options are now less successful, too.