Progress in successful surgical treatment of the obstructive sleep apnea/hypopnea syndrome (OSAHS) has been based on adjunctive treatment of the hypopharynx. Still the palate and oropharynx are the major areas of intervention, and certainly the most commonly operated upon. To ensure a successful outcome, appropriate surgical candidates must be identified. The authors present a method of clinical staging based on the position of the tongue relative to the soft palate as well as the size of the tonsils, aimed at identifying the most likely level of obstruction in patients who have OSAHS. We also present several surgical techniques that address obstruction at the level of the soft palate and oropharynx.
Obstructive sleep apnea/hypopnea syndrome (OSAHS) is a clinical entity resulting from obstruction, usually at multiple levels, of the upper airway during sleep. The current mainstay of management of OSAHS is continuous positive airway pressure (CPAP). CPAP, however, is not always an effective means of treatment of OSAHS, not only because it does not correct obstruction, but also because, in order to have a significant impact in OSAHS and its long-term repercussions at the cardiovascular level, it requires compliance from the patient, which, according to some studies, is lower than 50% over long-term follow-up . As otolaryngologists, we have the responsibility of helping the group of patients who cannot or will not accept CPAP as a permanent form of management. Surgical management of OSAHS first became an area of study when, in 1981, Fujita and colleagues introduced what is now considered the first procedure specifically designed to address obstruction of the upper airway for the treatment of OSAHS, the uvulopalatopharyngoplasty (UPPP). In spite of initial success, it became apparent that UPPP had limited effectiveness in curing OSAHS, as defined by reduction in the apnea-hypopnea index (AHI) by 50% to a final absolute value less than 20. A meta-analysis conducted by Sher and colleagues in 1996 reported data indicating that the procedure only had a 40% success rate in achieving cure in all patients undergoing UPPP for the treatment of OSAHS. Furthermore, a later study conducted by Senior and colleagues not only confirmed this figure, but actually described patients who worsened, both from the objective (polysomnogram) and subjective (daytime sleepiness symptoms and snoring) viewpoints following UPPP. This led to further investigation of the etiology of OSAHS, and it became clear that the causes for OSAHS were as multifaceted as the syndrome itself. It also became apparent that an effective system to identify the cause of upper airway obstruction in OSAHS patients—and the appropriate candidates for surgical intervention—was necessary, not only to improve outcomes, but to avoid treatment failures and complications.
On the other hand, manometric upper airway analysis studies by Woodson and Wooten showed that, aside from straightforward causes of obstruction such as craniofacial abnormalities, morbid obesity, and pan-airway obstruction, patients who present with persistent or recurrent OSAHS after UPPP have a residual retropalatal segment that keeps on causing obstruction in up to 75% of cases. These findings were confirmed by Metes and colleagues , who reported that after performing sleep nasendoscopy in patients who had surgical treatment failure, 50% presented with persistent retropalatal obstruction. So it is not only the appropriate selection of patients that is important in achieving the desired results, but also selection of the correct surgical procedure and adequately performing it.
Disease severity versus clinical staging: predictors of a successful outcome
Because of a significant failure rate of UPPP in curing OSAHS, it is evident that a selection process is necessary to identify appropriate candidates who benefit from the surgery to be performed. Without clinical studies, many otolaryngologists empirically treated patients who had mild disease, and avoided patients who had severe disease. Because OSAHS may be caused by multilevel obstruction, it is logical that mild as well as severe disease may be caused by hypopharyngeal obstruction. It became evident that the success rate of UPPP is not related to the severity of the disease. Localized obstruction at the level of the palate and tonsils may be mild, moderate, or severe. Patients who have obstruction localized to the oropharynx would be excellent candidates for UPPP. Studies by Friedman and colleagues have shown that severity is not a prognostic factor in determining success after the procedure. In fact, patients who have mild disease can be very poor candidates, and patients who have very severe disease have an excellent chance of being cured with UPPP. An anatomically-based staging system is thus able to identify areas of obstruction, and helps in tailoring the appropriate surgical treatment for each individual. It also helps identify the patients who have OSAHS who may not report clear-cut symptoms, and helps predict the success rate of the intervention, creating realistic expectations in both patient and surgeon. The severity of disease is a secondary factor, which plays a role in determining the need for treatment.
Parameters of the Friedman staging system
Tongue position
To assess the position of the tongue in relationship to the palate, the patient is asked to open his mouth wide without protruding the tongue. The procedure is repeated about five times, so that the observer can assign the most accurate position of the tongue. This tongue position is based on previous observations by Mallampati and colleagues , who suggested that the position of the tongue was an indicator of the ease or difficulty of endotracheal intubation by conventional techniques. This palate position was originally modified by Friedman and colleagues, and studied with respect to OSAHS. Originally named the “modified Mallampati palate position,” it was eventually renamed the “Friedman tongue position,” because it really assesses the position of the tongue with respect to the palate. Modifications by Friedman and colleagues were subsequently incorporated, yielding a staging system that is based on an assessment of the patient’s tongue in a neutral position (inside the mouth).
Mallampati originally described the palate position with the tongue protruded, and he only had three levels. The modification included the tongue in neutral position, and had four levels. This relates to the actual position of the tongue during sleep, as opposed to a protruded tongue, which is certainly not related to the mechanism of sleep apnea.
Tongue position I (Friedman tongue position I, or FTP I), allows the observer to visualize the entire uvula, tonsils, and tonsillar pillars. FTP II allows visualization of the uvula, but not the tonsils. FTP III allows visualization of the soft palate, but not the uvula, and FTP IV allows visualization of the hard palate only ( Fig. 1 ).
Tonsil size
The size of the tonsils also plays an important role in the staging and management of OSAHS patients. Tonsil size (TS) is graded from 0 to 4. TS 0 represents post-tonsillectomy patients. TS 1 implies tonsils hidden within the pillars. TS 2 represents tonsils that extend to the pillars. TS 3 refers to tonsils that extend beyond the pillars, but not all the way to the midline, whereas TS 4 tonsils (also known as “kissing tonsils”) reach the midline ( Fig. 2 ).
Body mass index
The relationship of body mass index (BMI), as calculated by the formula: weight (in kg)/(height (in m) 2 , and the presence and severity of OSAHS has been previously established . BMI can be graded based on accepted cutoff values. Grade 0 represents a BMI less than 20, grade I a BMI between 20 and 24, grade II a BMI between 25 and 29, grade III one between 30 and 39, and grade IV one 40 or greater. For the purpose of clinical staging, a cutoff of 40 for the BMI is considered to be an automatic inclusion criterion for stage IV. Most surgeons performing procedures for OSAHS agree that patients who have a BMI 40 or greater have a poor prognosis for cure after UPPP. BMI also substitutes for neck circumference, which is also an indicator of obesity.
Based on these parameters, patients can be divided in four anatomical stages, as shown in Fig. 3 . Stage I is defined as those patients who have FTP I or II, TS 3 or 4, and BMI less than 40. Stage II disease is defined as FTP I or II, and TS 0, 1, or 2, or FTP III and IV with TS 3 or 4, and BMI less than 40. Stage III disease is defined as FTP III or IV, and TS 0, 1, or 2, with a BMI less than 40. All patients who have BMI 40 or greater, or significant craniofacial or anatomical abnormalities (eg, micrognathia, midface hypoplasia) are grouped in stage IV .
Parameters of the Friedman staging system
Tongue position
To assess the position of the tongue in relationship to the palate, the patient is asked to open his mouth wide without protruding the tongue. The procedure is repeated about five times, so that the observer can assign the most accurate position of the tongue. This tongue position is based on previous observations by Mallampati and colleagues , who suggested that the position of the tongue was an indicator of the ease or difficulty of endotracheal intubation by conventional techniques. This palate position was originally modified by Friedman and colleagues, and studied with respect to OSAHS. Originally named the “modified Mallampati palate position,” it was eventually renamed the “Friedman tongue position,” because it really assesses the position of the tongue with respect to the palate. Modifications by Friedman and colleagues were subsequently incorporated, yielding a staging system that is based on an assessment of the patient’s tongue in a neutral position (inside the mouth).
Mallampati originally described the palate position with the tongue protruded, and he only had three levels. The modification included the tongue in neutral position, and had four levels. This relates to the actual position of the tongue during sleep, as opposed to a protruded tongue, which is certainly not related to the mechanism of sleep apnea.
Tongue position I (Friedman tongue position I, or FTP I), allows the observer to visualize the entire uvula, tonsils, and tonsillar pillars. FTP II allows visualization of the uvula, but not the tonsils. FTP III allows visualization of the soft palate, but not the uvula, and FTP IV allows visualization of the hard palate only ( Fig. 1 ).
Tonsil size
The size of the tonsils also plays an important role in the staging and management of OSAHS patients. Tonsil size (TS) is graded from 0 to 4. TS 0 represents post-tonsillectomy patients. TS 1 implies tonsils hidden within the pillars. TS 2 represents tonsils that extend to the pillars. TS 3 refers to tonsils that extend beyond the pillars, but not all the way to the midline, whereas TS 4 tonsils (also known as “kissing tonsils”) reach the midline ( Fig. 2 ).
Body mass index
The relationship of body mass index (BMI), as calculated by the formula: weight (in kg)/(height (in m) 2 , and the presence and severity of OSAHS has been previously established . BMI can be graded based on accepted cutoff values. Grade 0 represents a BMI less than 20, grade I a BMI between 20 and 24, grade II a BMI between 25 and 29, grade III one between 30 and 39, and grade IV one 40 or greater. For the purpose of clinical staging, a cutoff of 40 for the BMI is considered to be an automatic inclusion criterion for stage IV. Most surgeons performing procedures for OSAHS agree that patients who have a BMI 40 or greater have a poor prognosis for cure after UPPP. BMI also substitutes for neck circumference, which is also an indicator of obesity.
Based on these parameters, patients can be divided in four anatomical stages, as shown in Fig. 3 . Stage I is defined as those patients who have FTP I or II, TS 3 or 4, and BMI less than 40. Stage II disease is defined as FTP I or II, and TS 0, 1, or 2, or FTP III and IV with TS 3 or 4, and BMI less than 40. Stage III disease is defined as FTP III or IV, and TS 0, 1, or 2, with a BMI less than 40. All patients who have BMI 40 or greater, or significant craniofacial or anatomical abnormalities (eg, micrognathia, midface hypoplasia) are grouped in stage IV .
