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Modified uvulopalatopharyngoplasty for the treatment of obstructive sleep apnea-hypopnea syndrome: Resection of the musculus uvulae
Otolaryngology–Head and Neck Surgery (2009) 140, 924-929
ORIGINAL RESEARCH—SLEEP MEDICINE
Modified uvulopalatopharyngoplasty for the treatment of obstructive sleep apnea-hypopnea syndrome: Resection of the musculus uvulae Seung-Heon Shin, MD, Mi-Kyung Ye, MD, and Chang-Gyun Kim, MD, Daegu, South Korea No sponsorships or competing interests have been disclosed for this article. ABSTRACT OBJECTIVE: To assess the outcome of a modified uvulopalatopharynbgoplasty (UPPP) technique with preservation of the uvula mucosa and partial resection of the musculus uvula. STUDY DESIGN AND METHODS: A prospective randomized controlled trial. Sixteen male patients underwent a classic UPPP, and another 16 male patients underwent a modified UPPP. The parameters evaluated were the subjective symptom score, the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Stanford Sleepiness Scale (SSS), and polysomnography results. RESULTS: Postoperative snoring, apnea, morning headache, daytime sleepiness, pharyngeal foreign body sensation, and global discomfort were not significantly different between the two groups. Among seven subjective measures of sleep quality from the PSQI, the subjective sleep quality was significantly improved in both groups. Postoperatively, the SSS was not significantly changed in both groups; however, the ESS was significantly improved in both groups. The polysomnographic findings showed a statistically significantly improvement in the apnea index and the apnea-hypopnea index. CONCLUSION: Although the modified group did not have more profound improvement in sleep quality and decreased postoperative pharyngeal discomfort, modified UPPP was an effective surgical method for the treatment of obstructive sleep apneahypopnea syndrome. © 2009 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
O
bstructive sleep apnea-hypopnea syndrome (OSAHS) is a clinical entity resulting from obstruction of the upper airway during sleep. Structural narrowing of the pharyngeal airway increases the inspiratory pressure within this region, and apnea occurs when the inspiratory transpharyngeal pressure exceeds the pharyngeal dilating muscle tone. In 1981, Fujita et al1 introduced the uvulopalatopharyngoplasty (UPPP); the first procedure was specifically designed to address the obstruction of the upper airway for the treat-
ment of OSAHS. The goal of the UPPP is to reduce the obstruction by eliminating redundant mucosal folds, obstructing tonsils, and excess soft palate tissue. Despite initial success, there is about a 50 percent success rate in achieving cure in all patients undergoing the UPPP for the treatment of OSAHS.2 Furthermore, the UPPP has been associated with complications such as palatopharyngeal incompetency and palatopharyngeal stenosis. To reduce the complication rate without compromising the surgical response, several modified surgical techniques have been suggested.3-5 The uvula, although small and seemingly unimportant, has several physiological functions. The uvula prevents excessive nasality of the voice by controlling resonance of the air column over the larynx and prevents rhinolalia aperta. The uvula is the first tissue that an alimentary bolus contacts, and then the nasopharyngeal cavity is closed by the contraction of palateuvularis muscle. The stroma of the mucosa covering the uvula consists of a loose connective tissue, mixed seromucous glands, and adipose cells with diffuse interdigitated muscle fibers, which play a major role in moistening the oral cavity.6,7 The uvulotomy is a procedure for treatment of a large elongated uvula. The postoperative discomforts of an uvulotomy are feeling of obstruction in the throat, disordered sense of taste, and difficulty in disgorging fish bones while eating fish.8 A common late complication of surgery involving the removal of the uvula is pharyngeal dryness. This study was designed to assess the outcome of a modified UPPP technique with preservation of the uvula mucosa and partial resection of the musculus uvula. Measurements of the objective symptom score, sleep questionnaire, and postoperative polysomnographic findings were analyzed. The experimental group undergoing the modified procedure was compared with a group of patients treated by the classic UPPP.
METHODS Thirty-two patients who complained of snoring, sleep apnea, daytime sleepiness, and fatigue were included in the
Received August 27, 2008; revised January 9, 2009; accepted January 14, 2009.
0194-5998/$36.00 © 2009 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved. doi:10.1016/j.otohns.2009.01.020
Shin et al
Modified uvulopalatopharyngoplasty for the . . .
study. We conducted a prospective single-blind randomized controlled trial with a simple randomization method. Patients originally selected for UPPP were subsequently assigned into one of two groups. The first was the classic group, and the second was the modified group with resection of the musculus uvulae and uvula mucosal preservation. We included men with habitual snoring who were over 18 years old with an apnea-hypopnea index greater than 10 and who failed or refused therapy with continuous positiveairway pressure. Patients were excluded if they required nasal surgery or hyphopharyngeal and tongue base surgery and if they had gross maxillary or mandibular deformities (Fig 1). The study was approved by the Institutional Review Board of Daegu Catholicu University Medical Center, and each patient signed a consent form that outlined the objectives of the research and experimental risks.
Figure 1
925
Clinical Evaluation Each patient was evaluated preoperatively and at 6 months after the surgery. At both times, we assessed the body mass index (the weight in kilograms divided by the square of the height in meters), the Epworth Sleepiness Scale (ESS), the Stanford Sleepiness Scale (SSS), and the Pittsburgh Sleep Quality Index (PSQI). The PSQI consists of the subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, use of sleeping medication, daytime dysfunction, and the global PSQI score. The objective sleep symptom scores with scales ranging from 1 (irrelevant) to 10 (severely affected) were used to evaluate snoring, apnea, daytime sleepiness, morning headache, pharyngeal discomfort, and the overall impact of the disease on quality of life. These clinical evaluations were performed by a neuropsychologist who did not have the patient information.
A flow diagram of patient recruitment, enrollment, and follow-up.
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Otolaryngology–Head and Neck Surgery, Vol 140, No 6, June 2009
Polysomnography
Surgical Procedure
All subjects underwent an overnight polysomnography with a test time of 7 to 8 hours preoperatively, and 20 patients had a polysomnography performed at least 6 months after the surgery. Continuous recording of an electroencephalogram (C3-A2 and C4-A1), electro-oculogram, electrocardiogram, chin and anterior tibial electromyogram, abdominal and thoracic movement by inductive plethysmograph, nasal oral airflow, oxygen saturation by pulse oxymeter, and throat sonogram were performed during the recordings. The definition of apnea and hypopnea conformed to the recommended definition of the American Academy of Sleep Medicine. Apnea was defined as a cessation of breathing for at least 10 seconds. Hypopnea was defined as a reduction by more than 50 percent of the basal ventilator value or a reduction of 50 percent or less that is associated with a decrease in oxyhemoglobin saturation above 3 percent or with an arousal. The variables evaluated included the apnea-hypopnea index (AHI), apnea index (AI), mean oxygen saturation, lowest oxygen saturation, and sleep efficiency.
The classic and modified UPPP were performed under general anesthesia with oral intubation and with the heads of the patients extended. The classic UPPP performed was the Simmons’s method.9 We used 4.0 Vicryl (Ethicon Inc, Somerville, NJ) for all sutures. The modified UPPP started with a bilateral tonsillectomy; an incision of the dorsal surface of soft palate was performed at the root of the uvula, about 0.5 cm below the dimple point, and undermined the mucosa to expose the musculus uvulae (Fig 2). Then, 1 to 1.5 cm of full thickness of the musculus uvulae was exposed and resected with sharp dissecting scissors, and the musculus uvulae and incised mucosa were sutured. After that procedure, the uvula was everted with a tenting effect to widen the anterior-posterior dimension of the retropalatal area. To widen the pharyngeal space, releasing incisions in the posterior tonsillar pillars were performed at the level of the palatoglossal line and then the redundant pharyngeal mucosa and muscle were resected (Fig 2). The incision was carefully performed so as not to injure the uvular artery and vein, located in the posterior pillar about 3 to 4 mm from its edge running
Figure 2 Surgical findings of the modified uvulopalatopharyngoplasty. (A and C) The oral cavity shows the incision site for the dissection of musculus uvulae (hatched area) and palatoglossal line (dashed line). (B and D) Postoperative findings show several suture sites, and the retropalatal space was widened with the eversion of musculus uvulae.
Shin et al
Modified uvulopalatopharyngoplasty for the . . .
upwards and medially parallel to the muscle fibers, and to avoid postoperative swelling.10 The lateralized and separated posterior pillar and anterior pillar were closed with interrupted sutures so that the oropharyngeal cavity was enlarged and the lateral pharyngeal wall stabilized.
Statistical Analysis The sample size was calculated based on the mean and the standard deviation for pharyngeal discomfort with a moderate effect size of 0.5. The number of patients for the accuracy of the test was determined with 90 percent power. All statistical analyses were performed by using SPSS version 12.0.1 (SPSS Inc, Chicago, IL). Continuous data are displayed as the mean ⫾ standard deviation. A paired t test was used to compare the preoperative with the postoperative mean values within each group. A repeated-measures twofactor analysis and the Wilcoxon signed rank test were used for between-group comparisons.
RESULTS Thirty-two patients were included in this study. Table 1 shows the demographic data, including mean age, mean body mass index (BMI), AHI, oxygen saturation, sleep efficacy, and arousal index. There were no statistical differences between the two groups with regard to mean age, mean preoperative BMI, and the polysomnographic indexes.
Subjective Symptom and Sleep Quality Improvement The patients and their sleeping partners’ subjective assessment of disease severity and discomforts were collected at the time of the 6- to 12-month postoperative follow-up examination. Snoring, apnea, morning headache, daytime sleepiness, pharyngeal foreign body sensation, and global discomfort were compared between the UPPP and the modified UPPP groups. There were no significant differences between the two groups (Table 2).
Table 1 Demographic data for 32 patients who underwent either the UPPP or MUPPP for the treatment of the obstructive sleep apnea-hypopnea syndrome
Age BMI AHI PaO2 Sleep efficiency Arousal index
UPPP (n ⫽ 16)
MUPPP (n ⫽ 16)
P value
45.9 (28-77) 24.9 (20-31) 38.3 (10-70) 84.5 (70-95) 82.5 41.7
45.2 (30-70) 26.0 (21-30) 34.9 (16-72) 83.5 (74-93) 85.7 35.0
0.331 0.697 0.689 0.415 0.273
927
Table 2 Comparison of postoperative subjective symptoms between UPPP and MUPPP groups UPPP (n ⫽ 16) Snoring Apnea Morning headache Daytime sleepiness Pharyngeal discomfort Global discomfort
3.3 1.1 0.8 1.7 0.6 6.8
⫾ ⫾ ⫾ ⫾ ⫾ ⫾
0.7 0.6 0.4 0.6 0.3 0.5
MUPPP (n ⫽ 16)
P value
⫾ ⫾ ⫾ ⫾ ⫾ ⫾
0.661 0.828 0.810 0.700 0.358 0.971
3.7 1.3 0.7 1.4 1.1 6.9
0.7 0.6 0.4 0.5 0.4 0.5
The PSQI is an effective instrument that is used to measure the quality and pattern of sleep in adults by the measurement of seven areas: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Scoring of the answers is based on a 0 to 3 rating scale. Among the seven areas, the subjective sleep quality was significantly improved in both the UPPP and the modified UPPP groups. In addition, habitual sleep efficiency was improved in the modified group, and daytime dysfunction was significantly improved in the classic group (Fig 3). The SSS is a quick way to assess patient alertness, and the ESS is a questionnaire intended to measure daytime sleepiness. The SSS was not significantly changed in either the classic UPPP or the modified UPPP groups. However, the ESS was significantly changed in both groups (Fig 4). Among the 32 patients, we evaluated the postoperative polysomnography scores in 20 patients; the mean interval was 10 months after surgery (6-18 months). Table 2 shows the polysomnographic data for before and after the surgery. Both groups showed a statistically significant improvement of the AI and AHI. Patients who showed a 50 percent or more reduction in the AHI and postoperative AHI less than 20 were 30 percent in the UPPP group and 40 percent in the modified UPPP group. In addition, we noted a tendency toward an increase in the sleep efficiency, but this finding was not statistically significant. In addition, there was no significant change in the peripheral oxygen saturation (Table 3).
DISCUSSION UPPP was first reported by Fujita et al1 for the treatment of OSAHS. It is a surgical procedure designed to eliminate palatal and pharyngeal redundancy by resection of excess loose palatal and pharyngeal mucosa and submucosal tissue in addition to tonsillectomy. The classic UPPP includes an uvulotomy that specifically addresses an elongated and large uvula. Velopharyngeal insufficiency and nasopharyngeal stenosis are two dreaded postoperative complications of the UPPP. The complications of a uvulotomy are stenosis
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Otolaryngology–Head and Neck Surgery, Vol 140, No 6, June 2009
Figure 3 A comparison of preoperative versus postoperative measures on the Pittsburgh sleep quality index in patients with obstructive sleep apnea-hypopnea syndrome treated with the classic UPPP and MUPPP. *Significant difference between preoperative and postoperative values. P ⬍ 0.05.
of the pharynx, tubal disorders, and regurgitation of food through the nose. Considering the soft palate’s anatomy and the uvula’s function (deglutition, humidification of inspired air, speech, and pharyngeal airway dilation7,11), we suggest that the modified UPPP, in which the uvula mucosa is preserved and a portion of the musculus uvulae is removed, allows for the maintaining of the normal shape of the uvula and soft palate. The large elongated uvula is shortened by the musculus uvulae, and the retropalatal space should be widened with the eversion of the musculus uvulae by suturing. We thought that the improvement of the modified UPPP would include reduced postoperative pain and use of narcotic pain medication and would support an early return to a normal diet because the uvula and its mucosa were not removed. However, there were no significant differences between the two groups (data not shown). In some cases, the snoring and apnea were aggravated by the modified UPPP procedure because of the swelling of the uvula. The uvular artery and vein reach the wall of the pharynx at a point where the styopharyngeus muscle joins with the posterolat-
Figure 4 A comparison of preoperative versus postoperative measures on the SSS and the ESS in patients with obstructive sleep apnea-hypopnea syndrome treated by the classic UPPP and MUPPP. *Significant difference between preoperative and postoperative values. P ⬍ 0.05.
eral wall of the pharynx; inside the pharynx, they pass upwards and medially along the palatopharyngeus muscle in the posterior pillar of the palate. Here, the vessels are close to the tonsil.10 To prevent vessel injury and postoperative swelling of the uvula, careful dissection is required of the upper pole of the tonsil and the musculus uvulae. The uvula consists of three main components: the surface epithelium, the subepithelial region, and an area with glandular tissue.12 The uvula has an abundance of seromucous glands with the ability to produce large volumes of thin saliva. A common late complication of uvulotomy is pharyngeal dryness. The preservation of the uvula and its mucosa may improve postoperative pharyngeal discomfort, such as a foreign body sensation and dryness. However, the results of this study showed that the postoperative subjective symptoms were not significantly different in comparisons between the two groups. The seromucous glands were arranged into acini, and they were embedded in a network of striated muscle cell bundles and adipose cells.13 Although we preserved the shape and mucosa of the uvula, during the dissection of the musculus uvulae, the seromucous glands may have been damaged. The presence of a postoperative scar may also interfere with the production of saliva. UPPP has remained the main surgery for the OSAHS. However, about 50 percent of cases have nonresponders among unselected patients. Several modified methods have been suggested to improve the postoperative symptoms and to reduce the postoperative complications.3-5,14,15 In the present study, we evaluated the surgical efficacy with subjective questionnaires and objective polysomnography. The PQSI is designed to evaluate sleep quality in seven domains. When we compared the raw scores alone, subjective sleep quality was significantly improved in both groups. In addition, the habitual sleep efficiency was significantly improved in the modified UPPP, and daytime dysfunction was significantly improved with the classic UPPP. However, the global PQSI score was significantly improved with both the classic and modified UPPP. The postoperative PQSI and ESS scores were not significantly different between two
Shin et al
Modified uvulopalatopharyngoplasty for the . . .
929
Table 3 Comparison of pre- and postoperative polysomnographic data
UPPP (n ⫽ 10) Preoperative Postoperative MUPPP (n ⫽ 10) Preoperative Postoperative
AI
AHI
Mean SaO2
Lowest SaO2
Sleep efficiency
33.0 ⫾ 16.7 13.56 ⫾ 5.1
54.3 ⫾ 13.5 35.3 ⫾ 24.8
89.5 ⫾ 13.9 91.2 ⫾ 10.3
87.4 ⫾ 6.7 87.0 ⫾ 4.1
80.5 ⫾ 18.1 92.6 ⫾ 2.3
34.3 ⫾ 30.6 15.5 ⫾ 23.3
56.1 ⫾ 23.1 34.7 ⫾ 27.2
93.9 ⫾ 8.9 94.8 ⫾ 1.5
74.6 ⫾ 9.0 80.5 ⫾ 5.2
81.3 ⫾ 8.5 88.3 ⫾ 8.3
groups. According to the postoperative polysomnography, the AI and AHI were significantly improved in both groups, and there were no statistically significant differences between the two groups. When we compared the changes in sleep quality within the classic and modified UPPP groups, both groups had similar effects on the improvement of sleep quality and symptom improvement.
CONCLUSION The uvula, although small and seemingly unimportant, may have multiple functions, playing a role in speech, swallowing, and lubrication of the throat. The preservation of the shape and the mucosa of the uvula might be physiologically and morphologically important. Although the modified UPPP group in this study did not have more profound improvement in their sleep quality and decreased postoperative pharyngeal discomfort, the modified UPPP, which resects the musculus uvulae with mucosa preservation of the mucosa of the uvula, was an effective surgery for the treatment of OSAHS.
AUTHOR INFORMATION From the Department of Otorhinolaryngology, School of Medicine, Catholic University of Daegu, Daegu, South Korea. Corresponding author: Seung-Heon Shin, MD, Department of Otolaryngology, Daegu Catholic University Hospital, 3056-6 Daemyung 4 Dong, Nam-Gu, Daegu, South Korea 705-718. E-mail address: [email protected].
AUTHOR CONTRIBUTIONS Seung-Heon Shin, study design; Mi-Kyung Ye, data collection, data analysis, institutional review board approval; Chang-Gyun Kim, data analysis, writer.
DISCLOSURES Competing interests: None. Sponsorships: None.
REFERENCES 1. Fujita S, Conway W, Zorick F, et al. Surgical correction of anatomic abnormalities in obstructive sleep apnea syndrome: uvulopalatopharyngoplasty. Otolaryngol Head Neck Surg 1981;89:923–34. 2. Sher AE, Schechtman KB, Piccirillo JF. The efficacy of surgical modifications of the upper airway in adults with obstructive sleep apnea syndrome. Sleep 1996;19:156 –77. 3. Friedman M, Landsberg R, Tanyeri H. Submucosal uvulopalatopharyngoplasty. Op Tech Otolaryngol Head Neck Surg 2000;11:26 –9. 4. Woodson BT. Transpalatal advancement pharyngoplasty for obstructive sleep apnea. Op Tech Otolaryngol Head Neck Surg 2000; 11:36 – 40. 5. Cahali MB. Lateral pharyngoplasty: a new treatment for obstructive sleep apnea hypopnea syndrome. Laryngoscope 2003;113:1961– 8. 6. Series F, Cote C, Simoneau JA, et al. Physiologic, metabolic, and muscle fiber type characteristics of musculus uvulae in sleep apnea hypopnea syndrome and in snorers. J Clin Invest 1995;95:20 –5. 7. Huang MH, Lee ST, Rajendran K. Structure of the musculus uvulae: functional and surgical implications of an anatomic study. Cleft Palate Craniofac J 1997;34:466 –74. 8. Mukai S, Mukai C, Nitta M. Functions of the uvula and Z-pharyngoplasty. Psychiatry Clin Nerosci 2000;54:346 –7. 9. Simmons FB, Guilleminault C, Silvestri R. Snoring and some obstructive sleep apnea can be cured by oropharyngeal surgery: palatopharyngoplasty. Arch Otolaryngol 1983;109:503–7. 10. Girgis IH. Blood supply of the uvula and its surgical importance. J Laryngol Otol 1966;80:397– 402. 11. Series F, Simoneau JA, St Pierre S. Muscle fiber area distribution of musculus uvulae in obstructive sleep apnea and non-apneic snorers. Int J Obese Relat Metab Disord 2000;24:410 –5. 12. Back GW, Nadig S, Uppal S, et al. Why do we have a uvula?: Literature review and a new theory. Clin Otolaryngol 2004;29:689 –93. 13. Olofsson K, Mattsson C, Hammarstrom ML, et al. Structure of the human uvula. Acta Otolaryngol 1999;119:712–7. 14. Han D, Ye J, Lin Z, et al. Revised uvulopalatopharyngoplasty with uvula preservation and its clinical study. Otorhinolaryngol 2005;67: 213–9. 15. Friedman M, Ibrahim H, Lowenthal S, et al. Uvulopalatoplasty (UP2): a modified technique for selected patients. Laryngoscope 2004;114: 441–9.
ORIGINAL RESEARCH—SLEEP MEDICINE
Modified uvulopalatopharyngoplasty for the treatment of obstructive sleep apnea-hypopnea syndrome: Resection of the musculus uvulae Seung-Heon Shin, MD, Mi-Kyung Ye, MD, and Chang-Gyun Kim, MD, Daegu, South Korea No sponsorships or competing interests have been disclosed for this article. ABSTRACT OBJECTIVE: To assess the outcome of a modified uvulopalatopharynbgoplasty (UPPP) technique with preservation of the uvula mucosa and partial resection of the musculus uvula. STUDY DESIGN AND METHODS: A prospective randomized controlled trial. Sixteen male patients underwent a classic UPPP, and another 16 male patients underwent a modified UPPP. The parameters evaluated were the subjective symptom score, the Pittsburgh Sleep Quality Index (PSQI), the Epworth Sleepiness Scale (ESS), the Stanford Sleepiness Scale (SSS), and polysomnography results. RESULTS: Postoperative snoring, apnea, morning headache, daytime sleepiness, pharyngeal foreign body sensation, and global discomfort were not significantly different between the two groups. Among seven subjective measures of sleep quality from the PSQI, the subjective sleep quality was significantly improved in both groups. Postoperatively, the SSS was not significantly changed in both groups; however, the ESS was significantly improved in both groups. The polysomnographic findings showed a statistically significantly improvement in the apnea index and the apnea-hypopnea index. CONCLUSION: Although the modified group did not have more profound improvement in sleep quality and decreased postoperative pharyngeal discomfort, modified UPPP was an effective surgical method for the treatment of obstructive sleep apneahypopnea syndrome. © 2009 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
O
bstructive sleep apnea-hypopnea syndrome (OSAHS) is a clinical entity resulting from obstruction of the upper airway during sleep. Structural narrowing of the pharyngeal airway increases the inspiratory pressure within this region, and apnea occurs when the inspiratory transpharyngeal pressure exceeds the pharyngeal dilating muscle tone. In 1981, Fujita et al1 introduced the uvulopalatopharyngoplasty (UPPP); the first procedure was specifically designed to address the obstruction of the upper airway for the treat-
ment of OSAHS. The goal of the UPPP is to reduce the obstruction by eliminating redundant mucosal folds, obstructing tonsils, and excess soft palate tissue. Despite initial success, there is about a 50 percent success rate in achieving cure in all patients undergoing the UPPP for the treatment of OSAHS.2 Furthermore, the UPPP has been associated with complications such as palatopharyngeal incompetency and palatopharyngeal stenosis. To reduce the complication rate without compromising the surgical response, several modified surgical techniques have been suggested.3-5 The uvula, although small and seemingly unimportant, has several physiological functions. The uvula prevents excessive nasality of the voice by controlling resonance of the air column over the larynx and prevents rhinolalia aperta. The uvula is the first tissue that an alimentary bolus contacts, and then the nasopharyngeal cavity is closed by the contraction of palateuvularis muscle. The stroma of the mucosa covering the uvula consists of a loose connective tissue, mixed seromucous glands, and adipose cells with diffuse interdigitated muscle fibers, which play a major role in moistening the oral cavity.6,7 The uvulotomy is a procedure for treatment of a large elongated uvula. The postoperative discomforts of an uvulotomy are feeling of obstruction in the throat, disordered sense of taste, and difficulty in disgorging fish bones while eating fish.8 A common late complication of surgery involving the removal of the uvula is pharyngeal dryness. This study was designed to assess the outcome of a modified UPPP technique with preservation of the uvula mucosa and partial resection of the musculus uvula. Measurements of the objective symptom score, sleep questionnaire, and postoperative polysomnographic findings were analyzed. The experimental group undergoing the modified procedure was compared with a group of patients treated by the classic UPPP.
METHODS Thirty-two patients who complained of snoring, sleep apnea, daytime sleepiness, and fatigue were included in the
Received August 27, 2008; revised January 9, 2009; accepted January 14, 2009.
0194-5998/$36.00 © 2009 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved. doi:10.1016/j.otohns.2009.01.020
Shin et al
Modified uvulopalatopharyngoplasty for the . . .
study. We conducted a prospective single-blind randomized controlled trial with a simple randomization method. Patients originally selected for UPPP were subsequently assigned into one of two groups. The first was the classic group, and the second was the modified group with resection of the musculus uvulae and uvula mucosal preservation. We included men with habitual snoring who were over 18 years old with an apnea-hypopnea index greater than 10 and who failed or refused therapy with continuous positiveairway pressure. Patients were excluded if they required nasal surgery or hyphopharyngeal and tongue base surgery and if they had gross maxillary or mandibular deformities (Fig 1). The study was approved by the Institutional Review Board of Daegu Catholicu University Medical Center, and each patient signed a consent form that outlined the objectives of the research and experimental risks.
Figure 1
925
Clinical Evaluation Each patient was evaluated preoperatively and at 6 months after the surgery. At both times, we assessed the body mass index (the weight in kilograms divided by the square of the height in meters), the Epworth Sleepiness Scale (ESS), the Stanford Sleepiness Scale (SSS), and the Pittsburgh Sleep Quality Index (PSQI). The PSQI consists of the subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbance, use of sleeping medication, daytime dysfunction, and the global PSQI score. The objective sleep symptom scores with scales ranging from 1 (irrelevant) to 10 (severely affected) were used to evaluate snoring, apnea, daytime sleepiness, morning headache, pharyngeal discomfort, and the overall impact of the disease on quality of life. These clinical evaluations were performed by a neuropsychologist who did not have the patient information.
A flow diagram of patient recruitment, enrollment, and follow-up.
926
Otolaryngology–Head and Neck Surgery, Vol 140, No 6, June 2009
Polysomnography
Surgical Procedure
All subjects underwent an overnight polysomnography with a test time of 7 to 8 hours preoperatively, and 20 patients had a polysomnography performed at least 6 months after the surgery. Continuous recording of an electroencephalogram (C3-A2 and C4-A1), electro-oculogram, electrocardiogram, chin and anterior tibial electromyogram, abdominal and thoracic movement by inductive plethysmograph, nasal oral airflow, oxygen saturation by pulse oxymeter, and throat sonogram were performed during the recordings. The definition of apnea and hypopnea conformed to the recommended definition of the American Academy of Sleep Medicine. Apnea was defined as a cessation of breathing for at least 10 seconds. Hypopnea was defined as a reduction by more than 50 percent of the basal ventilator value or a reduction of 50 percent or less that is associated with a decrease in oxyhemoglobin saturation above 3 percent or with an arousal. The variables evaluated included the apnea-hypopnea index (AHI), apnea index (AI), mean oxygen saturation, lowest oxygen saturation, and sleep efficiency.
The classic and modified UPPP were performed under general anesthesia with oral intubation and with the heads of the patients extended. The classic UPPP performed was the Simmons’s method.9 We used 4.0 Vicryl (Ethicon Inc, Somerville, NJ) for all sutures. The modified UPPP started with a bilateral tonsillectomy; an incision of the dorsal surface of soft palate was performed at the root of the uvula, about 0.5 cm below the dimple point, and undermined the mucosa to expose the musculus uvulae (Fig 2). Then, 1 to 1.5 cm of full thickness of the musculus uvulae was exposed and resected with sharp dissecting scissors, and the musculus uvulae and incised mucosa were sutured. After that procedure, the uvula was everted with a tenting effect to widen the anterior-posterior dimension of the retropalatal area. To widen the pharyngeal space, releasing incisions in the posterior tonsillar pillars were performed at the level of the palatoglossal line and then the redundant pharyngeal mucosa and muscle were resected (Fig 2). The incision was carefully performed so as not to injure the uvular artery and vein, located in the posterior pillar about 3 to 4 mm from its edge running
Figure 2 Surgical findings of the modified uvulopalatopharyngoplasty. (A and C) The oral cavity shows the incision site for the dissection of musculus uvulae (hatched area) and palatoglossal line (dashed line). (B and D) Postoperative findings show several suture sites, and the retropalatal space was widened with the eversion of musculus uvulae.
Shin et al
Modified uvulopalatopharyngoplasty for the . . .
upwards and medially parallel to the muscle fibers, and to avoid postoperative swelling.10 The lateralized and separated posterior pillar and anterior pillar were closed with interrupted sutures so that the oropharyngeal cavity was enlarged and the lateral pharyngeal wall stabilized.
Statistical Analysis The sample size was calculated based on the mean and the standard deviation for pharyngeal discomfort with a moderate effect size of 0.5. The number of patients for the accuracy of the test was determined with 90 percent power. All statistical analyses were performed by using SPSS version 12.0.1 (SPSS Inc, Chicago, IL). Continuous data are displayed as the mean ⫾ standard deviation. A paired t test was used to compare the preoperative with the postoperative mean values within each group. A repeated-measures twofactor analysis and the Wilcoxon signed rank test were used for between-group comparisons.
RESULTS Thirty-two patients were included in this study. Table 1 shows the demographic data, including mean age, mean body mass index (BMI), AHI, oxygen saturation, sleep efficacy, and arousal index. There were no statistical differences between the two groups with regard to mean age, mean preoperative BMI, and the polysomnographic indexes.
Subjective Symptom and Sleep Quality Improvement The patients and their sleeping partners’ subjective assessment of disease severity and discomforts were collected at the time of the 6- to 12-month postoperative follow-up examination. Snoring, apnea, morning headache, daytime sleepiness, pharyngeal foreign body sensation, and global discomfort were compared between the UPPP and the modified UPPP groups. There were no significant differences between the two groups (Table 2).
Table 1 Demographic data for 32 patients who underwent either the UPPP or MUPPP for the treatment of the obstructive sleep apnea-hypopnea syndrome
Age BMI AHI PaO2 Sleep efficiency Arousal index
UPPP (n ⫽ 16)
MUPPP (n ⫽ 16)
P value
45.9 (28-77) 24.9 (20-31) 38.3 (10-70) 84.5 (70-95) 82.5 41.7
45.2 (30-70) 26.0 (21-30) 34.9 (16-72) 83.5 (74-93) 85.7 35.0
0.331 0.697 0.689 0.415 0.273
927
Table 2 Comparison of postoperative subjective symptoms between UPPP and MUPPP groups UPPP (n ⫽ 16) Snoring Apnea Morning headache Daytime sleepiness Pharyngeal discomfort Global discomfort
3.3 1.1 0.8 1.7 0.6 6.8
⫾ ⫾ ⫾ ⫾ ⫾ ⫾
0.7 0.6 0.4 0.6 0.3 0.5
MUPPP (n ⫽ 16)
P value
⫾ ⫾ ⫾ ⫾ ⫾ ⫾
0.661 0.828 0.810 0.700 0.358 0.971
3.7 1.3 0.7 1.4 1.1 6.9
0.7 0.6 0.4 0.5 0.4 0.5
The PSQI is an effective instrument that is used to measure the quality and pattern of sleep in adults by the measurement of seven areas: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Scoring of the answers is based on a 0 to 3 rating scale. Among the seven areas, the subjective sleep quality was significantly improved in both the UPPP and the modified UPPP groups. In addition, habitual sleep efficiency was improved in the modified group, and daytime dysfunction was significantly improved in the classic group (Fig 3). The SSS is a quick way to assess patient alertness, and the ESS is a questionnaire intended to measure daytime sleepiness. The SSS was not significantly changed in either the classic UPPP or the modified UPPP groups. However, the ESS was significantly changed in both groups (Fig 4). Among the 32 patients, we evaluated the postoperative polysomnography scores in 20 patients; the mean interval was 10 months after surgery (6-18 months). Table 2 shows the polysomnographic data for before and after the surgery. Both groups showed a statistically significant improvement of the AI and AHI. Patients who showed a 50 percent or more reduction in the AHI and postoperative AHI less than 20 were 30 percent in the UPPP group and 40 percent in the modified UPPP group. In addition, we noted a tendency toward an increase in the sleep efficiency, but this finding was not statistically significant. In addition, there was no significant change in the peripheral oxygen saturation (Table 3).
DISCUSSION UPPP was first reported by Fujita et al1 for the treatment of OSAHS. It is a surgical procedure designed to eliminate palatal and pharyngeal redundancy by resection of excess loose palatal and pharyngeal mucosa and submucosal tissue in addition to tonsillectomy. The classic UPPP includes an uvulotomy that specifically addresses an elongated and large uvula. Velopharyngeal insufficiency and nasopharyngeal stenosis are two dreaded postoperative complications of the UPPP. The complications of a uvulotomy are stenosis
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Otolaryngology–Head and Neck Surgery, Vol 140, No 6, June 2009
Figure 3 A comparison of preoperative versus postoperative measures on the Pittsburgh sleep quality index in patients with obstructive sleep apnea-hypopnea syndrome treated with the classic UPPP and MUPPP. *Significant difference between preoperative and postoperative values. P ⬍ 0.05.
of the pharynx, tubal disorders, and regurgitation of food through the nose. Considering the soft palate’s anatomy and the uvula’s function (deglutition, humidification of inspired air, speech, and pharyngeal airway dilation7,11), we suggest that the modified UPPP, in which the uvula mucosa is preserved and a portion of the musculus uvulae is removed, allows for the maintaining of the normal shape of the uvula and soft palate. The large elongated uvula is shortened by the musculus uvulae, and the retropalatal space should be widened with the eversion of the musculus uvulae by suturing. We thought that the improvement of the modified UPPP would include reduced postoperative pain and use of narcotic pain medication and would support an early return to a normal diet because the uvula and its mucosa were not removed. However, there were no significant differences between the two groups (data not shown). In some cases, the snoring and apnea were aggravated by the modified UPPP procedure because of the swelling of the uvula. The uvular artery and vein reach the wall of the pharynx at a point where the styopharyngeus muscle joins with the posterolat-
Figure 4 A comparison of preoperative versus postoperative measures on the SSS and the ESS in patients with obstructive sleep apnea-hypopnea syndrome treated by the classic UPPP and MUPPP. *Significant difference between preoperative and postoperative values. P ⬍ 0.05.
eral wall of the pharynx; inside the pharynx, they pass upwards and medially along the palatopharyngeus muscle in the posterior pillar of the palate. Here, the vessels are close to the tonsil.10 To prevent vessel injury and postoperative swelling of the uvula, careful dissection is required of the upper pole of the tonsil and the musculus uvulae. The uvula consists of three main components: the surface epithelium, the subepithelial region, and an area with glandular tissue.12 The uvula has an abundance of seromucous glands with the ability to produce large volumes of thin saliva. A common late complication of uvulotomy is pharyngeal dryness. The preservation of the uvula and its mucosa may improve postoperative pharyngeal discomfort, such as a foreign body sensation and dryness. However, the results of this study showed that the postoperative subjective symptoms were not significantly different in comparisons between the two groups. The seromucous glands were arranged into acini, and they were embedded in a network of striated muscle cell bundles and adipose cells.13 Although we preserved the shape and mucosa of the uvula, during the dissection of the musculus uvulae, the seromucous glands may have been damaged. The presence of a postoperative scar may also interfere with the production of saliva. UPPP has remained the main surgery for the OSAHS. However, about 50 percent of cases have nonresponders among unselected patients. Several modified methods have been suggested to improve the postoperative symptoms and to reduce the postoperative complications.3-5,14,15 In the present study, we evaluated the surgical efficacy with subjective questionnaires and objective polysomnography. The PQSI is designed to evaluate sleep quality in seven domains. When we compared the raw scores alone, subjective sleep quality was significantly improved in both groups. In addition, the habitual sleep efficiency was significantly improved in the modified UPPP, and daytime dysfunction was significantly improved with the classic UPPP. However, the global PQSI score was significantly improved with both the classic and modified UPPP. The postoperative PQSI and ESS scores were not significantly different between two
Shin et al
Modified uvulopalatopharyngoplasty for the . . .
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Table 3 Comparison of pre- and postoperative polysomnographic data
UPPP (n ⫽ 10) Preoperative Postoperative MUPPP (n ⫽ 10) Preoperative Postoperative
AI
AHI
Mean SaO2
Lowest SaO2
Sleep efficiency
33.0 ⫾ 16.7 13.56 ⫾ 5.1
54.3 ⫾ 13.5 35.3 ⫾ 24.8
89.5 ⫾ 13.9 91.2 ⫾ 10.3
87.4 ⫾ 6.7 87.0 ⫾ 4.1
80.5 ⫾ 18.1 92.6 ⫾ 2.3
34.3 ⫾ 30.6 15.5 ⫾ 23.3
56.1 ⫾ 23.1 34.7 ⫾ 27.2
93.9 ⫾ 8.9 94.8 ⫾ 1.5
74.6 ⫾ 9.0 80.5 ⫾ 5.2
81.3 ⫾ 8.5 88.3 ⫾ 8.3
groups. According to the postoperative polysomnography, the AI and AHI were significantly improved in both groups, and there were no statistically significant differences between the two groups. When we compared the changes in sleep quality within the classic and modified UPPP groups, both groups had similar effects on the improvement of sleep quality and symptom improvement.
CONCLUSION The uvula, although small and seemingly unimportant, may have multiple functions, playing a role in speech, swallowing, and lubrication of the throat. The preservation of the shape and the mucosa of the uvula might be physiologically and morphologically important. Although the modified UPPP group in this study did not have more profound improvement in their sleep quality and decreased postoperative pharyngeal discomfort, the modified UPPP, which resects the musculus uvulae with mucosa preservation of the mucosa of the uvula, was an effective surgery for the treatment of OSAHS.
AUTHOR INFORMATION From the Department of Otorhinolaryngology, School of Medicine, Catholic University of Daegu, Daegu, South Korea. Corresponding author: Seung-Heon Shin, MD, Department of Otolaryngology, Daegu Catholic University Hospital, 3056-6 Daemyung 4 Dong, Nam-Gu, Daegu, South Korea 705-718. E-mail address: [email protected].
AUTHOR CONTRIBUTIONS Seung-Heon Shin, study design; Mi-Kyung Ye, data collection, data analysis, institutional review board approval; Chang-Gyun Kim, data analysis, writer.
DISCLOSURES Competing interests: None. Sponsorships: None.
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