Uvulopalatopharyngoplasty for Treatment of Obstructive Sleep Apnea

Uvulopalatopharyngoplasty for Treatment of Obstructive Sleep Apnea

JOHN W. SHEPARD, Jr., M.D., Division of Thoracic Diseases and Internal Medicine; KERRY D. OLSEN, M.D., Department of Otorhinolaryngology

Currently, uvulopalatopharyngoplasty (UPPP) is the most common surgical procedure used for the treatment of obstructive sleep apnea. Patients with clinically significant obstructive sleep apnea in whom medical treatment has failed or who are unwilling to comply with medical therapy are considered candidates for UPPP. The initial surgical results obtained in nonselected patients with obstructive sleep apnea were highly variable, approximately halfofthe patients experiencing more than a 50% reduction in the frequency ofdisordered breathing events postoperatively. Although differences in surgical technique likely account for some of the variability, preoperative differences in the site (or sites) of upper airway collapse are also thought to influence the surgical results. Because UPPP involves resection of the uvula, distal margin ofthe soft palate, palatine tonsils, and any excessive lateral pharyngeal tissue, patients with anatomic narrowing and collapse confined to the velopharyngeal or retropalatal region of the upper airway are considered optimal surgical candidates. Fiberoptic pharyngoscopy, cephalometric roentgenography, computed tomography, and somnofluoroscopy are procedures that can be used preoperatively to help select optimal candidates for UPPP. The results suggest that the success rate ofUPPP can approach 66% with careful preoperative selection of patients.

In 1981, Fujita and associates' introduced uvulopalatopharyngoplasty (UPPP) as an alternative to tracheostomy for the treatment of obstructive sleep apnea. This procedure, which consists of resection of the uvula, distal margin of the soft palate, palatine tonsils, and any excessive lateral pharyngeal tissue, is a modification of the palatopharyngoplasty and partial uvulectomy procedure developed by Ikematsu/ in the 1960s for the treatment of snoring. Although UPPP has become the most widely used procedure to Individual reprints of this article are not available. The entire Symposium on Sleep Disorders will be available for purchase as a bound booklet from the Proceedings Circulation Office in October. Mayo Clin Proc 65:1260-1267, 1990

increase the patency of the upper airway, it is successful in only 50% of nonselected patients. Operative failures have generally been attributed to the fact that collapse of the airway does not occur at a single anatomic location. The multiple sites of involvement can range from the anterior aspect of the nose to the lower part of the hypopharynx. On the basis of this information, the concept of site-specific surgical intervention has been developed. The surgical procedures used are those designed to increase the patency of the regional segments thought to be involved. By careful selection of patients with upper airway anatomy considered favorable for UPPP, the success rate of this procedure can likely be increased. Because of the paucity of

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published information related to alternative forms of upper airway surgical procedures, this review will focus primarily on the indications for UPPP, the potential results, and the associated complications.

Maxillary

Mandibular

Advancement

~

SITE-SPECIFIC PROCEDURES

Most available surgical procedures for treatment of obstructive sleep apnea and the specific anatomic site in which obstruction is alleviated are illustrated in Figure 1. The importance of nasal obstruction in the pathogenesis of obstructive sleep apnea has been well substantiated. 3 Consequently, patients in whom maximal medical therapy fails to achieve adequate nasal patency are candidates for surgical correction of nasal obstruction from septal deviation, turbinates, polyps, cysts, masses, or choanal atresia. Obstruction of the nasopharynx from adenoids, although common in children, is rarely a problem in adults. Because collapse is initiated in the velopharyngeal or retropalatal segment of the upper airway in most patients.v" UPPP with resection of any residual palatine tonsillar tissue is usually the procedure of choice. In some patients, however, collapse of the upper airway extends into the retroglossal area. In such patients, surgical procedures to advance the anatomic position of the mandible or hyoid bone or to reduce the tissue at the base of the tongue have been used. Obstruction at the level ofthe larynx, thought to result from collapse of an infantile omega-shaped epiglottis, has been treated with partial resection of the epiglottis in a few cases. In addition to these surgical procedures that focus on eliminating obstruction at a specific site in the upper airway, tracheostomy is the definitive therapeutic measure that can effectively bypass all regions of obstruction in the upper airway.

INDICATIONS

Currently, UPPP is thought to be indicated for patients with clinically symptomatic obstructive sleep apnea who have appropriate anatomic features and who have experienced no relief with medical interventions or are unwilling to

Adenoidectomy

UPPP

Reduction Epiglollectomy glossectomy

~

Palatine

Ungual

Tonsillectomy

Fig. 1. Sagittal schematic view of upper airway, illustrating major anatomic segments and surgical procedures performed to increase patency of specific regions. Nasopharynx extends from choanae (posterior nares) to level of hard palate. Velopharynx or retropalatal segment extends from hard palate to caudal margin of soft palate and uvula. Oropharynx or retroglossal segment extends from caudal margin of soft palate and uvula to tip of epiglottis. Hypopharynx extends caudally from tip of epiglottis to vestibule of larynx. UPPP = uvulopalatopharyngoplasty.

comply with medical therapy. UPPP should be done in patients in whom the velopharynx is anatomically narrowed and has been defined as the site of airway collapse during sleep. In addition, patients should have adequate patency of the proximal and distal segments of the upper airway. Our clinical experience suggests that optimal candidates for UPPP should have some or all of the following anatomic findings: enlarged uvula, large tonsils, prominent posterior tonsillar pillars (palatopharyngeal muscles) in close approximation, and a narrow palate to posterior pharyngeal wall dimension. Examples of good and poor candidates for UPPP are depicted in Figure 2.

RESULTS

The criteria for a successful outcome of UPPP have not been established. Although the ultimate goal is the permanent elimination of sleepdisordered breathing and snoring, reductions in the frequency of disordered breathing events

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Fig. 2. Photographs of oropharynx of two patients referred for consideration of uvulopalatopharyngoplasty. A, In this good candidate, a large uvula (asterisk), hypertrophic palatine tonsils on either side, and a thickened soft palate caused major anatomic obstruction of the airway. B, In this poor candidate, the uvula (asterisk) is small (note posterior pharyngeal wall behind it), and no anatomic narrowing was visually evident at level of distal margin of soft palate.

below a threshold level will clearly produce the many of these patients subjectively experience desired goal of alleviating daytime hypersomno- increased alertness.!" Nonetheless, objective lence. Unfortunately, most studies have used a measurement of sleepiness with the multiple 50% or greater reduction in the apnea plus sleep latency test has shown that patients with hypopnea index as the definition of a successful no postoperative reduction in the apnea plus result. Use of this definition creates some prob- hypopnea index remain excessively sleepy. 17 The lems, inasmuch as a 60% reduction in the apnea often impressive subjective reports of clinical plus hypopnea index from 100 to 40 events per improvement may be related to improvement in hour would not produce the desired clinical re- nocturnal oxygenation, which has been noted in sult. If, however, surgical treatment has im- patients who fail to demonstrate a reduction in proved the patient's condition from the presence the apnea plus hypopnea index postoperatively. 15 of nonpositional to positionally dependent obBecause up to 50% of nonselected patients structive sleep apnea-as may have occurred in with obstructive sleep apnea who undergo UPPP the preceding example-then the desired clinical benefit may be achieved if the patient is able Table I.-Results of Uvulopalatopharyngoplasty to avoid sleeping in the supine position. Many in Published Reports of Nonselected Patients specialists in sleep disorders medicine would With Obstructive Sleep Apnea consider a reduction in the apnea plus hypopnea No. of Success index to fewer than 15 events per hour a successReport patients rate (%)* ful result. 49 50 Simmons et al" In Nonselected Patients.-In the initial re- Fujita et aF 66 50 46 30 ports":" of the surgical results of UPPP in non- DeBerry-Borowiecki et al" 9 42 Katsantonis & Walsh 26 selected patients, the apnea plus hypopnea inBlakley et apo o 9 dex decreased by more than 50% in half of the Wetmore et al! 1 52 27 patients studied (Table 1). Numerous factors, Dickson & Blokmanis'" 77 36 65 34 including both patient condition and surgical Gislason et aP3 Walker et aP4 11 9 technique, have undoubtedly contributed to the Shepard & Thawley'" 35 23 wide range (0 to 77%) of reported success rates. Overall 1560f311 50 Although the objective polysomnographic data *Successful results were defined as more than a 50% reducindicate a substantial postoperative failure rate, tion in the preoperative apnea plus hypopnea index.

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fail to achieve an objective response, the finding, in a retrospective study, of no significant difference in mortality rates in patients who underwent UPPP and an untreated control group was not surprising." This outcome emphasizes the importance of obtaining postoperative polysomnograms for objective assessment of the response to UPPP. The results of a study performed 2 to 3 months postoperatively will generally be similar to those obtained at 1 year.!? In Selected Patients.-In attempts to improve the 50% failure rate in nonselected patients who undergo UPPP, several groups have used a variety of techniques to select patients in whom the anatomy of the upper airway would be considered optimal for improvement with UPPP (Table 2). Fiberoptic Pharyngoscopy.-Patients with narrowing of the upper airway and collapse confined to the velopharyngeal segment are considered the best candidates for UPPP because this procedure produces maximal enlargement of this segment ofthe airway (Fig. 3). With use of fiberoptic pharyngoscopy in combination with performance ofthe Muller maneuver, Sher and associates'" selected a group of 30 patients in whom collapsibility ofthe upper airway under the influence of negative airway pressure was localized to the velopharyngeal segment. In this group ofpatients, UPPP produced a 73% success rate. Because no control group was included in that study, Wittig and colleagues" performed UPPP in 64 patients with obstructive sleep apnea who also had been assessed preoperatively with fiberoptic pharyngoscopy and performance of the Muller maneuver. Although all patients had 75 to 100% collapse ofthe velopharynx, 44 ofthe patients had less than 50% collapse of the retroglossal area of the oropharynx, and 20 had more than 50% collapse at this level. Although the success rate was 68% in the group with predominant velopharyngeal collapse and 55% in the group with velopharyngeal plus oropharyngeal collapse, the difference was not statistically significant. In a smaller series of 24 patients, Katsantonis and co-workers'" found that patients with predominantly velopharyngeal obstruction evident on fiberoptic pharyngoscopy

Table 2.-Results of Uvulopalatopharyngoplasty in Published Reports of Patients Selected as Having Favorable Upper Airway Anatomy for the Procedure Selection technique Fiberoptic pharyngoscopy with Muller maneuver, showing velopharyngeal collapse Sher et apo Wittig et aPl Katsantonis et aF2 Cephalometric roentgenography, demonstrating large posterior airspace-Riley et aP3 Computed tomography Normoglossia-Gislason et aP3 A . lower velopharynx*Sh~npard & Thawley'" Somnofluoroscopy, showing velopharyngeal collapseKatsantonis & Walsh" Overall

No. of patients

Success rate (%)

22 of 30 30 of 44 50f15

73 68 33

50f5

100

116f14

79

7 of 14

50

10 of 15 90 of 137

67 66

*Minimal cross-sectional area of the upper airway located in the lower velopharynx.

had a 33% success rate after UPPP in comparison with a success rate of only 22% in those patients with oropharyngeal and velopharyngeal collapse. Cephalometric Roentgenography.-In a retrospective analysis of cephalometric roentgenograms obtained preoperatively in nine patients in whom UPPP was ineffective, Riley and associates'" found narrowing of the posterior airspace, which corresponds to the retroglossal segment of the upper airway. In contrast, five patients with larger posterior airspace dimensions had a successful response to UPPP. Subsequently, this group and others have used the finding of a narrowed posterior airspace as a relative indication for mandibular advancement in order to increase the dimensions of a narrowed retroglossal airway. Computed Tomography.-Computed tomography has also been used in two separate studies for retrospective analysis of differences in anatomic features of the upper airway that would assist in the prediction of success or failure with UPPP. In a series of 32 patients, Gislason and associates!" found that the pres-

1264 UVULOPALATOPHARYNGOPLASTY FOR SLEEP APNEA

-

o

Before UPPP AfterUPPP

w

Velopharynx

ro

~

~

~

ro

Hypopharynx

ro

Airway length, mm

Fig. 3. Graph of upper airway cross-sectional areas before and after uvulopalatopharyngoplasty (UPPP) in 23 patients with obstructive sleep apnea. Level of 0 mm in the airway is located at the hard palate, levels 10 and 20 mm consistently represent the velopharynx (retropalatal airway), and the uvula is commonly observed at 30 and 40 mm. The tip ofthe epiglottis is characteristically visualized at 50 mm, and the hyoid bone is seen at 60 and 70 mm below the hard palate. Data are plotted as mean± SEM. (Data at 70 mm are for only 19 patients.) NS = not significant. (From Shepard and Thawley.l" By permission of the American Lung Association.)

ence of macroglossia was associated with a UPPP success rate of 56% (10 of 18 patients) in comparison with a successful result in 11 of 14 patients (79%) with a normal-sized tongue. The width of the tongue, however, did not correlate significantly with postoperative reductions in the apnea plus hypopnea index. Patients who were less obese and had less severe disease preoperatively were found most likely to benefit from UPPP. In 23 patients, Shepard and Thawley'" found that those in whom the minimal cross-sectional area of the airway was located in the lower part of the velopharynx were the best candidates for UPPP. When the minimal cross-sectional area was located in either a more proximal or a more distal segment, the surgical success rate was only 11% (one of nine patients). Somnofluoroscopy.-Although the foregoing studies used information obtained with the patients in the awake state, Katsantonis and Walsh" used fluoroscopy ofthe lateral aspect of the neck during sleep (somnofluoroscopy) to

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assess their patients scheduled to undergo UPPP. When narrowing and collapse were confined to the cephalad segment of the upper airway, 10 of the 15 patients (67%) had a successful result; in comparison, the success rate was only 9% (1 of 11 patients) with narrowing or collapse more caudally. Currently, fiberoptic pharyngoscopy and upper airway pressure monitoring are being used to ascertain the regions of airway collapse during sleep in order to select the optimal candidates for UPPP. The performance of computed tomographic scanning during sleep also holds considerable promise for preoperative assessment, with fast computed tomography being superior to conventional scanners.w'" Based on Surgical Technique.-Although the aforementioned studies have indicated the importance of selection of appropriate patients for UPPP, the surgical technique is probably equally important in determining the success rates. Caution exercised during initial operations to avoid potential complications may have inadvertently decreased the success rates; Kimmelman and colleagues'? reported that a more aggressive surgical approach yields a higher success rate. The surgical procedure must ensure adequate removal of palatal tissue and lateral and superior positioning of the posterior tonsillar pillars in a manner that avoids wound dehiscence and subsequent scarring. An example of a well-healed soft palate and a patent velopharynx after UPPP is shown in Figure 4. Because upper airway narrowing may involve multiple sites, surgeons may perform UPPP in combination or in sequence with other procedures to enhance the patency of the nasal or more caudal segments ofthe airway. Caldarelli and co-workers-" reported that submucous resection in combination with UPPP produced a 59% success rate, in comparison with a 35% success rate for submucous resection alone. With use of a combination ofUPPP and a surgical procedure to advance the position of the hyoid bone and enlarge a narrowed retroglossal airspace, Riley and associates'" achieved successful results in 62% of 42 patients. When inferior mandibular osteotomy and hyoid myotomy suspension were performed in seven pa-

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traoperatively, avoidance of excessive retraction pressure on the tongue will minimize postoperative edema. In addition, dissection along the lateral pharyngeal walls must be performed carefully to avoid vascular complications associated with the adjacent internal carotid and pharyngeal arteries. Postoperatively, the sparing use of analgesics and sedatives in order to minimize the likelihood of apnea contributes to the substantial pain associated with this procedure. Infection has been reported to occur in 0 to 10% of patients, hemorrhage in up to 6%, and nasopharyngeal stenosis in 0 to 4%.31-33 Although almost all patients experience nasophaFig. 4. Photograph of characteristic changes after success- ryngeal reflux and rhinolalia immediately after ful uvulopalatopharyngoplasty. Arrows denote resected UPPP, less than 10% will have significant longmargin of soft palate. term problems with these complicationa." Deaths have occurred in association with UPPP, tients in whom UPPP had previously been un- but adequate data on the frequency ofthis comsuccessful, the success rate was 86%. The effect plication are unavailable. ofthese combined procedures on the success rate is difficult to interpret because of the differences TRACHEOSTOMY in criteria used for selection of patients and the In patients with obstructive sleep apnea in whom small numbers that have been reported to date. both medical therapy and site-specific upper Operative Failure.-Numerous factors can airway surgical procedures have been unsuccause failure of UPPP, including inappropriate cessful, tracheostomy remains the procedure of selection of patients with airway collapse remote choice. Tracheostomy and nasal administration from the operative site and failure of the opera- of continuous positive airway pressure should be tive technique to increase the anatomic patency 100% effective in treating obstructive sleep or alter the collapsibility of the upper airway apnea; nevertheless, patients often are relucsufficiently. In addition, fibrosis along the re- tant to accept either of these measures. After a sected margin of the soft palate in conjunction partially effective site-specific operation, patient with tissue retraction can lead to narrowing of tolerance of nasally applied continuous positive the velopharyngeal outlet. 15 In a few patients in airway pressure may be enhanced because airwhom preoperative airway collapse was definitely confined to the velopharyngeal segment, Table 3.-Potential Complications Associated persistent collapse at the level of the proximal With Uvulopalatopharyngoplasty resected soft palate has been noted after unsucPreoperative cessful UPPP. 5 Apnea related to preoperative sedation Complications.-Complications associated Inability to intubate, need for emergency tracheostomy with UPPP are summarized in Table 3. Preop- Intraoperative Vascular accidents erative sedation with resultant collapse of the Edema from excessive retraction pressure on tongue airway and need for emergency tracheostomy Postoperative Sedation- and analgesia-related apnea because of inability to intubate was an initial Pain (100%) serious problem that has been diminished by Infection (0-10%) avoiding preoperative sedation in these paHemorrhage (0-6%) Nasopharyngeal reflux and rhinolalia (0-10%) tients and informing anesthesiologists about Nasopharyngeal stenosis (0-4%) the unique difficulties with these patients." In-

1266 UVULOPALATOPHARYNGOPLASTY FOR SLEEP APNEA

way patency can be maintained with pressures less than those required preoperatively (unpublished observation). Tracheostomy is indicated when life-threatening obstructive sleep apnea exists. Tracheostomy may also be performed in conjunction with a site-specific upper airway surgical procedure in patients with moderate or severe obstructive sleep apnea' who require protection of the airway.

CONCLUSION In all patients with clinically symptomatic obstructive sleep apnea, the upper airway should be carefully evaluated. The region of narrowing and collapse can be identified with use of fiberoptic pharyngoscopy, cephalometric roentgenography, computed tomography, or somnofluoroscopy. Proper selection of patients and surgical techniques should improve future reported results ofUPPP. Ifa site-specific surgical procedureis unsuccessful, tracheostomy remains the definitive procedure for maintaining a patent airway. The final decision about surgical therapy should be based on the anatomic findings, the severity of sleep apnea, and the response to medical therapy. REFERENCES 1.

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Shepard JW Jr, Stanson AW, Sheedy PF, Westbrook PR: Fast-CT evaluation of the upper airway during wakefulness in patients with obstructive sleep apnea. Prog Clin Biol Res 345:273-279, 1990 Stein MG, Gamsu G, de Geer G, Golden JA, Crumley RL, Webb WR: Cine CT in obstructive sleep apnea. AJR 148:1069-1074, 1987 Horner RL, Shea SA, McIvor J, Guz A: Pharyngeal size and shape during wakefulness and sleep in patients with obstructive sleep apnoea. Q J Med 72:719735, 1989 Kimmelman CP, Levine SB, Shore ET, Millman RP: Uvulopalatopharyngoplasty: a comparison of two techniques. Laryngoscope 95:1488-1490, 1985 Caldarelli DD, Cartwright RD, Lilie JK: Obstructive sleep apnea: variations in surgical management. Laryngoscope 95:1070-1073, 1985

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Riley RW, Powell NB, GuilleminauIt C: Inferior mandibular osteotomy and hyoid myotomy suspension for obstructive sleep apnea: a review of 55 patients. J Oral Maxillofac Surg 47:159-164, 1989 Fairbanks DNF: Uvulopalatopharyngoplasty complications and avoidance strategies. Otolaryngol Head Neck Surg 102:239-245, 1990 KatsantonisGP, Friedman WH,KrebsFJ, WalshJK: Nasopharyngeal complications following uvulopalatopharyngoplasty. Laryngoscope 97:309-313,1987 Harmon JD, Morgan W, Chaudhary B: Sleep apnea: morbidity and mortality of surgical treatment. South Med J 82:161-164,1989 Colman MF: Limitations, pitfalls, and risk management in palatopharyngoplasty. In Snoring and Obstructive Sleep Apnea. Edited by DNF Fairbanks, S Fujita, T Ikematsu, FB Simmons. New York, Raven Press, 1987, pp 171-184

END OF SYMPOSIUM ON SLEEP DISORDERS