Hostname: page-component-7c8c6479df-r7xzm Total loading time: 0 Render date: 2024-03-29T08:35:12.080Z Has data issue: false hasContentIssue false

Assessment of obstruction level and selection of patients for obstructive sleep apnoea surgery: an evidence-based approach

Published online by Cambridge University Press:  11 August 2009

C Georgalas
Affiliation:
Department of Otorhinolaryngology and Head and Neck Surgery, Academic Medical Centre, Amsterdam, The Netherlands
G Garas*
Affiliation:
Department of Otorhinolaryngology and Head and Neck Surgery, St Mary's Hospital, London, UK
E Hadjihannas
Affiliation:
Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital, Birmingham, UK
A Oostra
Affiliation:
Department of Otorhinolaryngology and Head and Neck Surgery, Academic Medical Centre, Amsterdam, The Netherlands
*
Address for correspondence: Dr George Garas, Flat 3C, 96 Sutherland Avenue, London W9 2QR, UK. Fax: +44 207 286 9016 E-mail: garas_george@yahoo.com

Abstract

Introduction:

Obstructive sleep apnoea has long been recognised as a clinical syndrome; however, high quality evidence on the effects of surgery for this condition is still missing. Despite this, a consensus seems to be evolving, albeit based on limited evidence, that surgery should be offered as a second line treatment to suitable patients with obstructive sleep apnoea.

Aims:

This article aims to assess the different methods of investigating upper airway obstruction in patients with obstructive sleep apnoea, in respect to these methods' relevance to surgical treatment, via a systematic review of the literature.

Methods:

The Cochrane Controlled Trials Register, Medline and EMBASE were searched from 1966 onwards. The search was performed in August 2008. A total of 2001 citations were retrieved.

Results and conclusion:

There is not yet a generally accepted way to assess surgical candidacy based on the level of obstruction. Better organised clinical studies with well defined endpoints are needed. In the meanwhile, it appears that sleep nasendoscopy, acoustic reflectometry and pressure catheters can all provide useful information, and their use may be decided upon based on the experience and resources available in individual departments.

Type
Review Article
Copyright
Copyright © JLO (1984) Limited 2009

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Wright, J, Johns, R, Watt, I, Melville, A, Sheldon, T. Health effects of obstructive sleep apnoea and the effectiveness of continuous positive airways pressure: a systematic review of the research evidence. BMJ 1997;7084:851–60CrossRefGoogle Scholar
2 Giles, TL, Lasserson, TJ, Smith, BJ, White, J, Wright, J, Cates, CJ. Continuous positive airways pressure for obstructive sleep apnoea in adults. Cochrane Database Syst Rev 2006;(3):CD001106CrossRefGoogle ScholarPubMed
3 Lim, J, Lasserson, TJ, Fleetham, J, Wright, J. Oral appliances for obstructive sleep apnoea. Cochrane Database Syst Rev 2006;(1):CD004435CrossRefGoogle ScholarPubMed
4 Sundaram, S, Sundaram, S, Lim, J, Lasserson, TJ. Surgery for obstructive sleep apnoea. Cochrane Database Syst Rev 2005;(4):CD001004CrossRefGoogle ScholarPubMed
5 Troell, RJ, Riley, RW, Powell, NB, Li, K. Surgical management of the hypopharyngeal airway in sleep disordered breathing. Otolaryngol Clin North Am 1998;31:9791012CrossRefGoogle ScholarPubMed
6 Fogel, RB, Malhotra, A, White, DP. Sleep. 2: pathophysiology of obstructive sleep apnoea/hypopnoea syndrome. Thorax 2004;59:159–63CrossRefGoogle ScholarPubMed
7 Rama, AN, Tekwani, SH, Kushida, CA. Sites of obstruction in obstructive sleep apnea. Chest 2002;122:1139–47CrossRefGoogle ScholarPubMed
8 Sher, AE, Thorpy, MJ, Shprintzen, RJ, Spielman, AJ, Burack, B, McGregor, PA. Predictive value of Muller maneuver in selection of patients for uvulopalatopharyngoplasty. Laryngoscope 1985;95:1483–7CrossRefGoogle ScholarPubMed
9 Fujita, S. Pharyngeal surgery for management of snoring and obstructive sleep apnea. In: Fairbanks, D, Fujita, S, Ikematsu, T, Simmons, FB, eds. Snoring and Obstructive Sleep Apnea. New York: Raven Press, 1987;101–28Google Scholar
10 Boot, H, Poublon, RM, Van Wegen, R, Bogaard, JM, Schmitz, PI, Ginai, AZ et al. Uvulopalatopharyngoplasty for the obstructive sleep apnoea syndrome: value of polysomnography, Mueller manoeuvre and cephalometry in predicting surgical outcome. Clin Otolaryngol Allied Sci 1997;22:504–10CrossRefGoogle ScholarPubMed
11 Doghramji, K, Jabourian, ZH, Pilla, M, Farole, A, Lindholm, RN. Predictors of outcome for uvulopalatopharyngoplasty. Laryngoscope 1995;105:311–14CrossRefGoogle ScholarPubMed
12 Fibbi, A, Ameli, F, Brocchetti, F, Peirano, M, Garaventa, G, Presta, A et al. Combined genioglossus advancement (ACMG): inferior sagittal mandibular osteotomy with genioglossus advancement and stabilization with suture in patients with OSAS. Preliminary clinical results [in Italian]. Acta Otorhinolaryngol Ital 2002;22:153–7Google ScholarPubMed
13 Katsantonis, GP, Maas, CS, Walsh, JK. The predictive efficacy of the Muller maneuver in uvulopalatopharyngoplasty. Laryngoscope 1989;99:677–80CrossRefGoogle ScholarPubMed
14 Petri, N, Suadicani, P, Wildschiodtz, G, Bjorn-Jorgensen, J. Predictive value of Muller maneuver, cephalometry and clinical features for the outcome of uvulopalatopharyngoplasty. Evaluation of predictive factors using discriminant analysis in 30 sleep apnea patients. Acta Otolaryngol 1994;114:565–71CrossRefGoogle ScholarPubMed
15 Thomas, AJ, Chavoya, M, Terris, DJ. Preliminary findings from a prospective, randomized trial of two tongue-base surgeries for sleep-disordered breathing. Otolaryngol Head Neck Surg 2003;129:539–46Google ScholarPubMed
16 Vilaseca, I, Morello, A, Montserrat, JM, Santamaria, J, Iranzo, A. Usefulness of uvulopalatopharyngoplasty with genioglossus and hyoid advancement in the treatment of obstructive sleep apnea. Arch Otolaryngol Head Neck Surg 2002;128:435–40CrossRefGoogle ScholarPubMed
17 Pringle, MB, Croft, CB. A comparison of sleep nasendoscopy and the Muller manoeuvre. Clin Otolaryngol Allied Sci 1991;16:559–62CrossRefGoogle ScholarPubMed
18 Skatvedt, O. Localization of site of obstruction in snorers and patients with obstructive sleep apnea syndrome: a comparison of fiberoptic nasopharyngoscopy and pressure measurements. Acta Otolaryngol 1993;113:206–9CrossRefGoogle ScholarPubMed
19 Boot, H, van der Meche, FG, Poublon, RM, Bogaard, JM, Gainai, AZ, Schmitz, PI. Upper airway patency and nocturnal desaturation in habitual snoring and obstructive sleep apnea: pathogenesis of sleep-related breathing disorders. Eur Neurol 1996;36:206–10CrossRefGoogle ScholarPubMed
20 Jager, L, Gunther, E, Gauger, J, Nitz, W, Kastenbauer, E, Reiser, M. Functional MRI of the pharynx in obstructive sleep apnea using rapid 2D FLASH sequences [in German]. Radiologe 1996;36:245–53Google ScholarPubMed
21 Lin, HS, Ibrahim, HZ, Kheng, JW, Fee, WE, Terris, DJ. Percutaneous endoscopic gastrostomy: strategies for prevention and management of complications. Laryngoscope 2001;111:1847–52CrossRefGoogle ScholarPubMed
22 Yao, M, Utley, DS, Terris, DJ. Cephalometric parameters after multilevel pharyngeal surgery for patients with obstructive sleep apnea. Laryngoscope 1998;108:789–95CrossRefGoogle ScholarPubMed
23 Steinhart, H, Kuhn-Lohmann, J, Gewalt, K, Constantinidis, J, Mertzlufft, F, Iro, H. Upper airway collapsibility in habitual snorers and sleep apneics: evaluation with drug-induced sleep endoscopy. Acta Otolaryngol 2000;120:990–4Google ScholarPubMed
24 Faber, CE, Hilberg, O, Jensen, FT, Norregaard, O, Grymer, L. Flextube reflectometry for determination of sites of upper airway narrowing in sleeping obstructive sleep apnoea patients. Respir Med 2001;95:639–48CrossRefGoogle ScholarPubMed
25 Terris, DJ, Hanasono, MM, Liu, YC. Reliability of the Muller maneuver and its association with sleep-disordered breathing. Laryngoscope 2000;110:1819–23CrossRefGoogle ScholarPubMed
26 Ritter, CT, Trudo, FJ, Goldberg, AN, Welch, KC, Maislin, G, Schwab, RJ. Quantitative evaluation of the upper airway during nasopharyngoscopy with the Muller maneuver. Laryngoscope 1999;109:954–63CrossRefGoogle ScholarPubMed
27 Hsu, PP, Tan, BY, Chan, YH, Tay, HN, Lu, PK, Blair, RL. Clinical predictors in obstructive sleep apnea patients with computer-assisted quantitative videoendoscopic upper airway analysis. Laryngoscope 2004;114:791–9CrossRefGoogle ScholarPubMed
28 Riley, R, Guilleminault, C, Herran, J, Powell, N. Cephalometric analyses and flow-volume loops in obstructive sleep apnea patients. Sleep 1983;6:303–11CrossRefGoogle ScholarPubMed
29 Woodson, BT, Conley, SF, Dohse, A, Feroah, TR, Sewall, SR, Fujita, S. Posterior cephalometric radiographic analysis in obstructive sleep apnea. Ann Otol Rhinol Laryngol 1997;106:310–13CrossRefGoogle ScholarPubMed
30 Miles, PG, Vig, PS, Weyant, RJ, Forrest, TD, Rockette, HE Jr. Craniofacial structure and obstructive sleep apnea syndrome – a qualitative analysis and meta-analysis of the literature. Am J Orthod Dentofacial Orthop 1996;109:163–72CrossRefGoogle ScholarPubMed
31 Hochban, W, Conradt, R, Brandenburg, U, Heitmann, J, Peter, JH. Surgical maxillofacial treatment of obstructive sleep apnea. Plast Reconstr Surg 1997;99:619–26CrossRefGoogle ScholarPubMed
32 Lee, NR, Givens, CD Jr, Wilson, J, Robins, RB. Staged surgical treatment of obstructive sleep apnea syndrome: a review of 35 patients. J Oral Maxillofac Surg 1999;57:382–5CrossRefGoogle ScholarPubMed
33 Prinsell, JR. Maxillomandibular advancement surgery in a site-specific treatment approach for obstructive sleep apnea in 50 consecutive patients. Chest 1999;116:1519–29CrossRefGoogle Scholar
34 Riley, RW, Powell, NB, Li, KK, Troell, RJ, Guilleminault, C. Surgery and obstructive sleep apnea: long-term clinical outcomes. Otolaryngol Head Neck Surg 2000;122:415–21CrossRefGoogle ScholarPubMed
35 Wagner, I, Coiffier, T, Sequert, C, Lachiver, X, Fleury, B, Chabolle, F. Surgical treatment of severe sleep apnea syndrome by maxillomandibular advancing or mental tranposition [in French]. Ann Otolaryngol Chir Cervicofac 2000;117:137–46Google ScholarPubMed
36 Millman, RP, Carlisle, CC, Rosenberg, C, Kahn, D, McRae, R, Kramer, NR. Simple predictors of uvulopalatopharyngoplasty outcome in the treatment of obstructive sleep apnea. Chest 2000;118:1025–30CrossRefGoogle ScholarPubMed
37 Woodson, BT, Conley, SF. Prediction of uvulopalatopharyngoplasty response using cephalometric radiographs. Am J Otolaryngol 1997;18:179–84CrossRefGoogle ScholarPubMed
38 Pepin, JL, Levy, P, Veale, D, Ferretti, G. Evaluation of the upper airway in sleep apnea syndrome. Sleep 1992;15(Suppl. 6):S50–5Google ScholarPubMed
39 Suratt, PM, Dee, P, Atkinson, RL, Armstrong, P, Wilhoit, SC. Fluoroscopic and computed tomographic features of the pharyngeal airway in obstructive sleep apnea. Am Rev Respir Dis 1983;127:487–92CrossRefGoogle ScholarPubMed
40 Tsushima, Y, Antila, J, Laurikainen, E, Svedstrom, E, Polo, O, Kormano, M. Digital fluoroscopy before and after laser uvulopalatopharyngoplasty in obstructive sleep apnea. Importance of pharyngeal collapsibility and hyoid bone position. Acta Radiol 1997;38:214–21Google ScholarPubMed
41 Katsantonis, GP, Walsh, JK. Somnofluoroscopy: its role in the selection of candidates for uvulopalatopharyngoplasty. Otolaryngol Head Neck Surg 1986;94:5660CrossRefGoogle ScholarPubMed
42 Walsh, JK, Katsantonis, GP, Schweitzer, PK, Verde, JN, Muehlbach, M. Somnofluoroscopy: cineradiographic observation of obstructive sleep apnea. Sleep 1985;8:294–7CrossRefGoogle ScholarPubMed
43 Pepin, JL, Ferretti, G, Veale, D, Romand, P, Coulomb, M, Brambilla, C et al. Somnofluoroscopy, computed tomography, and cephalometry in the assessment of the airway in obstructive sleep apnoea. Thorax 1992;47:150–6CrossRefGoogle ScholarPubMed
44 Haponik, EF, Smith, PL, Bohlman, ME, Allen, RP, Goldman, SM, Bleecker, ER. Computerized tomography in obstructive sleep apnea. Correlation of airway size with physiology during sleep and wakefulness. Am Rev Respir Dis 1983;127:221–6Google ScholarPubMed
45 Lowe, AA, Santamaria, JD, Fleetham, JA, Price, C. Facial morphology and obstructive sleep apnea. Am J Orthod Dentofacial Orthop 1986;90:484–91CrossRefGoogle ScholarPubMed
46 Stein, MG, Gamsu, G, de Geer, G, Golden, JA, Crumley, RL, Webb, WR. Cine CT in obstructive sleep apnea. AJR Am J Roentgenol 1987;148:1069–74CrossRefGoogle ScholarPubMed
47 Stauffer, JL, Zwillich, CW, Cadieux, RJ, Bixler, EO, Kales, A, Varano, LA et al. Pharyngeal size and resistance in obstructive sleep apnea. Am Rev Respir Dis 1987;136:623–7CrossRefGoogle ScholarPubMed
48 Gislason, T, Lindholm, CE, Almqvist, M, Birring, E, Boman, G, Eriksson, G et al. Uvulopalatopharyngoplasty in the sleep apnea syndrome. Predictors of results. Arch Otolaryngol Head Neck Surg 1988;114:4551CrossRefGoogle ScholarPubMed
49 Ryan, CF, Lowe, AA, Li, D, Fleetham, JA. Magnetic resonance imaging of the upper airway in obstructive sleep apnea before and after chronic nasal continuous positive airway pressure therapy. Am Rev Respir Dis 1991;144:939–44CrossRefGoogle ScholarPubMed
50 Caballero, P, Alvarez-Sala, R, Garcia-Rio, F, Prados, C, Hernan, MA, Villamor, J et al. CT in the evaluation of the upper airway in healthy subjects and in patients with obstructive sleep apnea syndrome. Chest 1998;113:111–16CrossRefGoogle ScholarPubMed
51 Bhattacharyya, N, Blake, SP, Fried, MP. Assessment of the airway in obstructive sleep apnea syndrome with 3-dimensional airway computed tomography. Otolaryngol Head Neck Surg 2000;123:444–9CrossRefGoogle ScholarPubMed
52 Li, HY, Chen, NH, Wang, CR, Shu, YH, Wang, PC. Use of 3-dimensional computed tomography scan to evaluate upper airway patency for patients undergoing sleep-disordered breathing surgery. Otolaryngol Head Neck Surg 2003;129:336–42Google ScholarPubMed
53 Horner, RL, Mohiaddin, RH, Lowell, DG, Shea, SA, Burman, ED, Longmore, DB et al. Sites and sizes of fat deposits around the pharynx in obese patients with obstructive sleep apnoea and weight matched controls. Eur Respir J 1989;2:613–22CrossRefGoogle ScholarPubMed
54 Donnelly, LF, Surdulescu, V, Chini, BA, Casper, KA, Poe, SA, Amin, RS. Upper airway motion depicted at cine MR imaging performed during sleep: comparison between young patients with and those without obstructive sleep apnea. Radiology 2003;227:239–45CrossRefGoogle ScholarPubMed
55 Schoenberg, SO, Floemer, F, Kroeger, H, Hoffmann, A, Bock, M, Knopp, MV. Combined assessment of obstructive sleep apnea syndrome with dynamic MRI and parallel EEG registration: initial results. Invest Radiol 2000;35:267–76CrossRefGoogle ScholarPubMed
56 Schwab, RJ, Pasirstein, M, Pierson, R, Mackley, A, Hachadoorian, R, Arens, R et al. Identification of upper airway anatomic risk factors for obstructive sleep apnea with volumetric magnetic resonance imaging. Am J Respir Crit Care Med 2003;168:522–30CrossRefGoogle ScholarPubMed
57 Kinefuchi, Y, Fukuyama, H, Suzuki, T, Kanazawa, M, Takiguchi, M. Development of a new catheter-tip pressure transducer. Tokai J Exp Clin Med 1999;24:8592Google ScholarPubMed
58 Hudgel, DW. Variable site of airway narrowing among obstructive sleep apnea patients. J Appl Physiol 1986;61:1403–9CrossRefGoogle ScholarPubMed
59 Chaban, R, Cole, P, Hoffstein, V. Site of upper airway obstruction in patients with idiopathic obstructive sleep apnea. Laryngoscope 1988;98:641–7CrossRefGoogle ScholarPubMed
60 Katsantonis, GP, Moss, K, Miyazaki, S, Walsh, J. Determining the site of airway collapse in obstructive sleep apnea with airway pressure monitoring. Laryngoscope 1993;103:1126–31CrossRefGoogle ScholarPubMed
61 Skatvedt, O, Grogaard, J. Infant sleeping position and inspiratory pressures in the upper airways and oesophagus. Arch Dis Child 1994;71:138–40CrossRefGoogle ScholarPubMed
62 Farmer, WC, Giudici, SC. Site of airway collapse in obstructive sleep apnea after uvulopalatopharyngoplasty. Ann Otol Rhinol Laryngol 2000;109:581–4CrossRefGoogle ScholarPubMed
63 Rollheim, J, Tvinnereim, M, Sitek, J, Osnes, T. Repeatability of sites of sleep-induced upper airway obstruction. A 2-night study based on recordings of airway pressure and flow. Eur Arch Otorhinolaryngol 2001;258:259–64CrossRefGoogle ScholarPubMed
64 Reda, M, Gibson, GJ, Wilson, JA. Pharyngoesophageal pressure monitoring in sleep apnea syndrome. Otolaryngol Head Neck Surg 2001;125:324–31CrossRefGoogle ScholarPubMed
65 Tvinnereim, M, Mitic, S, Hansen, RK. Plasma radiofrequency preceded by pressure recording enhances success for treating sleep-related breathing disorders. Laryngoscope 2007;117:731–6CrossRefGoogle ScholarPubMed
66 Kamal, I. Test-retest validity of acoustic pharyngometry measurements. Otolaryngol Head Neck Surg 2004;130:223–8CrossRefGoogle ScholarPubMed
67 Wilson, K, Stoohs, RA, Mulrooney, TF, Johnson, LJ, Guilleminault, C, Huang, Z. The snoring spectrum: acoustic assessment of snoring sound intensity in 1,139 individuals undergoing polysomnography. Chest 1999;115:762–70CrossRefGoogle Scholar
68 Faber, CE, Grymer, L, Hilberg, O, Norregaard, O. Flextube reflectometry and pressure-recordings for level diagnosis in obstructive sleep apnoea. Rhinology 2002;40:203–10Google ScholarPubMed
69 Faber, CE, Hilberg, O, Grymer, L. Flextube reflectometry for level diagnosis in patients with obstructive sleep apnoea and snoring. Rhinology 2002;40:122–8Google ScholarPubMed
70 Kamal, I. Acoustic pharyngometry patterns of snoring and obstructive sleep apnea patients. Otolaryngol Head Neck Surg 2004;130:5866CrossRefGoogle ScholarPubMed
71 Faber, CE, Grymer, L, Norregaard, O, Hilberg, O. Flextube reflectometry for localization of upper airway narrowing – a preliminary study in models and awake subjects. Respir Med 2001;95:631–8CrossRefGoogle ScholarPubMed
72 Fiz, JA, Abad, J, Jane, R, Riera, M, Mananas, MA, Caminal, P et al. Acoustic analysis of snoring sound in patients with simple snoring and obstructive sleep apnoea. Eur Respir J 1996;9:2365–70CrossRefGoogle ScholarPubMed
73 Issa, FG, Morrison, D, Hadjuk, E, Iyer, A, Feroah, T, Remmers, JE. Digital monitoring of sleep-disordered breathing using snoring sound and arterial oxygen saturation. Am Rev Respir Dis 1993;148:1023–9CrossRefGoogle ScholarPubMed
74 McCombe, AW, Kwok, V, Hawke, WM. An acoustic screening test for obstructive sleep apnoea. Clin Otolaryngol Allied Sci 1995;20:348–51CrossRefGoogle ScholarPubMed
75 Perez-Padilla, JR, Slawinski, E, Difrancesco, LM, Feige, RR, Remmers, JE, Whitelaw, WA. Characteristics of the snoring noise in patients with and without occlusive sleep apnea. Am Rev Respir Dis 1993;147:635–44CrossRefGoogle ScholarPubMed
76 Van Brunt, DL, Lichstein, KL, Noe, SL, Aguillard, RN, Lester, KW. Intensity pattern of snoring sounds as a predictor for sleep-disordered breathing. Sleep 1997;20:1151–6CrossRefGoogle ScholarPubMed
77 Brietzke, SE, Mair, EA. Acoustical analysis of snoring: can the probability of success be predicted? Otolaryngol Head Neck Surg 2006;135:417–20CrossRefGoogle ScholarPubMed
78 Miyazaki, S, Itasaka, Y, Ishikawa, K, Togawa, K. Acoustic analysis of snoring and the site of airway obstruction in sleep related respiratory disorders. Acta Otolaryngol Suppl 1998;537:4751CrossRefGoogle ScholarPubMed
79 Saunders, NC, Tassone, P, Wood, G, Norris, A, Harries, M, Kotecha, B. Is acoustic analysis of snoring an alternative to sleep nasendoscopy? Clin Otolaryngol Allied Sci 2004;29:242–6CrossRefGoogle ScholarPubMed
80 Hara, H, Murakami, N, Miyauchi, Y, Yamashita, H. Acoustic analysis of snoring sounds by a multidimensional voice program. Laryngoscope 2006;116:379–81CrossRefGoogle ScholarPubMed
81 Croft, CB, Pringle, M. Sleep nasendoscopy: a technique of assessment in snoring and obstructive sleep apnoea. Clin Otolaryngol Allied Sci 1991;16:504–9CrossRefGoogle ScholarPubMed
82 Pringle, MB, Croft, CB. A grading system for patients with obstructive sleep apnoea – based on sleep nasendoscopy. Clin Otolaryngol Allied Sci 1993;18:480–4CrossRefGoogle ScholarPubMed
83 Marais, J. The value of sedation nasendoscopy: a comparison between snoring and non-snoring patients. Clin Otolaryngol Allied Sci 1998;23:74–6CrossRefGoogle ScholarPubMed
84 Berry, S, Roblin, G, Williams, A, Watkins, A, Whittet, HB. Validity of sleep nasendoscopy in the investigation of sleep related breathing disorders. Laryngoscope 2005;115:538–40CrossRefGoogle ScholarPubMed
85 Sadaoka, T, Kakitsuba, N, Fujiwara, Y, Kanai, R, Takahashi, H. The value of sleep nasendoscopy in the evaluation of patients with suspected sleep-related breathing disorders. Clin Otolaryngol Allied Sci 1996;21:485–9CrossRefGoogle ScholarPubMed
86 Camilleri, AE, Ramamurthy, L, Jones, PH. Sleep nasendoscopy: what benefit to the management of snorers? J Laryngol Otol 1995;109:1163–5CrossRefGoogle Scholar
87 Abdullah, VJ, Wing, YK, van Hasselt, CA. Video sleep nasendoscopy: the Hong Kong experience. Otolaryngol Clin North Am 2003;36:461–71, viCrossRefGoogle ScholarPubMed
88 El Badawey, MR, McKee, G, Heggie, N, Marshall, H, Wilson, JA. Predictive value of sleep nasendoscopy in the management of habitual snorers. Ann Otol Rhinol Laryngol 2003;112:40–4CrossRefGoogle ScholarPubMed
89 Georgalas, C, Kotecha, B. Predictive value of sleep nasendoscopy in the management of habitual snorers. Ann Otol Rhinol Laryngol 2004;113:420CrossRefGoogle ScholarPubMed
90 Kotecha, BT, Hannan, SA, Khalil, HM, Georgalas, C, Bailey, P. Sleep nasendoscopy: a 10-year retrospective audit study. Eur Arch Otorhinolaryngol 2007;264:1361–7CrossRefGoogle ScholarPubMed