Computer-Assisted Quantitative Evaluation of Obstructive Sleep Apnea Using Digitalized Endoscopic Imaging with Muller Maneuver
Department of Otolaryngology, Chang Gung Memorial Hospital, Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan. The Laryngoscope
(Impact Factor: 2.14).
06/2008; 118(5):909-14. DOI: 10.1097/MLG.0b013e3181638187
To validate the technique of the Muller maneuver (MM) using videoendoscopy and to quantify the correlation between its clinical results and variables of polysomnography.
Prospective, controlled study.
Videoendoscopy with MM was performed in 70 patients who were categorized into two groups, with 35 patients giving a history suggestive of snoring and 35 patients without such history. The snoring group underwent further examination with polysomnography. Cross-sectional areas at the retropalatal (RP) and retrolingual (RL) levels during quiet respiration (RP(0) or RL(0)) and the maximal effort of MM (RP(1) or RL(1)) were calculated with the digital measurement software "Image J." One hundred forty pairs of data were acquired. The collapsing ratio (CR) was defined as the difference of RP(0) (or RL(0)) between RP1 (or RL(1)) divided by RP(0) (or RL(0)) to compare the difference between the two phases. These results were compared with each other and correlated to the variables obtained from polysomnographic studies.
There were significant differences in the CR of RP (CR(RP)), the CR of RL (CR(RL)), and body mass index (BMI) when comparing the two groups. In snoring patients, BMI was positively related to the respiratory disturbance index (RDI) and obstructive sleep apnea (OSA) staging but not to CR(RP) and CR(RL). CR(RP) had a significant positive relationship with RDI and OSA rather than CR(RL).
MM with videoendoscopy can be a simple, cost-effective, quantitative, and even predictable technique. This method allows us to examine the dynamic upper airway for more precise preoperative planning.
Available from: Yasumasa Okada
- "To avoid the complexity to induce sleep in OSA patients, the Müller maneuver, which consists of a forced inspiratory effort with the mouth and nose closed, could be applied as substitute of real sleep. This maneuver can mimic the pathophysiological condition of OSA during wakefulness, and has been applied to the studies of OSA (Ko and Su 2008; Gregorio et al. 2007; Liao et al. 2003; Terris et al. 2000; Jäger et al. 1998). A successful example of the Müller maneuver application is the evaluation of upper airway function by fiberoptic nasopharyngoscopy with this maneuver before surgical intervention to predict surgical outcome and to improve patient selection (Sher et al. 1985). "
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ABSTRACT: The Müller maneuver has been widely applied to mimic the pathophysiological condition of obstructive sleep apnea (OSA) during wakefulness. We applied cine MRI to elucidate dynamics of the upper airway during the Müller maneuver in healthy subjects (n = 7). Three sets of images (during quiet nose breathing, quiet mouth breathing, and Müller maneuver) were recorded on sagittal midline plane together with impedance pneumography. The position of the tongue root changed during a respiratory cycle when subjects breathed quietly. At the early inspiratory phase the tongue root moved forward and upward, the retroglossal airway size increased toward the middle of inspiration, and the airway size became smaller again toward the end of inspiration. During expiration the airway size became further smaller. When the subject performed the Müller maneuver, the movement of the oropharynx and its narrowing were greater than those of the velopharynx. However, the airway was not completely obstructed. A relatively large morphological change was observed in the retropalatal and retroglossal regions with the backward and downward motion of the tongue root and flattening of the tongue shape during the Müller maneuver. Although patterns of upper airway narrowing and tongue shape alterations were variable among subjects, upper airway narrowing was commonly prominent in the retroglossal area. Cine MRI with the Müller maneuver enables to visualize the upper airway dynamics and could be easily applied to evaluate upper airway collapsibility during wakefulness.
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ABSTRACT: To analyze computer-assisted quantitative measurements of endoscopic images taken during fiberoptic nasopharyngoscopy with Müller's maneuver that were processed with the use of fractal geometry and correlate them with the apnea-hypopnea index of patients with obstructive sleep apnea syndrome as well as habitual snorers.
Diagnostic test assessment for the analysis of images acquired through fiberoptic nasopharyngoscopy with Müller's maneuver and processed with the use of fractal geometry.
Sleep laboratory in a tertiary care private hospital in Athens, Greece.
A total of 42 subjects (25 patients, 17 control subjects) underwent fiberoptic endoscopic nasopharyngoscopy with Müller's maneuver and polysomnographic overnight testing. Endoscopic images were digitally analyzed, and fractal analysis software was used to determine fractal dimensions of postpalatal airway contour during quiet inspiration and Müller's maneuver. Findings were correlated with the apnea-hypopnea index.
Fractal dimension of collapsed airway and airway collapsibility was shown to be correlated with the apnea-hypopnea index (r = -0.481 and 0.518). We used 9.5 percent airway collapsibility on the basis of fractal dimensions as a cutoff (decided according to a receiver operating characteristic curve) and found that the predictability of obstructive sleep apnea had a sensitivity of 92.0 percent (95% confidence interval 75.03-97.78) and a specificity of 82.4 percent (95% confidence interval 58.97-93.8), with a positive predictive value of 88.5 percent and a negative predictive value of 87.5 percent (P < 0.0001).
Fractal analysis provides an additional measure of objectivity for the interpretation of computer-assisted quantitative endoscopic evaluation of patients with obstructive sleep apnea. Nevertheless, as confidence intervals show, some uncertainty remains regarding the real population estimate, and therefore additional studies involving larger population groups are encouraged.
Available from: Ching-Ting Tan
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ABSTRACT: The aim of this study was to investigate whether physical evaluations could be used for predicting the presence and severity of obstructive sleep apnea (OSA) in non-obese snoring patients.
This is a retrospective study, and a total of 244 non-obese (body mass index, BMI, <27 kg/m(2)) snoring patients (178 men and 66 women; mean age = 43.1 ± 12.1 years) were included. Each patient underwent polysomnography and a thorough physical examination, including flexible nasopharyngoscopy and Müller maneuver. Patients were divided into four groups based on apnea-hypopnea index (AHI) scores: normal (simple snoring), AHI < 5; mild OSA, 5 ≦ AHI < 15; moderate OSA, 15 ≦ AHI < 30; severe OSA, AHI ≧ 30. Logistic regression was used to identify risk factors for OSA severity.
Fifty-nine patients (24%) were simple snorers. The prevalence of sleep apnea (mild, moderate, or severe OSA) for our non-obese snoring patients was 76%. Univariate logistic analyses showed that higher BMI, male gender and retropalatal Müller grades were significantly associated with OSA severity. Multivariate logistic regression analysis identified male gender and retropalatal Müller grade as risk factors for OSA in non-obese snoring patients.
Physical examination may be useful for studying the upper airway in non-obese snoring patients. Flexible nasopharyngoscopy with Müller maneuver appears to be useful for evaluating the severity of OSA in non-obese patients. Retropalatal Müller grade is highly related to both the presence and severity of OSA, particularly in males.
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