[Pharyngeal pressure measurements in topodiagnosis of obstructive sleep apnea]

In order to improve the outcome of surgical treatment for obstructive sleep apnea syndrome certain reports have claimed to identify the site of obstruction in the upper airway. One of the various methods available for topodiagnosis is manometry using intraesophageal and intrapharyngeal pressure probes. In the present literature the surgical success rate for patients undergoing Uvulopalatoplasty (UPP) as treatment for retropalatal obstructions is approximately 50%. For patients with other sites of obstruction the success rate is below 10%. The aim of this study was to evaluate the different theories explaining the still low outcome of UPPP in patients with only retropalatal collapse. Findings showed that measurements within different sleep stages and at different pharyngeal activities during sleep can lead to different results concerning sites of obstruction. Additionally, any surgery to one part of the pharynx seems to influence the other parts of the pharynx in caudal and cranial directions. A literature theory dominates that the pharynx between the nasopharynx and lower hypopharynx acts like several Starling mechanism in series, in which are influences the other. Whether more complicated pressure measurements emphasizing the role of sleep stages and pharyngeal muscle activities could improve the surgical outcome of UPPP is the subject of present investigations. In any case the technical equipment and time consumption of the measurements required will probably disqualify the method for routine use.