Are the obstruction sites visualized on drug-induced sleep endoscopy reliable?

PURPOSE: Drug-induced sleep endoscopy (DISE) has been claimed to be a reliable tool, improving surgical results in obstructive sleep apnea syndrome (OSAS). One means of assessing reliability would be to ablate only a part of the sites observed on endoscopy and find only partial success versus ablating all observed sites and finding resolution of apnea. METHODS: A retrospective study included 24 OSAS patients, operated on following awake clinical examination. DISE was performed prior to surgery. Overnight sleep study was performed before and after surgery. Two groups of patients were obtained: success (postoperative apnea-hypopnea index (AHI) <10 and >50 % reduction in preoperative AHI) and failure. Obstruction sites found on DISE and those ablated or left after surgery were compared between the two groups. RESULTS: Mean AHI fell from 30.9 ± 12.4/h to 13.7 ± 14.2/h after surgery. In eight of the 14 patients in the success group, DISE showed an obstruction site not treated by surgery. In six patients out of the ten patients in the failure group, all DISE sites were treated by surgery, which nevertheless was not effective. Four patients had retrovelar concentric obstruction. CONCLUSION: DISE could in some cases explain surgical failure. However, it also seems to show additional obstruction sites which do not need to be treated. Proper knowledge of pharyngeal fluid dynamics and mastery of the DISE technique would probably help us understand better some of the DISE findings.

EK Sign: A Wrinkling of Uvula and the Base of Uvula in Obstructive Sleep Apnea-Hypopnea Syndrome.

Introduction. Diagnosis of obstructive sleep apnea-hypopnea syndrome (OSAHS) is suspected in the presence of symptoms and/or pharyngeal alterations and skeletal abnormalities of maxilla and mandible. Our aim is to find a new clinical sign that leads to suspicion of OSAHS in snorers. Methods. We reviewed the clinical data of 69 snoring patients with or without OSAHS. We defined EK sign as the presence of horizontal wrinkling of uvula and the base of uvula and tried to correlate its presence with OSAHS. Results. EK sign was present in 25 of 69 patients. The positive predictive value of EK sign is 100%. The presence of EK sign significantly correlated with OSAHS (44% if AHI ≥ 5 and 0% if AHI < 5; p = 0.01) and severity of OSAHS (7% if AHI < 15 and 58% with AHI ≥ 15; p < 0.001). Conclusions. The EK sign is a strong predictor of OSAHS with a specificity of 100%. We recommend performing sleep tests in presence of EK sign in snorers even in the absence of other abnormalities or symptoms.