TransNasal Esophagogastroduodenoscopy (TN-EGD) is Suitable for Evaluation of the Pharynx. A Prospective Study Compared With Conventional EGDS

Abstract

BACKGROUND AND AIMS: Transnasal esophagogastroduodenoscopy (TN-EGD) was unlikely to cause the gag reflex which led to the inadequate observations of the pharynx. We aimed to evaluate the utility of TN-EGD compared with transoral EGDs for observation of the pharynx in a large prospective group. METHODS: The study involved 375 patients referred for diagnostic EGD. We evaluated three points as follows: (1) Rate of completion for pharyngeal observation, (2) Numbers of gag reflex and cough reflex, and (3) Observation time of the pharynx. The EVIS LUCERA SPECTRUM® system (Olympus Corp., Tokyo, Japan) was used, and all patients underwent EGD without sedation performed by one endoscopist. Observation was performed on a predetermined way with narrow-band imaging system. When the cough or gag reflex occurred, we immediately finished evaluating the pharynx. RESULTS: The numbers of patients who underwent TN-EGD (the diameter of endoscope, 5.5mm), transoral EGD (6.5, 7.7, and 9.2 mm) were 149, 113, 40, and 73. (1) Rates of completion for pharyngeal observation in TN-EGD (n = 149) and transoral EGD (n=226) were 98.7 % (147 / 149) and 74% (166 / 226), respectively, which showed the statistical difference (p < 0.001, chi-square test). (2) The numbers of gag reflex in TN-EGD and transoral EGD were 0.67 % (1 / 149) and 29.2 % (66 / 226), respectively, which showed the statistical difference (p < 0.001, chi-square test). There was no significant difference in the rate of completion and number of gag reflex between each transoral EGD. The number of cough reflex was smaller in TN-EGD than in transoral EGD (4.0 % (6 / 149) vs. 8.0 % (18 / 226)), which showed no significant difference. (3) Observation time of the pharynx in TN-EGD was longer than in transoral EGD group (39.1 ± 15.8 sec vs. 31.4 ± 15.6 sec, p < 0.01, unpaired t-test). CONCLUSIONS: TN-EGD was suitable for observation of the pharynx in EGD for routine diagnosis.