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14 November 2018

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Int J Med Sci 2013; 10(9):1085-1091. doi:10.7150/ijms.6003

Research Paper

Utility and Stability of Transnasal Endoscopy for Examination of the Pharynx - A Prospective Study and Comparison with Transoral Endoscopy

Masaru Tsuboi, Makoto Arai, Daisuke Maruoka, Tomoaki Matsumura, Tomoo Nakagawa, Tatsuro Katsuno, Osamu Yokosuka

Department of Gastroenterology and Nephrology, Graduate School of Medicine, Chiba University, Chiba, Japan.


Objective: Transnasal endoscopy may be used to observe the head and neck part readily without excessive reflexes. We aimed to evaluate the utility and stability of transnasal esophagogastroduodenoscopy (TN-EGD) in comparison with transoral EGD (TO-EGD) for observation of the pharynx.

Study Design: Prospective study

Methods: A total of 497 patients received unsedated TN-EGD with a 5.5 mm diameter endoscope or unsedated TO-EGD with endoscopes of 6.5 mm, 7.9 mm and 9.2 mm diameter. The rate of completion of pharyngeal observation and numbers of gag reflexes and cough reflexes were recorded.

Results: TN-EGD was performed in 175 patients and TO-EGD was performed in 322 patients. Pharyngeal observation was completed in 173 patients (98.9%) in the TN-EGD group and 235 patients (73.2%) in the TO-EGD group, a significant difference (p<0.001). The TN-EGD group had a low rate of occurrence of gag reflex (0.57%), in contrast, 28.3% of the TO-EGD group had a gag reflex, a significant difference (p<0.01). Multivariable analyses revealed that the use of TN-EGD was the only predictive factor for completion of pharyngeal observation (p<0.0001).

Conclusions: TN-EGD is ideally suited to observation of the pharynx by unsedated EGD.

Keywords: Transnasal EGD, Transoral EGD, Pharynx, Cancer.

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) License. See for full terms and conditions.
How to cite this article:
Tsuboi M, Arai M, Maruoka D, Matsumura T, Nakagawa T, Katsuno T, Yokosuka O. Utility and Stability of Transnasal Endoscopy for Examination of the Pharynx - A Prospective Study and Comparison with Transoral Endoscopy. Int J Med Sci 2013; 10(9):1085-1091. doi:10.7150/ijms.6003. Available from