Current status and evaluation of transnasal esophagogastroduodenoscopy.

We reviewed the current status of transnasal esophagogastroduodenoscopy (EGD) with regard to tolerance, safety, feasibility and accuracy. Comparison of standard and ultrathin scopes and recently reported endoscopic techniques with transnasal insertion are also described as well as the current status of transnasal EGD in European countries compared with Japan. As several studies concluded that transnasal EGD can facilitate comfortable endoscopy without the need for sedative drugs, it has been tried in countries in which a relatively high number of unsedated EGD are carried out in daily practice. Long-tube intubation of the jejunum with the assistance of transnasal EGD will also be a part of the daily practice in the near future. However, its safety and accuracy should be further investigated. Even a standard scope whose charge-coupled device (CCD) has the same resolution as an ultrathin scope is superior to an ultrathin scope in terms of luminosity and resolution. Given the small number of procedures reported to date, the absolute complication rate of unsedated transnasal EGD is unknown. Methods of nasal anesthesia, as well as informed consent, indications and contraindications for transnasal EGD are not standardized. A guideline of transnasal EGD is under discussion by the Japanese Gastroenterological Endoscopy Society.