Abstract
GIF-Qw with an extra-wide visual angle, a further improved type of GIF-Q, was ap-plied to 1, 078 cases of upper G-I endoscopy. The introduction of this endoscope into patients was as easy as in the thin endoscopes, presenting the clear views without any blind point from the esophagus and gastric lumen to the duodenal bulb. The manipulation in the stomach was also excellent with easy U-or J-turn observations and this scope was able to be pulled into the esophagus on looking up in the cardia with the inversion of the scope. The duodenal bulb was also observed without marked blind points, and it was easy for us to introduce the scope into the descending part of the duodenum. The en face view of the papilla of Vater was, however, inferior to the side-view endoscoped. The examina-tion of the aberration revealed a barrel distortion due to the extra-wide angle of the view in observing a plane test chart. In fact, the en face view of the postrior wall of the middle or lower body of the stomach which is regarded as a weak point of the forward-view endo-scope, became not difficult and observation of the greater curvature immediately beyond the pyloric ring was also easy. The biopsy channel of this scope has a relatigely small diameter of 2 mm, but it had no problem in the conventional diagnosis.
