Technical skills and training of upper gastrointestinal endoscopy for new beginners

Figure 20 Withdrawal of scope and observation, J-turn and U-turn. A: Schematic diagram of the J-turn. Deflect the distal tip of the scope upward in the antrum of the stomach; B: The shaft of the scope is bent in a J-shape, as the gastric angle in an arched shape is observed; C: If the scope tip is deflected upward more sharply, the lesser curvature of the gastric body can be observed; D: Endoscopic image of the antrum of stomach before maneuvering a J-turn. The pyloric ring (arrow mark) is observed in the front; E: Endoscopic image of the antrum of stomach after maneuvering a J-turn. If the distal tip of the endoscope is deflected upward, the gastric angle (dotted line) in an arched shape is observed. At this point, the upper side is the greater curvature; the lower side is the lesser curvature; the left side is the anterior wall; the right side is the posterior wall. The left and right directions on an endoscopic image taken during a J-turn maneuver are not reversed; F: Endoscopic image taken in the J-turn. In this case, the distal tip of the endoscope is deflected upward too sharply and the gastric angle cannot be observed. Likewise, the left and right directions on an image taken in J-turn do not change, but only the up and down directions are reversed in this case; G: Schematic diagram of the U-turn. The U-turn can be maneuvered by rotating the scope in a J-turn by 180 degree; H: In the U-turn, the observation is usually done while pulling the scope up toward the gastric cardia; I: Endoscopic image taken in the U-turn. A U-turn changes the directions of the left and right sides; the upper side is the lesser curvature; the lower side is the greater curvature; the left side is the posterior wall; the right side is the anterior wall; J: Endoscopic image after pulling up the scope in a U-turn toward the gastric cardia. The directions of the left and right sides still remain reversed.