Efficacy of cap-assisted endoscopy for routine examining the ampulla of Vater

Figure 4 Incomplete observation of the ampulla of Vater by conventional endoscopy and outcomes of cap-assisted endoscopy. A: Incomplete observation of the ampulla of Vater (AV) by forward-viewing endoscopy due to a folded mucous membrane; C: Incomplete observation of the AV due to the close proximity of the endoscope tip to a superior ampulla lesion; E: Incomplete observations of the AV on the edge of diverticulum; B, D, F: Complete observation of the AV, including the orifice, by short cap-assisted endoscopy (A→B, C→D, E→F); G: Incomplete observation of the AV by short cap-assisted endoscopy due to a loop in the scope; H: Complete observation of the AV by long cap-assisted endoscopy (G→H).