The Usefulness of the Alpha-Retroflex Position in Biliary Cannulation on Single-Balloon Enteroscopy-Assisted Endoscopic Retrograde Cholangiopancreatography in Patients with Roux-en-Y Gastrectomy: A Retrospective Study

Figure 4

Creation of the alpha-retroflex scope position. The scope is manipulated to obtain upward angulation (a and b) and rotated clockwise (c and d), whereas the flexible part of the scope is pressed onto the duodenal wall opposite side of the inferior duodenal angle. By combining these steps with rightward angulation, the distal portion of the scope becomes shaped like the letter alpha (e and f). Here, the alpha-retroflex position provided an en face view of the papilla, although the endoscope tip was probably close to the papilla.

(a)

(b)

(c)

(d)

(e)

(f)