Comparing technical approach of peroral cholangioscopy with percutaneous transhepatic cholangioscopy

(A) Peroral cholangioscopy demonstrates the endoscope (blue) being passed through the oral cavity, through the small bowel, and into the biliary system.

(B) Percutaneous transhepatic cholangioscopy demonstrates the endoscope (blue) being passed directly into the biliary system through a percutaneous approach. Note the differences in the length of endoscope required between the two approaches, as well as, the normal proximal small bowel anatomy often required for a peroral approach.