Novel ex vivo training model for freehand insertion using a double-bending peroral direct cholangioscope

Background and aim: Several experts of direct peroral videocholangioscopy (D-PVCS) using a conventional ultraslim endoscope have reported its usefulness for the diagnosis and therapy of biliary tract diseases. We have additionally developed a dedicated double-bending D-PVCS technique for freehand scope insertion. In this study, we developed an ex vivo training model for the freehand double-bending D-PVCS technique and compared it with the technique using a conventional ultraslim endoscope.

Methods: The ex vivo model was made for training using a U-shape insertion pattern. A third prototype endoscope and an ultraslim upper gastrointestinal endoscope were used. Two experts and nine non-experts performed D-PVCS using the freehand technique.

Results: The two experts could not advance the tip of the endoscope to the hilar portion using the freehand technique, but they could achieve technical successful insertion to the hilar portion with the third prototype cholangioscope using the freehand technique alone. The non-experts could not advance the tip of the endoscope to the bile duct using the freehand technique. On the other hand, two (22.2%) non-experts could advance the tip of the third prototype cholangioscope using the freehand technique before the training conducted by the experts. After the training, all the non-experts could advance the tip of the third prototype cholangioscope to the hilar portion.

Conclusions: The novel ex vivo model using a third prototype cholangioscope was useful for training in the use of the freehand D-PVCS technique.