Abstract
Background Endoscopic stone extraction is often challenging in patients with a significant lower
bile duct corner pocket, where small stones are likely to escape and become impacted.
This study aimed to determine the utility of different types of baskets for retrieving
corner pocket stones.
Methods Seven types of retrieval baskets were evaluated on silicone models. The study outcomes
included the characteristics of each basket and technical success rates associated
with the retrieval of stones impacted in the corner pocket.
Results The overall success rate was only 27.5 %, with significant differences between the
baskets (P < 0.001). Only three baskets yielded successful removal. The success rates were 10 %,
25 %, and 70 % with the 8-wire Nitinol Basket, RASEN, and VorticCatch V, respectively,
all of which are helical eight-wire baskets. RASEN and VorticCatch V share similar
characteristics, including a strong spiral wire and smaller interwire spaces at their
distal ends. The addition of rotation significantly increased the success rate to
80 % with the 8-wire Nitinol Basket (P < 0.001) and 90 % with RASEN (P < 0.001).
Conclusions Robust helical eight-wire baskets with smaller interwire spaces at the tip may be
effective for extracting corner pocket stones, while the addition of rotational motion
may improve the efficacy of retrieval.
