Cystic duct stump stone removal by retrieval basket under direct visualization using a novel peroral choledochoscope

Calculus in a cystic duct remnant is one of the causes of postcholecystectomy syndrome. Surgical extraction of the stone with excision of the cystic duct can be carried out, but the adhesions caused by the prior operation make the reoperation more challenging [1]. Endoscopic retrograde cholangiopancreatography (ERCP) has been used to extract the stone in combination with lithotripsy [2] [3] [4], but is confined to only a small subset of patients. We present a novel peroral choledochoscope (Eye-Max CDS11001; Micro-Tech, China) with a 1.8-mm working channel to introduce therapeutic equipment ([Fig. 1]).