A 45-year-old obese Japanese woman presented with abdominal pain lasting 3 days. The pain started 3 hours after eating sausage and eggs. His medical history was notable only for uterine fibroids. She was not taking any medications, supplements or herbal remedies and no recent history of sick contacts or overseas travel. She drank occasionally and quit smoking more than 20 years ago. She denied any food or drug allergies.
At presentation, the patient was in moderate distress. His vital signs included a body temperature of 37.1 degrees, blood pressure of 112/74 mmHg, heart rate of 92 beats per minute and respiratory rate of 18 times per minute. Rebound tenderness in the right upper quadrant and Murphy’s sign were noted on physical examination. Laboratory results were significant for a white blood cell count of 19,500/mm3 (reference range: 2900–7800/mm3) and C-reactive protein of 28.9 mg/dL (reference range:
Antibiotics were started and percutaneous transhepatic gallbladder drainage (PTGBD) was performed the following day, with some symptomatic relief. However, the patient complained of severe abdominal pain 2 days after admission. Her body temperature rose to 38.8 degrees Celsius. Repeated laboratory tests revealed total bilirubin 5.3 mg/dL (reference range: 0.2–1.2 mg/dL), aspartate aminotransferase 159 U/L (reference range: 9–32 U/L), an alanine aminotransferase of 205 U/L (reference range: 3–38 U/L) and alkaline phosphatase of 1118 U/L (reference range: 103–289 U/L).
Several anatomical variations were noted on magnetic resonance cholangiopancreatography (MRCP). The cystic duct joins the distal third of the bile duct, suggesting a low insertion of the cystic duct (LICD). A long cystic duct ran parallel to the common bile duct. In addition, the right posterior sectoral bile duct opened directly into the common bile duct (Fig. 1A). A 3 mm stone was impacted into the inferior bile duct (4 mm in diameter) immediately below the insertion of the cystic duct (Fig. 1B,C). The patient was diagnosed with acute cholangitis due to an impacted common bile duct stone. The gastroenterology department was consulted.
Emergency ERCP was performed using the JF-260V duodenoscope (Olympus Corporation, Tokyo, Japan) (Supplementary File 1). Bile duct cannulation was performed with some difficulty, due to the LICD and parallel cystic duct. Fluoroscopy revealed a 5 mm stone in an undilated bile duct with LICD. Contrast material was also injected from the PTGBD tube, confirming that the cystic duct paralleled the common bile duct and overlapped with it on fluoroscopy, even when the C-arm was rotated (Fig. 2A).
After endoscopic sphincterotomy, an eight-wire stone extraction basket (MB-35-2X4-8; Cook Medical Inc., Bloomington, Indiana, USA) was selected for stone extraction. After several unsuccessful attempts, we switched to a stone extraction balloon (Multi-3V Plus; Olympus), but the catheter could not be advanced past the impacted stone. We therefore used a biliary balloon dilator with a pointed catheter tip (Eliminator PET biliary balloon dilator (8 mm × 3 cm); CONMED Corporation, Utica, New York, USA). Since we were concerned that expanding the balloon in the narrow lower bile duct (where the stone is) would lead to perforation of the bile duct, we decided to inflate the balloon above the stone, to use as a balloon calculation extraction. The balloon dilator was successfully advanced into the proximal bile duct. When the balloon was inflated above the stone and fired, the impacted stone did not move from its original position. The balloon was then deflated, but still could not be removed from the bile duct (Fig. 2B).
The duodenoscope fell back into the stomach while trying to retract the balloon dilator, causing the dilator shaft to break near the ampulla (Fig. 2C). We pulled the broken tip with a snare, which resulted in the balloon sheath separating from the shaft and being retained in the common bile duct (Fig. 2D). We finally recovered the stone and balloon complex by grasping the sheath with rat-toothed forceps (Fig. 2E,F). A 100 mm 6 French double pigtail plastic stent (Hanaco Medical Co., Ltd., Saitama, Japan) was inserted at the end of the procedure.
No signs of perforation were observed in a follow-up CT taken immediately after the procedure. Analysis of the extracted stone revealed that it was composed of pure cholesterol. Laboratory markers showed marked improvement the following day and post-treatment course was uneventful. The patient underwent laparoscopic cholecystectomy 3 months later with no complications. During surgery, the long cystic duct parallel to the bile duct could be confirmed (Fig. 3). MRCP taken after discharge revealed that 4 cm of cystic duct remained after surgery. No stones were observed in the bile duct or the cystic duct.