Liver transplantation has become a standard of care in patients with end-stage liver disease. After liver transplantation, approximately 1/3rd of patients are affected by biliary tract complications, and these result in significant morbidity and decreased patient survival, which is called the Achilles heel of liver transplantation1. Biliary leakage is the second most common complication after liver transplantation, with an incidence of 2%-21%2,3,4. Approaches commonly used for treating biliary complications involve endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangial drainage (PTCD), percutaneous transhepatic cholangioscopy (PTCS) and surgery5, but they are not all effective.
The goal of this method is to address complex biliary leakage after liver transplantation by combining ERCP, peroral single operator cholangioscopy, and PTCS.
The technical principle of this method is divided into three steps. First, through ERCP and peroral single operator cholangioscopy, the distal end of the biliary leakage is identified under direct vision, and a plastic stent is placed as a marker. Then, through PTCS, under the guidance of the plastic stent, the proximal end of the biliary leakage is searched from the common hepatic duct under direct vision, and the urinary catheter reconstructs the continuity of the biliary tract. Finally, through ERCP, a double-headed guide wire is used, the urinary catheter is removed, and the left and right hepatic duct stents are placed to reconstruct biliary continuity.
Peroral cholangioscopy (POCS) was first reported by Japan in 19766. Chen et al.7 first reported the first-generation single-operator visualization choledochoscope system, SpyGlass, in 2007, and the second-generation SpyGlass (SpyGlass DS) was launched by Boston in 20158. With the development of instruments, the peroral single operator cholangioscopy has become thinner and has more functions.
The biggest advantage of this method is that it can be performed under the direct vision of the peroral single operator cholangioscopy, which increases the success rate and safety of the operation9,10,11,12. Rainer9 reported successful stent placement using a direct biliary vision system in post-liver transplantation patients with ERCP stent implantation failure, and they suggested that direct visualization of the tiny opening at the biliary stricture was the only way to successfully pass the guidewire.
This method is suitable for patients with complex biliary leakage after liver transplantation who cannot be cured by ERCP, PTCD, PTCS, and surgery.
We report the case of a 38-year-old man who had a history of Crohn's disease and vitiligo in addition to acute-on-chronic liver failure brought on by an outbreak of the Hepatitis B virus. Liver function declined over time despite repeated artificial liver treatments. When a 15-year-old child with brain death provided a matching donor liver, bile leakage occurred 14 days after the liver transplantation (Figure 1A). The abdominal cavity drainage tube and PTCD were installed right away due to acute abdominal pain and septic shock. Following drainage, the patient's overall health improved, and the amount of peritoneal effusion was greatly reduced (Figure 1B).

Figure 1: Before and after drainage of bile leakage. (A) The white arrow shows the fluid before drainage. (B) The white arrow shows the fluid after drainage. Please click here to view a larger version of this figure.
After 3 weeks, the intrahepatic bile duct was insufficient to support the guide wire, which easily passed through the intrahepatic bile duct to other locations, so the attempt to reconstruct the biliary tract from top to bottom through the PTCD tube in the left and right hepatic ducts both failed (Figure 2). After 4 weeks, an attempt to reconstruct the biliary tract using ERCP from bottom to top was unsuccessful because the guidewire could not pass through stricture into the intrahepatic bile duct (Figure 3). After 2 weeks, the common bile duct could not be located, and there were numerous stones at the junction of the left and right hepatic ducts in the hilar, making it impossible to reconstruct the biliary tract from top to bottom with PTCS. About 4 weeks later, an attempt to reconstruct the biliary tract by choledochojejunostomy failed because of the obvious inflammation and edema of the tissue surrounding the biliary leak, and the patient's previous Crohn's history greatly increased the risk of postoperative biliary leak with intestinal fistula.

Figure 2: Biliary continuity reconstructed by PTC. (A) The white arrow indicates an attempt from the left hepatic duct. (B) The white arrow indicates an attempt from the right hepatic duct. Please click here to view a larger version of this figure.

Figure 3: Biliary continuity reconstructed by ERCP. The guidewire could not enter the intrahepatic bile duct. Please click here to view a larger version of this figure.
Here, we have found a new method of combining ERCP, peroral single operator cholangioscopy, and PTCS to treat complex bile leakage after liver transplantation. A plastic stent was first placed to locate the distal end of the bile leakage through ERCP and peroral single operator cholangioscopy. The proximal end of the bile leakage was then located by PTCS and B ultrasound, and finally, the continuity of the biliary tract was reconstructed by ERCP.