Percutaneous stone removal using cobra-shaped sheath and cholangioscopy for multiple hepatolithiasis with choledochoduodenal anastomotic stenosis

Management of multiple hepatolithiasis with choledochoenteral anastomotic stenosis remains difficult and time-consuming. We report a case of a 77-year-old man with severe right hypochondoralgia, treated with percutaneous transhepatic balloon dilatation of choledocoduodenal anastomotic stenosis and percutaneous stone removal using 8Fr. cobra-shaped sheath and cholangioscopy. Hilar hepatic stones were pushed out into the duodenum through the dilated anastomosis using 5Fr. balloon catheter covered with the sheath and cholangioscopy. For stones located in the left, right anterior and aberrant right posterior hepatic ducts, a guidewire and a removal balloon catheter were inserted by using the cobra-shaped sheath. Stones pulled from the intrahepatic bile ducts to the common hepatic duct were pushed out into the duodenum. Clearance of intrahepatic bile duct stones was confirmed by balloon-occluded cholangiography using the cobra-shaped sheath and 6Fr. balloon catheter. The use of cobra-shaped sheath improved percutaneous stone removal, but the procedure needs further improvement.


Introduction
Hepatolithiasis is a serious complication observed in a longterm follow-up after choledochoenterostomy such as choledochojejunostomy or choledochoduodenostomy [1 ,2] . There are some treatments for hepatolithiasis [3][4][5][6] , however, the ideal treatment for multiple hepatolithiasis with anastomotic stenosis after choledochoenterostomy has not been established. We report a case of multiple hepatolithiasis secondary to choledochoduodenal anastomotic stenosis that was treated with less invasive percutaneous stone removal using cobrashaped sheath and cholangioscopy.

Case report
A 77-year-old man was referred to our department with severe right hypochondoralgia. He had surgery for early gastric cancer at the age of 69.
At that time, he suffered a bile duct injury; and underwent cholecystectomy, choledochoduodenostomy, distal gastrectomy, and Roux-en-Y gastrojejunostomy. Post-surgery, he often suffered from recurrent cholangitis. During his latest recurrence of cholangitis with jaundice and leukocytosis, he was admitted to a nearby hospital and was treated with antibiotics. He was on long-term diuretics for chronic heart failure.
Percutaneous transhepatic biliary drainage (PTBD) was planned on the 4th day of hospitalization. Before PTBD, color Doppler US was performed to avoid vessel puncture ( Fig. 1 B). Percutaneous transhepatic cholangiography revealed multiple hepatolithiasis and choledocoduodenal anastomotic stenosis. Bile duct stones were distributed bilaterally in multiple segments. After introducing a guidewire into the bile duct through the puncture needle, first PTBD 8Fr. tube was inserted into the distal side of the left hepatic duct. Second PTBD 10Fr. tube was inserted into the common hepatic duct ( Fig. 3 A). The first tube was expected to decompress the bile duct and the second tube was expected to serve as a stone removal. The culture of bile showed the presence of Escherichia coli, Aeromonas caviae, and Enterococcus faecium.   On the 11th day, a guidewire from the second PTBD tube could not be passed through the choledochoduodenal anastomotic stenosis percutaneously. On the 19th day, a guidewire from the second PTBD tube could be passed through the stenosis by single-balloon endoscopy assistance. The second PTBD tube was replaced with 14Fr. internal-external biliary tube along the guidewire. On the 26th day, the tube was replaced with 18Fr. internal-external biliary tube ( Fig. 3 B).

Fig. 7 -(A) Balloon-occluded cholangiogram using cobra-shaped sheath and 6Fr. balloon catheter shows clearance of intrahepatic bile duct stones. The contrast medium is injected through the sheath. An inflated balloon 2cm in diameter to occlude dilated choledochoduodenal anastomosis is indicated by an arrow. (B) Cholangiogram shows good bile flow through the trans-anastomotic 18Fr. internal-external biliary drainage tube (arrow).
mosis was dilated with a balloon 10mm in diameter for 10 minutes ( Fig. 5 A). Then hilar hepatic stones were pushed out into the duodenum through the dilated anastomosis using 5Fr. balloon catheter covered with the sheath and cholangioscopy ( Fig. 5 B). After that, by using the sheath via the 1st PTBD route, a removal balloon catheter was introduced along the guidewire, crossing the stones into the peripheral right posterior and left bile ducts ( Fig. 6 A,B). The balloon was inflated and stones were pulled into the common hepatic duct. For stones located in the right anterior branches, a guidewire and a removal balloon catheter were inserted by using the cobra-shaped sheath via the 2nd PTBD route ( Fig. 6 C). Then, the balloon was inflated and stones were pulled into the common hepatic duct again. Stones moved from the intrahepatic bile duct to the common hepatic duct were pushed out into the duodenum in the same way as described above ( Fig. 6 D). Infrared spectroscopy revealed that the bile duct stone component was 61% bilirubin calcium and 39% fatty acid calcium.
On the 47th day, for residual stones stuck in the intrahepatic bile ducts, percutaneous transhepatic cholangioscopic lithotripsy (PTCSL) using electrohydraulic lithotripsy (EHL) [3 ,4] was performed. Clearance of intrahepatic bile duct stones was confirmed by balloon-occluded cholangiography using the cobra-shaped sheath and 6Fr. balloon catheter ( Fig. 7 A). Trans-anastomotic 18Fr. internal-external biliary drainage tube via the 1st PTBD route was left in situ to ensure bile flow through the dilated choledochoduodenal anastomosis ( Fig. 7 B). The indwelling tube will be left at the site for more than 3 months. Another tube via the 2nd PTBD route was removed. ALP, an indicator of cholestasis, normalized to 75 U/L after treatment. He was discharged on the 55th day.

Discussion
We reported a case of multiple hepatolithiasis that developed 7 years after choledochoduodenostomy for bile duct injury. The patient was treated with percutaneous transhepatic balloon dilatation of choledocoduodenal anastomotic stenosis and percutaneous stone removal using cobra-shaped sheath and cholangioscopy.
Hepatolithiasis is defined as the presence of stones in the bile duct peripheral to the confluence of the right and left hepatic ducts. Its prognosis is poor due to complications including recurrent intrahepatic stones, recurrent cholangitis, biliary cirrhosis, liver atrophy, and intrahepatic cholangiocarcinoma [10][11][12] . Intrahepatic bile duct stones formation is the longterm serious complication of choledochoenterostomy such as choledochojejunostomy or choledochodudenostomy [1 ,2] . In this case, biliary stasis secondary to choledochoduodenal anastomotic stenosis was considered to be the cause of biliary infection, recurrent cholangitis, and stone formation. The management of multiple hepatolithiasis with choledochoenteral anastomotic stenosis remains a challenging task. There are some treatments such as revision of the choledocoenterostomy [13] , PTCSL using EHL [3 ,4] , and hepatectomy [14 ,15] , however, multiple hepatolithiasis after choledochoenterostomy is still difficult to treat. No matter which treatment we choose, the stone removal procedure is not easy, it takes a long time, and it is surgically invasive. Therefore, it is important to devise more effective and less invasive treatment techniques.
Cobra-shaped sheath was used for stone removal, and it was useful for guiding the stone removal catheter to the pe-riphery of most of the liver segments. The 8 Fr. cobra-shaped sheath was developed for the treatment of gastric varices [7] . Its use in percutaneous papillary balloon dilatation for cholecytocholedocholithiasis has been reported [8 ,9] . The sheath contributes to ensuring the operability and strength of the balloon catheter in stone removal. We adopted this sheath for multiple hepatolithiasis with choledochoduodenal anastomotic stenosis.
Some patients with hepatolithiasis cannot tolerate surgery due to the severity of the condition. It cannot be treated endoscopically because of previous gastrointestinal surgery. Our patient had chronic heart failure and previous surgery. Percutaneous radiological stone removal is an option in a small number of patients in whom endoscopic techniques are unsuccessful or impossible. A major advantage of the percutaneous approach compared to the endoscopic approach is the ease of repeated stone removal. Also, PTCSL using EHL in combination with percutaneous radiological stone removal was particularly useful for residual stones.
Monitoring of choledochoduodenal anastomosis is important during follow-up after stone removal. An internalexternal drainage tube was left to monitor anastomosis and to prevent cholangitis and anastomotic restenosis.
The use of the cobra-shaped sheath improved the percutaneous stone removal, but the procedure needs further improvement.