Congenital dilatation of the bile duct, also known as congenital common bile duct cyst, is a common biliary tract malformation in children, and is generally believed to have a higher incidence in Asians than in Europe and the United States.
[Etiology].
The etiology of congenital bile duct dilatation is not well understood, and there are several theories. In the past, it was mostly thought to be related to abnormal development of the bile duct, weak development of the common bile duct wall and distal stenosis of the common bile duct. This disease combined with pancreaticobiliary duct abnormalities accounted for about 80% to 100%. There are also various factors such as the theory of infection and the theory of abnormal neuromuscular development of the distal common bile duct.
Pathological typing
Congenital bile duct dilatation is divided into three types according to the morphology of the cyst, type I: cystic dilatation of the common bile duct; type II: diverticulum of the common bile duct; type III: cystic prolapse of the mouth of the common bile duct, i.e., cyst within the wall of the duodenum of the common bile duct. Cystic dilatation of the common bile duct is the most common, while types II and III are less common. In 1958, Caroli was divided into three types, namely extrahepatic, mixed and intrahepatic, according to the morphology and location of intrahepatic and extrahepatic bile duct dilatation.
Clinical manifestations
The disease develops in about 70% of infants and children, and is less common in school-age children and adults. Abdominal pain, jaundice and abdominal masses are the three basic symptoms of the disease, the so-called “triad”, but not all children have three symptoms at the time of consultation, often appear clinically one or two, three or more account for only 20%-30%. In recent years, due to the development and popularization of B-ultrasound and other imaging techniques, the cystic type was considered to be more common in the past, and the masses could be found more often, but now the number of cases where the masses cannot be found is increasing.
Diagnosis
If the child has three basic symptoms of abdominal pain, jaundice and abdominal mass, the diagnosis is not difficult, but the child does not have all three signs, or only intermittent abdominal pain, recurrent or intermittent xanthogranuloma, fever, biliary tract infection, pancreatitis and other symptoms, attention should be paid to differentiation in order to achieve early diagnosis, timely ultrasound ultrasound, X-ray examination, and CT examination, etc.
Differential diagnosis
Congenital bile duct dilatation should be distinguished from the following diseases.
1. Infectious hepatitis Since hepatitis is more common, the diagnosis of hepatitis may be made when jaundice is present in children.
2, biliary atresia For jaundice appearing within 2-3 months after birth, progressive aggravation, white stools and dark yellow urine, biliary atresia or neonatal hepatitis should be considered first, both sometimes similar to biliary duct dilatation, but the diagnosis can be confirmed by careful examination of abdominal masses, ultrasound or X-ray.
3, liver worm cysts liver worm cysts in the liver parts of the mass, local pain and discomfort, combined with infection can appear gangrene and fever, but the difference, liver worm cysts are mostly seen in the livestock area, the disease is slow, progressive aggravation, eosinophilia, Casoni test positive rate of up to 80% to 95%, 80% complement binding test positive.
4, pancreatic cysts Children with pancreatic pseudocysts mostly have a history of trauma, when combined with infection can also be fever, epigastric swelling and abdominal pain. Unlike congenital bile duct dilatation, the pancreatic amylase in the serum is increased, and imaging examination shows widening of the posterior gastric space, and the gastric body and fundus are displaced anteriorly and superiorly.
5. Right hydronephrosis may be confused with cystic congenital bile duct dilatation, but hydronephrosis is more lateralized, with a full renal area and no xanthogranuloma, which can be differentiated by ultrasound and IVP.
6. Large omental or mesenteric cysts are located in the middle abdomen with clear boundaries and can be moved, abdominal pain is not obvious, and there is no jaundice, so they are easy to differentiate.
In addition to the above-mentioned diseases, we should pay attention to whether the cyst is a mildly dilated bile duct in the shape of a pike or column with abnormalities of the common bile duct and pancreaticobiliary syncope, and we should carefully perform ultrasound or ERCP or MRCP to confirm the diagnosis. Treatment
Treatment
Before the 1960s, external drainage or cystoenteric anastomosis was used, and the postoperative mortality rate was as high as 20% to 30%. After the 1970s, cystoenteric anastomosis was the main treatment, with good recent results, but the lesion was not removed, and postoperative complications such as episodic cholangitis, recurrent infection, anastomotic stenosis, bile sludge, bile duct stones, pancreatitis and carcinoma often occurred, with poor long-term results. Since the 1980s, radical surgery with cyst removal and bile duct reconstruction has been the basic surgical principle, and the operative mortality rate has decreased significantly to less than 5%. The number of cases with long-term survival for more than 10 to 20 years after surgery is increasing.
Indications for surgery
Congenital bile duct dilatation is a congenital abnormality in the development of bile ducts and is associated with abnormalities in the merging of pancreatic and biliary ducts. Because of the obstruction of bile drainage, pancreatic juice and bile mix, in infancy, it often causes septic cholangitis, pancreatitis, bile duct perforation, peritonitis and liver cirrhosis and other serious complications, often threatening the life of the child.
Surgical options
There are three common surgical methods: choledochal cystostomy, i.e. external drainage; cyst and intestinal anastomosis, i.e. internal drainage and cystectomy and bile duct reconstruction. At present, cystectomy and common hepatic duct duodenal anastomosis; cystectomy and common hepatic duct jejunostomy; cystectomy and jejunal interposition, etc. are generally used. Laparoscopic common bile duct cyst excision + hepatic duct jejunostomy.
Postoperative treatment
1. Fasting, continuous gastrointestinal decompression, and nutritional support therapy should be used after surgery; gastrointestinal decompression should be stopped after intestinal peristalsis is restored, and full liquid food should be given 72 hours after surgery, and semi-liquid food can be given after 4 to 5 days.
2. Connect the drainage tube to the sterile drainage bag at the bedside, fix it properly and keep it open. Observe and record daily the amount of bile discharge, color and turbidity. If poor drainage is found, gentle flushing with saline is sufficient. The abdominal flow tube is usually removed 2 to 3 days after surgery.
3. Continue to apply broad-spectrum antibiotics to control infection after surgery. When the child’s systemic and local inflammation disappears, the second radical surgery will be performed within 1 to 3 months.
4.Pay attention to the care of the drainage tube during this period. To reduce the large loss of bile, which causes ionic disorders, bile will be collected and taken orally after aseptic treatment.
5.If symptoms such as epigastric pain, fever and xanthogranuloma occur, mostly food reflux and biliary tract upstream infection, fasting should be given and broad-spectrum antibiotics should be given in combination.
[Prognosis].
Congenital choledochal cyst surgical mortality rate, in China in the 1960s up to about 30%, has significantly decreased in recent years, about 4%, the surgical cure rate has significantly improved, long-term survival cases are increasing, long-term complications of about 8% a 15%.
Long-term complications after surgery for congenital bile duct dilatation are closely related to the choice of surgery, incomplete resection of the lesion, anastomotic stenosis and duodenogastric reflux, so a comprehensive understanding of the morphology and distribution of the internal and external bile ducts should be carried out before surgery, and the lesion should be resected, pancreaticobiliary shunt and biliary reconstruction should be performed.