Bile duct dilation

　　At present, the etiology is not yet clear, but most scholars abroad believe that bile duct dilation is caused by abnormal bile duct development during embryonic development, congenital structural weakness, or sympathetic nerve deficiency.

　　1, During the development of the bile duct bud structure within the liver, as the bile duct evolves from solid to hollow, tissue proliferation is uneven, some segments develop slowly and are narrow, and their distal ends expand due to obstruction. The more severe the obstruction, the more obvious the expansion, thus forming cystic lesions of varying sizes.

　　2, Infected by hepatitis B virus from the mother, the bile duct epithelium undergoes giant cell transformation, the wall becomes weak, and elasticity decreases, causing cystic expansion.

　　About two-thirds of the cases are accompanied by congenital liver fibrosis, and there are often various kidney lesions such as polycystic kidney disease. In advanced cases, liver cirrhosis and portal hypertension may occur. If classified, they can be divided into congenital liver fibrosis, congenital intrahepatic bile duct dilatation, congenital common bile duct dilatation, and congenital liver cysts, collectively known as liver and bile duct fibromatosis. The characteristics of cholangiectasis are cystic dilatation of intrahepatic bile ducts with relative stenosis, which causes intrahepatic bile duct stasis and leads to intrahepatic bile duct stones, secondary bile duct infection, sepsis, and the formation of intrahepatic and subphrenic abscesses.

　　The cystic dilatation at the site of the lesion and the relative stenosis of the distal bile duct, which causes poor bile drainage or obstruction, is the root cause of complications. The main complications include the following points:

　　1, recurrent ascending cholangitis.

　　2, biliary cirrhosis.

　　3, bile duct perforation or rupture.

　　4, recurrent pancreatitis.

　　5, stone formation and wall cancer.

　　Cholangiectasis is a relatively common congenital bile duct malformation. In the past, it was considered to be a lesion confined to the common bile duct. Medicine has shown that abdominal mass, abdominal pain, and jaundice are considered classic symptoms.

　　An abdominal mass is located in the upper right abdomen, below the costal margin. Large masses can occupy the entire right abdomen. The mass is smooth, spherical, and may have a marked cystic elasticity. When the cyst is filled with bile, it can present a solid sensation, resembling a tumor. However, there are often changes in size, and during the period of infection, pain, and jaundice, the mass may increase in size, and it can slightly shrink after the symptoms subside. Small bile duct cysts are difficult to detect due to their deep location.

　　Abdominal pain occurs in the upper middle abdomen or the upper right abdomen, with varying degrees of pain, sometimes presenting as persistent bloating pain, and sometimes as colic. The patient often assumes a flexed knee prone position and refuses to eat to alleviate the symptoms. The onset of abdominal pain suggests bile duct outlet obstruction, increased intraductal pressure, and reciprocal reflux of pancreatic juice and bile, which can cause symptoms of cholangitis or pancreatitis. Therefore, fever is often accompanied by clinical symptoms, and nausea and vomiting may also occur.

　　During attacks, blood and urine amylase levels often increase. Jaundice is generally intermittent and is mainly a symptom in infants, with the depth of jaundice directly related to the degree of bile duct obstruction. In mild cases, jaundice may not be present clinically, but after the appearance of infection and pain, jaundice may temporarily appear, with feces becoming pale or grayish, and urine becoming darker, and other symptoms.

　　These symptoms are all intermittent. Due to the obstruction of the distal bile duct outlet, bile reflux can lead to clinical symptom发作. When bile can flow smoothly, the symptoms will subside or disappear. The interval between attacks is not the same, some attacks are frequent, and some can be asymptomatic for a long time. In the early stage of the disease, it is often diagnosed as cholecystitis or liver abscess. If there are other fibrocystic lesions such as congenital liver fibrosis or extrahepatic bile duct dilation, the symptoms will be more complex, and symptoms such as liver cirrhosis, extrahepatic bile duct obstruction, and urinary tract infection may occur. Sometimes, it is not possible to make a diagnosis because of this, and often requires surgical treatment to confirm the diagnosis.

　　Since bile duct dilation is a congenital disease, in order to prevent the occurrence of the disease, examinations should be performed during pregnancy to reduce the chance of getting the disease. At the same time, during pregnancy, it is necessary to stay away from various forms of radiation and factors that may cause fetal diseases, reducing the probability of the fetus being affected by the disease.

　　Bile duct dilation is a relatively common congenital bile duct malformation. The laboratory examinations for bile duct dilation include the following points:

　　1. B-ultrasonography

　　It has the advantages of direct vision, tracking, and dynamic observation. For example, when there is obstruction and dilation of the bile duct, it can correctly find the location and extent of the liquid content, the degree and length of bile duct dilation, and its diagnostic accuracy can reach more than 94%. It should be regarded as a routine examination method for diagnosis.

　　2. Biochemical examination

　　The measurement of blood and urine amylase should be regarded as a routine examination during the onset of abdominal pain, which is helpful for diagnosis. It can suggest the possibility of accompanying pancreatitis. Or it can suggest the possibility of abnormal convergence of the pancreatic and bile ducts, where high-concentration pancreatic amylase refluxing into the bile duct enters the blood through the bile canaliculi, causing hyperamylasemia. At the same time, the values of total bilirubin, 5'-nucleotidase, alkaline phosphatase, transaminase, etc., are all elevated, and they all return to normal in the remission period. In patients with a long course of the disease, there is liver cell damage, and in the examination of asymptomatic cases, it is normal.

　　3. Gastrointestinal barium meal examination

　　In cases of large cystic dilation, it can be shown that the duodenum is displaced to the left anterior, the duodenal ring is expanded, and there is a curved indentation. Its diagnostic value has been replaced by ultrasonic examination.

　　4. Intraoperative cholangiography

　　When performing surgery, the contrast medium can be directly injected into the common bile duct, which can show the full image of the intrahepatic and extrahepatic bile duct system and the pancreatic duct, understand the extent of intrahepatic bile duct dilation and the reflux situation of the pancreatic and bile ducts, and help to choose the surgical method and postoperative treatment.

　　5. Percutaneous liver puncture cholangiography

　　It is more likely to be successful in cases of intrahepatic bile duct dilation, and it can clearly show the intrahepatic bile ducts and their directions, clearly indicating whether there is bile duct dilation and the extent of dilation. It can be applied to jaundice cases to distinguish the cause or site of obstruction, and can observe the pathological changes of the bile duct wall and inside it, distinguishing the cause of obstruction based on the characteristics of the image.

　　6. Endoscopic retrograde cholangiopancreatography

　　With the help of duodenoscopy, a catheter can be inserted through the papilla opening to directly inject contrast medium into the bile duct and pancreatic duct, determining the extent of bile duct dilation and the site of obstruction, and showing the length and abnormalities of the common channel between the pancreatic and bile ducts.

　　Patients with bile duct dilation should pay special attention to their diet. First, the diet should be light and nutritious. Secondly, it is necessary to avoid spicy and刺激性 foods, greasy foods, alcohol, seafood, fishy foods, and substances that may cause inflammation. At the same time, it is important to maintain smooth bowel movements and a pleasant mood, etc., which can better help patients recover.

　　Mainly used for the prevention and treatment of cholangitis, long-term use of broad-spectrum antibiotics, but the therapeutic effect is generally not satisfactory. Surgery can also be used for the treatment of this disease, and the following are common surgical treatments for this disease.

　　1. External Drainage

　　Applied to individual severe cases, such as severe obstructive jaundice with liver cirrhosis, severe biliary tract infection, spontaneous bile duct perforation, and secondary treatment after the condition improves.

　　2. Cyst-to-intestine Internal Drainage

　　For example, in the case of cystic duodenal anastomosis, due to more complications such as recurrent cholangitis, anastomotic stenosis, and stone formation, it has been turned to cystic jejunal Roux-en-Y anastomosis, and various anti-reflux operations have been designed on the mesentery, but there is still the problem of pancreatico-biliary drainage, so cholangitis or pancreatitis symptoms still occur after surgery, and even reoperation may be required, and there have been frequent reports of postoperative cyst wall carcinogenesis. Therefore, it is rarely used now.

　　3. Bile Duct Dilatation Excision and Bile Duct Reconstruction

　　Advocating the excision of bile duct dilatation with radical significance and bile duct reconstruction to achieve the purpose of removing the focus and pancreatico-biliary分流. Physiological bile duct reconstruction can be adopted, with the jejunum placed between the hepatic duct and duodenum, or with the addition of a reflux prevention valve, or using Roux-en-Y hepaticojejunal anastomosis, hepaticojejunal anastomosis, etc., all of which can achieve good results. The most important thing is that the anastomosis must be large enough to ensure adequate bile drainage.

　　As for the treatment of intrahepatic bile duct dilatation, secondary to extrahepatic bile duct dilatation, its morphology is cylindrical dilatation, which often returns to normal after surgery. If it is cystic dilatation, it is a mixed type. After extrahepatic bile duct drainage, regardless of the size of the anastomosis, there is still intrahepatic bile stasis, infection, and formation of stones or cancer, so for those with limited cystic dilatation in the liver, most people advocate for partial hepatectomy and resection.

　　Even after radical surgery for bile duct dilatation, if the purpose of bile and pancreatic juice diversion is achieved, some cases still frequently appear clinical manifestations such as abdominal pain, increased pancreatic amylase in blood, and cholangitis or pancreatitis, which is related to intrahepatic bile duct dilatation and morphological abnormalities of the pancreatic duct. Symptoms can be relieved after fasting, anti-inflammatory, antispasmodic, and choleretic therapy, and the interval between attacks gradually extends over time.