Bile duct cyst

　　The etiology of bile duct cysts is not yet clear, and there are many hypotheses about this, because most cases are believed to be caused by congenital developmental malformation. Currently, there are two aspects of the hypothesis of congenital factors:

　　1. The bile duct wall is thin, and it is believed that there is a congenital defect in the supporting tissue of the bile duct wall, or there is ectopic pancreatic tissue that keeps the bile duct wall in a low-tension state.

　　2. Bile duct distal obstruction leads to increased intraluminal pressure, causing dilation.

　　Modern medicine has proven that the most common complication of bile duct cysts is jaundice, which is often the first noticed symptom in children, and can be intermittent or progressive. Severe jaundice can cause skin itching, grayish stools, and dark urine, which are manifestations of bile urine.

　　The clinical manifestations of bile duct cysts are intermittent upper abdominal pain, a mass in the upper right abdomen, and jaundice, known as the triad of common bile duct cysts, but it accounts for only 1/3 of the total number. 55% to 60% of cases have abdominal pain, 60% to 75% have a mass, and 65% to 80% have jaundice. The clinical manifestations are quite different, ranging from complete absence of pain to bearable dull pain in the upper abdomen, or even severe sharp pain in the upper right abdomen. Jaundice is the most common symptom, often the first noticed in children, and can be intermittent or progressive; progressive jaundice in infants should be considered as congenital bile duct atresia. Severe jaundice can cause skin itching, grayish stools, and dark urine, which are manifestations of bile urine. The degree of jaundice is directly related to the degree of bile duct obstruction and infection. A mass can be felt in the upper abdomen or right hypochondrium, and the large ones can occupy the entire right abdomen. It has a cystic sensation, is fixed and not movable, and small cysts can move slightly.

　　Secondly, if infection occurs, there will be obvious tenderness and rebound pain. If there is an ectasia of the common bile duct in the duodenum, there will also be symptoms of duodenal obstruction. In addition, nausea, vomiting, anorexia, diarrhea, and weight loss may occur, and chills, fever, and an increase in the number of white blood cells will occur if there is infection.

　　A reasonable diet, attention to nutritional balance, eating less fried foods, smoked foods, preserved foods, moldy foods, and foods containing additives, as well as quitting smoking and drinking, and regular exercise, can definitely prevent bile duct cysts. At the same time, it is noted that the early resection of bile duct cysts, bile-enteric anastomosis, and the diversion of pancreatic bile are of great significance in preventing the malignant transformation of bile duct cysts.

　　Therefore, the prevention of bile duct cysts is different from that of other tumors, and it is of little significance to adopt the common screening methods for tumors. The formulation of the prevention and treatment strategy for bile duct cysts still needs to be based on objective conditions and the national situation, strengthen follow-up and monitoring of high-risk populations, improve the level of diagnosis and treatment technology, emphasize the early detection, early diagnosis, and early treatment, in order to improve the overall therapeutic effect of bile duct cysts.

　　Cholangiocystadenoma (similar to choledochal cyst) often occurs in children before the age of 10, and is more common in women. The main clinical manifestations are abdominal pain, jaundice, vomiting, fever, and abdominal mass. The following are some points about the examination of cholangiocystadenoma:

　　1. CT

　　CT is still a routine examination method, which can show the dilatation of bile ducts inside and outside the liver. It can be seen that the proximal bile ducts near the obstruction are significantly dilated, the gallbladder is enlarged, the dilated bile ducts suddenly interrupt, the shape of the end is irregular, and there are shadows. Sometimes, the bile duct wall can be seen to be thickened, the lumen is irregularly narrowed, the enlarged gallbladder, and the involvement of surrounding tissues and organs, blood vessels, or small nodular shadows protruding into the cavity from the bile duct wall, which can provide evidence for the staging of the lesion and the possibility of surgical resection. Spiral CT angiography (SCTA) technology can complete a series of thin-section vascular images in a very short time, and three-dimensional vascular reconstruction technology can also provide important information for understanding the relationship between the tumor and the blood vessels, and whether the tumor at the hepatic hilum can be resected. CT scanning can achieve the same effect as B-ultrasound and clearer images.

　　2. Endoscopic ultrasound (EUS)

　　EUS is a new type of diagnostic tool combined with endoscopic and intracavitary ultrasound imaging techniques. Under EUS, the bile duct wall can be divided into three layers: the first layer is a high echo corresponding to the mucosa and interface echo; the second layer is a low echo of smooth muscle fibers and fibrous elastic tissue; the third layer is a high echo of loose connective tissue and interface echo. Cholangiocarcinoma appears as a low echo or high echo mass under EUS with a detection rate of 96%, and can also suggest the size of the mass and whether there is lymph node metastasis.

　　3. Percutaneous transhepatic cholangiography (PTC)

　　It is a basic method for diagnosing bile duct tumors, capable of displaying the location and extent of the tumor with a diagnostic accuracy of over 90%. PTC is suitable for patients with dilated intrahepatic bile ducts, and a catheter can be left in place after surgery for bile drainage (PTCD). PTC can be performed for patients with bile duct dilatation shown by B-ultrasound or CT examination. Not only can it directly display and clearly define the location of the tumor, the upper edge of the lesion, and the extent of the bile duct involved, but it can also understand the relationship between the tumor and the bile duct. This examination is of great significance for determining the surgical plan before surgery, and its correct diagnostic accuracy can reach over 90%.

　　4. Retrograde cholangiopancreatography (ERCP)

　　It is suitable for cases where the bile duct is not completely blocked. It can display the location of the obstruction from the distal bile duct and judge the extent of the lesion.

　　5. Fiberoptic cholangioscope

　　It can clearly define the location and extent of the lesion, especially suitable for early-stage tumors in the intrahepatic bile duct and duodenal-pancreatic segment of the bile duct. The fiberoptic cholangioscope not only can display the morphology of the lesion but can also perform biopsies to confirm the diagnosis. The percutaneous cholangioscope (PCS) and fiberoptic cholangioscope can directly visualize the lesions inside the bile duct and take tissue biopsies or cell brushings.

　　6. Selective angiography (SCAG) and portal vein angiography (PTP)

      The situation of the hepatic portal blood vessels entering the liver and their relationship with the tumor can be displayed. Cholangiocarcinoma mostly belongs to tumors with less blood supply, and angiography generally cannot make a diagnosis of the nature and extent of the tumor.

　　7. Magnetic Resonance Cholangiopancreatography (MRCP)

      It can display nearly 100% of extrahepatic bile ducts, and 90% of non-dilated intrahepatic bile ducts can also be traced upwards along the extrahepatic bile ducts. 85% to 100% can clearly define the site of obstruction. Compared with PTC and ERCP, MRCP can simultaneously display the bile ducts near and far from the obstruction, so it can calculate the length of the obstruction and the distance from the ampulla, which is convenient for the planning of surgical procedures. The routine transverse and coronal scans of MRI can also provide information on the involvement of the liver and surrounding tissues.

　　Patients with cholangiocystadenoma should pay attention to a semi-liquid diet mainly, which is easy to swallow and digest. Foods with less rough fiber can be chosen, such as thin noodles, congee, vegetable puree, meat puree, steamed egg pudding, milk, etc. Avoid fried foods, vegetables with a lot of rough fiber, or spicy seasonings. It is important to supplement various vitamins and inorganic salts. In addition, adequate rest should be ensured, and spicy, fried, grilled, and other dry and hot foods should be avoided. In life, alcohol, sugar, and fat should be avoided, and it is important to follow the doctor's instructions.

　　Cholangiocystadenoma is most common in children. This disease can be caused by congenital factors or secondary to other diseases. Therefore, the treatment should be classified according to the cause. The general treatment principles for this disease are as follows:

　　1. Refrain from eating and gastrointestinal decompression to reduce bile and pancreatic juice secretion and alleviate intrabiliary pressure.

　　2. Use antibiotics to control infection. Common bacteria in biliary tract infections are Gram-negative intestinal aerobic and anaerobic bacteria, mainly bacilli. Cephalosporins and metronidazole can be selected.

　　3. For those with significant abdominal pain, anticholinergic drugs can be used to relieve spasm appropriately.

　　4. For severely ill patients with acute suppurative cholangitis, severe obstructive jaundice, and early liver failure, initial intervention can be performed with endoscopic retrograde cholangiopancreatography (ERCP) with nasobiliary drainage or percutaneous liver biopsy cholangiography, followed by reducing jaundice and controlling infection before selecting surgical treatment.

　　5. For those with elevated serum amylase levels, treat as acute pancreatitis.

　　6. Actively prevent and treat shock, including blood transfusion and fluid replacement, correction of water, electrolyte, and acid-base imbalance, and monitoring vital signs.

　　7. Strengthen liver protection and nutritional support therapy. Supplement various fat-soluble vitamins (A, D, K, etc.) to maintain good nutritional status.