Congenital choledochal cyst in children

Introduction to congenital choledochal cyst in children Congenital choledochal cyst (congenitalcholedochocyst), also known as common bile duct dilatation, is the most common congenital anomaly, and other lesions can exist at the same time. basic knowledge Sickness ratio: 0.05% Susceptible people: children Mode of infection: non-infectious Complications: biliary cirrhosis, portal hypertension, cholangitis, pancreatitis

Causes of congenital choledochal cyst in children

(1) Causes of the disease

The cause of congenital choledochal cyst is still controversial. With the progress of the disease morphology, bile enzymology and animal experiments in the past ten years, the cause of this disease has been further understood. Most scholars believe that this disease and innate Abnormalities of bile duct and pancreatic ducts are associated with distal obstruction of the common bile duct.

1. Congenital pancreaticobiliary junction development malformation

The formation of confluence anomalies refers to the confluent anomalies of the pancreaticobiliary junctions that are not in the duodenal papilla, but outside the duodenal wall or in the confluence and anatomy of the congenital malformation. Since 1969, Babbitt proposed that the pancreaticobiliary confluence is abnormal. Since the cause of the expansion of the main duct, in recent years, this theory has been emphasized. For example, the embryonic common bile duct and the pancreatic duct fail to separate normally, resulting in abnormal connection of the distal end of the pancreatic duct and the common bile duct. The common bile duct is connected at a right angle or <30°. The normal pancreaticobiliary common tube (normal <2~4mm) is extended to an abnormal length of 20-35mm. The normal pancreatic duct pressure is 0.294~0.49kPa (3050mmH2O), and the bile duct internal pressure is 0.2470.294kPa (2030mmH2O). As a result, the pancreatic juice flows back into the common bile duct, causing repeated inflammation of the common bile duct to destroy the elastic fibers of the wall of the common wall, causing the tube wall to lose tension and expand, and some children cause recurrent acute or chronic pancreatitis due to elevated pancreatic duct pressure.

2. Biliary dysplasia

In 1936, Yotsu-Yanagi first proposed that during the embryonic period, the original bile duct epithelial cells proliferated unbalancedly. For example, when the distal hyperplasia occurred, the distal end of the stenosis was formed at the distal end to form the disease, and the common bile duct wall was congenital. The lack of sexual elastic fibers, when the internal pressure of the bile duct increases, gradually expands, and there is no obstruction at the distal end.

3. Virus infection

In recent years, through histopathological changes, it has been found that hepatitis B virus, cytomegalovirus, adenovirus, etc. can cause biliary obstruction or weakening of the wall, resulting in bile duct malformation.

4. Abnormal nerve distribution

Some scholars have compared the distribution of nerves in the distal stenosis of children with common bile duct dilatation by detecting the nerve distribution of the infant and the common bile duct. The number of nerve fiber bundles and ganglion cells in the stenosis of the children is significantly lower than that of the control group. Therefore, it is believed that the occurrence of common bile duct dilatation is related to the abnormal distribution of plexus and ganglion cells in the distal common bile duct, but the reduction of ganglion cells and neurodevelopmental abnormalities are congenital lesions or acquired secondary lesions.

(two) pathogenesis

Pathological change

The gross pathological manifestation is that the common bile duct is spherical or fusiform, and the degree of expansion varies from 2 to 3 cm to 20 to 30 cm. The wall thickness ranges from 2 to 3 mm to nearly 0.5 cm. The size of the tumor does not differ from the age of the child. In contrast, the wall structure can not maintain the mucosal and muscular layer of the common bile duct, showing changes in mucosal exfoliation and inflammation, and the muscle layer is mostly the muscle fiber of degenerative hypertrophy, mixed with a large amount of fibrous connective tissue, and the capsule is stored in dark green thick. Bile, sometimes with sediment-like stones, in some cases, bile bacteria culture is positive during surgery. Due to long-term chronic biliary obstruction, it can cause different degrees of cirrhosis. The liver is brownish-green and hard, usually after surgical decompression (disarming) "Back pressure"), cirrhosis is better than 2 to 6 months, and the clinical symptoms are improved. However, if surgery is not performed, repeated infections can cause chronic intrahepatic cholangitis, leading to progressive biliary cirrhosis and increased portal pressure. Secondary splenomegaly, hypersplenism, lower esophageal varices, varicose vein rupture caused a large amount of hematemesis, blood in the stool, due to cholestasis, bacterial growth and biliary Dyeing and stone formation, and can cause extrahepatic dilatation of the bile duct and cyst rupture, bile overflow and produce biliary peritonitis, long-term repeated infection of pancreatic juice reflux can cause malignant transformation of bile duct epithelium or acute, chronic pancreatitis, so according to its pathological changes, this The disease should be treated with active early surgery.

2. Classification

Congenital bile duct dilatation can occur in the intrahepatic and/or extrahepatic bile ducts, with cholangiocarcinoma being the most common, but with the development of imaging diagnostic techniques, other types of lesions, especially intrahepatic bile duct cystic dilatation (Caroli) Diseases are more common than in the past, so the classification is more and more chaotic. The classification method proposed by Flanigan is simple and practical:

(1) cystic dilatation of the common bile duct: the most common, accounting for 77%, cystic or fusiform expansion.

(2) diverticulal dilatation of the common bile duct: it may be a dilatation of the common bile duct or gallbladder, mostly cystic dilatation of the side wall of the common bile duct, with a narrow base or short pedicle connected to the side wall of the common bile duct, accounting for 2% to 3.1 %.

(3) cystic dilatation of the common bile duct: also known as bile duct bulging, the end of the common bile duct is dilated and embedded in the duodenum, which accounts for 1%.

(4) intrahepatic, cystic dilatation of the outer bile duct, including Caroli disease, accounting for 18.9%.

(5) cystic dilatation of the intrahepatic bile duct, that is, Caroli disease.

Prevention of congenital choledochal cyst in children

Early diagnosis as soon as possible, timely surgical treatment is the key to the prevention of this disease, should be supplemented with a variety of fat-soluble vitamins (A, D, K, etc.) to maintain a good nutritional status.

Complications of congenital choledochal cyst in children Complications biliary cirrhosis, portal hypertension, cholangitis, pancreatitis

Bile stasis

Due to biliary obstruction, the cysts of the bile are gradually increased, and the liver is cholestatic, which gradually develops into biliary cirrhosis, which seriously impairs liver function.

2. Portal hypertension

There are two reasons:

(1) huge cyst compression: huge cysts compress the portal vein and superior mesenteric vein, causing portal vein blood flow back to the liver blocked, forming extrahepatic portal hypertension.

(2) advanced biliary cirrhosis: extensive fibrosis and hardening nodules formed in the liver, squeezing small branches of the portal vein and hepatic lobes of the hepatic lobules, making them narrow or occluded, blocked by portal vein blood flow, and elevated in pressure Intrahepatic portal hypertension is formed. In addition, due to stenosis or occlusion of sinus stenosis due to cirrhosis, short circuit between portal vein and hepatic artery is open, and hepatic artery blood flow is introduced into the venous system, which makes the pressure of portal vein higher. 25%.

3. Cholangitis

Due to poor bile, local resistance is reduced, bacterial infection is likely to occur, resulting in acute cholangitis, intrahepatic infection, and even liver abscess. Repeated episodes of cholangitis often cause swelling of the bile duct wall, hypertrophy, fibrosis, etc., making the distal bile duct It is narrower and even occluded.

4. Pancreatitis

Abnormal pancreaticobiliary junction can cause high pressure bile duct bile to flow back into the pancreatic duct, damage the pancreatic duct and acinus, pancreatic juice infiltrates into the pancreatic parenchyma and cause pancreatic tissue autolysis, and pancreatitis.

5. Formation of stones in the cyst

Due to bile stasis, biliary tract infection and bile duct stricture, bile components can change, which is conducive to the formation of bile pigment stones. Wang Changlin reported a 13-year-old patient who took a large number of small granular bile pigment stones from the common bile duct cyst and left and right liver. There are also many stones in the tube. We have 3 cases of pediatric choledochal cysts combined with bile pigment stones. Yamaguchi summarized 1433 cases, and calculi with 8.0%.

6. Bleeding

Liver function damage caused by biliary obstruction, plus bile salts can not enter the intestine, fat-soluble vitamin absorption disorder, liver dysfunction of the synthesis of coagulation factors, can cause bleeding, including skin ecchymosis, bleeding gums, gastrointestinal bleeding.

7. Cyst perforation or rupture

The cyst gradually increases, and the pressure inside the capsule gradually increases. In the weak part of the wall, it is easy to perforate due to a sudden increase in abdominal pressure or trauma to the upper abdomen, causing acute biliary peritonitis. This is true in Taiwan, Japan, and China. Report, accounting for 1.8%.

8. Cyst cancer

Long-term bile stasis in the cyst, repeated episodes of cholangitis and abnormal pancreaticobiliary convergence, pancreatic juice back into the cyst, etc., can cause inflammation, ulceration, regeneration or metaplasia of the bile duct wall, on the basis of which cancer is induced, the cancer rate accounts for 2.5%.

Symptoms of congenital choledochal cyst in children Common symptoms Astragalus abdominal pain Abdominal mass fever, nausea and pain, high fever, bloating, biliary obstruction, peritonitis

Astragalus, abdominal pain, and lumps are the three basic symptoms of the disease, but not all patients have three main symptoms in their medical history or at the time of their visit. Clinically, only one or two symptoms are present, and all three symptoms have only 20% to 30%.

1. Abdominal pain secondary to the right upper abdomen or upper abdomen, the nature and extent of pain, sometimes colic, pulling pain or mild pain, secondary infection may be accompanied by fever, sometimes nausea and abdominal pain accounted for about 80 %~90%.

2. The mass is located under the costal margin of the right upper abdomen, and the upper boundary is covered by the edge of the liver. The large one can surpass the midline of the abdomen. The surface of the tumor is smooth, and the spherical capsule is sexy. The small cystic duct cyst is difficult to reach due to its deep position. In the case of infection, pain, and jaundice, the mass enlarges and can be reduced after the improvement. The upper right abdominal mass is about 70%.

3 About 50% of Astragalus patients have jaundice, and the degree of jaundice is directly related to the degree of biliary obstruction. Astragalus is usually recurrent, with multiple infections and fever. Most of the above symptoms are intermittent, because the distal end of the common bile duct is not smooth. The contents are stagnant, biliary tract infection occurs, and the symptoms appear. After a few days of treatment, the contents are drained smoothly, the symptoms are alleviated or disappeared, and some children have frequent episodes, and some may have a seizure once every month. It can be accompanied by nausea and vomiting. White terracotta-like stools can appear in jaundice, and urine color is deepened. Individual children, especially infants and young children, have cystic perforation, which causes acute biliary peritonitis, high fever and bloating and even shock.

Examination of congenital choledochal cyst in children

Most patients with blood, urine and feces were seen as obstructive jaundice, and a series of examinations for obstructive jaundice were abnormal, including serum bilirubin, mainly elevated direct bilirubin, alkaline phosphatase and gamma - glutamyl transpeptidase is also elevated, may have varying degrees of acute liver dysfunction, a small number of patients can be basically normal indicators, combined with cysts can be seen in peripheral blood, white blood cell count and neutrophil increase Higher inflammatory changes, a considerable proportion of cases of this disease, especially in the case of fusiforms, blood was found, urinary pancreatic amylase increased, and was misdiagnosed as simple acute pancreatitis, the actual clinical cases did include pancreas Inflammatory, but in most cases due to the abnormality of pancreaticobiliary confluence, pancreatic juice will flow back into the bile duct, and even the intrahepatic bile duct. In the capillary bile duct, pancreatic amylase can be caused by the hepatic sinus and flow back into the blood circulation, mostly non-true pancreatitis.

1.B Ultra

It is the most simple and non-invasive method of examination. It can be initially diagnosed. The low echo area with clear boundary below the liver can be used to determine the size of the cyst, the degree of stenosis at the distal end of the bile duct, and the extent and extent of intrahepatic bile duct dilatation. In the bile duct, this method has the advantages of no damage, no radiation, convenient and convenient, low cost, dynamic observation, etc., and the diagnostic accuracy rate can reach 94%.

2. CT scan

It can be clarified whether the intrahepatic or extrahepatic bile duct expands, the location, extent and shape of the dilatation, the degree of distal stenosis of the common bile duct, and the presence or absence of intrahepatic bile duct dilatation, the shape and location of the dilation, etc. The cross-sectional image shows the lesion, and the tubular structure can be displayed by intravenous injection of iodine contrast agent. It has high positioning and qualitative value, and has a similar effect to B-ultrasound, but it can only cross the bile duct, can not show the length of the obstructive bile duct, and has Radiation, expensive, complements B-ultrasound.

3. Endoscopic retrograde cholangio pancreatography (ERCP)

The use of pediatric duodenal fiber endoscopy through the duodenal papilla insertion catheter angiography can show the whole appearance of the pancreaticobiliary duct, especially for the abnormal development of pancreaticobiliary duct anastomosis, providing a reliable basis for the choice of treatment methods, ERCP injury is relatively small For children, general anesthesia is required. Adults only have mucosal infiltration anesthesia. There is no obvious organic damage. The imaging is easy to be successful, and the diagnosis effect is better than that of PTC. At present, the newborn can also successfully perform ERCP on the newborn. Examination, the diagnosis of pancreaticobiliary confluence abnormality is more effective, through the duodenoscope can directly inject the contrast agent into the bile duct and pancreatic duct, directly showing the whole appearance of the bile duct cyst, which is a routine examination method in adults, but for In children, certain conditions and equipment are required, and they are used more in older children.

4. Percutaneous hepatic cholangiography (PTC) examination

Pass this check to:

1 to understand the location of intrahepatic biliary cystic expansion, can provide guidance for surgical selection.

2 to understand the presence or absence of conjunctival abnormalities of the pancreatic duct and the pathological changes of the distal end of the pancreatic duct.

3 clear diagnosis, to understand the degree of stenosis of the distal and distal bile ducts.

4 Take bile, carry out bacteriological examination, check the prothrombin time before puncture. If the coagulation mechanism is not good, do not use this method. PTC uses small needle to directly inject the contrast agent into the intrahepatic bile duct, and through the development of the liver and the outer bile duct, The condition of biliary malformation can be directly observed, but because of the need for general anesthesia and large damage, the puncture failure, causing pneumothorax, bile leakage and bleeding, is currently replaced by ERCP.

5. Radionuclide hepatobiliary scan

99mTc can directly observe the shape and function of hepatobiliary system, and can also observe the location, size, shape and excretion of biliary cyst.

6. Upper digestive tract barium meal check

It can be seen that the duodenal window is enlarged, the anteroposterior diameter is flattened, the left and right diameters are widened, and the lateral displacement of the duodenum is seen as shown in Fig. 2, which can be confirmed.

7. Upper gastrointestinal X-ray angiography

When the cyst is large, a soft tissue mass with a smooth edge and a uniform density can be seen in the right upper abdomen, and the gastric antrum and duodenum can be displayed downward, shifted to the left, and the duodenum is enlarged, showing an arc-shaped impression; The tablets showed pressure on the stomach and duodenum, and the duodenum frame expanded and shifted forward. However, it is difficult to diagnose the common X-ray examination for fusiform bile duct dilatation.

8. Cholangiography

Oral or intravenous cholangiography, because the contrast agent is diluted, most of the development is unclear, when there is serious damage to liver function, it should not be used. At present, it is replaced by more advanced examination methods, the clinical has been basically stopped, intraoperative cholangiography, will The contrast agent is directly injected into the gallbladder or bile duct, showing the whole liver and the outer bile duct, and understanding the nature and extent of the lesion is helpful for diagnosis and determination of the surgical procedure.

9. Magnetic resonance cholangio pancreatography (MRCP)

It is the latest cholangiography method, which does not require contrast agent. After computer processing, only the clear three-dimensional structure image of the bile duct and the pancreatic duct is a high-tech non-invasive imaging technique that was matured and applied to the clinic in the 1990s. Using the special imaging technique of magnetic resonance to obtain clear pancreaticobiliary imaging effect, it is even possible to clearly determine whether the pancreaticobiliary confluence is abnormal. In recent years, a large number of clinical studies have shown that the diagnosis of simple bile duct dilatation is far from being able to adapt to correct guiding surgery.

Diagnosis and differential diagnosis of congenital choledochal cyst in children

According to the clinical manifestations of abdominal pain, jaundice and right upper abdominal cystic masses, the initial clinical diagnosis, some cases do not have "three main symptoms", laboratory and auxiliary examination should be carried out to help confirm the diagnosis.

Differential diagnosis

The early stage of the disease needs to be differentiated from biliary atresia and various types of hepatitis, and sometimes it needs to be differentiated from right renal hydronephrosis, pancreatic cyst, hepatic hydatid cyst, omentum and mesenteric cyst, with B-ultrasound and biochemical examination. Identification, if necessary, CT, ERCP to assist in differential diagnosis.

1. With the abdominal mass as a prominent performer

The choledochal cyst is characterized by a mass in the right upper quadrant or upper abdomen, and no jaundice should be differentiated from hepatic cyst, retroperitoneal cyst, hydronephrosis, renal embryonal tumor, omental cyst and mesenteric cyst.

(1) Hepatic hydatid disease: The difference between it and bile duct dilatation is that the patient has animal husbandry area and dogs, sheep and other animals in contact, the cyst will gradually increase, B-ultrasound and CT examination are shown as intrahepatic space occupying Lesions, the extrahepatic bile duct showed normal, and most of the eosinophils counted more. The positive rate of the Casoni test (invasive intradermal test) was as high as 80% to 95%, and the 80% complement fixation test was positive.

(2) Liver cyst: liver is large, hard and nodular, no tenderness, liver function tests are generally normal, polycystic liver patients can sometimes be accompanied by renal, pancreatic or spleen polycystic lesions, B-ultrasound And CT examination can clearly show that the cyst is located in the liver and the extrahepatic biliary tract is normal.

(3) retroperitoneal cystic masses: such as cystic teratoma, lymphangioma, etc., from the symptoms and signs are more difficult to identify with cystic dilatation of the common bile duct without jaundice, B-ultrasound, CT can be basically different, ERCP examination can exclude bile duct expansion.

(4) right hydronephrosis: physical examination is not easy to distinguish from bile duct dilatation, but hydronephrosis is more lateral side, waist triangle area is often full, especially with B-ultrasound, intravenous pyelography (IVP) or pancreaticobiliary retrograde angiography (ERCP) Both are easy to identify.

(5) Wilms tumor: The main differences are:

1 The tumor grows faster, may have high blood pressure or hematuria, and the general condition of the child is poor.

2 The tumor is solid and moderately hard.

3 Abdominal X-ray plain film can be seen to push the intestine to the medial side, sometimes there are scattered calcifications in the tumor. Intravenous pyelography can be seen that the renal pelvis is deformed or not destroyed by extrusion or only a small amount of contrast agent is visible in the renal pelvis.

(6) pancreatic cysts: children with pseudo-pancreatic cysts are closely related to trauma, cysts are mostly located in the left upper abdomen or umbilicus, often accompanied by abdominal pain, elevated urine sugar and blood sugar, elevated or normal serum amylase, to B-ultrasound, CT or ERCP examination, no more difficult to distinguish.

2. Take Huang Qi as a prominent performer

Common cholangiocarcinoma with jaundice as a prominent manifestation should be differentiated from biliary atresia, cholangiocarcinoma, and right upper abdomen retroperitoneal tumor compression bile duct.

(1) Biliary atresia: The main differences are:

1 After 1 to 2 weeks of birth, the child developed biliary stasis and jaundice, and quickly deepened without gaps. The urine was dark brown and the stool was pale yellow. Later, it developed into a clay-colored stool.

2 skin, sclera yellow staining is obvious, ascites or portal hypertension may occur in the later stage of the disease.

3 Ultrasound examination did not detect the common bile duct, no gallbladder or only atrophic gallbladder, and bile duct dilatation showed the expansion of extrahepatic bile duct.

(2) Peripheral cancer of the common bile duct: the main identification points are:

1 Most patients are middle-aged or above, and the course of disease is short.

2 Astragalus is progressively deep rather than intermittent.

3 The general condition deteriorates rapidly, and weight loss and anemia can occur.

4 The lumps are large, but they are hard and nodular.

5CT, B-ultrasound or MRI can be found in the ampulla of the common bile duct, but congenital biliary dilatation is not. It is worth noting that congenital biliary dilatation has higher biliary cancer morbidity and bile duct dilatation. After the onset of biliary tract cancer, abdominal pain caused by intermittent episodes, fever accounted for more than half of the complaints, compared with congenital biliary dilatation without cancer, this frequency is slightly higher, about 30% of jaundice and touch the abdomen Lump, when there is back pain, weight loss is prompted for advanced stage, because it has no specific performance after canceration, it is easy to be confused with the primary disease, therefore, B-ultrasound, CT, ERCP angiography, etc. once found in the dilated bile duct The shadow of the lumps should be highly suspected. More than 300 cases of cancerous cases were analyzed. The lesions were confined to the muscular layer, which was an early dissatisfaction of 10 cases. The diagnosis was extremely difficult.

3. Patients with abdominal pain as a prominent symptom

Common biliary cysts with acute right upper abdominal pain or upper abdominal pain as prominent symptoms should be differentiated from biliary ascariasis, acute cholecystitis, acute pancreatitis and intussusception.

(1) biliary ascariasis:

1 sudden onset of pain in the right upper abdomen or upper abdomen, can be relieved or returned to normal after the attack, the symptoms are severe and the signs are lighter.

2 more without jaundice, sometimes lighter.

3 There is no lump in the right upper abdomen or upper abdomen.

4 Ultrasound examination showed that there was a worm-like echo in the common bile duct, and the common bile duct could be slightly dilated, while the bile duct dilatation had no worm-like echo, showing cystic or fusiform dilatation of the common bile duct, ERCP showing bile duct dilatation and pancreas Biliary confluence is abnormal, while biliary aphids are absent.

(2) acute cholecystitis: more common in adults, fever, right upper quadrant pain, tenderness and muscle tension, Murphy sign positive, sometimes can touch the gallbladder with the breath moving and shallow, not as deep as the common bile duct dilatation and The scope is large, and the jaundice is lighter. B-ultrasound can easily identify the two, and the acute cholecystitis has no cystic or fusiform dilatation of the common bile duct.

(3) Intussusception: The main symptoms of this disease are regular paroxysmal abdominal pain. The abdominal mass is elliptical or oblong, easy to move, slightly tough, and the position is located at the upper right. There may be jam-like stools. The enema or air enema shows a typical cup-shaped mouth of the nested head.

(4) acute pancreatitis: this disease is more common in adults, abdominal pain is more dramatic, often located in the upper abdomen to the left, can involve the left back and left shoulder, severe cases can occur shock, nausea and vomiting, fever, may have peritoneal irritation Signs, biochemical examination showed that blood urease amylase was significantly increased, B-ultrasound, CT examination, visible enlarged pancreas and common bile duct is normal, especially noteworthy is about 20% to 40% of the course of congenital biliary dilatation High pancreatic amylase, and increased amylase in urine, some cases are true pancreatitis, and most of the amylase in the capillary tube flows back into the blood and causes so-called "pseudo-pancreatitis". Performance, this case is more mild pancreatic lesions.

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