Congenital cystic dilatation of the bile duct

Introduction to congenital biliary cystic expansion Congenital cystic dilatation (bileduct) is a surgical biliary disease with cholestasis. In 1723, Vater reported the first choledochal cyst, which was subsequently reported. Congenital biliary cystic dilatation can occur in the liver other than the gallbladder, any part of the outer bile duct, Caroli in 1958 detailed description of the cystic changes in the intrahepatic bile duct, so the name of congenital choledochal cyst can not include this All of the diseases, scholars believe that it is appropriate to refer to cystic dilatation or biliary cysts. basic knowledge The proportion of illness: 0.0003% Susceptible people: seen in young children Mode of infection: non-infectious Complications: bile duct dilatation gallstones peritonitis liver cirrhosis portal hypertension chronic cholecystitis

Congenital biliary cystic dilatation

(1) Causes of the disease

Congenital factors (30%):

(1) Abnormal proliferation of bile duct epithelium: In 1936, the theory of innate factors proposed by Yotsuyanagi was accepted by most people. He believed that the epithelial proliferation was abnormal during the bile duct development in the embryonic period, resulting in uneven epithelial hyperplasia throughout the bile duct. It refers to the narrowing of the intestine, which increases the pressure of the bile duct and expands the dysplasia of the upper bile duct. Alonson-Lej et al. suggest that the embryonic period is poorly developed, the bile duct epithelium is vacuolated, and the local wall is weak.

(2) Abnormalities of pancreas and bile duct confluence: People have found that there are almost all abnormalities of pancreaticobiliary ducts through various means. Miyano has indirectly proved the confluence abnormality by abnormally increasing the amylase value in the bile of the dilated bile duct.

Babbitt, John et al. observed the contrast of the patient's angiogram: 1 the junction of the main pancreatic duct and the common bile duct is far from the Vater ampulla, forming a common channel of 2 to 3.5 cm (normal <0.5 cm); 2 main pancreatic duct and gallbladder The general manifold merges into a right angle. The pressure in the pancreatic duct is as high as 2.94 to 4.9 kPa (22.1 to 36.8 mmHg), and the internal pressure in the common bile duct is 2.45 to 2.94 kPa (18.4 to 22.1 mmHg). This characteristic leads to reflux of pancreatic juice and enhanced pancreatic enzyme activity. Mucosal destruction, fibrosis of the wall, when the bile duct pressure is increased, it is easy to produce cystic dilatation. Neng's pancreatic juice is infused into the gallbladder of the goat during the experiment, and the morphology is similar to the change of congenital biliary dilatation. Intraoperative cholangiography was performed in 16 patients with biliary cysts by Arima et al., and all of them had abnormal connections of the pancreaticobiliary system.

(3) Neurodevelopmental abnormalities: In 1943, Shallow pointed out that there were defects in nerve cells in the site of congenital biliary cysts, similar to the changes in megacolon. Yang Hongwei and others passed the tissues of normal children and fetuses and the common nerves at the end of the common bile duct of the patient. The study found that the abnormal distribution of nerves in the distal stenosis of congenital biliary cyst is a primary lesion, and the stenosis of the distal common bile duct is one of the causes of this disease. This is a congenital anomaly phenomenon, pancreaticobiliary confluence Abnormalities may occur simultaneously with neurodevelopmental abnormalities at the end of the cyst. Due to abnormal stenosis in the distal segment of the neurodevelopmental abnormalities, the pancreatic juice secretion pressure is higher than the bile duct pressure, and the reflux persists, destroying the bile duct wall, and the two together form a bile duct cyst. Some scholars believe that biliary epithelial virus infection, such as hepatitis B antigen, can also cause luminal obstruction or weak wall and cyst abnormalities, bile duct atresia.

Acquired factors (30%):

Some scholars believe that bile duct cysts, especially adult bile duct cysts, are mainly due to complete or incomplete obstruction of the bile duct, leading to bile stasis, infection, fibrosis of the bile duct wall and loss of elasticity. When the pressure in the bile duct increases, it appears The proximal bile duct is dilated and gradually forms a cyst. The cause of obstruction is mostly bile duct inflammation, bile duct stones, tumor or secondary to injury, and pregnancy, hilar lymphadenopathy, pancreatic tumor, visceral drooping and duodenal papilla. Tumors and the like can cause obstruction of the lower end of the bile duct and cause the disease. Whether it can be denied that these acquired factors lead to cystic dilatation is premised on the existence of potential congenital anomalies and remains to be explored.

Congenital factors combined with acquired factors (20%):

Kozloff et al reported that one adult had a normal bile duct for laparotomy, but a choledochal cyst was found during reoperation. Kato et al. partially scraped the biliary mucosa of puppies and adult dogs and ligated the distal end of the bile duct. Dogs have biliary cysts, and this phenomenon has not been found in adult dogs. This experiment also shows that biliary cysts are caused by congenital weakening factors of the bile duct wall, and the formation of biliary cysts should generally have two Conditions: stenosis of the wall and increased pressure of the bile duct, the latter must be based on the obstruction of the lower end of the bile duct.

(two) pathogenesis

Biliary cystic dilatation is most common in the common bile duct, and its transverse diameter varies from 3 to 25 cm. The individual cyst volume is as high as 10 L. The cyst contains denaturing bile, mostly brownish green. If the infection is often Gram negative. Due to bacteria and/or anaerobic bacteria, some cases have bile or gallstones, and the bile duct wall is often thickened, about 2 to 10 mm. It is composed of fibrous inflammatory tissue with smooth muscle fibers and glandular tissue scattered in the middle. Normal mucosa, but often lined with columnar epithelium, sometimes with patchy necrosis, severe acute inflammatory lesions can cause necrosis of the cyst wall, and some cases with other congenital malformations, such as polycystic kidney, congenital liver fibrosis , biliary atresia, etc., about 2.5% of the wall cancer.

Congenital choledochal cystic dilatation has a variety of classification methods, the basic situation is as follows.

Type I: cyst type, clinically more common, accounting for more than 80%, bile (total) tube is cystic or fusiform expansion, and its three subtypes are narrowly defined choledochal cyst, segmental common bile duct dilatation and diffuse liver The outer bile duct is dilated.

Type II: diverticulum type, with a diverticulum from the side wall of the common bile duct, the common bile duct itself is normal or slightly dilated.

Type III: Duodenum (inner wall segment) bulging type, the end of the common bile duct is cystic in the duodenum, and the pancreatic duct and common bile duct merge into the bulging part.

Type IV: multiple diverticulum type with multiple diverticulum chambers on the side wall of the bile (total) tube.

To date, the more complete classification is to promote the Todani classification, which basically summarizes the disease.

Types I to III are the same as the above types.

Type IV-A: multiple cysts in the liver and extrahepatic bile ducts.

Type IV-B: multiple extrahepatic bile duct cysts.

Type V: single or multiple cysts in the intrahepatic bile duct.

Some authors in the country suggest that bile duct dilatation can be divided into two major categories, congenital and secondary, and then further classification according to location, morphology, and disease, which is worthy of discussion.

Congenital biliary cystic dilatation prevention

Diet is first considered as a priority.

Congenital biliary cystic dilatation complications Complications bile duct dilatation gallstone peritonitis liver cirrhosis portal hypertension chronic cholecystitis

1. Bile duct lesions: When the confluence is abnormal, the pancreatic duct pressure is higher than the bile duct pressure, causing the activated pancreatic juice to flow back into the bile duct, and stagnant with the infected bile to cause various lesions.

(1) High amylase bile: The concentration of amylase can reach 100,000 U. Children under 2 years old can be lower than normal because their pancreatic cells are immature. At this time, if trypsin I and lipase exhibit high values, It is suggested that there is countercurrent flow of pancreatic juice.

(2) bile duct dilatation: the common bile duct dilatation may be cystic and ribbed (cylindrical), the former is younger, but can be seen at any age, 1 in 1 year, accounting for about 1/4, about half of the intrahepatic bile duct dilatation The latter is more common after the age of 1 year, and the incidence of the disease within 1 year old is rare, easy to be found by B-ultrasound, the confluence of abnormalities is the main reason for bile duct expansion, but not the only reason.

(3) bile duct inflammation: associated with cholestasis and enzyme activation in pancreatic juice, often can cause bile duct infection, pancreatitis, suppurative cholangitis, severe liver abscess, sepsis, clinical manifestations of fever, abdominal pain, jaundice and Increased white blood cells, etc., may also be associated with hyperamylasemia.

(4) gallstones: local expansion of the bile duct and accompanied by bile stasis, these are the conditions for easy formation of gallstones, Yamaguehi analysis of 1433 cases of congenital biliary cystic dilatation, 80% of patients with gallstones and most of the gallstones Partially combined with intracapsular stones, a small number of concurrent pancreatic duct stones, domestic money and light, Huang Zhiqiang reported congenital biliary cystic dilatation 71.4% with bile duct stones, but all pigment stones, 1/4 in the intrahepatic bile duct, not Seeing gallstones, some scholars have reported that the detection rate of gallstones is about 3%, but it increases with age. Almost all of them have gallstones over 40 years old. The patients with the course of >20 years are almost always complicated, gallstones and jaundice, pancreas Inflammation is associated with the development of cancer.

(5) bile duct obstruction: this disease has different degrees of distal obstruction, which can lead to biliary cirrhosis and portal hypertension.

(6) perforation of bile duct cyst: may be related to pancreatic enzyme in countercurrent pancreatic juice, often occurs after strenuous activity, more common in children, almost all merged abnormalities, diffuse peritonitis can occur after perforation, severe can be life-threatening, sterile The condition of biliary ascites is better, and jaundice can occur after absorption.

(7) Carcinogenesis: Since Irwin et al reported in 1944 that congenital biliary cysts were cancerous, various scholars have reported some medical records, the incidence rate is 2.5% to 16.7%, adenocarcinoma is about 77.9% to 95%, and degenerative cancer is 21%. , squamous cell carcinoma 9%, undifferentiated carcinoma, adenadosal carcinoma, grape tumor and other occasional reports, about 67% of people under 36 years old, 10% of patients under 20 years old are not known for cystic cancer, may be related to many factors :

1 stone: After Todani counts cystic cancer cases, it is speculated that cystic carcinogenesis is related to gallstone, but the mechanism is unknown.

2 Chronic inflammation: After comparing the cancer rate of common bile duct and intrahepatic single cyst, Watts believes that the high cancer rate of the former is due to the long-term stimulation of bile fluid, the decomposition of lecithin in the pancreatic juice and the decomposition of lecithin in bile. For lysolecithin, these substances are repeatedly stimulated for a long time, causing inflammation, ulceration, regeneration and other changes in cystic epithelial cells. Todani concluded that all 49 specimens of cystectomy had inflammatory scar tissue and/or duodenal epithelialization. Health, Flanigan reported cystic cancer, 25% have cystic inflammation changes.

3 chemical stimulation: Irwin's first case report of choledochal cystic cancer has been mentioned. Stimulation of cholestasis can lead to squamous cell metaplasia and carcinogenesis. In 1962, Geonge et al. demonstrated bile acid and carcinogen methyl cholestyramine. There is a close chemical relationship. In 1984, Bull extracted high carcinogenic mutagens from the gallstones of patients with choledochal cysts. In the non-cyst patients, there was no such substance. The mutagen was metabolized by bacteria to produce carcinogenic effects.

4 internal drainage: especially in view of the case of cyst duodenal anastomosis, Todani et al. collected the world literature of cystic carcinogenesis, found that 57.1% of cancerous cases have undergone internal drainage, Flanigan has reported 50% of choledochal cysts Pathology has been treated with internal drainage within 4 years.

5 Anatomical abnormalities: As mentioned above, Miyano, Babbit, John, and Arima have confirmed the pathological changes of the pancreaticobiliary duct in the pathology of congenital biliary cystic dilatation by various methods. This abnormality causes pancreatic juice to reflux and stimulate the bile duct epithelium. Cause intestinal metaplasia.

6 primary cancer: Inbby in 1964, Asbby proposed that the choledochal cyst is a primary disease. He studied a case where the tumor was located in the posterior wall of the cyst and the bile duct was unclear. He believed that the tumor might originate in the common bile duct. Caused by obstruction, the congenital weak area of the common bile duct was stretched to form a cyst of the common bile duct. In addition, the pathology of the case reported that the common bile duct mucosa was intact, that is, the cancer actually caused the cyst, and this argument needs further confirmation.

Congenital cholangiocarcinoma has the following characteristics compared with primary cholangiocarcinoma:

1 The incidence rate is higher than the latter, which is 20 times that of primary cholangiocarcinoma;

2 younger people are more common than older people, and the latter are mostly older than 40 years old;

3 The former is more common in women (the ratio of male to female 1:2.5), the latter is more common in men;

4 The former has a clear racial inclination and the incidence of Asians is higher.

2. Liver lesions

(1) cirrhosis: 1 to 2 months old infants can appear, mostly associated with biliary atresia and congenital liver fibrosis, combined with portal hypertension, poor prognosis.

(2) portal hypertension: due to cirrhosis, biliary cyst compression and portal dysplasia.

(3) Liver vitamin D deficiency disease: long-term persistent jaundice, intestinal bile reduction, fat absorption disorder, leading to vitamin A deficiency, vitamin D deficiency, osteoporosis.

3. Infection or fever is mostly chronic cholecystitis or liver abscess, which is one of the causes of death.

Congenital biliary cystic dilatation symptoms Common symptoms Abdominal pain cysts thin and contain... Dull pain nausea Acute abdominal pain Anorexia Abdominal mass pain Painful peritonitis Cystic mass

The typical clinical manifestations of this disease are abdominal pain, jaundice and abdominal mass, but clinically typical triads are very rare, and most patients have no specific clinical manifestations.

1. Abdominal pain: generally manifested as recurrent episodes of the upper abdomen, paroxysmal dull pain in the right upper abdomen or around the umbilicus, pain or cramps, the child is very painful at the time of the attack, and later as normal, sometimes high fat or a large amount of diet It can induce abdominal pain, young children will not be told, often misdiagnosed, and some abdominal pain recurrent, lasting for several months or even years, pain is often accompanied by jaundice, and at the same time have nausea, vomiting, anorexia and other gastrointestinal symptoms Such as abdominal pain becomes persistent, accompanied by fever, jaundice, suggesting the performance of cholangitis; such as sudden acute abdominal pain and peritoneal irritation, common perforation of common bile duct, secondary peritonitis.

2. Abdominal mass: There is a cystic mass on the right upper abdomen or on the right side of the abdomen. The upper boundary is mostly covered by the edge of the liver. The size is different, sometimes due to the regression of inflammation and edema at the lower end of the common bile duct or the flap of the end of the common bile duct flap. The effect, bile discharge, the cyst becomes smaller, the jaundice also gradually subsides, thus causing cyst size changes, has a high reference value in the diagnosis of this disease, fusiform bile duct dilatation and cysts can not touch the abdominal mass when it is small.

3. Astragalus: Due to the different degrees of stenosis at the distal end of the common bile duct, the distal mucosal edema of cholangitis causes the lumen to be more narrow and obstructive jaundice appears. The appearance and deepening of jaundice indicate that bile drainage is not due to distal obstruction of the common bile duct. Due to the smoothness, it may be caused by combined intracapsular infection or pancreatic reflux. When the inflammation improves, the edema subsides, the bile discharges smoothly, and the jaundice can be relieved or subsided. Therefore, intermittent jaundice is characteristic, and this symptom exists in most cases. When the jaundice occurs, the interval varies. Severe jaundice may be accompanied by itchy skin and general malaise. When some children have increased jaundice, the color of the stool becomes lighter, even white clay color, and the urine color is dark yellow.

In addition to the three main symptoms, there may be fever in the infection of the cyst, the body temperature can be as high as 38 ~ 39 ° C, can also cause nausea due to inflammation, gastrointestinal symptoms of vomiting, long-term obstructive jaundice can cause liver and pancreatic function damage, It affects the digestive and absorbing function and causes malnutrition and bleeding tendency caused by fat-soluble vitamin absorption disorder.

Examination of congenital cystic dilatation of the bile duct

The purpose is to understand the patient's disease state, which is of little significance for the diagnosis of congenital biliary cystic dilatation itself.

1. Liver function test: For patients with or without jaundice, biliary obstruction and liver function, whether combined with cirrhosis.

2. Blood amylase: used to understand whether the patient has the possibility of pancreatitis. The increase of amylase may also indicate whether the patient has abnormal bile duct and pancreatic duct. The normal amylase does not mean that the patient has no bile duct and pancreatic confluence. Need to pay attention to.

3. Tumor marker detection: such as carcinoembryonic antigen, CEA, CAl9-9, in older patients with longer duration of disease, it is helpful to detect tumor patients.

According to the clinical manifestations, the diagnosis rate is very low. Ishide reports only 3.5%. Due to the improvement of the examination and diagnosis level, the diagnosis rate has reached 72%-90%. The baby is easier to diagnose than the adult. In order to improve the diagnosis rate, in addition to the general In addition to the physical examination, the following auxiliary inspection methods may also be considered as appropriate:

4. B-ultrasound, CT examination: It is a safe, effective and non-invasive examination method, which can better determine the size and location of cysts, and has a high diagnostic rate, and can identify liver abscesses and liver tumors, especially cheap and effective. B-ultrasound can be used as the first choice for examination. B-ultrasound should be alert to cancer if it is found to have thickened cysts or nodular changes in suspicious biliary cysts.

5. Abdominal X-ray examination: When the cyst is large, the flat shadow can be found in the same shadow as the cyst and the image of the inflated gastrointestinal pressure shift. The upper digestive tract barium meal or barium enema can more accurately reflect the enlargement of the cyst to compress the surrounding organs. In the case of the upper digestive tract barium meal, the duodenal C-type intestinal fistula is enlarged and displaced forward and downward. If the cyst is located in the duodenum and is equivalent to the ampulla, the duodenum can be seen. Deformation or filling of the defect, the colonic liver area can be displaced forward and downward.

6. Renal pyelography: It can be found that the enlargement of the ureter due to the enlarged cyst causes enlargement and deformation of the renal pelvis, and is conducive to the identification of tumors, deformities and retroperitoneal tumors of the kidney.

7. Selective celiac angiography: no vascular masses can be found.

8. Endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTC) can not only show the location and type of cysts, but also the entire bile duct system, for the presence or absence of stones, tumors, and for the pancreatic duct ERCP is particularly beneficial when the comorbidity abnormality is checked. When severe jaundice cholangitis or ERCP fails, PTC examination can be performed. If the PTC is guided by ultrasound, it is safer and more reliable. When the two are combined, there is no typical three main features for diagnosis. Or difficult cases are especially valuable.

9.131I Rose Red Scan: Can be used for the examination of biliary diseases in children.

10. Transvenous cholangiography: Due to the poor concentration of gallbladder in children, a large amount of bile in the gallbladder dilatation site is not fully developed. Therefore, if pediatric 5% glucose is used, 50 g of biliary glucamine is added intravenously, the effect of cholangiography is better. .

11.99mTc-HTDA scintillation: The anatomy and functional status of the bile duct can be displayed.

12. Cholangiography: can greatly improve the diagnosis rate of the disease, and understand the pathological changes of the entire bile duct.

13. MRI and magnetic resonance cholangiopancreatography (MRCP): is the latest technology, has the diagnostic value equivalent to ERCP, can clearly show the intrahepatic bile duct, gallbladder, pancreatic duct and biliary and pancreatic duct confluence, no induction The worries of acute cholangitis and acute pancreatitis, especially for patients who are not suitable for ERCP, are obvious, such as severe jaundice, authors of pancreatitis, and patients who have undergone biliary anastomosis.

Diagnosis and diagnosis of congenital biliary cystic dilatation

Children or young women with typical triads are not difficult to diagnose, but more than half of the patients need to be diagnosed with auxiliary examination.

Differential diagnosis

1. Biliary atresia: Astragalus appears early, progressive aggravation, liver cirrhosis is obvious after 3 months, B-ultrasound can confirm the diagnosis, liver cyst and hepatic hydatid cyst, cyst is located in the liver parenchyma, and biliary tract is not connected, cholangiography can help In the identification, the cystic fluid intradermal test and serum complement fixation test of this outsourcing cyst were positive.

2. Right hydronephrosis: intravenous pyelography can confirm.

3. Abdominal tumors: Right nephroblastoma and neuroblastoma are both malignant tumors, with rapid development of the disease, no jaundice, B-ultrasound and intravenous pyelography can be identified.

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