Congenital intrahepatic cystic dilatation of the bile duct

Introduction to congenital intrahepatic biliary cystic dilatation Congenital intrahepatic biliary cystic dilatation, also known as communicable intrahepatic biliary cystic dilatation, Caroli disease, in 1958, French scholar Caroli described in detail the multiple intrahepatic biliary cystic dilatation with the biliary system, the main range of lesions The hepatic bile duct may be a segment, a partial, one-leaf or bilateral intrahepatic bile duct, and thereafter domestic and foreign scholars define it as Caroli disease. basic knowledge The proportion of sickness: 0.004% - 0.006% Susceptible people: no specific population Mode of infection: non-infectious Complications: intrahepatic bile duct stones cholangiocarcinoma cholangitis liver abscess

Causes of congenital intrahepatic biliary cystic dilatation

Genetic (55%):

The exact cause of intrahepatic biliary cystic dilatation is not well understood. Most scholars believe that Caroli disease is a congenital disease caused by recessive chromosomal inheritance, which may be caused by weak congenital structure of the bile duct or lack of sympathetic nerve.

Pathogenesis

1 There are more small bile duct hyperplasia in the liver portal area, the bile duct cavity is often dilated, accompanied by fibrous tissue hyperplasia; 2 small branches of portal vein in the portal area are still visible, and there are often fibrous cords connected between the portal areas; 3 the structure of the hepatic lobule is basically normal. Mereadie pointed out that the typical lesions of this disease are common in the portal area, that is, only the bile duct in the hepatic lobe, the dilated bile duct and the proximal bile duct fibrous tissue infiltration, the bile duct wall thickening, and multiple expanded bile ducts. The bile duct epithelium may be papillary-like hyperplasia. In the gross specimen, the intrahepatic bile duct may be single or more round or oval, and the size is about 2 to 10 cm. The dilated bile duct is distorted and is "snake swimming", near the liver. Because of the many branches, the bile ducts of the portal can also be "clustered" or "dendritic". The obvious intrahepatic bile ducts are dilated. The vesicles of different sizes can be seen in the cut surface, which is easy to be confused with polycystic liver, but the cavity is reserved. Bile, not liquid, can be seen under the microscope, the epithelial cells are compressed and flattened, while the polycystic hepatic sac wall has no epithelium, the enlarged bile duct liver parenchyma color is normal, no atrophy, histological examination see dilated bile duct Wai is rich in nerve bundles, and some were adenomatous hyperplasia, lobular structure exists.

Some scholars have conducted a correlation study on congenital choledochal cyst, congenital intrahepatic biliary cystic dilatation and congenital liver fibrosis. It is found that there is a certain relationship between the three in pathogenesis, and the same disease spectrum may be different. The performance of the site, that is, the common bile duct cyst involving the extrahepatic bile duct; Caroli disease involving the larger bile duct in the liver; congenital liver fibrosis involving the intrahepatic microbiliary duct, the three can exist independently or simultaneously, in addition, the literature reported that 2.5% of Caroli disease ~ 15.0% cancer rate.

1.Caroli classification

Caroli divided it into type I and type II in 1968 and 1973. Type I is also called simple type, and is often accompanied by intrahepatic bile duct stones. The clinical manifestations are repeated biliary infections. Type II is also called fibrosis around the portal area. Most of this type is accompanied by congenital liver fibrosis, characterized by hepatosplenomegaly, portal hypertension and upper gastrointestinal bleeding. Caroli reported that type I is rare, while Caroli disease is more common in China, which may be congenital with China. Hepatic fibrosis is rare.

2.Flanigan classification

Flanigan was divided into type IV by analyzing 955 cases of congenital cystic dilatation of the common bile duct. Type IV was a choledochal cyst with intrahepatic biliary cyst, followed by a simple intrahepatic bile duct dilation as a Flanigan-classified V-type. Therefore, Caroli's disease usually includes patients with Flanigan IV, V type.

Congenital intrahepatic biliary cystic dilatation prevention

To prevent and treat cholangitis as the main method, long-term application of broad-spectrum antibiotics.

Complications of congenital intrahepatic biliary cystic dilatation Complications intrahepatic bile duct stones cholangiocarcinoma cholangitis liver abscess

1. Concurrent stones:

Caroli disease can be combined with intrahepatic bile duct stones or cyst stones, caused by bile duct bile duct infection.

2. Cholangiocarcinoma:

The incidence of cholangiocarcinoma in Caroli disease is 7% to 15%, and the cancer rate is 100 times that of normal people. The mechanism of cancer is easy to be cancerous: mechanical stimulation of gallstones changes the bile duct mucosa, and there is cholestasis in the biliary tract. Carcinogenic substances; Caroli is caused by congenital malformation. On the basis of this, even if there is no bile stasis, it is prone to cell aberration and form cancer.

3. Cholangitis.

4. Liver abscess.

5.60% to 80% of the disease is accompanied by sponge kidney. Watts et al believe that the simultaneous combination of sponge kidney is a strong evidence for the diagnosis of this disease.

Congenital intrahepatic biliary cystic dilatation symptoms Common symptoms chills and abdominal pain jaundice cyst-like changes cyst wall thin and contain... cyst liver enlargement liver fibrosis abscess sepsis

The disease is often asymptomatic in children or youth, mostly due to long-term cholestasis caused by gallstone formation after biliary infection, abdominal pain, chills, fever and jaundice are the main symptoms of this disease, the same as cholelithiasis, cholangitis, easy to cause Judgment errors, severe biliary infection can develop into biliary liver abscess and sepsis, no symptoms during remission, some patients may also have hepatomegaly and tenderness due to repeated biliary infection, eventually leading to cirrhosis and portal hypertension.

From the perspective of surgical treatment, Huang Zhiqiang divides the distribution of cysts in the liver and related pathological changes into the following clinical types according to the CT results of Caroli's disease:

Type I: simple or limited, often with hepatic lobe distribution, without liver fibrosis, which is divided into two subtypes, peripheral type (Ia), cyst group around the liver, one leaf or one side, central Type (Ib), the cyst group is in the central part of the liver and communicates with the main hepatic duct at the hepatic hilum.

Type II: diffuse, often accompanied by liver fibrosis.

Type III: diffuse type of intrahepatic cyst with segmental distribution.

Type IV: combined with cystic dilatation of the common bile duct.

Examination of congenital intrahepatic biliary cystic dilatation

In addition to mild elevation of alkaline phosphatase and glutamyl transpeptidase, most of them are normal. Patients with acute phase often have elevated white blood cells and abnormal liver function.

1.B Ultra

It can show the size and distribution of cysts. Marhal et al. describe the ultrasound-specific manifestation of Caroli's disease as intrahepatic bile duct dilatation, spheroidal protrusion in the lumen, and a dilated bile duct with a bridge extending from the bile duct wall into the lumen, a small branch of the portal vein. Some or all of the expanded intrahepatic bile ducts are surrounded.

2. CT examination

Caroli's disease is characterized by an enhanced scan of the contrast agent after injection to detect the central point shadow of the cystic dilatation, called the "central spot sign", which is equivalent to the small branch of the portal vein in the dilated bile duct to form a bridge shape, CT can still be found The bile duct at the hilar is relatively narrow, which facilitates preoperative evaluation and selection of surgical procedures. Seth et al. believe that the "central spot sign" is sufficient to provide an accurate diagnosis without resorting to a damaging or expensive examination.

3.99mTc radionuclide scanning

Excretory hepatobiliary angiography can clearly distinguish cysts from bile ducts, and is different from simple intrahepatic cysts. 99mTc liver scan, 99mTc residence time of Caroli patients exceeds 120min, while patients with multiple hepatic cysts are quickly eliminated, showing normal liver scans. image.

4. Percutaneous transhepatic cholangiography (PTC)

Endoscopic retrograde cholangiopancreatography (ERCP) is used to examine PTC. Although ERCP can clearly show the size and number of intrahepatic bile duct dilatation, they are invasive tests, which can lead to serious complications and induce biliary infection, especially ERCP principle. It should be contraindicated. For the PTC examination, it can be used cautiously in some patients to plan the surgical resection of the cyst group and the intrahepatic bile duct. Antibiotics should be used to prevent infection before and after angiography.

5. Magnetic resonance cholangiopancreatography (MRCP)

Static water according to the heavy T2 weight sequence, including bile duct and pancreatic duct endocrine, shows a high signal, and fluid blood has no signal due to the flow effect, so MRCP can obtain good contrast without contrast agent, and can display intrahepatic bile duct. The extent of the expansion, the location and the presence or absence of stones, the literature reported that MRCP sensitivity to bile duct dilatation or stenosis is 90% to 95%, the display rate of normal extrahepatic bile duct is nearly 100%, and because of the absence of contrast agents, Therefore, ERCP can reflect the degree of biliary and pancreatic duct expansion under physiological conditions more directly and objectively. Asselah et al believe that MRCP is a non-invasive angiography and may be the first choice for the diagnosis of Caroli disease.

Diagnosis and diagnosis of congenital intrahepatic biliary cystic dilatation

diagnosis

The disease mainly relies on imaging examination to confirm the diagnosis, especially direct imaging examination of biliary tract, such as ERCP or PTC.

Patients who have not been diagnosed before surgery should pay attention to careful exploration during surgery. Mercadire has described the "Caroli sign", that is, using the finger to press the liver lobe containing suspicious lesions, the cystic sac of cystic dilatation of the bile duct has a cystic sensation and continues to sag for a while. Intraoperative cholangiography is also helpful for definitive diagnosis.

Differential diagnosis

1. Identification of intrahepatic bile duct dilatation secondary to primary intrahepatic bile duct stones

(1) The age of patients with Caroli disease is lighter than that of secondary intrahepatic bile duct dilatation, and the latter often occurs gradually after long-term recurrent cholangitis with stones or stenosis leading to biliary obstruction.

(2) bile duct dilatation or bile duct dilatation in multiple sites of the same or similar form, mostly congenital expansion.

(3) secondary intrahepatic bile duct dilatation must have stones or bile duct stenosis at the lower end, and congenital bile duct dilatation only partially with bile duct stones or stenosis.

(4) Congenital bile duct dilatation has less mucosa on the wall of the bile duct and thinner wall, and the wall of the secondary bile duct is thicker.

(5) Congenital biliary dilatation with congenital liver fibrosis must be congenital.

2. Multiple intrahepatic cysts

Simple multiple intrahepatic cysts are not connected to the biliary tract, and PTC or 99m TcHIDA angiography can confirm the diagnosis.

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