Paediatric arteriohepatic dysplasia syndrome

Introduction to pediatric arterial liver dysplasia syndrome Arterial liver dysplasia syndrome, arterial hepatic dysplasia syndrome (arteriohepaticdysplasiasyndrome), also known as cholestasis syndrome, Alagille syndrome, this disease is a hereditary disease, is an autosomal dominant inheritance, has a family morbidity. basic knowledge Sickness ratio: 0.0002%-0.0005% Susceptible people: young children Mode of infection: non-infectious Complications: yellow tumor

Causes of pediatric arterial liver dysplasia syndrome

(1) Causes of the disease

This disease is autosomal dominant.

(two) pathogenesis

1. The physiology of bile excretion

Bile contains bile acid, which increases bile secretion and promotes the binding of bilirubin, cholesterol, phospholipids and other fat-soluble organisms (including certain drugs) from the bile. When bile acid enters the duodenum, it can Emulsify fat and form water-soluble micelle with fat decomposition products, so that fat is absorbed by intestinal mucosa. Cholic acid is produced by metabolism of blood cholesterol through hepatocytes, and combined with glycine and taurine in cells. After being discharged to the capillary tube and into the intestine, assisting the absorption of fat, most of it is absorbed in the distal part of the ileum, enters the portal vein and the intestinal-hepatic circulation, can be reused, and the liver cells convert cholesterol into bile acid. When the concentration of bile acid is regulated, the reaction can be inhibited, and when it is decreased, the reaction is promoted.

2. Pathophysiology and clinical features

When cholestasis occurs, the following pathophysiological changes and clinical consequences can be caused.

(1) substances that are normally excreted through the bile are detained or refluxed to the body, causing their blood levels to rise and produce corresponding clinical manifestations, such as high-binding bilirubinemia, causing jaundice; hypercholestericemia, Can cause skin itching; hypercholesterolemia, severe yellow tumor, serum phospholipids, lipoprotein X increase, for some drugs, contrast agents, such as sodium sulfonium bromide (BSP), 131I rose red and other excretion An obstacle has occurred.

(2) Reduce or lack of bile in the intestine, when the bilirubin is reduced, it causes the fecal color to be pale or grayish white; the reduction of bile acid leads to the absorption of fat and fat-soluble vitamins, and the child may develop steatorrhea, malnutrition, and growth. Developmental stagnation and fat-soluble vitamin deficiency, vitamin A deficiency can occur after ecchymosis, skin, mucosal keratosis; D deficiency causes rickets, hand and foot sputum; E deficiency can cause neuromuscular degeneration, proximal muscle atrophy; K deficiency Can cause intracranial, gastrointestinal and other bleeding, prolonged blood prothrombin time.

(3) Hepatocyte damage caused by primary disease and/or biliary stagnation in the bile duct can often cause focal necrosis of the liver, giant deformation of hepatocytes, hepatosplenomegaly and abnormal liver function, such as ALT, AST, Alkaline phosphatase, 5-nucleotidase and alpha-fetoprotein increase, albumin and coagulation factor synthesis disorders, lesion progression, can develop into biliary cirrhosis, eventually causing portal hypertension and/or liver failure However, most of the sick children can recover smoothly.

Prevention of pediatric arterial liver dysplasia syndrome

The disease is autosomal dominant, and precautions should be taken from pre-pregnancy to prenatal:

Pre-marital medical examination plays an active role in preventing birth defects. The size of the effect depends on the examination items and contents, including serological examination (such as hepatitis B virus, treponema pallidum, HIV) and reproductive system examination (such as screening for cervical inflammation). General medical examinations (such as blood pressure, electrocardiogram) and asking about the family history of the disease, personal medical history, etc., do a good job in genetic disease counseling.

Pregnant women should avoid harmful factors as far as possible, including away from smoke, alcohol, drugs, radiation, pesticides, noise, volatile harmful gases, toxic and harmful heavy metals, etc. In the process of antenatal care during pregnancy, systematic screening of birth defects is required, including Regular ultrasound examination, serological screening, etc., if necessary, a chromosome examination.

Once an abnormal result occurs, it is necessary to determine whether to terminate the pregnancy; the safety of the fetus in the uterus; whether there is sequelae after birth, whether it can be treated, how to prognose, etc., and take practical measures for diagnosis and treatment.

The prenatal diagnostic techniques used are: 1 amniocentesis cell culture and related biochemical tests (amniotic puncture time is appropriate for 16 to 20 weeks of pregnancy); 2 maternal blood and amniotic fluid alpha-fetoprotein determination; 3 ultrasound imaging (applicable in about 4 months of pregnancy) 4X line examination (after 5 months of pregnancy) is beneficial for the diagnosis of fetal skeletal malformation; 5 chromatin determination of villus cells (40 to 70 days of conception), predicting fetal sex to help diagnose X-linked genetic diseases; 6 application gene linkage analysis; 7 fetal microscopy.

Through the application of the above technology, the birth of a fetus with severe genetic diseases and congenital malformations is prevented.

Pediatric arterial liver dysplasia syndrome complications Complications

Delayed growth and development, mental retardation; yellow tumor, hypogonadism, often accompanied by congenital cardiovascular abnormalities.

Symptoms of pediatric arterial liver dysplasia syndrome Common symptoms Astragalus vascular malformation Skin itching ventricular septal defect Mental retardation

Sustained jaundice begins after birth, and itchy skin appears in 3 months or so. Chronic intrahepatic cholestasis with pigmentation or subcutaneous stains such as yellow tumors; characteristic appearance (protrusion of forehead, ocular depression, increased eye distance) , saddle nose, small chin margin, forward extension); spinal deformity; delayed growth; mental retardation; hypogonadism; cardiovascular malformation: more than 80% with congenital cardiovascular abnormalities, peripheral pulmonary artery The most common stenosis, the rest of the arterial catheter closure, atrial or ventricular septal defect, tetralogy of Fallot, permanent arterial trunk, aortic coarctation, renal artery, coronary artery and left subclavian artery stenosis.

Examination of pediatric arterial liver dysplasia syndrome

1. Blood examination: Blood cell counts in patients with advanced cirrhosis can show neutropenia and thrombocytopenia.

2. Blood biochemical examination: high binding bilirubinemia (34.2 ~ 256.5mol / L), serum alkaline phosphatase, -glutamate transferase and cholesterol are significantly increased, transaminase can be There is an increase, other liver proteins are usually normal, may have mild hemolysis, prolonged clotting time, mild acidosis.

3. Other blood tests: Hepatitis B virus infection is negative, and various pathogen tests are negative.

4. X-ray examination and angiography found cardiovascular malformations, spinal deformity, etc., other should be done abdominal B-ultrasound, electrocardiogram examination, echocardiography can determine the type of cardiovascular malformation and the degree of disease.

Diagnosis and diagnosis of pediatric arterial liver dysplasia syndrome

diagnosis

According to chronic intrahepatic cholestasis, peripheral pulmonary stenosis, specific facial and butterfly-shaped spine, cardiovascular malformations and other characteristics can be diagnosed.

Differential diagnosis

1. Hepatic cholestasis

Intrahepatic infectious cholestasis and hereditary, metabolic causes (congenital abnormalities) must be carefully distinguished because their clinical manifestations are very similar, and galactosemia, congenital fructose intolerance and tyrosinemia should be promptly performed. Check, because special diet therapy can be implemented, should also consider 1-antitrypsin deficiency, cystic fibrosis and neonatal iron storage abnormalities, when considering Alagille or Zellweger syndrome, special physical characteristics are helpful for diagnosis Unless the bile duct is spontaneously perforated, the child with extrahepatic cholestasis generally performs well; the stool is usually completely white, the liver is enlarged and hard, and the premature infant is considered to be infant hepatitis.

2. Bile Concentration Syndrome

This condition is due to the fact that some neonates with hemolytic disease (Rh, ABO) and some infants who receive total venous nutrition have their bile accumulated in the bile duct or medium-sized bile duct. The same mechanism can cause the obstruction of the common bile duct. Hypoxic-reperfusion injury in the absence of Rh blood group can also cause cholestasis. In severe hemolysis, cholestasis can be complete with white stool, and bilirubin levels can be as high as 40 mg/dl (684 mol/L). Direct reaction, if bile concentration occurs in the extrahepatic bile duct, it is more difficult to distinguish from bile duct atresia, feasible choleretic (cholestamide, phenobarbital, ursolic acid deoxycholic acid) test treatment, once the stool color turns For normal or 99mTc-DIDA scans to see bile excretion into the duodenum, it can be determined that the extrahepatic bile duct is open, and during the transition of stool color to normal, sometimes parents complain that small bile-colored plugs are found in the feces of the child. Although most cases need to recover slowly within 2 to 6 months, further examination (ultrasound, DIDA scan, liver biopsy) is required for complete cholestasis lasting more than 2 weeks. Laparotomy extrahepatic bile duct, common bile duct in a concentrated rinse bile obstruction substance removal if necessary.

When suspected to be idiopathic hepatitis (no infection, metabolic and poisoning causes), bile ducts should be confirmed rather than extrahepatic "surgical" diseases, DIDA scans and ultrasound examinations may be helpful in diagnosis, In the DIDA scan, a gut test was used to prove that the biliary tract is not occluded. Liver biopsy often has diagnostic significance, especially for infants older than 6-8 weeks. However, biopsy may be for infants under 4 weeks. Misleading, if the biliary tree is not detected, the liver biopsy does not have a typical diagnosis of the disease, or persistent total cholestasis (white stool), suggesting that an experienced surgeon needs to be small. Cholangiotomy and intraoperative cholangiography, occasionally showing a small but unclosed extrahepatic bile duct tree (hypopy), is likely the result of a reduction in bile flow, not a cause, without having to rebuild the hypoplastic bile duct .

3. Extrahepatic bile duct atresia

In patients with multiple malformations, the early liver is lighter, and later progressively increased, blood alkaline phosphatase, 5-nucleotidase and low-density lipoprotein (lipoprotein X, LP-X) increased significantly, although both There is a small overlap, B-ultrasound found in the gallbladder absent or dysplasia, if the gallbladder exists, but also to do cholangiography, there is yellow bile in the gallbladder, indicating that the proximal extrahepatic bile duct system is not locked, radiography is seen in ten The contrast agent in the duodenum can rule out obstruction of the distal extrahepatic bile duct.

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