Pediatric inferior vena cava occlusion syndrome
Introduction
Introduction to inferior vena cava obstruction syndrome in children Inferiorvenacavalobstructionsyndrome is a partial or complete obstruction of the inferior vena cava due to invasion of the inferior vena cava, compression or intracavitary thrombosis, and the inferior vena cava blood return due to obstacles. A series of clinical syndromes. The clinical manifestations vary with the location of the obstruction. Budd (1846), Chiari (1899) proposed that the obstruction occurs in the inferior vena cava of the hepatic venous segment, known as hepatic vein occlusion syndrome, or Chiari-Budd syndrome. basic knowledge The proportion of illness: the incidence rate of infants and young children is about 0.001%-0.002% Susceptible people: children Mode of infection: non-infectious Complications: varicose veins of the lower extremities
Cause
Causes of inferior vena cava obstruction syndrome in children
(1) Causes of the disease
Obstructive changes in the inferior vena cava can occur for a variety of reasons, such as congenital dysplasia or tumors, thrombosis, and the like.
1. Thrombosis: The primary cause of inferior vena cava obstruction is thrombosis. The incidence of thrombosis is high in Europe and the United States. It is caused by hypercoagulability of the blood. The thrombus is mainly derived from the deep venous thrombosis of the lower extremity. Second, pelvic vein thrombosis, primary inferior vena cava thrombosis, clinically rare.
2. Dysplasia: abnormal development of the posterior segment of the inferior vena cava or Eustachian flap, causing congenital obstruction of the inferior vena cava. The septum at the beginning of the lesion is sieve-like, resulting in completeness with the closure or fibrosis of the upper opening. Obstruction, therefore, can explain the reason that the inferior vena cava obstruction is congenital and the symptoms appear later. In Japan, the incidence rate in Africa is higher, accounting for about 64% of cases of inferior vena cava obstruction. The extensive development of venography has increased the number of cases.
3. Tumor: Primary inferior vena cava tumor is another cause of inferior vena cava obstruction. From Perl's first report in 1871 to 1985, a total of 93 cases were documented, and the vast majority (95.7%) were inferior vena cava. In leiomyosarcoma, the incidence is increasing in recent years.
4. Inflammation and Tumor: Inflammation and tumors in the peritoneal or retroperitoneal tissue can cause adhesions around the inferior vena cava, distortion or tumor invasion, and compression can cause obstruction of the inferior vena cava.
In addition, inflammation of the inferior vena cava itself can lead to stenosis of the lumen and affect its patency.
(two) pathogenesis
Pathogenesis
(1) Congenital anomalies: congenital hypoplasia of the inferior vena cava, formation of a membrane-like substance in the vein to block blood flow, or a segment of the vein becoming narrow and blocking the circulation.
(2) Tumor: The primary tumor of the inferior vena cava, such as leiomyomas and retroperitoneal tumors, is more common in children with renal embryonic tumors, and obstruction of the inferior vena cava due to tumor compression.
(3) thrombotic diseases: including primary and secondary thrombotic diseases, the former cause is unknown, the latter due to idiopathic retroperitoneal fibrosis, dehydration, polycythemia, increased blood coagulation can be the cause of obstruction Or reason.
2. Pathological changes
(1) Normal route: The inferior vena cava is formed by the plane of the left and right common iliac veins between the 4th and 5th lumbar vertebrae. It goes up the right side of the abdominal aorta and enters the thoracic cavity through the vena cava of the diaphragm. The ninth thoracic vertebra enters the right atrium slightly above, and the inferior vena cava is divided into three segments:
1 lower: the following part of the renal vein access.
2 middle section: the part between the renal vein and the hepatic vein.
3 upper segment: the upper part of the hepatic vein reinfusion, the inferior vena cava syndrome mostly refers to the inferior vena cava reflux disorder below the renal vein plane.
(2) collateral circulation: the inferior vena cava has abundant collateral circulation, which can be divided into 4 groups:
1 The shallow and deep two sets of traffic branches between the inferior vena cava and the superior vena cava.
2 Traffic branch between the inferior vena cava and the portal vein.
3 The traffic branch between the superior vena cava and the portal vein.
4 The traffic branch between the three segments of the inferior vena cava trunk.
When the inferior vena cava is blocked by blood flow for some reason, its collateral circulation gradually expands.
(3) When the inferior vena cava is blocked: its blood flow can flow into the vein that blocks the proximal side by:
1 originated from the total fetus, the abdominal wall of the external iliac vein and the common iliac vein was shallow, the circumflex stenosis and the iliac vein were shallow to the lumbar vein, the deep branch and the intercostal venous return.
2 The lumbar ascending vein originating from the common iliac vein or the same lumbar vein, returning to the lumbar vein or the lower intercostal veins, the left lumbar ascending vein and the left renal vein connecting to the semi-sham vein; the right lumbar ascending vein in the renal vein The following is introduced into the inferior vena cava, and the azygous vein is also introduced through the segmental vein. When the inferior vena cava is obstructed, the left and right lumbar ascending veins are the main collaterals and can be expanded very thick.
3 genital veins (including women's vagina, uterus and ovarian veins or men's testicular veins) into the renal vein, ovarian veins or testicular veins originating from the pelvic venous plexus, can be in a state of obvious expansion, even if the inferior vena cava is ligated After the operation, the embolus can still flow into the proximal side through the ovarian vein.
4 other minor collaterals have vertebral veins, etc., in the early stage of inferior vena cava obstruction, in the acute phase to play a shunt.
(4) High inferior vena cava obstruction: severely obstructs the reflux of the inferior vena cava and hepatic vein. It not only causes significant swelling of the lower extremities but also the scrotum, but also causes intra-abdominal organs (such as liver, spleen, kidney and total gastrointestinal tract). The road is in a state of high blood stasis, and the blood volume of the returning heart is also sharply reduced, so that the right heart is reduced, and the left heart is also reduced due to the lack of sufficient blood supply for a long time, thereby forming a small heart in anatomy and forming a heart in function. Insufficient storage function.
Prevention
Prevention of inferior vena cava obstruction syndrome in children
For patients with dehydration, polycythemia, and enhanced blood coagulation, they should be actively treated to prevent the occurrence of this disease.
Complication
Pediatric inferior vena cava obstruction syndrome complications Complications of lower extremity varicose veins
Upper inferior vena cava obstruction often combined with high aldosteronism, resulting in water and sodium retention, middle segment inferior vena cava obstruction can cause varying degrees of renal failure and hemorrhagic renal infarction, lower inferior vena cava obstruction may have walking disorders.
Symptom
Symptoms of inferior vena cava obstruction syndrome in children Common symptoms Abdominal pain Venous thrombosis Variceal hemoptysis Lower extremity Superficial varices Proteinuria Kidney involvement Chest pain Ascites jaundice
The clinical symptoms vary greatly depending on the location of the obstruction. The clinical manifestations depend on the location of the obstruction, the extent of the collateral circulation, and the mild obstruction may be unclear or obscured by the symptoms of the primary lesion; once completely Blocking, symptoms and signs can be typical.
1. Upper inferior vena cava obstruction (inferior vena cava liver) Lesions involving the hepatic vein or above, may have inferior vena cava hypertension, portal hypertension (including hepatosplenomegaly, ascites, esophageal varices and upper gastrointestinal bleeding) Insufficient cardiac reserve function (including sputum and shortness of breath), three groups of clinical manifestations, causing liver reflux disorder, clinical manifestations similar to acute or chronic extrahepatic (Chiari-Budd syndrome) occlusion, manifested as ascites, hepatomegaly Large, liver dysfunction, often associated with high aldosteronism, increased sodium retention, etc., acute hepatic vein occlusion can be due to rapid progressive ascites, hepatic encephalopathy and death, most patients with inferior vena cava obstruction syndrome liver function, white, Globulin inversion or abnormal liver function accounted for about 1/3, may be due to this disease hepatocyte pathological changes secondary, and to a lesser extent.
If the vena cava obstruction is caused by the tumor, the tumor itself has tumors and pains, liver infiltration or metastasis of the organs, jaundice, dysfunction of the digestive tract and hemoptysis, chest pain and the like.
2. Middle inferior vena cava obstruction (renal vein inflow) Kidney disease, blood pressure, dehydration, etc. are the cause of thrombotic obstruction. Thrombosis obstruction usually occurs in the renal vein inflow more, if the lesion involves the renal vein or above, It leads to renal venous hypertension, renal blood flow reduction, renal dysfunction, can make the renal vein - and block, and cause nephrotic syndrome, manifested as low back pain, kidney enlargement, and may have proteinuria, hematuria, such as entering chronic Period, due to long-term proteinuria, systemic edema, increased blood cholesterol, etc., can cause varying degrees of renal failure and hemorrhagic renal infarction.
3. The symptoms of the lower inferior vena cava obstruction (below the renal vein) caused by obstruction of the inferior vena cava, mainly the state of inferior vena cava:
(1) venous stasis of the lower extremities: the lower extremities and even the scrotum are obviously swollen, each time after walking, exacerbated after exercise, relieved after supine rest, shallow varicose veins of the lower extremities, nutritional changes in the skin, such as thin skin, hair loss, itching, eczema If the obstruction extends to the iliac vein, the femoral vein and the thigh vein, the two legs may have pigmentation and ulceration, and even form a long-lasting ulcer, especially in the lower limbs and the foot boots area, and there may be walking obstacles. Lower abdominal pain and so on.
(2) superficial vein dilatation: the subcutaneous, sub-abdominal and lateral abdominal veins of the chest wall are dilated, and the blood flow direction is toward the head side. Most of them are vertical and long-chain, and the diameter can reach more than 10 mm. Sometimes they can be twisted into a group. Vein-like changes, varicose veins are generally located in the anterior wall of the chest and abdomen, but also in the chest and abdomen side wall and back.
Examine
Examination of inferior vena cava obstruction syndrome in children
1. Blood tests may have elevated transaminase, increased blood sodium, increased serum creatinine, and increased urea nitrogen.
2. Urine examination may have proteinuria, hematuria.
3. Inferior vena cava angiography is the most reliable diagnostic method. It can make a clear diagnosis of the location, extent, intracavitary or extraluminal obstruction and collateral circulation of the inferior vena cava obstruction. Bidirectional inferior vena cava angiography It is a reliable method for diagnosing inferior vena cava obstruction. A small incision is made in the inguinal region. The catheter can be inserted from the saphenous vein branch to avoid damage to the femoral vein. Under the guidance of the TV screen, there is resistance at the inferior vena cava, and the catheter exits 10~ 15mm, another catheter was inserted into the right atrium through the superficial vein of the upper arm and then to the proximal end of the inferior vena cava. The distal catheter was infused with 40ml of 60% diatrizoate with a high-pressure syringe, and 20ml of contrast agent was pushed through the catheter of the upper arm. Continuous filming, venography can clearly show the location of the obstruction, the extent of the collateral circulation.
(1) The signs of intracavitary obstruction are:
1 The blocked end is cupped or cut off.
2 The obstruction site is filled with defects.
(2) The signs of extraluminal obstruction are:
1 The inferior vena cava obstruction is angled.
2 The narrow segment is gradually transitioned from the normal segment.
3 or the inferior vena cava has a twisted contour and the like.
4. Intravenous pyelography If the ureter is compressed and displaced, it should be suspected of idiopathic retroperitoneal fibrosis. If there is a ureteral depression, it is suspected and the venous curvature of the collateral circulation.
5. CT examination caused by obstruction of abdominal tumors, CT examination can be used to determine the plane range of obstruction, and the diagnosis of lesions can be roughly diagnosed. The application of CT combined with contrast agent can clearly show the lumen of different planes, accurate Diagnosis of vena cava obstruction, extent and possible causes, collateral circulation, venous dilatation, etc.
B-ultrasound examination B plays an important role in the diagnosis of vena cava obstruction. In 19 patients with hepatic inferior vena cava obstruction in Zhongshan Hospital, the results of B-ultrasound examination are basically the same as those of inferior vena cava angiography, and 1 case is inferior vena cava. X-ray angiography showed that the inferior vena cava was obstructed at the level of the upper edge of the ninth thoracic vertebrae. Because of the superior vena cava obstruction, catheterization could not be inserted. The extent of the lesion could not be determined, but the B-ultrasound was found to be about 20 mm from the entrance of the heart. There is a 4mm thick diaphragm in the inferior vena cava. B-ultrasound is accurate and convenient. Sometimes it can make up for the lack of contrast and can be used to screen patients for the main examination of inferior vena cava angiography. Liver enlargement and ascites can be seen.
7. Nuclide venography to understand the location of the inferior vena cava obstruction, degree and collateral circulation, this method is safe and simple, many experts have reported their successful experience.
Diagnosis
Diagnosis and diagnosis of inferior vena cava obstruction syndrome in children
diagnosis
All patients with bilateral lower extremity venous insufficiency and extensive superficial varices in the abdominal wall should consider the possibility of inferior vena cava syndrome.
When asking about medical history, there are often symptoms of deep vein thrombosis in the lower extremities. If the age of onset is mild and the course of disease is long, the inferior vena cava malformation should be considered. Short course of disease, rapid development of the disease, should consider the possibility of primary inferior vena cava tumor or exogenous compression such as renal tumor, pancreatic tumor compression of the inferior vena cava, which is characterized by the blockage position often in the middle, with obvious proteinuria and hematuria.
At the time of physical examination, attention should be paid to the direction of blood flow in the superficial veins of the chest and abdomen. Method: The patient is supine, and two varicose veins are taken on the anterior abdominal wall, one on the umbilicus and one on the umbilicus, with the two index fingers pressed against the vein. The veins are depressed from top to bottom, so that the venous blood is drained, and then the index finger is relaxed to observe the direction of blood flow when the vein is filled. When normal, the blood flow of the lower abdominal vein is from top to bottom, and the blood flow from the upper chest is from bottom to top. If the inferior vena cava is blocked, the blood flow in the chest and abdomen is from bottom to top. If the superior vena cava is blocked, the blood flow in the chest and abdomen is from top to bottom, which can be used as an identification.
The judgment of the lesion site is conducive to the choice of treatment plan. Where the obstruction is located in the lower segment, only the lower extremity and the genital and lower abdominal wall are swollen, and the superficial vein is engorged. In the middle segment, there is still a basis for kidney involvement, and the upper segment is blocked. Symptoms based on Budd Chiari syndrome.
Differential diagnosis
Should be differentiated from advanced schistosomiasis cirrhosis, constrictive pericarditis, tuberculous peritonitis, generally by detailed inquiry of medical history and physical examination, according to their clinical characteristics is not difficult to make a diagnosis, when differential diagnosis is difficult, use B-ultrasound or Inferior vena cava angiography can be diagnosed.
Judgment on the extent of lesions: Where the obstruction is located in the lower segment, only the lower limbs, the genital and anal sites, in the middle segment, there is still a basis for kidney involvement; in the upper segment, there will be symptoms of hepatic vein obstruction.
The superior inferior vena cava obstruction should be differentiated from those caused by cirrhosis. The middle vena cava obstruction should be differentiated from nephrotic syndrome.
