Definition: Buga syndrome (BLldd a Chiari syndroYne) is a post-hepatic portal hypertension characterized by obstructive lesions of the hepatic veins and the inferior vena cava above its opening, often accompanied by inferior vena cava hypertension.
Hepatic vein obstruction or inferior vena cava obstruction is usually due to (1) thrombosis of the hepatic veins due to hypercoagulable blood (caused by oral contraceptives, erythrocytosis); (2) foreign compression of the veins by tumors; (3) invasion of the hepatic veins by cancer (e.g., hepatocellular carcinoma) or inferior vena cava (e.g., renal carcinoma, adrenal carcinoma); and (4) congenital abnormalities in the development of the inferior vena cava (septum formation, stenosis, atresia). In western countries such as Britain and the United States, cases of hepatic vein thrombosis are predominant and often do not involve the inferior vena cava. In contrast, in Eastern countries, such as China, India, and Japan, 1/3 of cases are due to malformation of the septum of the hepatic segment of the inferior vena cava.
The septum of the hepatic segment of the inferior vena cava is usually very thin, 1 to 2 mm thick, located 3 to 4 cm from the opening of the inferior vena cava in the right atrium. 41% of the septum is above the opening of the hepatic vein, 40% of the septum runs obliquely from the lower left to the upper right, between the left and middle hepatic veins and the opening of the right hepatic vein, separating the veins, and 19% is below the opening of the hepatic vein. In cases of inferior vena cava septum, stenosis, or atretic malformation, the hepatic vein may have no opening, the opening may be blocked by thrombus, or the opening may be patent. Even if the hepatic vein is patent, hepatic venous return may be impeded by obstruction of the proximal inferior vena cava.
Clinical manifestations
In the acute phase of simple hepatic vein thrombosis, the patient has fever, right upper abdominal pain, rapid onset of massive ascites, jaundice, hepatomegaly, tenderness in the liver area, and oliguria. Death can occur within days or weeks due to circulatory collapse (shock), liver failure, or gastrointestinal bleeding. The non-acute phase of simple hepatic vein thrombosis is characterized by portal hypertension, hepatosplenomegaly, intractable ascites, and ruptured blood from esophageal varices. In simple inferior vena cava obstruction, there are superficial varices of the thoracoabdominal wall and back (venous blood flow from bottom to top) and varicose veins of the lower extremities, swelling, hyperpigmentation and ulcers. Patients may have shortness of breath due to reduced blood return to the heart due to obstruction of the hepatic and inferior vena cava.
It varies according to the number of vessels involved, the degree of involvement and the nature and state of the obstructing lesion. It can be divided into acute, subacute and chronic types.
Acute type: Mostly caused by complete obstruction of hepatic veins, the obstructive lesions are mostly thrombosis. Most of them start at the exit of hepatic vein, and the thrombus can be rapidly multiplied to the inferior vena cava. The onset of the disease is rapid, with sudden onset of epigastric distention and pain, accompanied by nausea, vomiting, abdominal distention, diarrhea, resembling fulminant hepatitis, progressive enlargement of the liver, pressure pain, mostly accompanied by jaundice, splenomegaly, rapid growth of ascites, and at the same time, pleural effusion. In fulminant cases, hepatic encephalopathy may rapidly develop, with progressive worsening of jaundice, oliguria or anuria, and may be complicated by diffuse intravascular coagulation (DIC), multiorgan failure (MOSF), spontaneous bacterial peritonitis, (SBF), etc. Most can die rapidly within days or weeks due to circulatory collapse (shock), hepatic failure, or gastrointestinal bleeding. Ascites, hepatomegaly and the rapid appearance of MOSF are the prominent manifestations of the disease.
Subacute type: Mostly, the hepatic veins and inferior vena cava are involved simultaneously or successively. Intractable ascites, hepatomegaly and lower limb edema are often present simultaneously, followed by superficial varices of the abdominal wall, low back and chest, whose blood flow is directed upward, an important feature that distinguishes Budd-Chiari syndrome from other diseases. Jaundice and hepatosplenomegaly are seen in only 1/3 of patients and are mostly mild or moderate. In many cases, ascites formation is rapid and persistent, with elevated abdominal pressure and diaphragm elevation, and in severe cases, abdominal septal compartment syndrome (ACS) may develop, causing systemic physiological disturbances. If the abdominal pressure rises to 25 cmH2O and 50 cmH2O, oliguria and anuria occur, respectively. Thoracic volume and pulmonary compliance decrease, cardiac output decreases, pulmonary vascular resistance increases, and hypoxemia and acidosis occur.
Chronic type: The disease can last for more than several years, mostly in patients with septal obstruction, and is mostly mild, but there are mostly striking signs, such as thick sinuous angry veins in the chest and abdominal wall, pigmentation seen in the foot and shoe area, and in some cases chronic ulcers. Although ascites may be present to varying degrees, most tend to be relatively stable. There may also be angry jugular veins, varicose veins of the spermatic cord, giant inguinal hernias, umbilical hernias, and hemorrhoids. Esophageal varices are often unnoticed by the patient and are only confirmed by endoscopy or radiography when sudden vomiting of blood, black stool or enlarged spleen is detected. Hepatomegaly in this type of patient is less pronounced than in subacute cases and is mostly hemihepatomegaly, but the degree of sclerosis increases, and the spleen is mostly moderate, rarely the giant spleen seen in intrahepatic portal hypertension.
In advanced patients, the typical “spider” physique may appear due to malnutrition, protein loss, increased ascites, and emaciation. The disease is more common in young men, with a male to female ratio of about (1.2 to 2):1, with an age range of 2.5 to 75 years, with 20 to 40 years being the most common.
Examination
(A) Laboratory examination Hematological examination, acute cases may have hematocrit and hemoglobin increase and other polycythemia sign performance, blood routine examination may have leukocyte increase, but it is not characteristic. In advanced cases of chronic type, if there is upper gastrointestinal bleeding or splenomegaly or hypersplenism, there may be anemia or thrombocytopenia or leukocytopenia. In acute cases, there may be increased serum bilirubin, increased ALT, AST and ALP, prolonged prothrombin time and decreased serum albumin, while in chronic cases, there are no significant changes in liver function tests. In chronic cases, there is no change in liver function tests. In ascites, if there is no spontaneous bacterial peritonitis, the protein concentration is often below 30 g/L and the cell count does not show an increase. Immunological examination, serum IgA, lgM, IgG, IgE and C3 showed no significant characteristic changes.
(b) Ultrasound The abdominal ultrasound can make the initial correct diagnosis in most cases, and the compliance rate can reach more than 95%. The site and length of hepatic vein and inferior vena cava obstruction can be detected at the top of the diaphragm and at the second hepatic portal to determine whether septal type is present. Hepatomegaly and ascites are prominent findings in acute Budd-Chiari syndrome. Doppler ultrasound is of high diagnostic value. Therefore, abdominal ultrasound exploration is the preferred, valuable, non-invasive test for Budd-Chiari syndrome.
（Angiography is the most valuable method to establish the diagnosis of B-CS. The following types of angiography are commonly used: (1) inferior vena cava angiography and manometry; (2) percutaneous hepatic venography (PTHV); (3) percutaneous splenic venography (PTSP); and (4) arteriography. Inferior vena cava angiography and manometry A femoral vein is cannulated superiorly through the inferior vena cava into the opening of the hepatic vein, and contrast is injected to see if the hepatic vein is obstructed. In case of obstruction in the inferior vena cava of the hepatic segment, in addition to cannulation from the femoral vein, a cannulation from the forearm or jugular vein is also inserted inferiorly through the right atrium to the inferior vena cava, and contrast is injected up and down simultaneously to show the site, length and shape of the obstruction, the patency of the hepatic vein and the collateral circulation, which can help to decide the indication for surgery and the choice of surgical method. Inferior vena cava pressure can be measured during inferior vena cava cannulation. The normal inferior vena cava pressure is 0.78-1.18 kPa (80-120 mm H2O), while the upper limb venous pressure is normal in hepatic segment inferior vena cava obstruction, and the inferior vena cava pressure is above 2.94 kPa (300 mm H2O). In pure hepatic venous obstruction, compensatory hypertrophy of the caudal lobe may compress the inferior vena cava, and narrowing of the inferior vena cava in this segment is seen on inferior vena cava angiography.
(iv) CT scan In the acute phase of Budd-Chiari syndrome, CT scan shows diffuse hypodense enlargement of the liver with large amount of ascites, and the specific manifestation of CT scan is a highly recessional filling defect (60-70 Hu) in the posterior segment of the inferior vena cava and the main hepatic vein. Enhancement scans are important for the diagnosis of Budd-Chiari syndrome. 30s after contrast injection, speckled enhancement (central speckled area) was seen near the hepatic hilum, and the enhancement was not obvious in the peripheral regions of the liver, and there was extensive portal vein visualization, suggesting that portal blood left the liver. Sixty seconds after contrast injection, a low-density band-like shadow appears in the liver with marginal enhancement, or a filling defect in the hepatic veins and inferior vena cava, which is highly suggestive of intraluminal thrombosis, and the marginal enhancement is due to the development of trophoblastic vessels in the vessel wall.
（MRI can clearly show the open state of the hepatic veins and inferior vena cava, and even distinguish fresh thrombus from mechanized thrombus or tumor thrombus; MRI can also show spider web-like changes in the intrahepatic collateral circulation. MRI can also show the spider web-like changes in the intrahepatic collateral circulation and the extrahepatic collateral circulation, so MRI can be used as a non-invasive examination method for Budd-Chiari syndrome.
（The venous blood from the caudal lobe of the liver returns directly from the short hepatic vein to the inferior vena cava. In simple hepatic venous obstruction, the short hepatic vein is patent, and isotope scanning reveals sparse radioactivity in the hepatic region and dense radioactivity in the caudal lobe. The diagnosis of Budd-Chiari syndrome is not specific on nuclear scan, but only in some cases there is a relative increase in radioactive uptake in the caudate lobe, which is an important reference value in identifying cavernous hepatic hemangioma.
(vii) Endoscopy Gastroscopy is not very helpful for the diagnosis of Budd-Chiari syndrome. However, in chronic cases, especially for those who have had gastrointestinal bleeding, further understanding of the cause and site of bleeding can be obtained; in suspicious or difficult to identify cases, biopsy can be taken under direct vision to make a clearer diagnosis. Laparoscopic biopsy has the advantage of being safer and more reliable.
(H) Liver puncture biopsy In the acute stage of simple hepatic vein thrombosis, the central veins of liver lobules, liver sinusoids and lymphatic vessels are dilated, the liver sinusoids are depressed with blood, and the liver is diffusely hemorrhagic. Blood cells leak from the hepatic sinusoids into the perisinusoidal space and mix with the cells of the liver plate. There is hepatocyte necrosis around the central vein. At intervals, the hepatic plate cells are replaced by red blood cells. In late stages, the necrotic hepatocytes in the central region of the hepatic lobules are replaced by fibrous tissue, forming cirrhosis, with regeneration of hepatocytes in the rest of the liver and dilatation of both hepatic veins and sinusoids.
Diagnosis.
Acute Budd-Chiari syndrome is mostly characterized by right upper abdominal pain, massive ascites and hepatomegaly; chronic cases are mostly characterized by hepatomegaly, portal-somatic collateral circulation formation and persistent ascites. Noninvasive real-time ultrasound and Doppler ultrasound and CT scan can suggest the clinical diagnosis of Budd-Chiari syndrome in more than 95% of cases. Careful analysis of the medical history and systematic physical examination should not be neglected, but the diagnosis of Budd-Chiari syndrome also depends on inferior vena cava and hepatic venography and liver tissue biopsy for final establishment.
Treatment
1.Interventional surgery: Budd-Chiari syndrome is preferred to be treated by interventional surgery, which is less invasive and more effective. If the inferior vena cava or hepatic vein is combined with thrombosis, it can be treated with intubation thrombolysis first, and balloon dilation is feasible after the thrombus is completely dissolved to open the narrowed section. If the effect of balloon dilation is poor, the hepatic vein and or inferior vena cava stenting treatment is feasible.
2. Internal treatment: Internal treatment includes low-salt diet, diuretic, nutritional support, autologous ascites transfusion, etc. For patients in the acute phase of simple thrombosis within 1 week of onset, they can be treated with anticoagulants, but most cases are not diagnosed until weeks or months after thrombosis. In most cases, conservative treatment may buy time for collateral circulation to develop, but the patient will eventually require surgery. Patients with Bard-Gialli syndrome, especially in advanced stages, often have intractable ascites and severe malnutrition. As a supportive therapy before surgery, medical treatment can improve the patient’s general condition, reduce surgical mortality, and facilitate the patient’s postoperative recovery.
3.Surgical treatment Because of the large trauma, open surgery is not used at present
(1) septal laceration: trans-right atrial septal laceration: the method is to enter the thoracic cavity through the right anterior 4th rib external thoracotomy or through the sternotomy, and cut the pericardium longitudinally in front of the right phrenic nerve. (2) Inferior vena cava-right atrial shunt: (1) anterior hepatic approach: enter the abdomen through a median abdominal incision or a right rectus abdominis incision, and the inferior vena cava can be exposed by the following methods: A, making a Kocher incision to free and turn the duodenum to the left to reveal the inferior vena cava; B, turning the transverse colon and its mesentery upward, pushing the small intestine to the left, opening the retroperitoneum below the level of the duodenum and to the right of the superior mesenteric vein. Dissect in the direction of the abdominal aorta. The inferior vena cava should be exposed for at least 4 cm. A transthoracic incision can be made through a sternotomy or a right anterior external thoracic incision, and a 14- or 16-mm-diameter artificial vessel is used to perform a terminal anastomosis to the inferior vena cava at one end and a right auricular anastomosis at the other end. The artificial vessel usually passes behind the transverse colon, in front of the stomach and liver, and then into the thoracic cavity. The posterior hepatic route: The patient is placed in the left lateral position and the chest is entered from the 7th rib on the right side. The pericardium is opened to reveal the thoracic segment of the inferior vena cava. The diaphragm is incised and the inferior vena cava is dissected down to its dilated or relatively normal portion. The artificial vessel is anastomosed to the distal dilated portion of the narrowed inferior vena cava at one end and to the inferior vena cava or right auricle of the diaphragm at the other end. Compared with the anterior hepatic route, the posterior hepatic route requires shorter artificial vessels and less chance of thrombosis, but the procedure is more difficult, prone to bleeding, and has a relatively higher incidence of postoperative celiac pleural effusion. Inferior vena cava-right auricular shunt restores blood return to the inferior vena cava and is suitable for cases where the inferior vena cava has a long obstructive lesion and the hepatic veins are relatively patent. (3) Superior mesenteric vein-right atrium shunt: The abdomen is entered through a median incision in the upper abdomen, and the superior mesenteric vein is sought at the root of the transverse colic mesentery, to the right of the flexor ligament. The thoracic incision can be made through a sternotomy or a right anterior external thoracotomy. A 14- or 16-mm-diameter artificial vessel is used to perform a terminal anastomosis to the superior mesenteric vein at one end and a right auricular anastomosis at the other end. (4) Radical surgery: For septal type cases with high vena cava obstruction, the lesion can be removed by dissecting out the thoracic segment and part of the ventral segment of the inferior vena cava and controlling the two ends of the lesion. If the obstructive lesion is extensive or there is a large amount of thrombosis distally, the inferior vena cava of the hepatic segment can be dissected longitudinally under extracorporeal circulation, the septum and thrombus can be removed, the hepatic vein can be explored and its patency restored, and the inferior vena cava can be repaired with Gore-Tex or Dacron patches. Although radical surgery directly removes the primary lesion, there is still a possibility of recurrence in cases with concomitant inflammation of the inferior vena cava.
Addendum.
The acute phase of simple hepatic vein thrombosis (within 1 week of onset) can be treated with anticoagulants. However, most cases are diagnosed several weeks or months after thrombosis. In the chronic phase, the obstruction of the inferior vena cava and hepatic veins can be surgically removed. Removal of hepatic venous return obstruction is more important than removal of inferior vena cava return obstruction, as portal hypertension due to hepatic venous return obstruction can lead to progressive impairment of liver function, intractable ascites and bleeding esophageal varices, which are more life-threatening to the patient. Surgical treatment varies depending on whether the lesion is simple hepatic venous obstruction or hepatic segmental inferior vena cava obstruction.
(a) Simple hepatic venous obstruction with a patent inferior vena cava can be treated with portal shunt or splenopulmonary fixation. In the case of hepatic venous obstruction the portal vein has become the outflow tract of hepatic blood flow, so the portal end-lateral shunt cannot be used, only the portal lateral shunt can be used. If the portal shunt is difficult due to compensatory hypertrophy of the caudal lobe of the liver, an intestinal shunt can be performed. Splenopulmonary fixation is performed by transthoracic resection of a 10-cm piece of the left diaphragm, and then the upper pole of the spleen (after envelope removal) and the diaphragmatic surface of the left lower lung are sewn to the upper and lower parts of the diaphragm, respectively, and the two are pressed against each other at the diaphragmatic defect to form a side branch, so that the high-pressure portal blood flows through the spleen and lung into the low-pressure body veins. The ascites must be controlled by abdominal vena cava shunt before splenopulmonary fixation.
(2) Simple hepatic segmental inferior vena cava obstruction with no obstruction of hepatic venous return If the obstruction is caused by the septum, the inferior vena cava septum can be stabbed open. Method: Transthoracic incision of the right atrium, insertion of the index finger into the right atrium, entry into the inferior vena cava, and stabbing open the septum when it is touched, as in the case of mitral junctional dissection. If the septum is thick, the posterior part of the inferior vena cava of the hepatic segment can be exposed through the chest and abdomen, and the inferior vena cava can be dissected at the diaphragm after blocking the inferior vena cava flow, and the septum can be removed under direct vision. The incision of the inferior vena cava is sutured with a pericardial piece graft to prevent stenosis. If the obstruction is not caused by a septum but is long, splenopulmonary fixation or right atrial bridging of the inferior vena cava can be performed. In the latter case, an artificial vessel is used to bridge the inferior vena cava to the right atrium. If the stenotic segment of the inferior vena cava is short, the stenotic segment of the inferior vena cava can be incised and the lumen can be enlarged with a venous patch sutured to the inferior vena cava incision.
(C) Obstruction of the inferior vena cava in the hepatic segment with obstruction of hepatic venous return If the return of blood to all three hepatic veins is obstructed, a T-shaped bypass of the inferior vena cava mesenteric vein in the right atrium must be performed. This is done by bridging the right inferior atrioventricular vein or common iliac vein with a long artificial vessel and then using another short artificial vessel to make a T-shaped anastomosis between the superior mesenteric vein and the middle segment of this long artificial vessel. This is a complex procedure and the artificial vessel is prone to thrombosis and obstruction after surgery. Because inferior vena cava obstruction does not cause death, splenopulmonary fixation or right atrial bridging shunt of the superior mesenteric vein is sometimes used in these patients to address only portal hypertension; inferior vena cava obstruction is not addressed. As long as one of the left, middle, or right hepatic veins is patent, a right atrial bridging shunt of the inferior vena cava can be considered to reduce inferior vena cava pressure. In the liver, there is often a thick traffic branch between the patent and the occluded hepatic vein, through which blood from the occluded hepatic vein can flow back to the right atrium via the patent hepatic vein and the inferior vena cava.
If surgery to remove the obstruction or reduce the pressure in the portal or inferior vena cava is not possible, abdominal vena cava shunt can be done to resolve ascites to reduce the symptoms.