Buga syndrome is a form of 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. In the acute phase, the patient has fever, right upper abdominal pain, rapid onset of massive peritoneal fluid, jaundice, hepatomegaly, tenderness in the liver area, and oliguria. 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.
1.Etiology
Mainly include.
(1) congenital macrovascular malformation.
(2) hypercoagulable and hyperviscous states.
(3) toxins.
(4) intraluminal non-thrombotic obstruction.
(5) exogenous compression.
(6) vascular wall lesions.
(7) Diaphragmatic factors.
(8) abdominal trauma, etc.
2.Clinical manifestations
In the acute stage of simple hepatic vein thrombosis, the patient has fever, right upper abdominal pain, rapid appearance of a large amount of abdominal fluid, jaundice, liver size, tenderness in the liver area, and oliguria. Death can occur within days or weeks due to circulatory collapse, liver failure, or gastrointestinal bleeding. The non-acute phase of simple hepatic vein thrombosis is characterized by portal hypertension, hepatosplenomegaly, intractable peritoneal effusion, and bleeding from ruptured esophageal varices.
In the case of 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 obstruction of the hepatic veins and inferior vena cava and reduced blood return to the heart. It varies according to the number of vessels involved, the degree of involvement and the nature and status of the obstructing lesion. It can be divided into acute, subacute and chronic types.
1.Acute type
Most of them are caused by complete obstruction of hepatic vein, and 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 distension and pain, accompanied by nausea, vomiting, abdominal distension, diarrhea, similar to fulminant hepatitis, progressive enlargement of the liver, pressure pain, mostly accompanied by jaundice, splenomegaly, rapid growth of abdominal fluid, and at the same time there may be pleural effusion. In fulminant cases, hepatic encephalopathy may rapidly appear, jaundice is progressively aggravated, oliguria or anuria occurs, and can be complicated by diffuse intravascular coagulation (DIC), multi-organ failure (MOSF), spontaneous bacterial peritonitis, (SBF), etc. Most of them can die rapidly within days or weeks due to circulatory collapse (shock), hepatic failure or gastrointestinal bleeding.
2.Sub-acute type
Mostly, the hepatic veins and inferior vena cava are involved simultaneously or successively. Intractable peritoneal fluid, hepatomegaly and lower limb edema are mostly present simultaneously, followed by superficial varices in the abdominal wall, low back and chest, whose blood flow is directed upward, which is an important feature that distinguishes Buga syndrome from other diseases. Jaundice and hepatosplenomegaly are seen in only 1/3 of patients and are mostly mild or moderate. In many cases, the formation of peritoneal fluid is rapid and persistent, with increased abdominal pressure and diaphragm elevation, and in severe cases, abdominal compartment syndrome (ACS) may develop, causing systemic physiological disturbances. Oliguria and anuria occur. Thoracic volume and pulmonary compliance decrease, cardiac output decreases, pulmonary vascular resistance increases, and hypoxemia and acidosis occur.
3.Chronic type
The disease can last for more than several years, mostly seen in patients with septal type obstruction, the disease 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, some appear chronic ulcers. Most tend to be relatively stable, although there may be varying degrees of pneumoperitoneum. There may also be angry jugular veins, varicose veins of the spermatic cord, giant inguinal hernias, umbilical hernias, and hemorrhoids. In the late stage, the patient may have a typical “spider man” physique due to malnutrition, protein loss, increased fluid in the abdominal cavity and wasting.
3.Examination
1.Laboratory examination
Hematological examination, acute cases may have polycythemia vera and increased hemoglobin, and routine blood tests may have increased white blood cell counts, but they are not characteristic. In advanced cases of chronic type, if there is upper gastrointestinal bleeding or splenomegaly or hypersplenism, there may be anemia or decreased platelet and white blood cell counts. 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. On examination of peritoneal fluid, 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 have no obvious characteristic changes.
2.B ultrasound examination
Abdominal ultrasound can make the initial correct diagnosis in most cases, and its 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 the second hepatic portal to determine whether the septum type is present. Hepatomegaly and fluid accumulation in the abdominal cavity are prominent findings in acute Buga syndrome. Doppler ultrasound is of high diagnostic value. Therefore, abdominal ultrasound exploration is the preferred, valuable and non-invasive test for Buga syndrome.
3.Hepatic vein, inferior vena cava, portal vein and arteriogram
Angiography is the most valuable method to establish the diagnosis of B-CS, and the following angiograms are commonly used.
(1) Inferior vena cava angiography and manometry.
(2) Percutaneous hepatic thoracic venography (PTHV).
(3) Percutaneous splenic puncture portal venography (PTSP).
(4) Arteriography.
4.CT scan
In the acute phase of Budd-Chiari syndrome, CT scan shows diffuse hypodense enlargement of the liver with a large amount of ascites, and a highly recessional filling defect (60-70 Hu) in the posterior segment of the inferior vena cava and the main hepatic vein is the specific manifestation of CT scan. Enhanced scans are important for the diagnosis of Budd-Chiari syndrome.
5.Magnetic resonance imaging (MRI)
In Budd-Chiari syndrome, MRI can show low-intensity signals in the liver parenchyma, suggesting liver stasis and increased free water in the tissues. MRI can clearly show the open state of the hepatic veins and inferior vena cava, and even distinguish fresh thrombus in the vessels from mechanized thrombus or tumor thrombus; MRI can also show spider web-like changes in the intrahepatic collateral circulation, and it can also show the extrahepatic collateral circulation.
6.Nuclear scan of the liver
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 scan shows sparse radioactivity in the hepatic region and dense radioactivity in the caudal lobe. Nuclear scan is not specific for the diagnosis of Buga syndrome, but only in some cases there is a relative increase in radioactive absorption in the caudate lobe, which is an important reference value in identifying cavernous hepatic hemangioma.
7.Endoscopy
Gastroscopy is not very helpful for the diagnosis of Buga 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 for a clearer diagnosis. Laparoscopic biopsy has the advantage of being safer and more reliable.
8.Liver puncture biopsy
In the acute stage of simple hepatic vein thrombosis, the central vein of liver lobules, hepatic sinusoids and lymphatic vessels are dilated, the hepatic sinusoids are depressed, 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 stage, the necrotic hepatocytes in the central region of the hepatic lobules are replaced by fibrous tissue, forming cirrhosis, and the hepatocytes in the rest of the liver regenerate, and both the hepatic veins and sinusoids dilate.
4.Diagnosis
Acute Buga syndrome is mostly characterized by right upper abdominal pain, massive peritoneal fluid and hepatomegaly; chronic cases are mostly characterized by hepatomegaly, portal-somatic collateral circulation formation and persistent peritoneal fluid. Non-invasive real-time ultrasound and Doppler ultrasound and CT scan can suggest the clinical diagnosis of Buga syndrome in more than 95% of cases.
5.Treatment
1.Interventional surgical treatment
Interventional surgery is preferred for the treatment of Buga syndrome, 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 of the vessel. If the effect of balloon dilation is poor, the hepatic vein and or inferior vena cava stenting treatment is feasible.
2.Medical treatment
Internal treatment includes low-salt diet, diuretic, nutritional support, autologous pneumoperitoneum transfusion and so on. Patients in the acute phase with simple thrombosis within 1 week of onset 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 Buga syndrome, especially in advanced stages, often have intractable peritoneal effusions 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
(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.
(3) Superior mesenteric vein-right atrial shunt.
(4) Radical surgery Although radical surgery directly removes the primary lesion, there is still a possibility of recurrence in cases with concomitant inferior vena cava inflammation.