Medical treatment is regarded as the primary course of action in patients with Budd–Chiari syndrome (BCS). Its efficacy, however, is limited, and most patients require interventional treatment during follow-up. Short-segment stenosis or the occlusion (the so-called web) of hepatic veins or the inferior vena cava are frequent in Asian countries. An angioplasty with or without stent implantation is the treatment of choice to restore hepatic and splanchnic blood flow. The long-segment thrombotic occlusion of hepatic veins, common in Western countries, is more severe and may require a portocaval shunting procedure to relieve hepatic and splanchnic congestion.
1. Introduction
Budd–Chiari syndrome (BCS) occurs in many forms, ranging from asymptomatic or mild disease to severe liver failure. The variability in the presentation of the disease depends on the extent of thrombosis, the velocity of its formation, and the presence and capacity of collaterals
[1][2][3]. In addition to the hepatic veins, the portal vein as well as the inferior vena cava (IVC) may develop thromboses, which aggravate the disease and influence outcomes. With increasing collateralization, the congestion of the liver and intestine decreases, and the disease may change to follow a chronical course. The congestive state may be abbreviated and the damage reduced by interventional treatment, such as angioplasty in case of a short-segment (web-like) BCS, or portosystemic side-to-side shunts, which allow the transition of the portal vein into an outflow, thereby facilitating hepatic arterial perfusion.
Based on a study published in 2006
[4] a step-up therapeutic algorithm was proposed starting with medication, followed by angioplasty in patients with web-like BCS amenable to angioplasty including stenting, transjugular intrahepatic portosystemic shunt (TIPS) intervention, and, last of all, liver transplantation. Treatment escalation depends on non-response, which is defined by clinical and biochemical factors
[4][5]. Medical treatment is essential for preventing further thrombus growth and formation. It is, however, ineffective with respect to the recanalization of hepatic veins, and 80–90% of patients do not show a clear and durable clinical response
[6].
2. Interventions
2.1. Angioplasty
2.1.1. Rationale
The recanalization of a short-segment occluded hepatic vein or the IVC may result in the restoration of the splanchnic and hepatic blood flow and lead to a clinical improvement. In the absence of cirrhosis, the procedure may be potentially curative
[7].
2.1.2. Technique
A percutaneous transluminal balloon angioplasty with or without stent implantation can be performed by a transjugular, transfemoral, or percutaneous transhepatic access. The technical success rates are over 90% for both hepatic veins and IVC webs
[8][9][10][11][12][13][14][15][16]. After an angioplasty is performed and the stenosis or occlusion is resolved, the hepatic venous pressure gradient (wedged minus free hepatic vein pressure) should be determined and a transjugular biopsy should be performed at the same time. Both of these measures are important to better predict progression and exclude the earlier extension of the BCS into small hepatic veins and the presence of advanced fibrosis.
2.2. TIPS
2.2.1. Rationale
The rapid occlusion of the hepatic veins causes congestive liver damage due to reduced portal and arterial blood supply. In patients with a complete occlusion of all hepatic veins, hepatic blood flow depends on the development of intra- or extrahepatic collaterals which may discontinue disease progression and gradually change acute disease into chronical disease. If collateral formation is too slow or insufficient and does not increase blood flow adequately, the course of the disease may be progressive or deleterious, requiring immediate interventional or surgical treatment.
With respect to the enlargement of the caudate lobe, surgical porto-caval or meso-caval shunts alone were often ineffective and required an additional cavo-atrial anastomosis
[17][18][19]. The TIPS, however, bypasses the stenosed IVC segment and operates with or without the enlargement of the caudate lobe (
Figure 1).
Figure 1. (A) Complete BCS. The portal vein is used as outflow tract. Enlarged caudate lobe leads to stenosis of the inferior caval vein; (B) Angiography of the inferior caval vein showing complete occlusion by the enlarged liver (VCI: inferior caval vein).
2.2.2. Technique of TIPS Implantation
The intervention begins with a transjugular cavography to show or exclude IVC involvement (Figure 1B). By moving the needle catheter assembly along the lateral wall of the IVC, a hepatic vein stump may be discovered and can be used to enter the hepatic parenchyma. About half of patients do not show remnants of hepatic veins, and, therefore, a puncture through the wall of the IVC is performed [27]. After having advanced the needle through the right lateral wall of the IVC, a small amount of diluted contrast confirms the intrahepatic position of the needle tip (Figure 2A). The next step is the puncture of the intrahepatic right portal branch which should be guided by transcostal sonography (Figure 2B). Sonographic guidance is important to reach a high level of technical success which may otherwise be limited by very small intrahepatic portal branches, which are often dislocated by the enlarged caudate lobe. A guidewire and catheter are now used to carry out angiographies and pressure measurements. The patency of the portal vein and the presence of varices may be demonstrated (Figure 3A). After the dilatation of the needle track, a covered stent is introduced and dilatated with a 10 mm balloon. It is strongly recommended to create a shunt with a diameter of at least 10 mm to achieve sufficient shunt flow and to relieve hepatic and intestinal congestion. Finally, angiography and pressure measurements are performed to control shunt function (Figure 3B).
Figure 2. (A) Hand-injection of contrast into the parenchyma of the liver showing retrograde filling of a portal branch. (B) Sonographic guidance of the puncture. The location of the needle (arrow) and the portal vein is demonstrated.
Figure 3. (A) Portography (DSA) after successful puncture of a very narrow right intrahepatic branch of the portal vein. (B) Simultaneous portography and cavography demonstrating good shunt function and perfect modelling of the two stents at both ends. This patient had only mild stenosis of the inferior caval vein by the enlarged caudate lobe.
2.2.3. Pre- and Post-Interventional Management
Anticoagulation is mandatory as soon as a diagnosis of BCS is made. Heparin should be avoided since about 30% of patients have heparin antibodies at the onset of the disease
[6][20]. This is why low-molecular-weight heparin is preferred. A phlebotomy and acetylic salicylic acid (100 mg/day) should be applied in patients with polyglobulia or thrombocytosis, respectively. Unspecific medication consisting of albumin, diuretics, dopamine, and antibiotics should be given as required.
After a patient is discharged, anticoagulation has to be continued and a specific treatment of the hematological disease or coagulation disorder should be initiated. Duplex sonography before and every 3 to 6 months after a patient is discharged is recommended to assure the patency of the shunt and the portal vein. A reduced flow velocity of <60 cm/s or an increased flow velocity of >180 cm/s anywhere in the stent indicates shunt malfunction (
Figure 4)
[20][21]. In cases with a simple stenosis, the approximated Bernoulli equation (Δp = 4 v
2) allows us to calculate the pressure gradient Δp in mmHg from the maximum flow velocity (in m/s) across the stenosis
[21]. In the case presented in
Figure 4, the maximum flow velocity of 2 m/s corresponds to an estimated pressure gradient of 16 mmHg, confirming the need for shunt revision. Shunt revision is also indicated when the flow velocity in the extrahepatic portal vein decreases to <30 cm/s. In addition to the duplex sonographic findings, any persistence of complications of portal hypertension (ascites, varices) should give rise to radiological shunt revision.
Figure 4. Duplex sonography showing stenosis in the proximal stent with a turbulent flow and a maximum flow velocity of 200 cm/s (2 m/s). According to the Bernouilli equation, the maximum flow velocity corresponds to a pressure gradient across the stenosis of 16 mmHg.
2.3. Pre- and Post-Interventional Management
Anticoagulation is mandatory as soon as a diagnosis of BCS is made. Heparin should be avoided since about 30% of patients have heparin antibodies at the onset of the disease [6,29]. This is why low-molecular-weight heparin is preferred. A phlebotomy and acetylic salicylic acid (100 mg/day) should be applied in patients with polyglobulia or thrombocytosis, respectively. Unspecific medication consisting of albumin, diuretics, dopamine, and antibiotics should be given as required.
After a patient is discharged, anticoagulation has to be continued and a specific treatment of the hematological disease or coagulation disorder should be initiated. Duplex sonography before and every 3 to 6 months after a patient is discharged is recommended to assure the patency of the shunt and the portal vein. A reduced flow velocity of <60 cm/s or an increased flow velocity of >180 cm/s anywhere in the stent indicates shunt malfunction (Figure 4) [29,39]. In cases with a simple stenosis, the approximated Bernoulli equation (Δp = 4 v2) allows us to calculate the pressure gradient Δp in mmHg from the maximum flow velocity (in m/s) across the stenosis [39]. In the case presented in Figure 4, the maximum flow velocity of 2 m/s corresponds to an estimated pressure gradient of 16 mmHg, confirming the need for shunt revision. Shunt revision is also indicated when the flow velocity in the extrahepatic portal vein decreases to <30 cm/s. In addition to the duplex sonographic findings, any persistence of complications of portal hypertension (ascites, varices) should give rise to radiological shunt revision.
Figure 4. Duplex sonography showing stenosis in the proximal stent with a turbulent flow and a maximum flow velocity of 200 cm/s (2 m/s). According to the Bernouilli equation, the maximum flow velocity corresponds to a pressure gradient across the stenosis of 16 mmHg.
Shunt failure is seen in about 25% of patients when covered stents are used
[20][22][23][24]. The problem can be solved by stent-in-stent implantation or by parallel stenting, achieving secondary long-term patency rates of 95%
[20][25].
3. Outcomes
3.1. Hemodynamics
In a single-center study including 59 patients with acute (4 weeks from diagnosis, 15 patients), subacute (6 months from diagnosis, 26 patients), and chronic BCS (18 patients), the portal pressures were highest in the acute group of patients (40.4 ± 10.1 mmHg) and somewhat lower in the subacute (33.3 ± 7.5 mmHg) and chronic disease (32.2 ± 8.9 mmHg) groups
[25]. Acute/fulminant disease may result in extremely high portal pressures of up to almost 60 mmHg. The TIPS reduced the pressure gradient to 10.8 ± 4.9 mmHg. The shunt resulted in an increase in the blood flow velocity in the portal vein from 12.7 ± 10.0 cm/s to 48.6 ± 16.9 cm/s
[20][25]. This was accompanied by an increase in the retrograde blood flow in the intrahepatic portal branches from +2 ± 11 cm/s to −11 ± 13 cm/s, giving clear evidence that the hepatic congestion was reduced or eliminated by the TIPS
[20].
3.2. Liver Function and Hepatic Encephalopathy (HE)
With respect to biochemical variables, the TIPS improved hepatic and renal test results, almost reaching normal values within 2 weeks. This was, in particular, true for patients with acute or fulminant disease
[20][25]. As shown in our study and in other studies
[23][26][27], the Child–Pugh score, the Clichy prognostic BCS index
[28], and the Rotterdam prognostic BCS index
[29] improved significantly after TIPS implantation. The effect was greatest in patients with acute disease.
3.3. Survival
Survival may depend on the type of the BCS. In patients with short-segment BCS without a cirrhosis angioplasty with or without stenting may have a physiological restitution of the hepatic blood flow, resulting in excellent survival
[8][9][10][11][12][13][14][15][16]. However, more than half of the patients required TIPS implantation during follow-up
[27][30].
Several studies have suggested that TIPS may improve survival
[20][26][31][32][33][34][35][36][37], but comparable or randomized studies are lacking. A review on TIPS for BCS including 160 studies from 29 countries showed one-year and five-year survival rates of 80–100% and 74–78%, respectively
[38]. The largest multicentre retrospective European study including 124 TIPS patients with long-term follow-ups
[26] showed one-, five-, and ten-year OLT-free survival rates of 88%, 78%, and 70%, respectively. Survival cannot be predicted by the Rotterdam score
[29] but it can be predicted by a new prognostic index (BCS PI TIPS), which includes age, bilirubin, and INR
[26].