Cirrhosis leads to complications related to portal hypertension, including hepatic encephalopathy (HE), varices, and ascites. In the past, surgical decompression was used when portal decompression was warranted; however, this approach is associated with significant risks. Transhepatic intrahepatic portosystemic shunt (TIPS) stent placement is a minimally invasive procedure that is preferred for the management of portal decompression.
Model for End-Stage Liver Disease
transjugular intrahepatic portosystemic shunt
A TIPS stent is placed via interventional radiology using an aseptic technique with conscious sedation. A needle catheter is passed via the right internal jugular vein to the hepatic vein, and then a tract is made to the intrahepatic portion of the portal vein. The hepatic tract is then dilated and kept patent through deployment of a metal stent. The TIPS placement is illustrated in Fig. 1. The technical goal of TIPS placement is to decrease the hepatic venous pressure gradient to <12 mm Hg unless there is clinically significant encephalopathy, in which case clinical judgment must be used.
The individual patient factors and clinical scenario should be evaluated when considering TIPS placement. Table 1 outlines the absolute and relative contraindications for a TIPS shunt. Patients should have baseline blood work to assess their liver and kidney function. A high bilirubin level can lead to poor outcomes post-TIPS. The Model for End-Stage Liver Disease (MELD) score was created to identify 3-month mortality post-TIPS. There is no absolute MELD score above which TIPS is not possible; however, as the MELD score increases, so does mortality. Patients with a clinical history suggestive of cardiac disease should undergo a cardiac evaluation, as TIPS increases the cardiac filling volume. The TIPS stent shunts blood directly from the portal circulation to the hepatic vein, raising the concern for HE. In general, if a patient has a history of HE, one should cautiously evaluate whether TIPS is appropriate in this setting.
|Absolute Contraindications||Relative Contraindications|
|Congestive heart failure||International normalized ratio > 5|
|Severe pulmonary hypertension||Platelet count < 20,000/cm3|
|Multiple hepatic cysts||Moderate pulmonary hypertension|
|Uncontrolled systemic infection; sepsis||Portal vein thrombosis|
|Unrelieved biliary obstruction|
Indications for TIPS
The current accepted indications for TIPS placement are seen in patients who fail medical therapy for prevention of variceal rebleeding or in acute variceal bleeding that is refractory to medical management, and for management of refractory ascites.
There are two settings in which TIPS is considered in subjects with variceal hemorrhage. First, in patients who present with severe active hemorrhage and continue to bleed or have early rebleeding despite initial control with pharmacological and endoscopic treatment, TIPS has been shown to induce hemostasis in over 90% of subjects and substantially improve survival. TIPS is also effective in establishing hemostasis in subjects with isolated gastric varices, which are not amenable to endoscopic treatment. The first-line treatment for secondary prophylaxis of variceal hemorrhage is a combination of endoscopic band ligation and nonselective beta blockade. Subjects who experience recurrent bleeding despite an adequate attempt to provide secondary prophylaxis should also be considered for TIPS. Two studies have demonstrated that the timing of TIPS may be an important determinant of outcomes. In subjects with variceal hemorrhage, early institution of TIPS (within 72 hours) is associated with superior outcomes compared with medical therapy. The results of this study are outlined in Fig. 2. This may be particularly true for patients who have a hepatic venous pressure gradient >20 mm Hg, a critical threshold that is associated with a greater risk of failure of medical management of active bleeding.[8, 9]
Refractory ascites is defined as ascites that is unresponsive to diuretics or ascites that prevents patients from tolerating diuretics due to side effects. Studies that have evaluated TIPS compared with repeated paracentesis have demonstrated that TIPS is superior in managing ascites. The impact of TIPS on survival in randomized controlled trials has varied, with two studies demonstrating a survival advantage[11, 12] and three demonstrating no such advantage.[12-15] However, of the two studies that demonstrated a survival advantage, one included patients with both refractory ascites and recivident ascites (defined as at the occurrence of tense ascites at least three times in 12 months despite a low sodium diet and diuretics), and the other included only patients with relatively preserved liver and renal function.[11, 12] Although conventional meta-analyses have failed to show a survival benefit with TIPS, as illustrated in Fig. 3, a single meta-analysis that stratified subjects by the MELD score found that those undergoing TIPS had a survival advantage.[16-18]
Other Uses of TIPS in the Management of Portal Hypertension
TIPS has been used in the management of other complications of portal hypertension, including hepatic hydrothorax, hepatorenal syndrome, and portal vein thrombosis; however, these are not widely accepted indications, and they have not been studied in rigorous randomized controlled trials.
The complications of TIPS placement can be related to the technique or to portosystemic shunting or can be unique complications.
Complications Related to the Technique or Stent
Complications that may occur during stent placement include inadvertent puncture of the carotid artery, cardiac arrhythmia, hepatobiliary fistula, capsule puncture, or stent migration. Periprocedural infection can take the form of bacteremia or stent infection, known as endotipsitis. It is recommended to administer prophylactic antibiotics prior to the procedure. TIPS-induced hemolysis is another recognized complication. An important complication of TIPS stent is stent occlusion, and although the advent of covered stents has resulted in lower occlusion rates compared with uncovered stents, it remains a complication.
Complications Related to Portosystemic Shunting
HE is an important complication of TIPS. Risk factors include pre-TIPS recurrent HE, age, and liver dysfunction.[25, 26] Prophylactic lactitol or rifaximin has not been shown to decrease the incidence of post-TIPS HE. Post-TIPS HE can be treated with standard of care treatment for HE. Recurrent HE that does not respond to standard treatment may require shunt revision to decrease the diameter or shunt occlusion.
There are no guidelines of frequency of follow-up imaging to ensure the TIPS stent is patent. However, it is generally accepted that Doppler ultrasound imaging should be performed initially at 3 months and then every 6 months to assess patency of the shunt. Shunt revision may be required if the complications for which the TIPS was inserted return, such as varices or ascites. Shunt thrombosis may be required in patients with post-TIPS HE refractory to medical therapy.
TIPS has been used to manage the complications of portal hypertension that are refractory to medical management, including varices and refractory ascites. With the introduction of covered stents, shunt patency is improved compared with the previously used uncovered stents. Evaluations should be made prior to consideration of TIPS to assess individual patient suitability. Providers should be aware of the periprocedural and stent-related complications of TIPS. Once the stent is placed, regular follow-up of shunt patency is recommended.