Embolization of Large Spontaneous Portosystemic Shunts for the Prevention of Post-TIPS Hepatic Encephalopathy
Condition: Liver Cirrhosis
MeSH terms: Liver Cirrhosis; Hepatic Encephalopathy; Brain Diseases
Study type: Interventional

Summary: 
      The purpose of this study is to determine whether transjugular intrahepatic portosystemic
      shunt (TIPS) combined with large spontaneous portosystemic shunts embolization are effective
      in the prevention of hepatic encephalopathy (HE).
    

Detailed description: 
      Transjugular intrahepatic portosystemic shunt (TIPS) has been used for more than 20 years
      since 1988 to treat some of the complications of portal hypertension, especially variceal
      bleeding and ascites refractory to conventional therapy. However, this procedure has two
      major disadvantages: shunt dysfunction and hepatic encephalopathy (HE). Notabley, the use of
      expanded polytetrafluoroethylene (ePTFE)-covered stent has significantly reduced the risk of
      shunt dysfunction, but the post-TIPS HE remains a problem even with these new stents.

      The incidence of post-TIPS HE ranges between 5% and 35% HE during the first year and tends to
      be particularly frequent during the first months after TIPS and less common with time.
      Meta-analysis has that increased age, prior HE and higher Child-Pugh class/score were the
      most robust predictors for post-TIPS HE.

      There is no consensus on the management of post-TIPS HE. Episodic HE after TIPS can be
      treated traditionally. The cornerstones of the treatment of this type of HE are the
      identification and treatment of the precipitating event and the general support of the
      patients. Refractory HE not responding to standard treatment is, in our opinion, the most
      important problem faced when a patients has to be treated with TIPS. In some cases, the
      occurrence of this complication may deeply reduce the patient's quality of life and the cure
      may be worse than the disease. Refractory HE can be treated by reducing the diameter of the
      stent or by occluding the shunt. However, the procedure is not without dangers and may not
      solve the problem in all patients, and the complications of portal hypertension, such as
      varices or refractory ascites, which were supposed to be managed by the TIPS, may recur as a
      consequence of shunt reduction or occlusion.

      Besides, there are no established methods or drugs to effectively prevent the occurrence of
      HE after TIPS. One possibility is the use of stents with a small diameter, since post-TIPS HE
      was related to the amount of blood shunted. Riggio et al. compared the incidence of HE after
      TIPS created with 8-or 10-mm PTFE-covered stents and the study was stopped because of higher
      complications due to portal hypertension after TIPS in the 8-mm group. Our center performed a
      RCT to evaluate the effectiveness of L-ornithine-L-aspartate (LOLA) on plasma ammonia in
      cirrhotic patients after TIPS. Another RCT reevaluateing the effect of TIPS with 8- or 10-mm
      covered stent for the prevention of variceal rebleeding in cirrhotic patients was also
      undergoing.

      But for those with large spontaneous portosystemic shunts(SPSS), embolization might also
      represent a therapeutic target.SPSS is, as the name implies, potential communications between
      the portal venous circulation and the systemic venous circulation that can open, develop, and
      potentially grow to enable flow within them when one of these circulations (portal or venous)
      has high pressure or is obstructed or both in an effort to reduce pressure or bypass an
      obstruction or both. SPSS mainly include splenorenal shunt, gastrorenal shunt, paraesophageal
      vein, paraumbilical vein, et al. For patients with decompensated cirrhosis, the portal vein
      pressure increased significantly and some blood were diverted to the systemic circulation by
      collateral vessels between the splenorenal vein, short gastric veins, posterior gastric vein,
      and so on, namely SPSS. The nature history of SPSS in patients with liver cirrhosis is still
      unclear. Most patients were diagnosed by chance.

      Previous reports have suggested that the incidence of SPSS was 16% in patients with liver
      cirrhosis and portal hypertension and the incidence of refractory HE was about 46%. A study
      published in 2005 revealed that about 71% of the patients with cirrhosis with refractory HE
      have large SPSS. Therefore, the presence of a SPSS not only provides an explanation for the
      persistence or recurrence of HE despite an acceptable liver function, it might also represent
      a therapeutic target. Nowadays, several series have reported embolization of large SPSSs for
      the treatment of chronic therapy-refractory HE.To date, no data was about the safety and
      efficacy of embolization of large SPSS in the prevention of post-TIPS HE.
    

Intervention name(s): TIPS; SPSS embolization
Intervention type(s): Procedure; Procedure
Intervention description(s): TIPS is performed with a standard technique. TIPS revision will be planned if any evidence of shunt dysfunction is observed.; Embolization of SPSS will be conducted via the same jugular vein before TIPS implantation. The major procedures included (a) angiography of SPSS after successful intrahepatic puncture of a branch of the portal vein and (b) embolization of SPSS with coils of varying diameters or Amplatzer Vascular Plug, which resulted in the SPSS disappearing at postembolization angiography.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Prevention
Keywords: hepatic encephalopathy (HE); vericeal bleeding; spontaneous portosystemic shunts (SPSS); transjugular intrahepatic portosystemic shunt (TIPS); embolization