Embolization of Large Spontaneous Portosystemic Shunts for the Prevention of Post-TIPS Hepatic Encephalopathy
Embolization of Large Spontaneous Portosystemic Shunts for the Prevention of Post-TIPS Hepatic Encephalopathy
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).
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.
Inclusion Criteria:

 -  Signed written informed consent

 -  Dignosis of liver cirrhosis (clinical or by liver biopsy)

 -  Admission due to variceal bleeding occurred 5 to 42 days prior and standard treatment
 for secondary prophylaxis failed

 -  Confirmed splenorenal shunt, gastrorenal shunt or paraesophageal vein

 -  Sum of targeted SPSS diameters greater than half the diameter of portal vein

 -  Child-Pugh score ≤13

 Exclusion Criteria:

 -  Hepatic carcinoma and/or other malignancy diseases

 -  Portal vein thrombosis (≥50% of the lumen)

 -  Budd-Chiari syndrome

 -  Other spontaneous portosystemic shunts

 -  Sepsis

 -  Spontaneous bacterial peritonitis

 -  Uncontrollable hypertension

 -  Serious cardiac or pulmonary dysfunction

 -  Renal failure

 -  With TIPS contraindications

 -  Pregnancy or breast-feeding

 -  History of liver transplantation