Transjugular intrahepatic portosystemic shunt

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Transjugular intrahepatic portosystemic shunt
hepatic vein and after needle puncture, a guidewire was passed into a portal vein branch. The tract was dilated with a balloon, and contrast injected. A self-expandable metallic stent has yet to be placed over the wire.
Other namesTransjugular intrahepatic portosystemic stent shunting
SpecialtyInterventional radiology
ICD-9-CM39.1
MeSHD019168
]

Transjugular intrahepatic portosystemic shunt (TIPS or TIPSS) is an artificial channel within the

liver cirrhosis) which frequently leads to intestinal bleeding, life-threatening esophageal bleeding (esophageal varices) and the buildup of fluid within the abdomen (ascites
).

An

endovascular (via the blood vessels) approach, with the jugular vein
as the usual entry site.

The procedure was first described by

Oregon Health and Science University. It was first used in a human patient by Dr. Ronald Colapinto, of the University of Toronto, in 1982, but did not become reproducibly successful until the development of endovascular stents in 1985. In 1988 the first successful TIPS was realized by M. Rössle, G.M. Richter, G. Nöldge and J. Palmaz at the University of Freiburg.[1]
The procedure has since become widely accepted as the preferred method for treating portal hypertension that is refractory to medical therapy, replacing the surgical portocaval shunt in that role.

Medical uses

TIPS is a life-saving procedure in bleeding from esophageal or gastric varices. A randomized study showed that the survival is better if the procedure is done within 72 hours after bleeding.[2] TIPS has shown some promise for people with hepatorenal syndrome.[3] It may also help with ascites.[4]

Complications

Severe procedural complications during a TIPS procedure, including catastrophic bleeding or direct liver injury, are relatively uncommon. In the hands of an experienced physician, operative mortality is less than 1%[medical citation needed]. On the other hand, up to 25% of patients who undergo TIPS will experience transient post-operative hepatic encephalopathy caused by increased porto-systemic passage of nitrogen from the gut.[5]

A less common, but more serious complication, is hepatic ischemia causing acute liver failure. While healthy livers are predominantly oxygenated by portal blood supply, long-standing portal hypertension results in compensatory hypertrophy of and increased reliance on the hepatic artery for oxygenation. Thus, in people with advanced liver disease the shunting of portal blood away from hepatocytes is usually well tolerated. However, in some cases suddenly shunting portal blood flow away from the liver may result in acute liver failure secondary to hepatic ischemia.[6] Acute hepatic dysfunction after TIPS may require emergent closure of the shunt.[citation needed]

A rare but serious complication is persistent TIPS infection, also known as endotipsitis.[7]

Lastly, the TIPS may become blocked by a blood clot or in-growth of endothelial cells and no longer function. This has been significantly reduced with the use of polytetrafluoroethylene (PTFE)–covered stents.[8]

Mechanism of action

Portal hypertension, an important consequence of liver disease, results in the development of significant

rectal varices).[citation needed
]

A TIPS procedure decreases the effective vascular resistance of the liver through the creation of an alternative pathway for portal venous circulation. By creating a shunt from the portal vein to the hepatic vein, this intervention allows portal blood an alternative avenue for draining into systemic circulation. In bypassing the flow-resistant liver, the net result is a reduced pressure drop across the liver and a decreased portal venous pressure. Decreased portal venous pressure in turn lessens congestive pressures along veins in the intestine so that future bleeding is less likely to occur. The reduced pressure also makes less fluid develop, although this benefit may take weeks or months to occur.[citation needed]

Implantation

Steps in a TIPS procedure: A) portal hypertension has caused the coronary vein (arrow) and the umbilical vein (arrowhead) to dilate and flow in reverse. This leads to varices in the esophagus and stomach, which can bleed; B) a needle has been introduced (via the jugular vein) and is passing from the hepatic vein into the portal vein; c) the tract is dilated with a balloon; D) after placement of a stent, portal pressure is normalized and the coronary and umbilical veins no longer fill.

Transjugular intrahepatic portosystemic shunts are typically placed by an interventional radiologist under

hepatic vein by traveling from the superior vena cava into the inferior vena cava and finally the hepatic vein
.

Once the catheter is in the hepatic vein, a wedge pressure is obtained to calculate the pressure gradient in the liver. Following this, carbon dioxide is injected to locate the portal vein. Then, a special needle known as a Colapinto is advanced through the liver parenchyma to connect the hepatic vein to the large portal vein, near the center of the liver. The channel for the shunt is next created by inflating an angioplasty balloon within the liver along the tract created by the needle. The shunt is completed by placing a special mesh tube known as a stent or endograft to maintain the tract between the higher-pressure portal vein and the lower-pressure hepatic vein. After the procedure, fluoroscopic images are made to show placement. Pressure in the portal vein and inferior vena cava are often measured.[citation needed]

See also

References

  1. S2CID 32164746
    .
  2. PMID 20573925
    .
  3. PMID 15381144
    .
  4. ^ "Ascites - Hepatic and Biliary Disorders". Merck Manuals Professional Edition. May 2016. Retrieved 14 December 2017.
  5. ^ Rossle M, Piotraschke J. Transjugular intrahepatic portosystemic shunt and hepatic encephalopathy. Dig Dis 1996; 14:12–19.
  6. ^ Mayan H, Kantor R, Rimon U, Golubev N, Heyman Z, Goshen E, Shalmon B, Weiss P.: "Fatal liver infarction after transjugular intrahepatic portosystemic shunt procedure." Liver, 2001;21(5):361-4.
  7. PMID 19929905
    .
  8. PMID 23811307
    .
  9. ^ "What You Need to Know about the Transjugular Intrahepatic Portosystemic Shunt (TIPS)". Cleveland Clinic.

External links

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