| Transjugular intrahepatic portosystemic shunt | |
|---|---|
| Intervention | |
Fluoroscopic image of TIPS in progress. A catheter has been passed into the 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. |
|
| ICD-9-CM | 39.1 |
| MeSH | D019168 |
A Transjugular Intrahepatic Portosystemic Shunt (commonly abbreviated as TIPS or TIPSS, for "Stented Shunt") is an artificial channel within the liver that establishes communication between the inflow portal vein and the outflow hepatic vein. It is used to treat portal hypertension (which is often due to liver cirrhosis) which frequently leads to intestinal bleeding (esophageal varices) or the buildup of fluid within the abdomen (ascites).
An interventional radiologist creates the shunt using an image-guided endovascular (via the blood vessels) approach, with the jugular vein as the usual entry site.
The procedure was first described by Josef Rosch in 1969 at 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.
Contents |
A TIPS decreases the effective vascular resistance of the liver. The result is a reduced pressure drop over the liver and a decreased portal venous pressure. This, in turn, lessens the pressure on the blood vessels 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.
Transjugular intrahepatic portosystemic shunts are typically placed by an interventional radiologist under fluoroscopic guidance.[2] Access to the liver, as the name transjugular suggests, is gained via the jugular vein in the neck. Once access to the jugular vein is confirmed, a guidewire and introducer sheath are typically placed to facilitate the shunt's placement. This enables the interventional radiologist to gain access to the patient's hepatic vein via the vena cava. The shunt is created by advancing a special needle through the sheath system 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 measurements in the portal vein and inferior vena cava are often done.
TIPS has shown some promise for patients with hepatorenal syndrome.[3]
Procedural complications during a TIPS procedure, including bleeding and direct injury to the liver, are uncommon. In the hands of an experienced physician, operative mortality is less than 1%. On the other hand, because TIPS reduces or eliminates first-pass clearance of nitrogen from the gut, up to 25% of patients who undergo TIPS will experience transient post-operative hepatic encephalopathy.[4] In general, this can be managed with a reduction in dietary protein and medication that reduces the absorption of nitrogen.
A less common but more difficult complication is hepatic ischemia. Portal hypertension—the condition shared by all TIPS patients regardless of etiology—generally causes compensatory hypertrophy of the hepatic artery and a decreased reliance of the liver upon the portal vein for its oxygenation. For this reason, shunting of the portal blood away from hepatocytes is usually well tolerated. In some cases, however, TIPS creation can cause an ischemic injury to the liver.[5] Acute hepatic dysfunction after TIPS may require emergent closure of the shunt.
A complication of umbilical hernia has been recently reported.[6]
