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Patients with chronic liver disease who have intractable variceal bleeding
or ascites despite conservative therapy may be candidates for percutaneous
portosystemic shunting.
Basic Facts About the
Liver
Your liver, the largest organ in your body, weighs about three pounds and is
roughly the size of a football. It lies in the upper right side of your
abdomen situated mostly under the lower ribs. The normal liver is soft and
smooth and is connected to the small intestine by the bile duct which
carries bile formed in the liver to the intestines. Nearly all of the blood
that leaves the stomach and intestines must pass through the liver. Acting
as the body’s largest chemical factory, it has thousands of functions
including the production of clotting factors, blood proteins, bile, enzymes,
the metabolism of cholesterol, maintenance of normal blood sugar
concentration, hormone regulation, and the detoxification of drugs and
poisons including alcohol and ammonia. Because of the liver’s many functions, liver
disease can cause widespread disruption of body functions.The Liver’s Circulatory System and Portal
Hypertension
Most of the blood flowing to the liver comes
from the portal vein. Blood leaving the liver flows through the hepatic
vein, which empties into the inferior vena cava, a large blood vessel
leading to the heart. Portal hypertension, an increased pressure in the
portal venous system (the veins on the gut side of the liver), results when a large pressure difference exists
between the portal vein and the inferior vena cava. Portal hypertension is
most commonly caused by cirrhosis, but can also be seen in portal vein
obstruction from unknown causes. With cirrhosis, the normal liver cells are
damaged and replaced by scar tissue, decreasing the amount of normal liver
tissue. This distortion of the normal liver structure interferes with the
flow of blood through the liver. The body responds by diverting this blood
through blood vessels surrounding the upper portion of the stomach and the
lower portion of the esophagus. The increased blood volume in these veins
causes formation of varices (swollen veins with weakened walls), which often
rupture under increased pressure. Esophageal varices may be controlled by
any one or all of the following therapies: Compression of bleeding vessels
using a balloon-tamponade tube which applies direct pressure to the varices,
drugs to decrease portal venous pressure, sclerotherapy, or by the formation
of a transjugular intrahepatic portosystemic shunt (TIPS).
Reasons for a TIPS Procedure
The TIPS procedure is performed in patients with portal hypertension causing
severe variceal bleeding or to prevent rebleeding. It may also be performed
in an emergency when the bleeding can’t be controlled by other means. TIPS
also may be used as a treatment to control bleeding when the patient is a
candidate for
liver transplantation and becomes unstable secondary to bleeding. The
TIPS procedure is often a successful alternative to surgery when medical
management is no longer effective. TIPS may also be used to control ascites
not responsive to maximal medical therapy.
Preparation for the Procedure
Before the procedure, the TIPS will be explained by a physician and you will
be asked to sign a consent form. You will not be able to have anything to
eat or drink for several hours before the procedure.
Procedure
You will be given medication to make you sleepy and relaxed. A catheter,
shown above, will be placed in the jugular vein on the right side of your
neck. The catheter is threaded through the superior and inferior vena cava
to the hepatic vein. The wall of the hepatic vein is punctured and the
needle is directed across an approximate 2 inch gap to the portal vein.
Successful passage into the portal vein is determined by the pattern of dye
injected through the catheter.
A guide wire, shown above, is threaded through the needle to maintain the
passage between the hepatic and portal veins.
A balloon, shown above, may be used across the passage to
widen the holes in the vessel walls and the passage through the liver
tissue.
A
stent, above, is then positioned along the
passage, overlapping in the liver tissue and extending into both veins. The
stent is opened to its' maximum width with balloon dilation.
Blood flow from the portal vein across the stent to the hepatic vein and on
to the vena cava is confirmed with dye injection.
Care After a TIPS Procedure
You will be monitored closely for several hours after the procedure. Your
blood pressure and pulse will be checked frequently and you will monitored
for any signs of bleeding. The head of your bed will be kept at 30 degrees
or more for a few hours after you return to your room. You will also not be
able to have anything to eat or drink for a few hours after the procedure.
The catheter will remain in the jugular vein in the right side of your neck
and IV fluid will be run through the catheter. This line will probably
remain in place for a day or more after the TIPS. An abdominal ultrasound
will usually be done the day after your procedure to check the effectiveness
of the TIPS procedure.
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