martes, 3 de septiembre de 2019

TIPS Procedure (Transjugular Intrahepatic Porto-systemic Shunt)

Download PDF Copy

TIPS stands for Transjugular (via jugular vein) Intrahepatic (within the liver) Porto-systemic (between a portal vein and a hepatic vein) Shunt (stent that is used to route blood flow within or between different organs). The TIPS procedure is usually carried out on patients suffering from serious liver diseases.

TIPS is a minimally invasive medical procedure that utilizes interventional X-ray technology to treat serious liver disorders such as esophageal varices, gastric varices, portal hypertensive gastropathy, and portal hypertensive colopathy. The portal blood flow is bypassed through a stent that is placed between a branch of the portal vein branch and a hepatic vein. The portosystemic gradient should be less than 12 mm of Hg following a successful TIPS procedure.

Necessity of TIPS

Generally, the TIPS procedure is recommended for patients with portal hypertension. This is a condition that occurs when the blood flow into the liver from the veins draining the stomach, esophagus, and intestines is blocked because of severe liver injury or obstructions in the veins of the liver. This results in increased portal blood pressure and backflow of blood through the portal veins which become stretched, engorged and tortuous. This drastic increase in portal blood pressure may lead to rupture of and very severe bleeding from the portal veins.

Complications of portal hypertension include variceal bleeding (bleeding from the dilated tortuous veins of the gastrointestinal tract [GI] as a result of the backflow from the portal vein), the development of fluid in the abdomen, known as ascites, and the development of fluid in the chest cavity, called hydrothorax.

TIPS thus regularizes the blood flow from the various parts of the GI tract to some extent. The complete procedure may be sub-categorized into:

Pre-procedural process
the main procedure
Post-procedural process.

Follow-up is another major element after the completion of TIPS.

Pre-Procedural Process

Patients are advised to undergo blood tests such as serum electrolytes, a complete blood count, and kidney function tests as well as an electrocardiogram (EKG) and chest X-ray, before the TIPS procedure is planned.

Pre-procedural evaluation also comprises tests to assess the liver function; this is carried out to assess the severity of liver damage. A detailed physical examination is necessary to detect the existence of other complications such as hepatic encephalopathy and ascites in these patients.

Before deciding to proceed with TIPS, the physician must rule out any allergic reactions due to the contrast dye used in this procedure. If so, anti-allergic medicines are essential. The possibility or presence of pregnancy is to be ruled out in all female patients in the reproductive age group. Patients who are taking blood thinners such as warfarin, heparin, or aspirin will be asked to stop them three to nine days prior to the procedure.

On the day before the procedure, the patient can consume food as usual. The patient will be advised to take only clear liquids from six hours before the planned time of the procedure. Any medicine that has to be consumed on the day of procedure is ingested with a small sip of water. The patient should plan to stay at the hospital after the procedure.

During the Procedure

The interventional radiologist performs the procedure by inserting a flexible tube called a catheter into the jugular vein in the neck through a small incision. A tiny balloon and a tube (which is a metal mesh stent) attached to one end of the catheter is introduced through the jugular vein into the liver with the help of an X-ray machine.

To ensure clarity of imaging, a contrast material (dye) is infused into the vein. The balloon is inflated to help fix the stent in position, so that it connects the portal vein and any hepatic vein. The patient may feel a little pain while the stent balloon is being inflated.

After positioning and securing the stent, blood flow is allowed to bypass the portal circulation through the stent and the pressure in the portal vein is measured. This helps to ensure that portal pressure has been lowered by the procedure. The catheter is carefully removed after the procedure. Usually, no stitches are required and only a small bandage is applied over the neck to cover the tiny incision once the procedure is over. It usually takes about 60 to 90 min to complete the procedure.

This new stent passage lets the blood flow with ease through the hepatic circulation and, therefore, will lower the blood pressure on the veins of the liver, stomach, intestines, and esophagus.

Post-Procedural Process

After the process, the patient is kept under constant observation and monitored for bleeding. Generally, there is no pain after this procedure.

It takes nearly 7 to 10 days for most patients to return to normal life. Repeated ultrasound scans are suggested in the first few weeks immediately after the procedure to ensure that the stent is functioning properly and is in correct position.

Prognosis

Many patients recover well. About 80% to 90% cases of portal hypertension are treated by TIPS. This procedure involves no incision or stitches and is hence much less dangerous.