Transjugular intrahepatic portosystemic shunt (TIPS) is the percutaneous formation of a tract between the hepatic vein and the intrahepatic segment of the portal vein in order to reduce the portal venous pressure. The blood is shunted away from the liver parenchymal sinusoids, thus reducing the portal pressure. TIPS, therefore, represents a first-line treatment for complications of portal hypertension, typically in patients with decompensated liver cirrhosis. Indications Accepted indications Uncontrolled variceal hemorrhage from esophageal, gastric, and intestinal varices that do not respond to endoscopic and medical management[4] Refractory ascites Hepatic pleural effusion (hydrothorax) Controversial indications Bridge to transplantation and retransplantation[5, 6] Budd-Chiari syndrome Hepatorenal syndrome (HRS) Veno-occlusive disease (VOD) Contraindications Absolute contraindications for transjugular intrahepatic portosystemic shunt (TIPS) include the following: Severe and progressive liver failure (Based on Childs-Pugh Score - Scores A and B have a better outcome than C) Severe encephalopathy Polycystic liver disease Severe right heart failure Relative contraindications for TIPS include the following: Portal and hepatic vein thrombosis Pulmonary hypertension Hepatopulmonary syndrome Active infection Tumor within expected path of shunt Technique Preparation Review preprocedure vascular ultrasound or CT abdomen studies (ensure patency of portal vein and assess for anatomic limitations) Evaluate Model for End-stage Liver Disease (MELD) score (helps predict short term post-transjugular intrahepatic portosystemic stent [TIPS] mortality; mortality higher with MELD score ≥18).[9] See the MELD Score for End-Stage Liver Disease calculator. Obtain informed consent. Ensure that the patient has no contrast allergy, a platelet count greater than 50,000/μL, and a relatively normal international normalized ratio (INR). Consider broad spectrum antibiotic prophylaxis. Procedure If the patient has ascites with significant volume, perform paracentesis first. Clean the skin on the neck with chlorhexidine or povidone-iodine solution. Use ultrasonographic guidance to choose a point on the skin above the vein. Make a small (≤1 cm) horizontal skin incision. Using ultrasonographic guidance and a micropuncture or an 18-ga access needle, puncture the anterior wall of the vein and enter the vein (see video below). Aspirate venous blood to ensure position. Ultrasound-guided puncture. Advance the 0.035 guidewire and insert the accompanying 5F sheath over the wire. Use a curved catheter and Terumo hydrophilic wire to access the right hepatic vein. Wedge the catheter in the hepatic vein. Obtain wedged hepatic and inferior vena cava (IVC)/right atrial pressure measurements and calculate gradient. If available, perform portal angiography using medical CO2 (see image below). Because the catheter is wedged, an indirect portogram along with a hepatic venogram can be obtained. Use the images to ensure patency of both veins.[11] Use the image as a fluoroscopic fade/roadmap or mark the portal vein and hepatic veins on screen. Either way, lock the table in position. CO2 angiography. CO2 angiography. Insert an Amplatz wire and then exchange the Cobra-2 catheter and 5F sheath for the 10F sheath with dilator. Remove the dilator and introduce the inner sheath, loaded together with the metal stiffener. Insert the system up to 1 cm from the point of intersection of both veins. Remove the wire and insert the catheter with needle. Turn the system using the metal arrow on the stiffener anteriorly (assuming placement in right hepatic vein), and advance the needle with catheter in an anteroinferior direction parallel to the spine, aiming for the portal vein. Start the throw approximately 2 cm from the confluence of the right hepatic vein and the IVC. The right portal vein is typically accessed 0.5-1.5 vertebral body widths lateral to the spine between T10 and T12. Remove the needle and attach a small syringe with 1 mL of contrast to the catheter. Aspirate while gently withdrawing. A loss of resistance is felt when in the portal vein. Confirm by aspiration and then injection of contrast. Once in the portal vein, insert a Terumo Glidewire. Advance the wire into the superior mesenteric or splenic vein and advance the catheter. Obtain portal and central pressure measurements to confirm gradient. Exchange the Terumo wire for an 180-cm Amplatz wire. Perform angioplasty of the tract (6 or 8 mm balloon). Advance a 10F sheath (replacing dilator is likely helpful) into the portal vein. Exchange the catheter for a calibrated pigtail catheter (see first image below). Perform a double flush angiogram via both the pigtail and side arm of the sheath (with the inner metal stiffener removed and sheath pulled back into the hepatic vein) to obtain images of hepatic and portal veins (see second image below). Use these images to calculate the length of stent required. Measure from portal vein to the confluence of the hepatic vein and IVC. To correctly size a Viatorr stent, add 1-2 cm to the measured length. Pigtail for calibration. Pigtail for calibration. Pre-stent portal and right atrial pressures. Pre-stent portal and right atrial pressures. Reinsert the Amplatz wire and advance the sheath back into the portal vein. Remove the pigtail catheter. Insert the stent over the wire into position (be careful to keep the Viatorr stent confined by the packaging sheath until fully introducing into the 10F sheath, and do not advance the stent beyond the sheath tip in the portal vein). Sheath and stent should extend approximately 3 cm into the portal vein. Withdraw the outer TIPS sheath and then deploy the stent as per its prescribed mechanism. With Viatorr, an upstream 2 cm uncovered segment is deployed by withdrawing the sheath (see images below). Positioning may be fine-tuned at this point to achieve the goal of placing the uncovered portion in the portal vein and the covered portion in the tract/hepatic vein (undersizing the initial tract angioplasty may help give a tactile sense of the junction of the portal vein and the tract. Deploying of stent. Deploying of stent. Deploying. Deploying. Perform a portogram to assess flow through stent and any waisting. Measure pressures to ensure a typical goal portohepatic gradient of < 12 mm Hg. If required, dilate the stent with an 8-mm balloon. If the stent does not reach the confluence of the hepatic vein and the IVC, it may be extended with an additional uncovered stent. The images below depict post-stent dilatation. Complications Immediate complications of transjugular intrahepatic portosystemic shunt (TIPS) include the following: Inability to place stent Bleeding (hemoperitoneum; 3%) Trauma to liver and heart Stent infection Bile leak and peritonitis Encephalopathy (15%; may be amenable to medical therapy; if severe, shunt may need to be narrowed or embolized) Heart failure Stent thrombosis Death (1%) Stent malposition Nephropathy Delayed complications of TIPS include the following Encephalopathy In-stent stenosis (Greater than 50% stenosis is seen in 25% of TIPS cases. This can be addressed with angioplasty.) Stent thrombosis Stent occlusion Hemolytic anemia Severe hyperbilirubinemia Radiation injury
Posted on: Tue, 08 Jul 2014 02:14:23 +0000
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