Transjugular intrahepatic portosystemic shunt

TIPS (also: TIPSS ) is the abbreviation of a transjugular intrahepatic portosystemic ( stent ) shunt and refers to an angiographically established connection between the portal vein and hepatic vein through the liver ( portosystemic shunt). With the TIPS is to be achieved, that a certain portion of the blood flow from the portal vein does not flow in the liver, but directly into the systemic circulation. Used a TIPS in the treatment of portal hypertension.

Description

Portal hypertension ( portal hypertension ) describes the pressure increase in the current area of the portal vein. This can lead to varicose collaterals Running ( esophageal varices, fundal varices, hypertensive gastropathy, Caput medusae ) with bleeding risk, as well as for splenomegaly and ascites. Most of portal hypertension is the result of liver cirrhosis. Is through the TIPS, the one in the liver ( " intrahepatic " ), this short-circuit connection (shunt) between the portal vein and hepatic vein, a certain portion of the blood flow to the liver is inferior passing through the hepatic vein into the inferior vena cava and thus directly into the systemic circulation derived. The height of the portion of the blood flow that is to be passed to the liver over can be varied by the diameter of the tip. This allows the liver but also less of their detoxification function to fulfill, as the blood flows in part without passage through the liver. TIPS, which is made of metal mainly (sometimes it is also coated with plastic material ) is about 4-5 cm long and has a diameter of about 6-10 mm.

Indications

• Moderate to severe ascites: ascites If conservative ( that is, by means of brisk diuresis or Aszitespunktionen ) can not be adequately treated, there is a proven benefit of TIPS.
• Acute variceal bleeding ( emergency TIPS): If by endoscopic and pharmacological measures (eg, terlipressin, somatostatin ) no hemostasis can be achieved. If a TIPS created an emergency basis at an uncontrollable bleeding, but there is a high mortality rate.
• Secondary prophylaxis of variceal bleeding (after Erstblutung ): In addition to drug and endoscopic therapy, TIPS implantation is an effective treatment of varicose veins, if this had already led to a greater variceal bleeding. If it was already once been a variceal bleeding, there is a high likelihood of recurrence of bleeding.
• Hypertensive gastropathy: make necessary case of recurrent bleeding, the blood transfusions.
• Budd -Chiari syndrome: a rare indication for which by a closure of the hepatic veins threatening liver failure. The TIPS system at this rare disease usually leads to good results with restoration of perfusion and function.
• Excessive splenomegaly: This is a rare indication that comes in question in cases where a splenectomy is not possible or not desirable.
• (Primary) prevention of Erstblutung from varices: Varicose veins are first treated with drugs ( eg, propranolol). If these are not sufficient measures endoscopic ( sclerotherapy or band ligation ) to be performed. Whether in case of failure of all these possibilities, a TIPS should be used prophylactically (ie if it was never been a hemorrhage), is not yet fully understood. However, this may be considered in individual cases, it is then a balancing of the risks posed by a TIPS placement with the risks posed by the risk of variceal bleeding.

Contraindications

• Cavernous portal vein thrombosis
• Right heart failure
• Pulmonary hypertension
• Spontaneous bacterial peritonitis
• Polycystic liver disease
• Very poor coagulation tests (INR > 2) or thrombocytopenia ( < 50.000/μl )
• Hepatic encephalopathy

History

Since the 1960s for the treatment of portal hypertension were portocavale on operating way mesocavale and created peritoneovenöse shunts. In the following years, various experimental tests have been made in order to establish a non -operative way a transjugular portosystemic shunt, but without reaching the stage of clinical application. This was achieved in 1982 for the first time Colapinto, but his method were granted no long-term success, because he created by balloon dilatation Shunttrakte between hepatic vein and portal vein collapsed without support by the stent ( metal prostheses) and soon led to closures of the tract. The final breakthrough came only after Julio Palmaz 1985 in experimental fundamental work for the first time splinting of the Parenchymtraktes in dogs with he developed stents introduced (flexible metal mesh ). After a further development of these stents led M. Rössle, GM Richter, G. and J. Palmaz Nöldge in radiology of the UKL Freiburg in January 1988, the first successful TIPSS - conditioning on a patient with cirrhosis and portal hypertension by. Due to the low stress for the patient of the TIPS is an increasingly important alternative to surgical procedures in importance. Compared to a surgically created portocaval shunt ( with a portocaval anastomosis ) offers the TIPS the advantage that a subsequent liver transplantation is not impeded or prevented.

Technology

On the neck, the jugular vein is usually punctured and pushed an angiographic catheter through the superior vena cava through the atrium into the inferior vena cava. This is done under fluoroscopic guidance in an angiography. Using specially shaped probing catheter is a hepatic vein (usually the right hepatic vein ) explored and introduced a very stable controllable hollow needle into the hepatic vein after insertion stable guiding catheter / locks. By ( usually by means of the use of an ultrasound device controlled ) puncture of the TIPS needle is stabbed through the lower surface of the probed hepatic vein through the hepatic parenchyma on the intrahepatic portal vein. After successful puncture of the intrahepatic portal vein connection (shunt) is created between the hepatic vein and a branch of the portal vein by balloon dilation. This tract is then held open by a Metallendoprothese (stent ). In addition to balloon-expandable stent ( very good radial force, limited flexibility ), self-expandable stent ( good radial force, excellent flexibility ) come specially developed for TIPS with a layer of plastic -lined stent ( good radial force, excellent flexibility, lower frequency of closures ) are used. Since the puncture of the Pfortaderwand and dilations are painful, the TIPS system is usually done in conscious sedation (depending on the clinical situation of the patient in general anesthesia ).

The TIPS system represents a major technical intervention, which is therefore carried out usually only in large hospitals or university hospitals.

Complications

We must distinguish between early, usually angiography -related complications and late effects by the TIPS system. The most common complication in the TIPS system is the risk of bleeding. The greatest danger during the TIPS system is in a puncture for non-covered by liver tissue ( extrahepatic ) portal vein, which for a non-recognition of this complication is very dangerous for the patient.

Due to the redistribution of blood flow ( a part of the portal vein flows now virtually unfiltered no longer in the liver parenchyma, but by the TIPS tract on the liver parenchyma by in the atrium) favors a TIPS system, the development of hepatic encephalopathy. The rate of encephalopathy after TIPS plant is 15-40 %. When using balloon-expandable stents, however, it is possible to extend this by means of appropriate balloon dilatation in diameter gradually and so the portosystemic pressure gradient ( ie, the difference in pressure between the portal vein and the atrium) gradually adapt to each patient. Thus, the treatment of therapy -refractory ascites requires a lower target pressure as a TIPS due to esophageal varices that had taken place.

The TIPS through the use of exogenous material ( metal stent ) to a reaction of the vessel wall (so-called neointima formation ) with the following formation of a Neogefäßwand on the metal struts. Depending on the formation of this layer within the lumen of the TIPS tract, there is a shunt stenosis or dysfunction in up to 50 % of cases. Therefore, patients should be followed up closely with a TIPS. Here's addition to the use of duplex ultrasound (advantage: no invasiveness / disadvantage: suboptimal results after the insertion of a plastic -coated stent grafts ) also re- angiography is used. In the centers of different time intervals for the controls are used, however, is of a Reinterventionsnotwendigkeit assumed (eg, balloon dilation or re- extension of the TIPS tract by means of another stent ) of approximately 50-75 % in the first postintervention year.