Transjugular intrahepatic portosystemic shunt (TIPSS) is a nonsurgical technique that transfers blood flow from the portal system to the body circulation via the liver parenchyma, thereby creating a portal shunt. Under fluoroscopic guidance, a puncture catheter is first passed percutaneously into the internal jugular vein, then sequentially into the superior vena cava, right atrium, inferior vena cava, and (in most cases) the right hepatic vein. A fine needle is inserted through the puncture catheter to perform a parenchymal puncture of the liver, creating a channel between the hepatic vein and the right branch of the portal vein. Once TIPSS is successful, portal venous flow is rapidly reduced and portal hypertension is immediately relieved. History The study of TIPSS began between the late 1960s and 1970s with the earliest investigators looking at portal circulation images through the jugular vein route. Their success in accessing the portal vein via the hepatic parenchyma led to the idea of achieving a portal shunt by creating a channel between the hepatic and portal veins.The first attempts at TIPSS were made in animal models using a nondilatable catheter that was punctured and then frozen with a cryoprobe, a method that often resulted in shunt dysfunction and maintained patency for a maximum of two weeks. The advent of the balloon angioplasty puncture catheter in the late 1970s was key to the success of TIPSS. It has been demonstrated in animal models that despite a high rate of early occlusion, TIPSS can be maintained patency for up to 1 year with periodic dilation. 1982 saw the first clinical use of TIPSS by Colaptinto et al, who significantly reduced portal vein pressure using a 9 mm catheter. Further studies in patients with cirrhosis and ruptured variceal bleeding found that although TIPSS significantly reduced portal vein pressure, most patients rebleed and died or required surgical treatment. The fact that most sinusoids were found to be patent at autopsy suggests that further measures are still needed to maintain a low pressure state in the portal vein. The use of expandable metal stents was initiated in the mid-1980s, followed by the advent of the 10 mm Palmaz stent, initially used in animal models. These stents provided better patency in patients with chronic portal hypertension than in patients with acute portal hypertension, lasting up to 48 weeks. These trials led to the first clinical use of expandable metal stents with two Palmaz stents simultaneously, resulting in improvements in both portal hypertension hemodynamics and clinical symptoms. Although the shunt was confirmed to be patent at autopsy, the patient unfortunately died of adult respiratory distress syndrome on day 12. These early experiences sparked great interest among interventional radiologists and gastroenterologists, and many research centers began using TIPSS and refining their techniques, further expanding the indications for TIPSS. Hemodynamic effects of TIPSS The hyperdynamic circulation due to cirrhosis and portal hypertension was first described by Kowalski and Abelmann and later confirmed by others. It is characterized by an increase in cardiac output and a decrease in the vascular resistance of the body circulation. Heart rate and output per beat are also increased, in proportion to cardiac output. Arterial blood pressure was normal or lower in patients with portal hypertension than in controls. In addition, the severity of liver disease is inversely related to arterial blood pressure. the effects of TIPSS on this type of hyperdynamic circulation have been well studied. Portal circulation Successful TIPSS results in a rapid reduction in portal pressure. Typically we use a portal pressure gradient [portal pressure gradient (PPG) i.e. portal venous pressure – inferior vena cava (IVC) pressure]. It used to be generally accepted that variceal rupture and bleeding was unlikely when the hepatic venous pressure gradient (HPG) was below the threshold of 12 mmHg, which is currently adopted as a therapeutic target for TIPSS, and this target has been achieved in most patients in our and others’ studies. The ideal target PPG to be achieved after TIPSS has not yet been determined, and the lower the PPG after TIPSS, the greater the likelihood of controlling variceal bleeding and preventing rebleeding. This needs to be weighed against the risk of hepatic encephalopathy and the reduction in hepatic blood flow, the latter two of which are often seen with large-bore shunts. TIPSS diverts portal blood from the liver directly into the body circulation, thereby reducing perfusion of the liver by the portal vein. The larger the shunt caliber, the greater the effect of this shunt. TIPSS has been shown to reduce hepatic blood flow, most dramatically in the acute phase, but can be restored after 3 months. This recovery of hepatic blood flow is thought to be due to a compensatory increase in hepatic blood flow, possibly mediated by the buffering effect of the hepatic artery. The degree of recovery of hepatic blood flow depends on the severity of the primary disease of the liver. In patients with progressive cirrhosis, the decrease in hepatic blood flow after TIPSS is more pronounced due to the reduced buffering capacity of the hepatic artery. Odd-vein flow, a measure of collateral circulation blood flow, decreases rapidly after TIPSS, with a maximum decrease of up to 30% of baseline values at one year after TIPSS. This study also confirms that changes in PPG after TIPSS are somewhat correlated with odd-vein flow. Body circulation TIPSS has been shown in several studies to exacerbate pre-existing hyperdynamic circulatory states.21 The acute phase effect of TIPSS at 30 minutes postoperatively is characterized by increased cardiac output (CO), right atrial pressure (RAP), pulmonary artery pressure, and pulmonary capillary wedge pressure (PWP), as well as decreased vascular resistance (SVR) of the body circulation. No changes in heart rate (HR) and mean arterial pressure (MAP) were found. The decrease in portal pressure gradient was associated with an increase in CO and a decrease in SVR. These above changes were confirmed in a recent study on a large sample of patients one year after TIPSS. In addition to the acute phase effects, HR and MAP were also increased. The increase in CO in the acute phase can last up to 3 months, while SVR starts to increase after one week (Figure 1). Other parameters of the body circulation return to normal after one year.