Portal hypertension is an important pathophysiological link in the development of cirrhosis and one of the important clinical manifestations in the decompensated phase of cirrhosis. Transjugular intrahepatic portosy stemicshunt (TIPS) is one of the key measures to reduce portal vein pressure in cirrhotic patients by creating a shunt tract in the liver parenchyma between the lunar trunk vein and portal vein in a minimally invasive manner and significantly reducing portal vein resistance structurally.
With proper selection of cases, it can effectively reduce the complications of cirrhosis such as rebleeding of esophagogastric varices and recurrence of ascites, improve the quality of life of cirrhotic patients, and reduce or delay the need for liver transplantation.
TIPS has been used in clinical practice for more than 20 years. After a series of exploration of concepts, techniques, devices and combined drug therapy, the effectiveness and safety of the technique is becoming more and more mature, and patients have significantly benefited in terms of survival time and quality, which has been widely recognized by domestic and foreign colleagues.
In 2013, the Gastroenterology Interventional Group of the Chinese Medical Association invited some domestic experts in related disciplines to reach a consensus on TIPS for the treatment of portal hypertension in cirrhosis, with the aim of helping more clinicians to apply this minimally invasive procedure in the treatment of portal hypertension in cirrhosis.
I. Indications for TIPS (a) ruptured esophagogastric varices and bleeding (EGVB) The incidence of esophagogastric varices in cirrhotic patients is about 30%-70%, respectively, and about 30% of patients are at risk of EGVB within I year after the detection of definite esophagogastric varices.
1. Acute EGVB: Patients have a morbidity and mortality rate of approximately 20% within 6 weeks, and resuscitation therapy is required for fatal hemorrhage. On the basis of maintaining airway patency and blood circulation stability, and depending on the conditions of each hospital, consider.
(i) remedial TIPS, which is the second-line option when drug combined with endoscopic treatment fails; and (ii) early TIPS, which is the first-line option for resuscitation within 72 h after massive bleeding. Early TIPS has a hemostatic success rate of >95% and is more effective than drug-combined endoscopic therapy in controlling fatal hemorrhage and reducing rebleeding, reducing intensive care and hospitalization time, and significantly improving patient survival. Patients with cirrhotic Child-Pugh class C but with a score <13 benefit more from early TIPS.
EGVB secondary prevention: After cessation of acute EGVB, patients are at high risk of rebleeding and death. In untreated patients, the average rebleeding rate is 60% and the morbidity and mortality rate is up to 33% within 1-2 years, thus all patients recovering from acute bleeding should receive secondary prophylaxis.
Although the rate of variceal rebleeding after TIPS (9.0%-40.6%) is significantly lower than that of drug and endoscopic treatment (20.5%-60.6%), drug and endoscopic treatment is still the first choice for secondary prevention and TIPS is the second-line option due to the lack of adequate clinical study data on the survival rate of TIPS in recent years.
（The average survival of patients with refractory ascites is about 6 months. tIPS is the first-line treatment option for refractory ascites, which not only reduces portal vein pressure and relieves ascites, but more importantly improves urinary sodium excretion and renal function. tIPS relieves ascites and improves survival better than laparotomy for fluid release.
(iii) Refractory hepatic pleural effusion TIPS can relieve refractory hepatic pleural effusion and reduce the number of thoracentesis required, but the impact on survival is unclear. Due to the lack of effective measures for refractory hepatic pleural effusions, TIPS is still considered an important treatment for refractory hepatic pleural effusions.
(iv) Hepatorenal syndrome (HRS) The median survival time of HRS is only 3 months, including I months for untreated type I HRS. TIPS may improve renal function by increasing renal perfusion, which may improve the survival of patients with type 2 HRS.
(v) Buga syndrome (BCS) BCS is a post-hepatic portal hypertension caused by obstructive lesions of the hepatic venous outflow tract and the inferior vena cava of the posterior hepatic segment from various causes. TIPS is usually not required for short-range occlusion of the hepatic vein or inferior vena cava with high long-term patency rate by balloon dilation or combined with stent implantation; TIPS establishes an artificial shunt through the portal vascular bed to reduce portal pressure and improve liver stasis and liver function, and is suitable for patients for whom medical treatment or angioplasty has failed.
(vi) Portal vein thrombosis (PVT) PVT is a common complication of portal hypertension in cirrhosis, the incidence can be as high as 36%, and its mechanism involves the decrease of portal blood flow velocity and imbalance of coagulation function due to portal hypertension in cirrhosis. PVT not only aggravates the already existing portal hypertension, but also reduces liver perfusion and impairs liver function, and untreated can form extensive occlusion of portal vein and spongiosis. TIPS can not only open the portal vein, reduce its pressure and increase its flow rate, but also prevent the recurrence of PVT.
1. Absolute contraindication: unproven portal hypertension in cirrhosis.
Relative contraindications: ①Child-Pugh score>13; ②renal insufficiency; ③severe right heart failure; ④moderate pulmonary hypertension; ⑤severe coagulation disorder; ⑥uncontrolled intrahepatic or systemic infection; ⑦biliary obstruction; ⑧polycystic liver; ⑨extensive primary or metastatic liver malignancy; ⑩portal vein cavernous lesions.
3. TIPS operation procedure (a) Preoperative preparation 1. elective TIPS (selectiveTIPS): routine blood and urine, liver and kidney function, blood glucose, electrolytes and coagulation function are all preoperative basic tests. Enhanced CT or MRI of abdomen is an important examination to understand the condition of liver, portal vein and hepatic vein, which helps to assess the degree of opening of collateral circulation of portal vein geniculate branches and to understand the presence of thrombosis and portal vein spongiosis. The detection of the etiology of cirrhosis is beneficial to the cause-specific treatment before and after TIPS. Severe anemia, severe platelet reduction or coagulation dysfunction should be improved as much as possible.
2. Salvage TIPS (salvageTIPS): In case the bleeding cannot be stopped by medication or endoscopic treatment. When the indication for surgery is lost, a three-lumen double-bladder tube can be used to temporarily compress the hemorrhage to create conditions for salvage TIPS and complete the above examination as much as possible.
3. Doctor-patient communication: Before implementing TIPS, the operating physician should explain in detail to the patient and family the necessity of TIPS, the expected results and possible surgical complications, and the patient’s designated delegate should sign an informed consent form.
(B) TIPS routine operation techniques 1. TIPS puncture kits: Ring and Rosch-Uchida are the 2 most commonly used TIPS puncture kits at present, and their components and operation methods are similar, the main difference is the matching puncture needle. There is no significant difference in the success rate and complications between the two puncture kits, and the operating physician can choose according to his personal experience.
2. Vascular route: The TIPS operation route is generally chosen from the right internal jugular vein, which can provide a straighter and smoother path and facilitate the operation. If necessary, the internal jugular vein can be punctured under ultrasound guidance to avoid injury to the internal carotid artery or complications such as pneumothorax. The left internal jugular vein, right external jugular vein or subclavian vein can also be chosen when the right internal jugular vein is obstructed or the puncture is not smooth.
3. Hepatic vein cannulation: A balloon catheter is inserted into the hepatic vein and the hepatic venous pressure gradient (HVPG) is measured to clarify the diagnosis. The TIPS kit is inserted into the hepatic vein, usually the right or middle hepatic vein is chosen, the left hepatic vein is smaller and almost perpendicular to the inferior vena cava and is not usually chosen. Hepatic venography is performed to confirm the location, exchange the balloon catheter or wedge the catheter into the liver parenchyma, and perform CO2 imaging to help understand the portal vein anatomy.
4. Portal vein puncture: The right branch of the portal vein is usually located anterior to the right hepatic vein and posterior to the middle hepatic vein, whereas the left branch of the portal vein is located anterior to the middle hepatic vein and posterior to the left hepatic vein. Based on the preoperative imaging data or intraoperative CO2 imaging to guide portal vein puncture, the puncture target should be selected within 2 cm of the portal vein bifurcation and the intrahepatic portal vein branches.
After the catheter is withdrawn from the portal vein, a small amount of contrast is injected to clarify the location of the puncture, and the catheter is exchanged with an attractive guidewire, and the portal vein pressure is measured and the portal pressure gradient (PPG) is calculated.
5. Stent implantation: After portal venography, a balloon catheter of 4-8 cm in length and 8-10 mm in diameter is selected to dilate the intrahepatic shunt. The 2 indentations (indentation) on the balloon during expansion represent the distance between the hepatic vein and portal vein, i.e. the length of the shunt tract, and a 8-10 mm diameter PTFE-coated stent is placed. The venous end of the stent should be continued to the confluence of the hepatic vein and the inferior vena cava.
After stent placement, portal venography is repeated and post-TIPS PPG is measured; a postoperative PPG of <12 mmHgdmmHg (133 kPa) or a 25% decrease from baseline is generally recommended.
(iii) TIPS extended technique is a supplement to conventional TIPS, which can improve its effectiveness, increase the success rate of special cases and expand the indications.
TIPS supplemented with endovascular embolization of varices: A recent prospective controlled clinical study showed that TIPS supplemented with endovascular embolization of esophagogastric varices significantly improved stent patency at 6 months (96.2% vs. 82.0%) and reduced the 2-year rebleeding rate (29.0% vs. 47.0%) compared with single TIPS.
2. Direct portal shunt via inferior vena cava (DIPS): A transjugular puncture needle is delivered to the inferior vena cava of the hepatic segment, a direct puncture is made through the inferior vena cava of the hepatic segment, a puncture is made through the parenchyma of the caudate lobe to the portal vein, and a stent is placed in the parenchyma of the caudate lobe to establish a lateral-lateral portal shunt through the caudate lobe. This technique is suitable for patients with portal hypertension who have atrophied or occluded hepatic veins or who have difficulty finding them.
IV. Complications of TIPS Complications of TIPS are mainly related to operation and shunt, as shown in Table 1.
Most of the operation-related complications can be alleviated by symptomatic management, and the incidence of fatal complications is 0.6%-4.3%. Intraoperative ultrasound, CO2 angiography, and other adjunctive guidance modalities can further reduce the incidence of such complications.
Shunt failure is mostly due to acute in-stent thrombosis and pseudoendothelial hyperplasia. Prevention of acute thrombosis is described in detail in postoperative management. Pseudoendoplasia within the stent, unsmooth shunt surfaces, long-term irritation and damage to the liver parenchyma and hepatic veins from high-velocity blood flow, and poor biocompatibility of the stent itself are associated.
The problem of shunt failure once caused the clinical application of TIPS to be at a low point. With advances in stent construction and materials, the problem of shunt failure has been greatly improved. A randomized controlled clinical study concluded that Teflon-coated stents significantly reduced I-year shunt failure compared to bare stents (10% vs. 50%), and TIPS with simultaneous embolization of abnormal collateral circulation also helped maintain shunt patency.
The incidence of hepatic encephalopathy is positively correlated with the patient’s preoperative liver function Child-Pugh score and shunt diameter; therefore, the Child-Pugh classification should be selected for elective surgery whenever possible. v. Postoperative management of TIPS 1. Postoperative anticoagulation: Acute thrombosis is mostly formed 24 h after surgery, which can be confirmed by ultrasonography or angiography and is associated with bile leak, hypercoagulable state and improper stent selection. Although the postoperative anticoagulation regimen lacks evidence from clinical studies, most scholars suggest that short-term postoperative anticoagulation, such as low-molecular heparin, can reduce the occurrence of acute thrombosis. The use of postoperative drugs such as antiplatelet is also subject to further clinical studies.
1.Ultrasound is the preferred method to follow up the shunt tract after TIPS. Portal venography can confirm the diagnosis of shunt tract failure, and the management measures mainly include balloon dilation, stent implantation or parallel TIPS.
2, hepatic encephalopathy: TIPS postoperative hepatic encephalopathy mostly occurs within six months after surgery, in addition to the patient’s preoperative liver function status, but also with postoperative infection, constipation, inappropriate use of drugs, excessive protein intake and increased brain perfusion in the short term after surgery and other factors, mostly benign, can be recovered by conventional medical management.
3. The successful application of TIPS requires the advantages of gastroenterology in patient selection, perioperative management and postoperative follow-up management. Gastroenterology physicians should continue to incorporate vascular mediator knowledge in the process of cirrhosis diagnosis and treatment. When TIPS is successfully rooted in the gastroenterology department, patients with cirrhotic portal hypertension will benefit significantly.