Portal hypertension is an important pathophysiological link in the development of cirrhosis and one of the key clinical manifestations of cirrhosis in the decompensated phase. Transjugular intrahepatic portal vein shunt (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, which significantly reduces 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) Esophageal and gastric variceal bleeding (EGVB)
The incidence of esophageal and gastric variceal bleeding 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 esophageal and gastric varices.
1. Acute EGVB: The morbidity and mortality rate of patients within 6 weeks is about 20%, and resuscitation treatment 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.
① remedial TIPS, which is a second-line option for failed drug combined with endoscopic treatment.
②Early 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 cirrhosis Child-Pugh grade C, but with a score <13, may benefit more from early tips. < span="">
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% over 1-2 years and the morbidity and mortality rate can be 33%, thus all patients recovering from acute bleeding should receive secondary prophylaxis.
Although the rebleeding rate of varicose veins after TIPS (9,0%-40,6%) is significantly lower than that of drug and endoscopic therapy (20,5%-60,6%), drug and endoscopic therapy are 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.
(ii) Refractory ascites (refractoryascites)
The average survival of patients with refractory ascites is about 6 months, and TIPS is the first-line treatment option for refractory ascites, not only to reduce portal pressure and relieve ascites, but also to improve urinary sodium excretion and renal function, and TIPS is better than laparotomy to relieve ascites and improve survival.
(iii) Refractory hepatic hydrothorax (refractory hepatic pleural effusion)
TIPS can relieve refractory hepatic hydrothorax 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) hepatorenalsyndrome (HRS)
The median survival time for HRS is only 3 months, including I months for untreated type I HRS. TIPS may improve renal function by increasing renal perfusion and may improve survival in patients with type 2 HRS.
(V) Budd-Chiarisyndrome (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, with an incidence of up to 36%, and its mechanism involves decreased portal flow velocity and imbalance of coagulation due to portal hypertension in cirrhosis. TIPS can not only open the portal vein, reduce its pressure and increase its flow rate, but also prevent the recurrence of PVT.
Second, TIPS contraindications
1.Absolute contraindication: unproven portal hypertension in cirrhosis.
2. 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.
III. 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 the abdomen is an important examination to understand the condition of the liver, portal vein and hepatic vein, which is helpful to assess the degree of opening of the collateral circulation of the portal vein branches, and to understand the presence of thrombosis and portal vein sponge-like changes. 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): When the hemorrhage cannot be stopped by drugs or endoscopic treatment and 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 to 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 two most commonly used TIPS puncture kits at present, their components and operation methods are similar, the main difference is the matching puncture needle. There is no significant difference between the two puncture kits in terms of surgical success rate and complications, and the operating physician can choose according to his personal experience.
2.Vascular route: The TIPS operation route is generally chosen for 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 hepaticvenous pressure gradient (HVPG) is measured to clarify the diagnosis. The hepatic vein is usually selected as the right or middle hepatic vein, while the left hepatic vein is smaller and almost perpendicular to the inferior vena cava, which is usually not chosen. Hepatic venography is used 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 portal vein is usually located in front of the right hepatic vein and behind the middle hepatic vein, while the left branch of portal vein is located in front of the middle hepatic vein and behind the left hepatic vein. According to the preoperative imaging data or intraoperative CO2 imaging to guide the portal vein puncture, the puncture target should be selected within 50px of the portal vein bifurcation of the intrahepatic portal vein branches.
After the catheter retracts the portal blood, inject a little contrast agent to clarify the puncture location, draw the guidewire to exchange the catheter, and measure the portal pressure and calculate the portalpressuregradient (PPG).
5.Stent implantation: After portal venography, a balloon catheter of 4-200 px in length and 8-10 mm in diameter is selected to dilate the intrahepatic shunt. The 2 depressions (indentations) on the balloon during expansion represent the distance between the hepatic and portal veins, 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 performed again 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
It is a supplement to conventional TIPS, which can improve its effectiveness, increase the success rate of special cases and expand the indications.
1, 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 within 6 months (96,2% vs. 82,0%) and reduced the 2-year rebleeding rate (29,0% vs. 47,0%) compared with single TIPS.
2.directintra-hepaticportocavalshunt (DIPS): The transjugular venous puncture needle is delivered to the inferior vena cava of the hepatic segment, the inferior vena cava of the hepatic segment is punctured directly through the caudate lobe parenchyma to the portal vein, and the stent is placed in the caudate lobe parenchyma to establish a lateral-lateral portal shunt through the caudate lobe. This technique is suitable for patients with portal hypertension who have hepatic vein atrophy, occlusion or difficulty in finding it.
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 that simultaneous embolization of abnormal collateral circulation with TIPS 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, 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 related to bile leakage, hypercoagulable state and improper stent selection. Although there is a lack of clinical research evidence for postoperative anticoagulation treatment plan, 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.
Ultrasonography 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.