Introduction:
Radiologists are highly involved in the diagnostic and treatment planning of portal hypertension. However, due to innovations in radiology, various minimally invasive procedures for managing portal hypertension have been introduced. It includes shunt formation, variceal hemorrhage control, and recanalization approaches. These innovations made radiologists play an important role in treating portal hypertension.
What Is Portal Hypertension?
Portal hypertension is a rise in blood pressure that occurs within the portal venous system, a network of veins. The portal vein, which divides into smaller vessels and passes through the liver, is formed when the veins from the stomach, intestine, spleen, and pancreas combine. Blood cannot flow through the liver normally if liver disease has blocked its arteries. High pressure consequently arises within the portal system. The development of big veins called varices in the esophagus, stomach, rectum, or umbilical region (belly button) may result from this elevated pressure in the portal vein. Varices have the ability to burst and bleed, leading to serious consequences.
What Are the Novel Methods in Interventional Radiology for Portal Hypertension?
The several portal vein interventions fall under the following general categories:
Radiological interventions that decrease portal hypertension:
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Transjugular intrahepatic portosystemic shunts (TIPS).
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Hepatic venous outflow recanalization.
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Recanalization of the tributaries and the obstructed portal vein.
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Partial splenic embolization.
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Correction of radiologically or surgically blocked portosystemic shunts.
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Arterioportal fistula embolization.
Radiological interventions to reduce portal hypertension symptoms:
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Balloon retrograded transvenous obliteration of gastric varices (BRTO).
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Percutaneous transhepatic variceal embolization.
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Percutaneous peritoneovenous shunt.
The radiological interventions that decrease portal hypertension are described below:
1. Transjugular Intrahepatic Portosystemic Shunts (TIPS):
With TIPS, an intrahepatic stent is inserted to create a low-resistance channel connecting the portal vein and hepatic vein. Depending on the patient's health, either conscious sedation or general anesthesia is used during the procedure, which is guided by fluoroscopic and ultrasound images.
TIPS is indicated for the treatment of patients with cirrhosis (liver disorder) and portal hypertension who have refractory ascites (fluid built up in the abdomen) and refractory variceal hemorrhage. Other indications include Budd-Chiari syndrome (a disease where the veins draining the liver become clogged or narrowed) and refractory acute bleeding varices (inability to manage bleeding or ineffectiveness of additional prophylaxis).
Procedure-related immediate complications include hematoma (bleeding outside blood vessels), arrhythmia (irregular heartbeat), stent displacement, biliary tract infection, and shunt thrombosis (formation of a blood clot in the blood vessel). Congestive heart failure, portal vein thrombosis, and TIPS malfunction (blockage of the shunt) are examples of chronic consequences.
2. Hepatic Venous Outflow Recanalization:
A diverse collection of conditions known as Budd-Chiari syndrome (BCS) is defined by hepatic venous blockage at the level of the hepatic veins, the inferior vena cava (IVC), or the right atrium. Depending on the degree and severity of obstruction as well as the sufficiency of residual collateral circulation, the symptoms might vary from immediate liver failure to persistent liver disease.
3. Recanalization of the Tributaries and the Obstructed Portal Vein:
Five to ten percent of instances of PHT are caused by a localized PHT that is caused by blockage of the portal vein or one of its tributaries. Patients typically have a variceal hemorrhage, ascites, or stomach pain when they have blockage, which can have either a benign or malignant etiology. These symptoms can be lessened by recanalization of the clogged vein with angioplasty (a procedure performed to open the blocked blood vessels) and stenting.
4. Partial Splenic Embolization:
PSE is used to lower blood flow into the portal vein, which also decreases the portal venous pressure. The intrasplenic artery branches are catheterized and embolized during the surgery. By doing this, the splenic size is decreased, the portal vein pressure is lowered, and the thrombocytopenia (decreased platelet count) brought on by hypersplenism (highly active spleen) is improved. Treatment outcomes are favorable, and the likelihood of major side effects is minimal when using the current methods.
5. Correction of Radiologically or Surgically Blocked Portosystemic Shunts:
Portosystemic shunts are created surgically to treat portal hypertension. Sometimes, these shunts will be blocked by thrombosis. Such instances are difficult to treat surgically and have a significant morbidity rate. Through the endovascular approach, occluded shunts can be effectively recanalized.
6. Arterioportal Fistula Embolization:
APFs, or arterioportal fistulae, are an uncommon source of pulmonary hypertension. They could be inherited or the result of liver cancers, percutaneous biopsies, trauma, surgery, or other liver treatments. Some patients with large APFs may present with signs of PHT, including bleeding, ascites, and splenomegaly (enlarged spleen), even though they are usually asymptomatic. Transarterial embolization of the feeding artery with adhesive, removable balloons, or coils is the chosen course of treatment.
The radiological interventions that reduce the symptoms of portal hypertension are described below:
1. Percutaneous Transhepatic Variceal Embolization (PTE):
PTE, the first technique used for portal hypertension, is a means of treating refractory variceal hemorrhage. A remarkable 70 to 90 percent initial rate of success was reported in later research. These trials showed a 30 to 65 % recurrent bleeding incidence since the surgery by itself did not treat the underlying problems of portal hypertension. The operation was then advised in acute situations where balloon tamponade, vasopressin infusion, and endoscopic sclerotherapy failed to reduce variceal bleeding. Additionally, it might be applied to the treatment of bleeding stomach varices that are challenging to locate with endoscopy.
2. Balloon Retrograded Transvenous Obliteration of Gastric Varices (Brto):
BRTO is a procedure that is frequently used to address gastric varices through a gastrorenal shunt. A balloon catheter is inserted through the femoral vein towards the gastrorenal shunt outlet as part of this procedure. Then, using a balloon catheter, a sclerosant combined with contrast is delivered into the varices. For sufficient thrombosis to take place in the varices, the angiographic balloon must remain inflated for some time, ranging from one to 24 hours. The balloon is deflated, the catheter is taken out, and the hemolyzed blood with the leftover sclerosant is aspirated after giving the thrombi time to develop. After two to four days, a CT (computed tomography) scan is done to assess the prompt reaction. Depending on various patient characteristics, a follow-up CT scan or endoscopy is performed every three to six months.
3. Percutaneous Peritoneovenous Shunt:
TIPS has largely superseded surgical peritoneovenous shunts in most locations. However, they are still available to patients who are unable to cope with TIPS. Due to the use of local anesthetic, radiologists can now perform the shunt insertion technique with fewer complications. Additionally, with USG (ultrasonogram) guidance, venous entrance puncture is potentially more accurate, and access is simpler.
Conclusion:
There are numerous treatment options available for individuals with portal hypertension. Depending on the cause, symptoms, and individual’s overall health condition, the suitable treatment method will be decided. If individuals experience any of the symptoms associated with portal hypertension, consult the doctor right away and determine the treatment method as soon as possible to prevent the complications.
