1. To appreciate the role of multidisciplinary treatment of portal hypertension.
2. To learn about imaging and intervention in portal hypertension.
3. To discuss outcomes of interventions in portal hypertension.
Portal hypertension is characterized by high pressure in the hepatic portal venous circulation. Clinically significant portal hypertension is diagnosed when the hepatic venous pressure gradient (HVPG) exceeds 10 mmHg. It may be caused by hepatic, pre-hepatic or post-hepatic aetiologies. Diagnostic radiology plays a crucial role in establishing the aetiology, identifying complications and in planning management. Interventional radiology (IR) plays a major role in both the diagnostic and therapeutic management of portal hypertension. HVPG measurement is a minimally invasive IR technique that establishes the diagnosis of portal hypertension. Different therapeutic IR procedures may be used in different clinical scenarios and have replaced more invasive open surgical techniques. The hepatobiliary radiologist is a key player in the multidisciplinary team caring for patients with portal hypertension. The imaging findings of portal hypertension and the different IR procedures used in this condition will be discussed during this session. Emphasis will be made on the practical aspects of interventional radiology procedures, including transjugular intrahepatic portosystemic shunt (TIPS), variceal embolization, splenic artery embolization and balloon-occluded retrograde transvenous obliteration (BRTO) - including their indications, methodology, complications, and clinical outcomes.
1. To appreciate imaging features of portal hypertension.
2. To discuss the appropriate choice and timing of imaging technique in investigation of portal hypertension
and its complications.
3. To learn about relevant findings that influence therapy choice in portal hypertension.
Portal hypertension (PH) represents a fearful complication of several diseases (most frequently liver cirrhosis), associated with high morbidity and mortality. Definitive diagnosis of PH is based on the measurement of hepatic venous pressure gradient (HVPG). PH is diagnosed by measuring a HVPG higher than 5 mmHg, it is considered clinically significant when HVPG is higher than 10 mmHg and severe when HVPG is above 12 mmHg. A direct relation has been demonstrated between HVPG and risk of variceal bleeding, hepatic decompensation and liver related mortality, and HVPG has become a surrogate endpoint in the assessment of treatment response and reduction of risk of liver-related mortality. However, HVPG measurement is invasive, is not routinely available and it is reliably standardized only in expert centers. Thus, non-invasive methods, such as elastography, are under investigation, in the attempt to diagnose and grade PH, and to predict presence, extent and risk of variceal bleeding. Non-invasive imaging, such as ultrasound (US), computed tomography (CT) and magnetic resonance imaging (MR) may enable diagnosis of PH through the identification of complications (such as varices, splenomegaly, ascites). The anatomic information provided by these imaging modalities becomes essential to identify the causes of PH and when treatment planning is required (such as in patients indicated for TIPS or candidate for liver transplantation). Imaging plays a crucial role also to assess response to treatment and post-treatment complications.
1. To discuss the rationale for embolisation.
2. To learn about the selection of technique and choice of material.
3. To understand outcomes from embolisation techniques.
Portal hypertension is most common secondary to liver cirrhosis, however it can also be caused by portal/splenic vein thrombosis or occlusion. A bleeding secondary to portal hypertension, usually originates from esophageal or gastric varices, other sites may be duodenal, stomal or rectal varices. A bleeding from esophageal varices is primarily most often treated endoscopically with sclerotherapy or rubber banding. Gastric varices are less prevalent, but more difficult to treat endoscopically. If medical and endoscopic treatment methods fail, interventional treatment is the next option, which includes embolisation of varices, TIPS, BRTO and partial splenic arterial embolisation. Embolisation of varices may be performed by percutaneous or transjugular-transhepatic approach, but transsplenic route or direct puncture of the stomal varices are also reported. A BRTO may be applied in patients with a splenorenal shunt and secondary gastric varices. Partial splenic embolisation may decrease inflow of blood to the portal vein and secondary decrease the portal hypertension. In most cases a combination of different techniques is necessary to achieve good results.
1. To discuss the selection of patients for TIPS.
2. To learn about the techniques for TIPS formation.
3. To discuss outcomes of TIPS and role of imaging surveillance.
TIPS is a minimally invasive method of creating a portosystemic shunt for decompression of portal hypertension (PH). A side-to-side shunt of determined diameter is created to shunt blood flow from the portal vein (PV) to hepatic vein or inferior vena cava above the liver using transjugular approach, long needle, balloon angioplasty, and stent-graft. The most often indication for TIPS is cirrhotic ascites, which is sometimes combined with severe hydrothorax. However, TIPS is used in those patients who are intolerant of repeated large-volume paracenthesis. TIPS has been used as a rescue treatment in rare cases of endoscopically uncontrollable variceal bleeding, especially from gastric fundal varices. Emergent TIPS (in 72 hours) performed in patients with severe PH and high risk of early rebleeding, has been proved to have better bleeding control and survival in 1 year. Partial or complete PV thrombosis does not change usual technique of TIPS. TIPS is technically difficult in chronic extrahepatic PV obstruction, in children, and in patients with massive hepatic veins thrombosis (Budd-Chiari Syndrome - BCS). The absence of hepatic veins and distorted anatomy due to the caudate lobe hypertrophy requires sometimes direct transcaval approach to the PV in patients with BCS. Moreover, these patients must be anticoagulated life long due to underlying hypercoagulopathy. TIPS demonstrated good control of ascites and reversal of liver failure in large series of patients with BCS. All patients with TIPS must be followed regularly in specialized multidisciplinary center, and the surveillance of TIPS function is mandatory.