What are the effects and management of portal hypertension?

Portal Hypertension: Effects and Management

Portal hypertension is a pathological increase in portal pressure that leads to severe complications including variceal bleeding, ascites, and hepatic encephalopathy, significantly impacting morbidity, mortality, and quality of life. Understanding its pathophysiology and implementing appropriate management strategies are crucial for improving patient outcomes.

Pathophysiology

Portal hypertension results from increased resistance to portal blood flow and can be classified based on the anatomic location of obstruction:

• Prehepatic: Involving the splenic, mesenteric, or extrahepatic portal vein
• Intrahepatic: Most commonly due to cirrhosis (predominant cause in Western countries)
• Posthepatic: Diseases blocking hepatic venous outflow 1

The development of portal hypertension involves:

• Fixed structural changes: Distortion of liver microcirculation by fibrosis, angiogenesis, nodule formation, and vascular occlusion
• Dynamic changes: Increased vascular tone from vasodilators and vasoconstrictors affecting hepatic vasculature 1
• Portal-systemic collateral formation: Bypassing the liver and diverting portal blood to systemic circulation 1, 2

Clinical Manifestations and Complications

1. Gastrointestinal Complications

• Variceal bleeding: Most frequent and life-threatening complication 2

  • Develops from esophageal, gastroesophageal, and isolated gastric varices
  • Occurs when portal-systemic gradient exceeds 12 mmHg 3
  • 30% of cirrhotic patients develop bleeding with 30-day mortality of 20% 3

• Portal hypertensive gastropathy: Causes chronic bleeding and iron-deficiency anemia

  • Diagnosed by snake-skin appearance or mosaic pattern on endoscopy 2

• Other GI manifestations: Portal hypertensive enteropathy and colopathy 2

2. Ascites

• Most common complication in cirrhotic patients
• Nearly 60% of patients develop ascites within a decade of compensated cirrhosis diagnosis
• Heralds onset of decompensation with survival decreasing from 80% to 50% at 5 years 1
• Can be classified as:
  • Grade 1: Mild, only detectable by ultrasound
  • Grade 2: Moderate symmetrical distension
  • Grade 3: Large marked distension 1

3. Hepatic Encephalopathy

• Occurs in more than 10% of all cirrhosis cases 2
• Results from liver's inability to clear toxic chemicals like ammonia
• Presents as confusion, drowsiness, and potentially coma 1

4. Hepatorenal Syndrome (HRS)

• Frequent complication of refractory ascites
• Results from arterial vasodilation in splanchnic circulation triggered by portal hypertension
• Two types: progressive severe type 1 and more constant type 2 associated with refractory ascites 1

5. Other Complications

• Vascular: Recurrent thrombosis in splanchnic area 2
• Biliary: Portal cholangiopathy causing compression of bile ducts 2

Diagnosis

1. Clinical assessment: Consider portal hypertension in patients with features of hypersplenism, risk for portal vein thrombosis, or unexplained abdominal pain 2

2. Imaging studies:

   • Doppler ultrasound
   • CT or MR imaging with vascular contrast agents 2

3. Hemodynamic measurement:

   • Hepatic venous pressure gradient (HVPG)
   • Clinically significant portal hypertension defined as HVPG ≥10 mmHg 2

4. Endoscopy: To detect and assess varices

Management

Management depends on the stage of portal hypertension and specific complications:

1. Patients with Mild Portal Hypertension (HVPG >5 but <10 mmHg)

• Focus on treating underlying liver disease
• Non-selective beta-blockers (NSBBs) are generally ineffective at this stage 1

2. Patients with Clinically Significant Portal Hypertension (HVPG ≥10 mmHg)

• Goal is to prevent decompensation
• NSBBs may be beneficial to lower portal pressure 1, 2

3. Management of Variceal Bleeding

• Acute bleeding:

  • Resuscitation
  • Combination of vasoactive drugs and endoscopic band ligation 1
  • Transjugular intrahepatic portosystemic shunt (TIPS) for refractory bleeding 1

• Prevention of first bleeding:

  • NSBBs for patients with high-risk varices
  • Endoscopic band ligation for those with contraindications to NSBBs 1

• Prevention of rebleeding:

  • Combined therapy with NSBBs plus endoscopic band ligation 1
  • Elective TIPS for treatment failures 1

4. Management of Ascites

• Salt restriction (<90 mmol/day)
• Diuretic therapy (spironolactone up to 400 mg/day and furosemide up to 160 mg/day) 1
• Large volume paracentesis for grade 3 ascites
• TIPS for refractory ascites 1

5. Management of Hepatic Encephalopathy

• Medical therapy for most cases
• May require TIPS occlusion in severe cases 1

6. Special Considerations for TIPS

• Effective for:
  • Acute variceal bleeding unresponsive to other treatments
  • Prevention of variceal rebleeding
  • Management of refractory ascites or hydrothorax 1
• Contraindicated in patients with severe liver disease who cannot tolerate the procedure 1
• Risk of hepatic encephalopathy in approximately one-third of patients 1

Monitoring and Follow-up

• Screen for gastroesophageal varices in patients with unrecanalised portal vein 2
• Perform MR cholangiography in patients with persisting cholestasis 2
• Regular assessment of liver function and complications

Portal hypertension management requires a multidisciplinary approach involving hepatologists, interventional radiologists, and gastroenterologists to address the various complications and improve patient outcomes.