What is the treatment plan for a patient admitted with right portal vein thrombosis?

Management of Right Portal Vein Thrombosis

Immediate anticoagulation with low-molecular-weight heparin (LMWH) is recommended as first-line treatment for patients admitted with right portal vein thrombosis. 1

Initial Assessment and Diagnosis

• Evaluate the extent of thrombosis using Doppler ultrasound as first-line investigation, followed by CT scan for confirmation and assessment of extension 1
• Determine if the patient has underlying cirrhosis or other liver disease 1
• Assess for signs of intestinal infarction (severe abdominal pain, rectal bleeding, ascites, or multiorgan dysfunction) which requires urgent intervention 1
• Rule out neoplastic portal vein thrombosis if there is underlying hepatocellular carcinoma using contrast-enhanced imaging 1
• Consider screening for underlying genetic thrombophilic conditions 1

Anticoagulation Therapy

Immediate Treatment

• Start LMWH at therapeutic dose immediately in the absence of major contraindications 1
• For patients with cirrhosis, implement adequate prophylaxis for gastrointestinal bleeding before starting anticoagulation 1
• Monitor anti-Xa activity in overweight patients, pregnant patients, and those with poor kidney function 1

Anticoagulation Options

• For patients without cirrhosis or with Child-Pugh A/B cirrhosis: LMWH, vitamin K antagonists (VKA), or direct oral anticoagulants (DOACs) are all reasonable options 1
• For patients with Child-Pugh C cirrhosis: LMWH alone is preferred (or as bridge to VKA in patients with normal baseline INR) 1
• Screen for heparin-induced thrombocytopenia (HIT) in patients with sudden unexplained platelet count fall ≥50% or to <150×10^9/L, especially with unfractionated heparin 1

Duration of Treatment

• Continue anticoagulation for a minimum of 6 months 1
• For patients awaiting liver transplantation, continue anticoagulation until transplant 1
• For patients with superior mesenteric vein thrombosis or history of intestinal ischemia, consider lifelong anticoagulation 1
• After portal vein recanalization, consider prolonging anticoagulation to prevent rethrombosis, as recurrence rates up to 38% have been reported when anticoagulation is stopped 1

Monitoring Response

• Perform cross-sectional imaging every 3 months to assess response to treatment 1
• Recanalization of the portal vein can be expected to occur up to 6 months after starting treatment 1
• If clot regresses, continue anticoagulation until resolution or transplantation 1
• Time interval between diagnosis and start of anticoagulation less than 6 months is the most important factor predicting successful recanalization 1

Management of Portal Hypertension

• Screen for esophageal varices before initiating anticoagulation 1
• Use either beta-blockers or band ligation to prevent variceal bleeding in patients with varices 1
• Be aware that over half of patients (55%) not achieving recanalization will develop gastroesophageal varices during follow-up 1

Advanced Interventions

• Consider transjugular intrahepatic portosystemic shunt (TIPS) for:
  • Liver transplant candidates with progressive PVT not responding to anticoagulation 1
  • Patients with additional indications such as refractory ascites or variceal bleeding 1
• Avoid local thrombolysis due to high risk of major bleeding complications (reported in 50% of treated patients) 1
• Surgical thrombectomy has limited success (30% recanalization) and high recurrence rates 1

Cautions and Complications

• Overall bleeding complications with anticoagulation occur in approximately 5-14% of patients 1, 2
• Risk factors for bleeding include history of variceal bleeding, low serum albumin, and platelet count less than 50×10^9/L 1, 2
• Severe portal biliopathy can develop in 30% of patients with acute PVT within 1 year 1
• Patients with advanced liver cirrhosis and history of variceal bleeding should be carefully evaluated before anticoagulation 2

By following this treatment algorithm, the goal is to achieve portal vein recanalization, prevent extension of thrombosis, and reduce the risk of complications such as intestinal infarction and worsening portal hypertension 3.