What is the treatment for portal vein thrombosis?

Treatment of Portal Vein Thrombosis

Anticoagulation with low-molecular-weight heparin (LMWH) should be initiated immediately for portal vein thrombosis that is recent (<6 months), involves >50% occlusion of the main portal vein, or extends to mesenteric vessels, as this achieves 71% recanalization rates and reduces mortality without significantly increasing variceal bleeding risk. 1, 2

Immediate Triage and Risk Assessment

Start anticoagulation urgently if the patient presents with:

• Abdominal pain out of proportion to examination findings 2
• Elevated lactate or sepsis 2
• Imaging showing mesenteric fat stranding or dilated bowel loops 2
• These signs indicate impending intestinal ischemia, which carries 10-20% mortality 2

Do not delay anticoagulation while waiting for endoscopy - delays decrease recanalization rates, and endoscopy can be performed after starting treatment 2

Indications for Anticoagulation

Anticoagulation is indicated for 1, 2:

• Acute complete occlusion of the main portal vein
• Recent (<6 months) thrombosis with >50% occlusion of the portal vein trunk
• Progression of thrombus on short-term follow-up (1-3 months)
• Superior mesenteric vein involvement
• Symptomatic PVT (abdominal pain, intestinal ischemia)
• All patients awaiting liver transplantation with PVT, regardless of extent 1

Observation alone is appropriate for 2:

• Intrahepatic portal vein branch involvement only
• <50% occlusion without progression
• Spontaneous recanalization occurs in 40% of these cases

Variceal Screening Before Anticoagulation

Screen for esophageal varices immediately, but do not delay anticoagulation 3, 2:

• Perform gastroscopy as soon as possible after starting anticoagulation 2
• If high-risk varices are present, ensure adequate prophylaxis with nonselective beta-blockers (propranolol, nadolol, or carvedilol) or band ligation 3, 2
• The presence of varices is not a contraindication to anticoagulation 2

Anticoagulant Selection by Cirrhosis Severity

Child-Pugh Class A or B Cirrhosis

Use DOACs, LMWH, or VKA - all are reasonable options 1, 3:

• DOACs are preferred due to convenience, no INR monitoring required, and comparable or superior recanalization rates 2
• LMWH at therapeutic dose (e.g., enoxaparin 1 mg/kg twice daily or dalteparin 200 U/kg daily) 4, 5
• VKA (warfarin) can be used for maintenance 1

Child-Pugh Class C Cirrhosis

Use LMWH alone (or as bridge to VKA if baseline INR is normal) 1, 3:

• DOACs carry increased bleeding risk in decompensated disease 2
• LMWH is the safest option in advanced cirrhosis 1

Initial Therapy

Start with LMWH or unfractionated heparin for acute presentations 1, 3:

• LMWH is preferred for initial treatment 1, 3
• Can transition to VKA or DOAC for maintenance in Child-Pugh A/B 1

Duration of Anticoagulation

Minimum 6 months of treatment for all symptomatic or progressive PVT 1, 6:

• Continue until transplantation in liver transplant candidates 1, 3
• Continue until complete recanalization in non-transplant candidates 2
• Consider lifelong anticoagulation if superior mesenteric vein involvement, history of intestinal ischemia, or inherited thrombophilia 1, 2
• Recurrence rates reach 38-56.6% after anticoagulation withdrawal 1, 4

Monitoring Response to Treatment

Perform cross-sectional imaging (CT or MRI) every 3 months to assess treatment response 3, 2:

• Complete recanalization occurs in 33-75% of patients 4, 5, 7
• Partial recanalization occurs in 50% 5
• Recanalization can take up to 6-11 months 3, 8
• Time from diagnosis to anticoagulation <6 months is the most important predictor of successful recanalization 3

Bleeding Risk and Contraindications

Bleeding complications occur in 5-14% of patients on anticoagulation 3, 4, 7:

Risk factors for bleeding include 3, 4:

• History of variceal bleeding
• Low serum albumin
• Platelet count <50×10⁹/L
• Child-Pugh class C cirrhosis

Absolute contraindications 3:

• Active bleeding
• Major bleeding within the last 3 months
• Severe thrombocytopenia (<50×10⁹/L)
• Impaired renal function (for LMWH)

Reassess bleeding risk every 6 months and withdraw anticoagulation if active bleeding or significant increase in bleeding risk 1

Advanced Interventions

Consider TIPS (transjugular intrahepatic portosystemic shunt) for 3, 2:

• Liver transplant candidates with progressive PVT not responding to anticoagulation
• Patients with additional indications (refractory ascites, variceal bleeding)

Avoid local thrombolysis - high risk of major bleeding complications 3

Surgical thrombectomy has limited success and high recurrence rates 3

Critical Pitfalls to Avoid

• Do not use INR to assess bleeding risk in cirrhosis - INR reflects synthetic function, not bleeding risk 2
• Do not assume cirrhosis is a contraindication to anticoagulation - meta-analysis shows no significant increase in variceal bleeding (11% vs 11%) 2
• Do not discontinue anticoagulation prematurely - recurrence rates are high, especially in transplant candidates 1, 2, 8
• Do not delay anticoagulation for endoscopy - this decreases recanalization odds 2

Survival Benefit

Anticoagulation is associated with improved survival 1, 7:

• 68.4% vs 48.7% survival at 5 years in treated vs untreated patients 7
• 92.7% vs 77.8% survival at 1 year 7
• Survival benefit persists even accounting for bleeding complications 7