Makindo Medical Notes

🩸 Renal Vein Thrombosis (RVT) A serious complication most commonly linked to nephrotic syndrome. Loss of anticoagulant proteins (antithrombin III, protein C, protein S) in the urine → a **hypercoagulable state**. It can be acute (sudden flank pain, haematuria) or chronic (asymptomatic, discovered incidentally).

📖 About

• Thrombosis of the renal vein draining the kidney.
• Reducing proteinuria lowers hypercoagulability risk (ACEi/ARBs are protective).
• Can be unilateral or bilateral; bilateral disease is more likely to cause AKI.

⚠️ Aetiology

• Nephrotic syndrome (esp. membranous GN, minimal change in children).
• Loss of natural anticoagulants → prothrombotic state.
• Trauma, dehydration, sepsis (esp. in infants).

🔗 Associations

• Membranous GN and lupus nephritis (SLE).
• Renal cell carcinoma invading the renal vein.
• Systemic prothrombotic states (e.g. Antiphospholipid antibody syndrome).

🩺 Clinical Features

• Acute RVT: Flank pain, macroscopic haematuria, AKI, enlarged kidney, nephrotic oedema.
• Chronic RVT: Often silent, discovered on imaging in nephrotic syndrome patients.
• May present with pulmonary embolism as first manifestation.

❓ Differentials

• UTI (loin pain, pyuria).
• Renal stones (colicky pain, haematuria).
• Papillary necrosis (e.g. sickle cell disease, analgesic nephropathy).

🧪 Investigations

• Bloods: Proteinuria >3 g/day, hypoalbuminaemia, hypercholesterolaemia.
• USS with Doppler: Loss of flow in renal vein.
• MRI venography: Becoming preferred modality (non-invasive).
• CT venography / Renal angiogram (venous phase): Gold standard but invasive.
• IV Pyelography (historical): Enlarged kidney with delayed excretion.
• Renal biopsy: Important for underlying cause (e.g. membranous GN).

💊 Management

• Underlying disease: Treat nephrotic syndrome (ACEI/ARB to reduce proteinuria, diuretics for oedema).
• Lipid control: Statins if hypercholesterolaemia.
• Immunosuppressants: Ciclosporin or other agents for membranous nephropathy.
• Anticoagulation: Prevent extension/PE. Long-term anticoagulation is usually indicated.
• Thrombolysis/thrombectomy: Considered in severe bilateral acute RVT or progressive AKI.

📌 Clinical Pearls

• RVT is one of the few causes of renal disease where anticoagulation is central to management.
• Always look for nephrotic syndrome if RVT is diagnosed.
• In children, RVT often presents with dehydration or sepsis.
• Pulmonary embolism can be the first sign — think RVT in a nephrotic patient with unexplained PE.

📚 References

• BNF – Anticoagulation guidance.
• UK Renal Association Clinical Practice Guidelines.
• KDIGO Guidelines for Nephrotic Syndrome.