Renal vein thrombosis

1. Renal vein thrombosis Nephrology discussion Dr. Coetser Prof. Van Rensburg and dr. Rossouw

2. Our case

3. RVT is seen in 10-50% of patients with nephrotic syndrome • RVT seen in 20-60% of membranous nephropathy • Also associated with: • Minimal change glomerulonephritis • Membranoproliferativeglomerulonephritis • Focal segmental glomerulosclerosis • Other associations: • Renal malignancy • External compression from e.g. lymphnodes, aneurysms • Oral contraceptive use and pregnancy • Hypovolaemia secondary to severe dehydration • Inherited procoagulant disorders • Antiphospholipid syndrome, factor V Leiden • Trauma, including kidney bx Epidemiology

4. Hypercoagulability • Decreased levels of antithrombin III and plasminogen • Hyperfibrinogenaemia • Increased platelet activation • Fibrinogen moieties circulating • Inhibition of plasminogen activation • Tendency to thrombose in renal vein • Loss of fluid over glomerulus causes increased haematocrit in post-glomerular venous circulation Pathogenesis of RVT in the nephrotic syndrome

5. Complete venous obstruction causes swelling of the kidney, compromising arterial blood flow and leading to a haemorrhagic infarct • Thrombosis can be unilateral or bilateral, can extend into the inferior vena cava • Acute RVT • Asymptomatic • Flank pain • Microscopic or macroscopic haematuria • Nausea and vomiting • Chronic RVT • Asymptomatic, usually presents with pulmonary embolism Clinical presentation

6. Gold standard is selective renal venography • Other options: • CT abdomen with contrast • MRI • Doppler ultrasonography • Blood tests: • Rise in urea and creatinine if bilateral • Rise in LDH Diagnosis

7. Thrombus extending from the left renal vein into the inferior vena cava Inferior cavography

8. A thrombus extends from the left renal vein to the inferior vena cava. Note that the left renal vein runs retroaortic. Contrast CT abdomen

9. Left renal vein thrombosis in a patient with renal cell carcinoma. MRI

10. Not recommended to routinely screen for RVT in all patients with nephrotic syndrome: • No proven benefit in diagnosing occult disease • A patient with a negative test can develop RVT at a later stage, meaning that sequential tests need to be done • Not recommended to look for RVT in patients presenting with embolic phenomenon, e.g. pulmonary embolism • Difficult to prove that embolism originated in renal vein • In situ pulmonary thrombosis could occur in nephrotic syndrome • Both nephrotic patients presenting with thromboembolism and those with RVT need anticoagulation therapy Screening

11. Not routinely recommended in nephrotic syndrome • Authors of UpToDate recommend prophylaxis in: • Severe proteinuria >10g/day • Albumin <20g/L • Another risk factor for venous thromboembolism, e.g. orthopaedic or gynaecological surgery, immobilization etc. Prophylaxis for RVT

12. Anticoagulation • Can be used alone if: • Normal renal function • No flank pain • No other evidence of thromboembolism • Unfractionated or low molecular weight heparin, followed by warfarin for minimum of 6-12 months • Recommended to continue as long is nephrotic syndrome persists Treatment of RVT

13. Fibrinolysis • Systemic fibrinolysis is not recommended due to the complication of haemorrhage and increased mortality (14-49% mortality) • Local fibrinolysis very effective in reports: • 7 patients received local thrombolysis for 22h following catheter thrombectomy. All had restoration of renal venous flow, improvement in creatinine and no recurrence of RVT in the 2 year follow-up • No haemorrhagic complication reported • No particular agent proven to be superior at present Treatment of RVT

14. Indications for fibrinolysis • Acute bilateral RVT and acute renal failure • Extension of thrombus into inferior vena cava • Acute renal failure • Massic thrombus with high risk of systemic embolization • Pulmonary embolism present • Severe flank pain Treatment of RVT

15. Contraindications to fibrinolysis • History of haemorrhagicstroke • Active intracranial neoplasm • Recent (< 2 months) intracranial surgery or trauma ABSOLUTE • Active or recent internal bleeding in prior 6 months • Bleeding diathesis • Uncontrolled severe hypertension (systolic BP >200 mmHg or diastolic BP >110 mmHg) • Nonhaemorrhagicstroke within prior 2 months RELATIVE • Surgery within the previous 10 days • Thrombocytopenia (<100,000 platelets per mm3) • Post-partum thrombolysishaemorrhagic risk is highest in first 8h following delivery. No clear guidelines exist as only a few case reports have been described. Treatment of RVT

16. Catheter thrombectomy • Technique described in 7 patients: • Treated initially with heparin to keep PTT 2-2,5x normal • Percutaneous access via right femoral vein • Catheter guided into thrombosed renal vein • Direct renal venogram obtained • Mechanical thrombectomy done with AngioJet or Helix Clot Buster • Residual thrombosis treated with local fibrinolysis (alteplase or urokinase) • Any remaining stenosis treated with balloon venoplasty • Heparin infusion reinitiated, followed by chronic anticoagulation with warfarin Treatment of RVT

17. Surgery • Surgical thrombectomy only indicated in acute bilateral RVT with acute renal failure which can not be treated with local fibrinolysis or catheter thrombectomy Treatment of RVT

18. Fauci, AS, Braunwald, E. Harrison’s principles of internal medicine, 17th edition, 2008. 1815. • Hyun, S et al. Catheter-directed thrombectomy and thrombolysis for acute renal vein thrombosis. Journal of vascular interventional radiology, 2006. 17:815-822 • Radhakrishnan, J. Renal vein thrombosis and hypercoagulable state in nephrotic syndrome. UpToDate v17.3 • Saddiqi, A et al. Renal vein thrombosis. http://emedicine.medscape.com/article/382686-overview • Tapson, VF. Fibrinolytic (thrombolytic) therapy in pulmonary embolism and deep vein thrombosis. UpToDate v17.3. • Waldemar, E et al. Clinical characteristics and long-term follow-up of patients with renal vein thrombosis. American journal of kidney diseases, 2008. 51:224-232. Bibliography