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Renal vein thrombosisNephrology discussion
Dr. CoetserProf. Van Rensburg and dr. Rossouw
Our case
Epidemiology
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 Membranoproliferative glomerulonephritis 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
Pathogenesis of RVT in the nephrotic syndrome
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
Clinical presentation
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
Diagnosis
Gold standard is selective renal venographyOther options:
◦ CT abdomen with contrast◦ MRI◦ Doppler ultrasonography
Blood tests:◦ Rise in urea and creatinine if bilateral◦ Rise in LDH
Inferior cavography
Thrombus extending from the left renal vein into the inferior vena cava
Contrast CT abdomen
A thrombus extends from the left renal vein to the inferior vena cava. Note that the left renal vein runs retroaortic.
MRI
Left renal vein thrombosis in a patient with renal cell carcinoma.
Screening
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
Prophylaxis for RVT
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.
Treatment of RVT
AnticoagulationCan 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
FibrinolysisSystemic 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 reportedNo particular agent proven to be superior at
present
Treatment of RVT
Indications for fibrinolysisAcute bilateral RVT and acute renal failureExtension of thrombus into inferior vena cavaAcute renal failureMassic thrombus with high risk of systemic
embolizationPulmonary embolism presentSevere flank pain
Treatment of RVT
Contraindications to fibrinolysis History of haemorrhagic stroke 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) Nonhaemorrhagic stroke within prior 2 months RELATIVE
Surgery within the previous 10 days Thrombocytopenia (<100,000 platelets per mm3)
Post-partum thrombolysis haemorrhagic risk is highest in first 8h following delivery. No clear guidelines exist as only a few case
reports have been described.
Treatment of RVT
Catheter thrombectomyTechnique 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
SurgerySurgical thrombectomy only indicated in acute
bilateral RVT with acute renal failure which can not be treated with local fibrinolysis or catheter thrombectomy
Bibliography
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.