Renal vein thrombosis occludes of one or both main renal veins, resulting in acute kidney injury or chronic kidney disease. Common causes include nephrotic syndrome, primary hypercoagulability disorders, malignant renal tumors, extrinsic compression, trauma, and rarely inflammatory bowel disease. Symptoms of kidney failure and sometimes nausea, vomiting, flank pain, gross hematuria, decreased urine output, or systemic manifestations of venous thromboembolism may occur. Diagnosis is by CT, magnetic resonance angiography, or renal venography. With treatment, prognosis is generally good. Treatment is anticoagulation, support of kidney function, and treatment of the underlying disorder. Some patients benefit from thrombectomy or nephrectomy.
Etiology of Renal Vein Thrombosis
Renal vein thrombosis is associated with malignancy in approximately two-thirds of cases (1, 2). Nephrotic syndrome is another important cause of renal vein thrombosis due to both local and systemic hypercoagulability. Nephrotic syndrome in this setting is most often associated with membranous nephropathy, as well as minimal change disease or membranoproliferative glomerulonephritis. The risk of thrombosis due to nephrotic syndrome appears to be proportional to the severity of the hypoalbuminemia. Overly aggressive diuresis or prolonged high-dose corticosteroid treatment may contribute to thrombosis of the renal vein in patients with these conditions.
Other causes include
Estrogen therapy
Pregnancy
Primary hypercoagulability disorders (eg, antithrombin III deficiency, protein C deficiency, protein S deficiency, factor V Leiden mutation, prothrombin G20210A mutation)
Renal vasculitis
Sickle cell nephropathy
Less common causes are related to reduced renal vein blood flow and include malignant renal tumors that extend into and obstruct the renal veins (typically renal cell carcinoma), extrinsic compression of the renal vein or inferior vena cava (eg, by vascular abnormalities, tumor, retroperitoneal disease, ligation of the inferior vena cava, aortic aneurysm), oral contraceptive use, trauma, dehydration and, rarely, thrombophlebitis migrans and cocaine use disorder.
Etiology references
1. Wanaratwichit P, Chai-Adisaksopha C, Inmutto N, Noppakun K. Risk factors of worsening kidney function and mortality in patients with renal vein thrombosis: a retrospective study. J Nephrol 2024;37(1):131-140. doi:10.1007/s40620-023-01761-2
2. Wysokinski WE, Gosk-Bierska I, Greene EL, Grill D, Wiste H, McBane RD 2nd. Clinical characteristics and long-term follow-up of patients with renal vein thrombosis. Am J Kidney Dis 2008;51(2):224-232. doi:10.1053/j.ajkd.2007.10.030
Symptoms and Signs of Renal Vein Thrombosis
Usually, onset of renal dysfunction is insidious. However, onset may be acute, causing renal infarction with nausea, vomiting, flank pain, gross hematuria, and decreased urine output.
When the cause is a hypercoagulability disorder, signs of venous thromboembolic disorders (eg, deep venous thrombosis, pulmonary embolism) may occur. When the cause is a renal cancer, its signs (eg, hematuria, weight loss) predominate.
Diagnosis of Renal Vein Thrombosis
Vascular imaging
Renal vein thrombosis should be considered in patients with renal infarction or any unexplained deterioration in kidney function, particularly in patients with nephrotic syndrome or other risk factors.
The traditional diagnostic test of choice and the standard is venography of the inferior vena cava; this test is diagnostic, but it may mobilize clots. Magnetic resonance venography and CT angiography are preferred due the risks of direct venography.
CT angiography provides good detail with high sensitivity and specificity and is fast but requires administration of a radiocontrast agent, which may be nephrotoxic and should be avoided if the glomerular filtration rate (GFR) < 30 mL/minute. Magnetic resonance venography with gadolinium contrast carries the risk of nephrogenic systemic fibrosis in patients with decreased GFR, but group II gadolinium contrast agents can be used to minimize this potential risk when medically necessary. Doppler ultrasound sometimes detects renal vein thrombosis but has high false-negative and false-positive rates. Notching of the ureter due to dilated collateral veins is a characteristic finding in some chronic cases.
Serum electrolytes and urinalysis are done and confirm deterioration of kidney function. Microscopic or gross hematuria is often present, and serum lactate dehydrogenase (LDH) can be markedly elevated in acute renal vein thrombosis. Proteinuria may be in the nephrotic range.
If no cause is apparent, testing for hypercoagulability disorders should be initiated (see Thrombotic Disorders). Renal biopsy is nonspecific but may detect a coexisting renal disorder.
Treatment of Renal Vein Thrombosis
Anticoagulation
For acute renal vein thrombosis, thrombolysis and sometimes thrombectomy, usually percutaneous catheter-directed thrombectomy
Treatment of underlying disorder
Treatment options for renal vein thrombosis include anticoagulation, and catheter-directed or surgical thrombectomy.
Long-term anticoagulation should be started immediately if no invasive intervention is planned. Anticoagulation minimizes risk of new thrombi, promotes recanalization of vessels with existing clots, and improves kidney function. The choice and duration of anticoagulant(s) is as for deep venous thrombosis in general. If a hypercoagulability disorder (eg, persistent nephrotic syndrome) exists, consider anticoagulation indefinitely.
Patients with acute renal vein thrombosis and acute kidney injury should undergo thrombolytic therapy with or without thrombectomy. Use of a percutaneous catheter for thrombectomy or thrombolysis is currently recommended. Surgical thrombectomy is rarely used but should be considered if it cannot be treated with percutaneous catheter thrombectomy and/or thrombolysis.
The underlying disorder should be treated.
Prognosis for Renal Vein Thrombosis
Death is rare and usually related to complications such as pulmonary embolism and those due to nephrotic syndrome associated with malignancy.
Key Points
The most common cause of renal vein thrombosis is nephrotic syndrome associated with membranous nephropathy.
Consider renal vein thrombosis in patients with renal infarction or any unexplained deterioration in kidney function, particularly those who have nephrotic syndrome or other risk factors.
Confirm the diagnosis with vascular imaging, usually magnetic resonance venography (if GFR > 30 mL/minute) or CT angiography.
Initiate anticoagulation, thrombolysis, or thrombectomy and treat the underlying disorder.
