Renal Vein Thrombosis

Renal vein thrombosis usually results from local and systemic hypercoagulability due to nephrotic syndrome Overview of Nephrotic Syndrome Nephrotic syndrome is urinary excretion of > 3 g of protein/day due to a glomerular disorder plus edema and hypoalbuminemia. It is more common among children and has both primary and secondary... read more associated with membranous nephropathy Membranous Nephropathy Membranous nephropathy is deposition of immune complexes on the glomerular basement membrane (GBM) with GBM thickening. Cause is usually unknown, although secondary causes include medications... read more (most often), minimal change disease Minimal Change Disease Minimal change disease causes abrupt onset of edema and heavy proteinuria, mostly in children. Renal function is typically normal. Diagnosis is based on clinical findings or renal biopsy. Treatment... read more , or membranoproliferative glomerulonephritis Membranoproliferative Glomerulonephritis Membranoproliferative glomerulonephritis (MPGN) is characterized by a pattern of glomerular injury on light microscopy, including hypercellularity and thickening of the glomerular basement membrane... read more . 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

Less common causes are related to reduced renal vein blood flow and include malignant renal tumors that extend into the renal veins (typically renal cell carcinoma Renal Cell Carcinoma Renal cell carcinoma (RCC) is the most common renal cancer. Symptoms can include hematuria, flank pain, a palpable mass, and fever of unknown origin (FUO). However, symptoms are often absent... read more ), 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 Cocaine Cocaine is a sympathomimetic drug with central nervous system stimulant and euphoriant properties. High doses can cause panic, schizophrenic-like symptoms, seizures, hyperthermia, hypertension... read more .

Usually, onset of renal dysfunction Acute Kidney Injury (AKI) Acute kidney injury is a rapid decrease in renal function over days to weeks, causing an accumulation of nitrogenous products in the blood (azotemia) with or without reduction in amount of urine... read more 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 Deep Venous Thrombosis (DVT) Deep venous thrombosis (DVT) is clotting of blood in a deep vein of an extremity (usually calf or thigh) or the pelvis. DVT is the primary cause of pulmonary embolism. DVT results from conditions... read more , pulmonary embolism Pulmonary Embolism (PE) Pulmonary embolism (PE) is the occlusion of pulmonary arteries by thrombi that originate elsewhere, typically in the large veins of the legs or pelvis. Risk factors for pulmonary embolism are... read more ) may occur. When the cause is a renal cancer Renal Cell Carcinoma Renal cell carcinoma (RCC) is the most common renal cancer. Symptoms can include hematuria, flank pain, a palpable mass, and fever of unknown origin (FUO). However, symptoms are often absent... read more , its signs (eg, hematuria, weight loss) predominate.

Renal vein thrombosis should be considered in patients with renal infarction or any unexplained deterioration in renal function, particularly in patients with nephrotic syndrome Overview of Nephrotic Syndrome Nephrotic syndrome is urinary excretion of > 3 g of protein/day due to a glomerular disorder plus edema and hypoalbuminemia. It is more common among children and has both primary and secondary... read more 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. Because of the risks of conventional venography, magnetic resonance venography and CT angiography CT angiography CT shows a focal area of osteolysis (arrows) involving the right acetabulum that is consistent with particle disease. In CT, an x-ray source and x-ray detector housed in a doughnut-shaped assembly... read more are being used increasingly.

CT angiography CT angiography CT shows a focal area of osteolysis (arrows) involving the right acetabulum that is consistent with particle disease. In CT, an x-ray source and x-ray detector housed in a doughnut-shaped assembly... read more 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 also risks nephrogenic systemic fibrosis (NSF) in patients with decreased GFR, but can be done with group II gadolinium contrast agents if medically necessary to minimize potential risk of NSF. Doppler ultrasonography Doppler In ultrasonography, a signal generator is combined with a transducer. Piezoelectric crystals in the signal generator convert electricity into high-frequency sound waves, which are sent into... read more 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 renal 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 Overview of Thrombotic Disorders In healthy people, homeostatic balance exists between procoagulant (clotting) forces and anticoagulant and fibrinolytic forces. Numerous genetic, acquired, and environmental factors can tip... read more ). Renal biopsy Renal biopsy Biopsy of the urinary tract requires a trained specialist (nephrologist, urologist, or interventional radiologist). Indications for diagnostic biopsy include unexplained nephritic or nephrotic... read more is nonspecific but may detect a coexisting renal disorder.

The underlying disorder should be treated.

Treatment options for renal vein thrombosis include anticoagulation with heparin, thrombolysis, and catheter-directed or surgical thrombectomy. Long-term anticoagulation with low molecular weight heparin or oral warfarin 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 renal function. Anticoagulation should be continued for at least 6 to 12 months and, if a hypercoagulability disorder (eg, persistent nephrotic syndrome Overview of Nephrotic Syndrome Nephrotic syndrome is urinary excretion of > 3 g of protein/day due to a glomerular disorder plus edema and hypoalbuminemia. It is more common among children and has both primary and secondary... read more ) is present, indefinitely.

Patients with acute renal vein thrombosis and AKI 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.

Death is rare and usually related to complications such as pulmonary embolism Pulmonary Embolism (PE) Pulmonary embolism (PE) is the occlusion of pulmonary arteries by thrombi that originate elsewhere, typically in the large veins of the legs or pelvis. Risk factors for pulmonary embolism are... read more and those due to nephrotic syndrome Overview of Nephrotic Syndrome Nephrotic syndrome is urinary excretion of > 3 g of protein/day due to a glomerular disorder plus edema and hypoalbuminemia. It is more common among children and has both primary and secondary... read more associated with malignancy.