genitourinary disorders
Renal Vein Thrombosis
Diagnosis of Renal Vein Thrombosis
Vascular imaging Renal vein thrombosis should be considered in patients with renal infarction or any unexplained deterioration in renal function, particularly in patients with Overview of 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. Because of the risks of conventional venography, magnetic resonance venography and CT angiography are being used increasingly. 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 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. 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 Overview of Thrombotic Disorders ). 