Renal Vein Thrombosis

Renal vein thrombosis (RVT), the presence of thrombus in the major renal veins or its tributaries, is a rare clinical entity. It can present acutely or go unnoticed and can result in acute kidney injury or chronic kidney disease. Rayer, a French nephrologist, was the first to describe RVT and its association with proteinuria in the 1840s. It is commonly associated with nephrotic syndrome, primary hypercoagulability disorders, malignant renal tumors, extrinsic compression, infections, trauma, or as a post-renal transplant complication. Almost two-thirds of patients have bilateral renal vein involvement. The left renal vein is more commonly involved due to its extensive venous network compared to the right. Thrombosis may extend from the vena cava into the peripheral venules or may originate in the peripheral veins and propagate to the main renal vein. The severe passive congestion that develops causes the kidney to swell and become engorged, leading to degeneration of nephrons and causing symptoms of flank pain, hematuria, and decreased urine output.