Rapid renal salvage in acute renal vein thrombosis secondary to membranous nephropathy using large-bore mechanical thrombectomy

Renal vein thrombosis (RVT) is a rare but serious complication of nephrotic syndrome, particularly in primary membranous nephropathy. Acute RVT with renal impairment and inferior vena cava (IVC) extension carries a high risk of irreversible renal injury. Thrombolysis may be contraindicated due to bleeding risk. We report a 56-year-old man who presented with acute left flank pain, gross hematuria, anemia, and acute kidney injury. Investigations revealed nephrotic-range proteinuria and positive anti-phospholipase A2 receptor antibodies, consistent with primary membranous nephropathy. Computed tomography demonstrated extensive left renal vein thrombosis extending into the infrarenal IVC. Due to active hematuria and severe anemia, thrombolysis was contraindicated. Large-bore mechanical thrombectomy using the FlowTriever system was performed with temporary caval protection, achieving complete thrombus removal and restoration of renal venous outflow without thrombolytics. Hematuria resolved immediately and renal function stabilized. Large-bore mechanical thrombectomy represents a safe and effective thrombolytic-free option for acute extensive RVT, particularly in nephrotic syndrome patients with high bleeding risk. Early restoration of renal venous outflow may facilitate renal salvage and prevent long-term renal impairment.