The prognosis of renal vein thrombosis: a re-evaluation of 27 cases.

Twenty-seven patients with renal vein thrombosis were retrospectively studied to evaluate their long-term prognosis and relevant prognostic factors. Twenty-four patients presented with a nephrotic syndrome, and 15 had renal impairment (8 acute; 7 moderate). Ten patients had a previous history of proteinuria, and 14 of nephrotic syndrome. Renal biopsy performed in 20 patients, of whom 19 were nephrotic, showed membranous glomerulonephritis in 14, focal segmental glomerulosclerosis in three, minimal change glomerulonephritis in two, and periarteritis nodosa in one. Renal vein thrombosis was angiographically proven in all patients and was bilateral in 18, localised to the left renal vein in seven, and to the right in two. Thrombosis of the inferior vena cava was associated in seven patients. Ten patients were treated by anticoagulants alone, nine by surgical thrombectomy, seven by thrombolysis, and two did not receive any specific treatment. One patient underwent successively thrombectomy and then thrombolysis. Eleven patients died within the first 6 months, mainly from haemorrhagic complications (n = 5) or severe sepsis (n = 2). Survivors were followed up from 6 months to 19 years. Nephrotic syndrome improved or even disappeared in 12 patients, and renal function did not worsen throughout the follow-up in any patients. The main prognostic factors were initial renal function and type of nephropathy: patients with membranous glomerulonephritis had a significantly better renal function and a lower mortality rate than patients with other nephropathies. Initial renal insufficiency was significantly associated with a poor prognosis. There was no advantage, in terms of survival, kidney function and nephrotic syndrome, of either thrombectomy or thrombolysis over anticoagulants alone, despite two complete venous recanalisations after thrombolysis. Accordingly, patients with renal vein thrombosis from membranous glomerulonephritis should be treated by anticoagulants alone, since the long-term prognosis of this disease seems unaffected by intercurrent renal vein thrombosis. With respects to the risk-to-benefit ratio, thrombectomy should be avoided and thrombolysis considered only in patients with initial acute renal failure from acute renal vein thrombosis.