Renal vein thrombosis in children: evidence of early flow recovery with Doppler US.

PURPOSE

To characterize renal arterial and venous Doppler signals in pediatric renal vein thrombosis (RVT) and to study changes in the circulation in the months following the acute event.

MATERIALS AND METHODS

Ten patients with proved acute RVT (eight infants and two boys with renal allografts) were studied with serial Doppler ultrasonography (US) of the inferior vena cava and the main renal and intrarenal veins and arteries.

RESULTS

The resistance index in the affected vessel was increased by 10% compared with that of the normal side in patients with unilateral RVT. Only the allografts had reversed diastolic flow. Venous flow, which was detected around the thrombus and in intrarenal veins in all native kidneys, was absent during the 1st week in the transplanted kidneys but reappeared thereafter in one. Perirenal collateral vessels were demonstrated with color Doppler US in one baby. Seven of eight native kidneys atrophied, and the allografts failed.

CONCLUSION

Classic Doppler signs of RVT--absent venous flow and reversed diastolic arterial flow within the kidney--were present in only the acute phase in transplanted kidneys. These signs are unreliable in RVT of native kidneys.