Vascular complications in renal allografts: detection with duplex Doppler US

Renal allografts are subject to many vascular complications. Over a 2-year period, 334 duplex Doppler ultrasonographic (US) examinations were performed in 88 renal allograft recipients. Vascular occlusion on the basis of severe vascular rejection was documented in ten patients (11.4%) for a sensitivity and specificity of 100%. Seven patients, for whom there was clinical and Doppler US evidence for renal artery stenosis, underwent angiography. A significant stenosis was confirmed and treated by angioplasty in four patients; one had an insignificant stenosis in an accessory artery, one had kinking of the renal vessels, and another had normal findings. The most reliable criteria for stenosis were a high-velocity jet exceeding 7.5 kHz and distal turbulence. One arteriovenous fistula was diagnosed by the presence of an intrarenal high-velocity jet. Duplex Doppler US is a useful, noninvasive, and portable initial procedure with which to screen patients for vascular complications of renal transplantation.