[Vascular complications in the transplanted kidney: detection with Doppler ultrasonography]

To determine the utility of renal duplex sonography in the detection of vascular complications in renal grafts.

45 patients with a median post-transplant follow-up of 39.3 +/- 28.8 months were evaluated. The renal artery maximum systolic velocity (SVmax) and the renal artery/iliac artery Svmax ratio (RIR) were utilized to detect stenosis.

The SVmax was > 200 cm/sec in 6 cases, indicating renal artery stenosis (RAS). Angiographic evaluation of 5 patients revealed 3 had RAS > 60% and 2 had RAS < 60%. The 3 patients with RAS > 60% had RIR > 2. Increased vascular resistance in renal parenchyma was detected in 8 patients (1 acute rejection, 1 acute tubular necrosis, 6 histopathologically confirmed chronic rejection). Seventeen patients had one or more biopsies done during the follow-up. Six patients had a Doppler pattern compatible with arteriovenous fistula; two were confirmed by arteriography and one of these was embolized.

Duplex sonography is no substitute for the other methods utilized in the early detection of vascular complications in the renal graft, but it can identify those patients requiring angiographic assessment and can therefore reduce the number of biopsies for posttransplant evaluation.