[Duplex sonography in the diagnosis of renal artery stenoses following allogenic kidney transplantation].

Posttransplant renal artery stenosis (TRAS) as a cause of secondary hypertension is reported with an incidence of 1 to 10%. Early diagnosis of TRAS should be made by non-nephrotoxic and non-invasive means to lower the risk of hypertension. One to 66 months after kidney transplantation 335 patients underwent Duplex-scanning, 38 of cases for clinical tentative diagnosis of TRAS. Parameters for clinical diagnosis of TRAS were diastolic hypertension greater than 100 mm Hg with resistance to therapy (A), an abdominal bruit over the transplant (B), disturbance of renal function (serum-creatinine greater than 2 mg/dl) (C). Admission to study followed the parameter-combination A + B. A + C, B + C. Rejection crisis was excluded in 18/38 cases by fine needle biopsy, cyclosporine over-dosage was negative in 38/38 cases, 20/38 cases had normal renal function. Duplex-/Doppler-ultrasound criteria for TRAS were systolic peak velocity greater than 100 cm/s-1 and broadening of the diastolic frequency spectra with a smooth decline in diastole to an elevated diastolic level. In 32/38 cases (84.2%, n = 38) diagnosis of TRAS was made by duplex-scanning, angiography confirmed the result in 30/32 cases (93.75%, n = 32); sensitivity was 88.2% with a specificity of 66.6%. Duplex-scanning as a primary diagnostic means for TRAS seems a promising method compared to e.g. radionuclide imaging or angiography. Duplex-scanning is a non-nephrotoxic and non-invasive procedure repeatable at any time with only few preliminary conditions.(ABSTRACT TRUNCATED AT 250 WORDS)