Hemodialysis grafts: color Doppler flow imaging correlated with digital subtraction angiography and functional status

Twenty-two patients with hemodialysis grafts were prospectively evaluated with color Doppler flow imaging and digital subtraction angiography (DSA). Eighteen patients had normal functional parameters during hemodialysis, and four had increased venous pressure during hemodialysis. Color Doppler flow imaging allowed identification of nine macroaneurysms related to wall degeneration, two cases of spontaneous fistula formation between the graft and peripheral veins, and 20 stenoses. Use of color Doppler flow imaging led to overestimation of the degree of stenosis at the venous anastomosis when compared with use of angiography. Three cases of subclavian venous stenosis were identified only at angiography. Color Doppler flow imaging appears accurate in the detection of stenoses and seems sufficient for follow-up of normally functioning grafts. However, because of its low sensitivity for identification of proximal stenoses and the necessity of obtaining an angiogram to plan surgical or percutaneous correction, DSA remains the technique of choice.