Hemodialysis access graft stenosis: US detection.
OBJECTIVE
To prospectively evaluate the sensitivity of ultrasonography (US) in diagnosing stenosis of hemodialysis access grafts and their drainage veins in patients clinically suspected of having graft dysfunction.


METHODS
Thirty-eight patients in whom dysfunction of their hemodialysis access grafts was suspected underwent both Doppler US and angiography. Gray-scale and color US were combined with spectral analysis of the graft, anastomoses, and venous outflow. Flow velocity at anastomoses and suspected stenotic areas was measured. The volume of flow in the graft was also measured. The prospective US criterion for diagnosis of stenosis was a focal twofold or higher elevation of peak systolic velocity (PSV) compared with the PSV immediately upstream. A blinded angiographic evaluation of the graft and drainage veins followed US. Angiographic diagnosis of stenosis required at least 50% narrowing in luminal diameter. US and angiographic results were then compared.


RESULTS
Angiography allowed diagnosis of 43 stenoses in 34 patients. US depicted 92% (37 of 40) of these stenoses, with a 94% positive predictive value for any individual patient. Focal 2- to 2.9-times PSV elevation was associated with 75% or greater stenosis. Graft flow volume and resistive index change did not correlate with stenosis.


CONCLUSIONS
US reliably depicts stenoses of hemodialysis access grafts and drainage veins in a clinically selected population when PSV criteria are used.
Dept of Radiology, University of Alabama, Birmingham 35233, USA.
M L
ML
Robbin
R F
RF
Oser
M
M
Allon
M W
MW
Clements
J
J
Dockery
T M
TM
Weber
K M
KM
Hamrick-Waller
J K
JK
Smith
B C
BC
Jones
D E
DE
Morgan
S
S
Saddekni
D000328:Adult; D000368:Aged; D000792:Angiography; D001166:Arteriovenous Shunt, Surgical; D001783:Blood Flow Velocity / Q000502:physiology; D001810:Blood Volume / Q000502:physiology; D005260:Female; D005583:Fourier Analysis; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012680:Sensitivity and Specificity; D018608:Ultrasonography, Doppler; D014655:Vascular Resistance / Q000502:physiology