HEMODIALYSIS ACCESS GRAFT STENOSIS - US DETECTION

PURPOSE: To prospectively evaluate the sensitivity of ultrasonography (US) in diagnosing stenosis of hemodialysis access grafts and their dr ainage veins in patients clinically suspected of having graft dysfunct ion. MATERIALS AND METHODS: Thirty-eight patients in whom dysfunction of their hemodialysis access grafts was suspected underwent both Doppl er US and angiography. dray-scale and color US were combined with spec tral analysis of the graft, anastomoses, and venous outflow. Flow velo city at anastomoses and suspected stenotic areas was measured. The vol ume of flow in the graft was also measured. The prospective US criteri on for diagnosis of stenosis was a focal twofold or higher elevation o f peak systolic velocity (PSV) compared with the PSV immediately upstr eam. 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% pos itive predictive value for any individual patient. Focal 2- to 2.9-tim es PSV elevation was associated with 50%-74% stenosis, while a threefo ld or greater increase was associated with 75% or greater stenosis. Cr aft flow volume and resistive index change did not correlate with CONC LUSION: US reliably depicts stenoses of hemodialysis access grafts and drainage veins ina Clinically selected population when PSV criteria a re used.