Color Doppler ultrasonography imaging to guide transluminal angioplasty ofvenous stenosis

Background The objective of access surveillance is the early recognition of dysfunction in order to be able to correct the stenosis by angioplasty or surgery before access thrombosis occurs. The advent of color Doppler imagin g has enabled studies of color Doppler ultrasonography (CDU) for the guidan ce of percutaneous transluminal angioplasty (PTA). The aim of the present s tudy was to investigate whether color Doppler imaging alone can be safely a nd effectively used to diagnose vascular graft access stenoses and guide su bsequent PTA. Methods. Using the ultrasound velocity dilution method, we measured access blood flow (Qa) during the first hour of hemodialysis every month in patien ts with grafts as vascular access. When the decrease in Qa from the baselin e value was 40% or more, CDU was performed and immediately followed by PTA in the presence of a stenosis of more than 50%. The Qa was then measured du ring the first dialysis after PTA and one month later. Repeated-measure ana lysis of variance was applied to evaluate the early and late (after one mon th) effect of PTA. Results. Twelve PTAs were performed under CDU guidance in nine patients and led to the elimination of the stenosis or its reduction (two cases). The m ean Qa was 809 +/- 263 mL/min at baseline, 468 +/- 153 before PTA, and 820 +/- 281 after PTA. The difference between the pre-PTA and post-PTA values w as highly significant (P < 0.001), and the mean value after PTA was not dif ferent from baseline (P = 0.672). There were no relevant complications dire ctly related to the procedure. Conclusions. The CDU procedure is effective for the diagnosis of vascular a ccess stenosis and as a guide during the PTA procedure. It could improve st enosis screening by avoiding the risks of exposure to ionizing radiation an d of adverse reactions to contrast media.