Randomized comparison of ultrasound surveillance and clinical monitoring on arteriovenous graft outcomes

Arteriovenous graft thrombosis is a frequent event in hemodialysis patients, and usually occurs in grafts with significant underlying stenosis. Regular surveillance for graft stenosis, with pre-emptive angioplasty of significant lesions, may improve graft outcomes. This prospective, randomized, clinical trial allocated 126 hemodialysis patients with grafts to either clinical monitoring alone ( control group) or to regular ultrasound surveillance for graft stenosis every 4 months in addition to clinical monitoring ( ultrasound group). The two randomized groups were closely matched with respect to demographic, clinical, and graft characteristics, with the exception of a lower frequency of diabetes in the ultrasound group. The primary outcome was graft survival, and the secondary outcome was thrombosis-free graft survival. The frequency of pre-emptive graft angioplasty was 64% higher in the ultrasound group than in the control group ( 1.05 vs 0.64 events per patient-year, P < 0.001), whereas the frequency of thrombosis was not different ( 0.67 vs 0.78 per patient-year, P = 0.37). The median time to permanent graft failure was similar between the two groups ( 38 vs 37 months, P = 0.93). Likewise, the median time to graft thrombosis or failure did not differ ( 22 vs 25 months, P = 0.33). There was no significant association between diabetes and time to graft failure ( P = 0.93) or time to graft thrombosis or failure ( P = 0.88). In conclusion, the addition of regular ultrasound surveillance for graft stenosis to clinical monitoring increases the frequency of pre-emptive angioplasty, but may not decrease the likelihood of graft failure or thrombosis.