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

Abstract

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.

Effect of hemodialysis access blood flow on cardiac events after coronary artery bypass grafting using an internal thoracic artery

“…Third, we were unable to investigate a possible change of blood flow rate through HD AVFs, which is known to increase with time (22). The regular measurement of dialysis access blood flow has not been proven to be beneficial (23) and is not performed routinely in our center. Finally, we recognize a non-statistically significant difference (p = 0.36) between the study groups in types of AV vascular access: the forearm AV access was more prevalent in the group of ipsilateral location of AV access and ITA CABG.…”

Current Management of Vascular Access

“…The positive predictive value of various monitoring tests for Ͼ50% graft stenosis has been determined by obtaining fistulograms in patients with abnormal monitoring parameters. A positive predictive value ranging from 70 to 100% has been documented for clinical monitoring (56,58,70 -72), static venous pressure (67), flow monitoring (69,73), and Duplex ultrasound (72).…”

A New Computerized Program for Surveillance of Prosthetic Arteriovenous Fistulas

“…Finally, it is well documented that pVAs are more prone to thrombosis than autogenous vascular access (8).…”

“…Finally, some authors underline how many clinical trials are affected by incorrect patient recruitment, underestimation of hemodynamic values and overtreatment of asymptomatic patients (13). The National Kidney Foundation (NKF) Kidney Disease Outcome Quality Initiative (KDOQI) Clinical Practice Guidelines (12) declare that surveillance strongly depends on narrow clinical monitoring performed by skilled personnel, with 70% positive predictive value and 90% specificity (8,14). However, evidence based on everyday experience suggests that careful instrumental monitoring is required to prevent thrombosis most of the time.…”