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1Renal Division, Emory University School of Medicine, Atlanta, GA 30322, USA. jwork1@emory.edu
Insights
Surveillance and intervention for hemodialysis graft stenosis may improve survival, but evidence from randomized trials is limited. Further research is needed to confirm the effectiveness of blood-flow monitoring for graft surveillance.
Area of Science:
- Nephrology
- Vascular Surgery
- Medical Devices
Background:
- Hemodialysis graft survival is often prolonged by preemptive correction of stenosis.
- However, robust evidence from prospective randomized controlled trials (RCTs) confirming this benefit is scarce.
- Existing studies are largely non-randomized or use historical controls.
Purpose of the Study:
- To evaluate the effectiveness of surveillance and intervention strategies in preventing thrombosis and prolonging hemodialysis graft survival.
- To assess the role of blood flow monitoring as a surveillance method.
- To address the controversy surrounding the accuracy of ultrasound dilution in predicting graft thrombosis.
Main Methods:
- Review of existing prospective randomized controlled trials and non-randomized studies.
- Analysis of surveillance methods, focusing on stenosis detection and blood flow monitoring (ultrasound dilution).
- Evaluation of outcomes including graft thrombosis and survival rates.
Main Results:
- Limited RCTs support the benefit of stenosis surveillance and intervention, primarily for new grafts.
- The efficacy of blood flow monitoring (ultrasound dilution) in predicting thrombosis remains controversial.
- No definitive benefit has been established for universal surveillance of all grafts using blood-flow monitoring.
Conclusions:
- While correcting stenosis before thrombosis may enhance graft survival, high-quality evidence from RCTs is lacking.
- The predictive accuracy of blood flow measurements for thrombosis requires further investigation.
- Current evidence does not support the routine implementation of blood-flow monitoring for all hemodialysis grafts.
Abstract:
It is widely accepted that surveillance with correction of stenosis before thrombosis prolongs hemodialysis graft survival. However, few prospective randomized controlled trials have confirmed the efficacy of this approach. Most studies have been nonrandomized or have included historic rather than concurrent controls. Although graft dysfunction as assessed by blood flow determination has been widely recognized as the surveillance method of choice, all fully randomized prospective studies that have found a benefit in terms of decreased thrombosis or increased survival have evaluated stenosis and the benefit has only been in new grafts. Finally, the accuracy of blood flow measurements as determined by ultrasound dilution in predicting thrombosis is controversial. Some have reported that predictive accuracy is adequate, whereas others have reached the opposite conclusion. Thus, further studies are needed to explore the effectiveness of surveillance with intervention in improving graft survival. Until such studies establish the use of surveillance programs, surveillance of all grafts using blood-flow monitoring cannot be supported.