Related Experiment Videos
Predicting hemodialysis access failure with color flow Doppler ultrasound
W H Bay1, M L Henry, J M Lazarus
1Department of Internal Medicine, Ohio State University Hospital, Columbus 43210-1228, USA.
Insights
Color flow Doppler ultrasound can predict hemodialysis access failure by measuring blood flow in prosthetic grafts. Reduced blood flow below 500 ml/min significantly increases failure risk, enabling early intervention.
Area of Science:
- Nephrology
- Vascular Surgery
- Radiology
Background:
- Hemodialysis access failure is a significant complication.
- Predicting access failure is crucial for patient outcomes and healthcare costs.
- Color flow Doppler ultrasound is a noninvasive imaging technique.
Purpose of the Study:
- To evaluate the value of color flow Doppler ultrasound in predicting hemodialysis access failure.
- To identify predictors of hemodialysis access failure.
- To assess the correlation between access blood flow and graft survival.
Main Methods:
- A prospective study of 2,792 hemodialysis patients.
- Color flow Doppler ultrasound assessment of vascular access function.
- Follow-up for at least 6 months or until graft failure.
- Cox model analysis to determine case mix predictors of failure.
Main Results:
- 23.5% of patients experienced access failure.
- Decreased access blood flow measured by color flow Doppler was the most significant predictor of failure (p < 0.0001).
- Relative risk of graft failure increased by 40% with blood flow < 500 ml/min and doubled with blood flow < 300 ml/min.
Conclusions:
- Color flow Doppler ultrasound effectively quantifies blood flow in prosthetic grafts, identifying those at risk for failure.
- This noninvasive technique can guide preemptive repair of anatomical abnormalities, reducing patient morbidity and costs.
- Color Doppler volume flow could not predict native arteriovenous fistula survival.
Abstract:
Color flow doppler ultrasound examination of the hemodialysis access was conducted in 2,792 hemodialysis patients to evaluate its value in predicting hemodialysis access failure. After baseline assessment of vascular access function with clinical and laboratory tests including color flow doppler evaluation these patients were followed for a minimal of 6 months or until graft failure occurred (defined as surgery or angioplasty intervention, or graft loss). The patient demographics and vascular accesses were typical of a standard hemodialysis patient population. On the day of the color flow doppler examination systolic and diastolic blood pressure, hematocrit, urea reduction ratio, dialysis blood flow, venous line pressure at a dialysis blood flow of 250 ml/min, and access recirculation rate were measured. At the conclusion of the study 23.5% of the patients had access failure. Case mix predictors for access failure were determined using the Cox Model. Case mix predictors of access failure were race, non-white was higher than white (p < 0.005), younger accesses had a higher risk than older accesses (p < 0.025), accesses with prior thrombosis had a higher risk of failure (p=0.042), polytetrafluoroethylene (PTFE) grafts had a higher risk than native vein fistulae (p < 0.05), loop PTFE grafts had a higher risk than straight PTFE grafts (p < 0.025), and upper arm accesses had a higher risk than forearm accesses (p=0.033). Most significant, however, was decreased access blood flow as measured by color flow doppler (p < 0.0001). The relative risk of graft failure increased 40% when the blood flow in the graft decreased to less than 500 ml/min and the relative risk doubled when the blood flow was less than 300 ml/min. This study has shown that color flow doppler evaluation, quantifying blood flow in a prosthetic graft, can identify those grafts at risk for failure. In contrast, color doppler volume flow in native AV fistulae could not predict fistula survival. This technique is noninvasive, painless, portable, and reproducible. We believe that preemptory repair of an anatomical abnormality in vascular access grafts with decreased blood flow may decrease patient inconvenience, associated morbidity, and associated costs.