Doppler ultrasound and calcification score: improving vascular access surveillance

Area of Science:

• Nephrology
• Vascular Surgery
• Radiology

Background:

• Vascular access (VA) dysfunction, primarily due to thrombosis from neointimal hyperplasia, significantly increases morbidity and mortality in hemodialysis patients.
• Systemic factors like atherosclerosis, inflammation, and calcification contribute to VA failure, necessitating improved surveillance strategies.
• A simple vascular calcification score (SVCS) has been developed to predict vascular calcification and arterial stiffness.

Purpose of the Study:

• To evaluate the role of systemic factors, particularly the simple vascular calcification score (SVCS), in influencing blood access flow (Qa).
• To assess the predictive power of SVCS for detecting stenosis in vascular access for hemodialysis.

Main Methods:

• A transversal study involving 50 patients undergoing hemodialysis.
• Blood access flow (Qa) was measured using the Blood Temperature Monitor (BTM) and Doppler methods.
• Clinical, laboratory, and radiological variables, including SVCS, were recorded, and non-parametric tests were used to analyze their association with Qa.

Main Results:

• Pearson's correlation between DU-Qa and TD-Qa was 0.851 (p<0.001).
• DU-Qa showed significant variation with age, VA type, SVCS, intra-access arterial pressure, and time on dialysis.
• BTM-Qa varied significantly with diabetes status, age, first VA status, intra-access arterial pressure, and dialysis time; gender, hypertension, and analytical parameters did not significantly affect flow values.

Conclusions:

• A higher SVCS was associated with lower direct ultrasound (DU)-measured access flow (Qa), indicating a potential advantage of this method for assessing vascular access.
• The simple vascular calcification score (SVCS) can be a valuable tool for risk stratification and guiding new surveillance recommendations for hemodialysis vascular access.