Abstract
Objective: To describe upper-limb vascular abnormalities detected by preoperative Doppler ultrasound mapping, identify factors associated with an unsuitable radial artery and forearm cephalic vein, and evaluate the radial artery reactive hyperaemia test in predicting arteriovenous fistula (AVF) outcomes in end-stage kidney disease (ESKD). Methods: Prospective case-series of 51 ESKD patients undergoing preoperative Doppler ultrasound mapping before autogenous AVF creation at Viet Tiep Friendship Hospital (December 2020 - June 2021), followed for 12 months. The reactive hyperaemia test (3-minute clenched fist) was performed with measurement of the resistive index (RI); a positive test was conversion of the Doppler waveform from triphasic to monophasic with RI ≤ 0.7. Maturation was assessed at 4 weeks by the “rule of 6”. Thirty-one patients whose vessels were selected by physical examination alone served as comparison for the 1-year outcome. Results: The radial artery was unsuitable in 47.06% of patients (diameter < 2 mm 43.14%; absent or poor dilatation after reactive hyperaemia, RI > 0.7, 37.25%; anterior-wall calcification 9.80%); the forearm cephalic vein was unsuitable in 54.91%. Age > 65 years was strongly associated with an unsuitable radial artery (80.0% vs 33.33%; OR = 8.0; 95% CI: 1.891-33.850; p = 0.02); sex and diabetes were not (p > 0.05). Maturation at 4 weeks was 82.35%. Post-hyperaemia RI correlated inversely with the increase in radial artery diameter at 4 weeks (r = −0.486; p = 0.026; n = 21). At 1 year, functional patency was 78.43% versus 58.06% (HR = 0.269; 95% CI: 0.114-0.624; p = 0.003). Conclusion: Preoperative Doppler mapping identifies arterial or venous abnormalities precluding wrist AVF creation in about half of ESKD patients - abnormalities physical examination cannot detect. Advanced age is the strongest predictor of an unsuitable radial artery. The reactive hyperaemia test is not merely a vessel-selection criterion but a functional predictor of postoperative arterial remodelling, and warrants routine inclusion in mapping protocols.
