Unexpected identification of peak systolic velocity in the radial artery as a risk factor for functional primary patency of radiocephalic fistulas.

Objective: As radiocephalic fistula is not necessarily appropriate for all patients with advanced kidney disease, our aim was to investigate the sensitive indicators that affect the functional primary patency of radiocephalic fistulas.

Methods: This prospective observational study included consecutive patients referred to the Second Hospital of Dalian Medical University for initial creation of radiocephalic fistula from July 2017 to December 2019. Preoperative ultrasound parameters, demographic characteristics, serum indicators and comorbidities were recorded. The functionality of radiocephalic fistulas would be assessed every 6 months until March 2023, following their unassisted maturation, unless AVF dysfunction, kidney transplantation, mortality or loss to follow-up occurred. Kaplan-Meier analysis was employed to illustrate differences in functional primary patency of radiocephalic fistulas, while log-rank tests were utilized to compare survival curves. Univariate and multivariable Cox proportional hazard models were performed, yielding hazard ratios and 95% confidence intervals. The significance level was set at 5% for a two-sided test.

Results: The studies included a total of 182 patients who successfully underwent radiocephalic fistulas with primary unassisted maturation. The mean age of the study population was 58 years, with 66 percent being male. All AVFs were placed on the forearm, with 84% located on the left side. The primary patency rates of eleven parameters exhibited significant differences between groups stratified by cut-off values at different time points. Notably, the group with a peak systolic velocity of the radial artery near the elbow ≤59cm/s demonstrated a higher primary patency rate compared to the >59cm/s group at 2 years (78.4% vs 57.5%, P=0.026). In the univariate Cox proportional hazard models, the P values for gender, the diameter of radial artery near the elbow, the peak systolic velocity of radial artery near the elbow, the diameter of brachial artery near the elbow were less than 0.1. The multivariable Cox proportional hazard model revealed that only the peak systolic velocity of radial artery near the elbow exhibited a significant impact on the functional primary patency of radiocephalic fistula (HR=1.017, 95%CI 1.002-1.031, P=0.021).

Conclusions: The peak systolic velocity of the radial artery near the elbow is a significant risk factor for functional primary patency of radiocephalic fistula. Preoperative evaluation of the peak systolic velocity could allow to identify patients with a lower likelihood of long-term radiocephalic fistula patency, facilitating improved selection of candidates for radiocephalic fistula creation.