To explore whether accessory renal artery affects the local blood perfusion of the kidney by contrast-enhanced ultrasound.

The ultrasound data of 31 patients (33 kidneys in total) with accessory renal artery detected by contrast-enhanced ultrasound at Beijing Hospital from September 2019 to December 2021 was retrospectively analyzed, and renal cortical blood perfusion in different parts of the kidney (upper, middle, and lower poles) was analyzed to obtain time-intensity curve and related parameters, including peak enhancement, wash-in area under the curve (AUC), rise time (RT), mean transit time-local, time to peak, wash-in rate, wash-in perfusion index, wash-out AUC, wash-in and wash-out AUC (WiWoAUC), fall time, and wash-out rate. By comparing the blood perfusion related parameters of different parts of the kidneys and the hemodynamic parameters of the main renal artery and the accessory renal artery, the blood perfusion of the kidneys with accessory renal artery was evaluated.

The vascular diameter of the accessory renal artery was significantly smaller than that of the main renal artery [(3.2±0.7)mm vs (4.6±0.7)mm, P＜0.001]. The hemodynamic indexes of the main renal artery and the accessory renal artery, such as peak systolic velocity, resistance index, and acceleration time, had no statistical differences (P＞0.05). When comparing renal cortical blood perfusion parameters of the upper, middle, and lower poles, the WiWoAUC of the upper pole was slightly higher than that of the middle pole (t=0.041), and there was no significant difference in other parameters (P＞0.05).

The existence of accessory renal artery has little effect on the local blood perfusion of the kidney, but more research is needed to confirm this finding.