Prospective Evaluation of Ipsilateral and Contralateral Renal Blood Flow During Retrograde Intrarenal Surgery.

Objectives: To evaluate the changes of peak systolic velocity(PSV), end-diastolic velocity(EDV), and resistive index(RI) of renal and arcuate arteries at the ipsilateral and contralateral kidneys during the retrograde intrarenal surgery.

Methods: The patients who had RIRS for the treatment of renal stones were prospectively included in the study. An experienced radiologist performed doppler ultrasonography of the ipsilateral and contralateral kidney before the surgery just after the anesthesia and at the end of the surgery before stenting. The PSV, EDV, and RI of renal and arcuate arteries at the ipsilateral and contralateral kidneys were measured.

Results: A total of 53 patients were included in the study. The postoperative mean PSV, EDV, and RI of renal arteries at the ipsilateral and contralateral arteries were similar to preoperative values. The mean PSV and RI of the arcuate arteries at the ipsilateral kidney significantly increased postoperatively (P = 0.032, P = 0.012) The postoperative mean PSV, EDV, and RI of arcuate arteries did not change significantly during the surgery. The age, gender, and flexible ureteroscopy time did not affect the change of renal and arcuate arterial PSV, EDV, and RI at the ipsilateral and contralateral kidneys.

Conclusion: The elevation of intrarenal pressure during RIRS did not change the blood flow at the major arteries of the ipsilateral and contralateral kidneys. On the other hand, there was a significant increase at the RI of the arcuate arteries in the ipsilateral kidney which was proposed to be related to the vasoconstriction of minor vasculature of the kidney.