Changes in renal Doppler ultrasonographic parameters in patients managed with rigid ureteroscopy.

Background: There has been no study evaluating the intrarenal hemodynamic changes after ureteroscopy in the published literature.

Purpose: To determine preoperative and postoperative intrarenal vascular parameters such as resistive index (RI), pulsatility index (PI), peak systolic velocity (PSV), end-diastolic velocity (EDV), measure changes on these values (ΔRI, ΔPI, ΔPSV, ΔEDV) after ureteroscopy (URS) and compare the outcomes with the results of normal contralateral kidneys, and finally investigate possible parameters that would affect renal vascular resistance changes.

Material And Methods: We prospectively studied 47 patients who underwent rigid URS. Preoperative gray-scale and Doppler ultrasonography (CDUS) measurements were obtained 24 h before URS. Similarly, postoperative CDUS measurements were done 24 h after the operation. The degree of hydronephrosis and location of stones in the obstructed kidneys, diameters of both kidneys, and thickness of renal parenchyma were evaluated with gray-scale US followed by CDUS with calculation of the intrarenal RI, PI, PSV, and EDV values for each kidney.

Results: For the operated kidneys, statistically significant P values were noticed when RI and PI values were considered (P < 0.001). ΔRI and ΔPI of the operated kidneys were also significantly greater than the values for non-operated kidneys (P < 0.001). However, it was not the case for ΔPSV and ΔEDV values. In Spearman correlation coefficient analysis, ΔRI was found to be correlated with the parameters: "operative time" and "irrigation fluid volume". No significant relation was documented between ΔRI and the other parameters: age, gender, side of ureteroscopy, stone location, and degree of hydronephrosis.

Conclusion: Significant changes in RI and PI values in patients treated with URS reveal that URS can cause a significant increase in renal vascular resistance. With the increase in operative time and irrigation fluid volume used during the operation, RI seems to be significantly increased.