Evaluation of renal resistive index, maximum velocity, and mean arterial flow velocity in a hydronephrotic partially obstructed pig model

RATIONALE AND OBJECTIVES. The authors investigate, in a controlled pig model, the usefulness of Doppler sonographic measurements of resistive index (RI), maximum velocity (V-max), and mean velocity (V-max) in diagnostic evaluation of the partially obstructed kidney, METHODS. Seven female pigs underwent surgical partial unilateral renal obstruction at the ureteropelvic junction, Doppler parameters of RI, V-max, and V-mean were measured preoperatively and postoperatively in obstructed and contralateral nonobstructed kidneys. The General Linear Model multivariate analysis of variance was used for statistical analysis of data, RESULTS. There was no significant difference in the preoperative control values of RI (P = 0.71), V-max (P = 0.27), and V-mean (P = 0.12), There was a statistically significant decrease in the V-max and V-mean after postoperative day 5 in the obstructed kidney compared with the contralateral nonobstructed kidney (P = 0.01 and 0.03, respectively), There was no statistically significant difference in RI during the study, CONCLUSIONS. In this study, RI was not a reliable indicator of partial renal obstruction, Measurements of maximal and mean blood flow velocities reached discriminatory significance only after the fifth postobstructive day, proving insensitive in the immediate postobstructive period, V-max and V-mean demonstrated a decrease in the partially obstructed renal collecting system after 5 days of obstruction and mag serve as useful parameters in the evaluation of obstruction after the immediate acute period, when compared With a nonobstructed contralateral system.