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 resistiv e index (RI), maximum velocity (V-max), and mean velocity (V-max) in d iagnostic evaluation of the partially obstructed kidney, METHODS. Seve n 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 an d contralateral nonobstructed kidneys. The General Linear Model multiv ariate analysis of variance was used for statistical analysis of data, RESULTS. There was no significant difference in the preoperative cont rol 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 stu dy, CONCLUSIONS. In this study, RI was not a reliable indicator of par tial renal obstruction, Measurements of maximal and mean blood flow ve locities reached discriminatory significance only after the fifth post obstructive day, proving insensitive in the immediate postobstructive period, V-max and V-mean demonstrated a decrease in the partially obst ructed renal collecting system after 5 days of obstruction and mag ser ve as useful parameters in the evaluation of obstruction after the imm ediate acute period, when compared With a nonobstructed contralateral system.