Renal Doppler Ultrasound findings of partial ureteral obstruction: experimental study in rabbits

Journal of Korean Society of Medical Ultrasound 1994;13(1): 19-26.

ABSTRACT

The purpose of this experimental study was the investigation of the usefulness of Doppler ultrasound study inthe diagnosis and follow-up of the unilateral partial obstructive uropathy. The materias were 20 New Zealand whiterabbits. We ligated the left ureter with an angiographic guide wire of 0.97mm in outer diameter and then removedthe guide wire to establish partial ureteral obstruction. We performed ultrasonography, Doppler study, and99mTc-DMSA scan before and 6 hours(except DMSA scan), 1 day, 3 days, 1,2,3,4 and 6 weeks after the ureterligation. Doppler resistive index(RI) of the obstructed kidneys significantly elevated from 6 hours to 3 daysafter the ureter ligation(P<0.05). Then RI decreased at 1 week after the ligation and did not change significantlythereafter. Percent uptake of 99mTc-DMSA of the obstructed kidneys decreased significantly at 1 day after theureter ligation and showed no signifcant changes thereafter. In summary, RI during the initial 3 days after thepartial obstruction of the ureter represented the elevation of the renal vascular resistance. Subsequent decreasein RI frm 7 days after the obstruction suggested that Doppler study using RI might lead to an erroneousinterpretation of renal hemodynamics. In conclusion, we believe that the estimation of RI scan be useful for theevaluation of partial obstructive uropathy during the acute and subacute phases. However, it is hardly considereduseful during the chronic phase.

Keywords: Ureter,stenosis or obstruction