The value of ultrasound scanning of the upper urinary tract in patients with bladder outlet obstruction.

Ultrasound scanning of the upper urinary tract enables a urologist to allocate a degree of urgency for surgery when upper tract dilatation is present. We have studied whether other assessments of bladder outlet obstruction could eliminate this investigation. The study group comprised 223 consecutive patients who had ultrasound scans for bladder outlet obstruction. Estimation of urea, creatinine, residual urine and flow rate could not predict the presence of upper tract dilatation and it was concluded that ultrasound scanning of the upper tracts should continue to be used as a means of deciding how urgently a patient requires prostatic surgery.