The use of uroflowmetry to diagnose recurrent stricture after urethral reconstructive surgery

The ability of uroflowmetry to diagnose recurrent stricture disease after urethroplasty has not been fully investigated.

Our routine post-urethroplasty monitoring includes retrograde urethrogram and voiding cystourethrogram at 3 and 12 months, in addition to uroflowmetry at 3-month intervals for a year. All uroflowmetry data, including maximum flow rate, voided volume and voiding curve shape, as well as retrograde urethrogram/voiding cystourethrogram and voiding symptom data are stored in a prospectively maintained urethroplasty database that was analyzed for patients with postoperative retrograde urethrogram/voiding cystourethrogram and satisfactory uroflowmetry in the same period. Uroflowmetry data points and urinary symptoms were compared with corresponding findings on retrograde urethrogram/voiding cystourethrogram to determine the ability of uroflowmetry to predict recurrence.

A total of 278 men (68%) met study inclusion criteria, of whom 63 (23%) had recurrent stricture. Using a maximum flow rate of less than 10 ml per second resulted in only 54% test sensitivity to predict recurrence. The highest sensitivity and negative predictive value (each 99%) were achieved when all men with symptoms and/or obstructed flow curves were evaluated. Symptoms alone had a high specificity (87%), sensitivity (88%) and negative predictive value (95%).

Uroflowmetry is an adequate test to screen for postoperative stricture recurrence but only when the voiding curve and urinary symptoms are also evaluated. The flow rate alone does not appear to be a reliable tool to evaluate stricture recurrence.