It is concluded that although symptoms are not reliable in predicting those who will require a prostatectomy, it is possible to select those where a prostatectomy may not treat the main symptoms. Thus the patient with frequency and urgency and urge incontinence due to detrusor instability will gain little from a prostatectomy unless there is good urodynamic evidence of outflow obstruction. The most satisfactory way to screen the patient for significant obstruction is a urinary flow rate. This objective measure will give a reliable indication of the extent of the obstruction; a flow rate is the best single guide to the severity and if done serially, to the progression of an obstruction.

The debate over the usefulness of an intravenous urogram is not yet resolved. However, modern imaging techniques such as ultrasonography have already become important in screening the urinary tract and in some centers are the basic screening methods.

The interpretation of symptoms, the use of the best available imaging methods and the use of urodynamics for selected cases is the most acceptable approach to determining which patient needs surgery for outflow tract symptoms.

Keywords: urinary tract obstruction, urodynamics