The Whitaker test: 35 years on.

OBJECTIVE

To describe a 25-year experience of using the Whitaker test in a single tertiary centre for assessing upper urinary tract dilatation, and to evaluate the role of perfusion pressure-flow studies in contemporary urological surgery for equivocal upper tract obstruction.

PATIENTS AND

METHODS

In all, 143 patients with suspected upper urinary tract obstruction were investigated by at least one Whitaker test. The original method was extended to include observations on high flow-rate perfusion, abnormal renal pelvic peristalsis and loin pain with no pressure increase. Data on clinical presentation, perfusion pressure-flow studies, diuresis renography and choice of initial therapy were collected prospectively, and the long-term clinical outcome was analysed retrospectively.

RESULTS

In total, 145 studies were assessed; the Whitaker test showed obstructive features at conventional or higher flow rates in 61 cases and unobstructive patterns in 53. There were four equivocal results. Seventeen studies showed abnormal peristalsis within the renal pelvis and in 10 there was 'sensory' loin pain during the test. In patients with idiopathic hydronephrosis, there was agreement between the results of the pressure-flow studies and diuresis renography in 72%. The Whitaker test determined or contributed to the clinical management in 84% of the cases studied. It was accurate in its prediction of outcome in 77% of cases where obstruction was diagnosed and in 77% of unobstructive cases.

CONCLUSIONS

The Whitaker test continues to have a role in modern urological surgery. It should be reserved for assessing potential upper urinary tract obstruction in the following circumstances: equivocal results from less invasive tests; suspected obstruction with poor kidney function; loin pain with a negative diuresis renogram; suspected intermittent obstruction; and gross dilatation with a positive diuresis renogram.