Long-term monitoring of renal pelvic pressures in man.

In spite of improvements in the techniques of radiological, urodynamic and radionuclide investigations there are patients in whom it remains very difficult to determine whether upper urinary tract dilatation is associated with obstruction. We describe a technique for the long-term monitoring of renal pelvic pressures and compare the results of this investigation with other methods. We believe that this technique is more useful than standard urodynamic tests and is of particular value in patients with equivocal pelviureteric junction obstruction and in those who have undergone previous surgery.