Upper urinary tract videourodynamics: a more complete Whitaker test.

A modification of the Whitaker test is described using only a single nephrostomy tube for both inflow and pressure measurement. The technique also includes ureteral transit time and fluoroscopic imaging. This technique has been used in ten patients, all of whom had symptoms and/or imaging suggesting obstruction. Five patients had no obstruction on testing with true renal pelvic pressures </= 10 cm of H20 at all times. Five patients were obstructed (four distally and one proximally) with true renal pelvic pressure >20cm. This technique requires only one access port into the renal pelvis. The addition of fluoroscopy and ureteral transit time considerably aided our interpretation of the test. These modifications have made the Whitaker test more complete.