POSITIONAL VARIATION IN THE WHITAKER TEST

PURPOSE: To describe positional variation in the outcome of the Whitak er test.MATERIALS AND METHODS: The authors retrospectively reviewed th e cases of six patients in whom the pressure gradient during Whitaker testing varied by at least 10 cm of water and changed from normal (les s than or equal to 13 cm of water) to abnormal (>13 cm of water) when patients were placed in different positions. RESULTS: Four patients ha d obstruction only in nonstandard positions. All had intermittent symp toms, and three had ureteral kinks at fluoroscopy. Two patients with i leal conduits had abnormal results in the standard position but normal results at repositioning related to compression of the conduits (seen as conduit distention at fluoroscopy). All six had undergone urinary tract surgery. Gradient differences with positional change ranged from 10 to >38 cm of water.CONCLUSIONS: Whitaker testing in different posi tions may help identify intermittent obstructions that might otherwise go undetected or prevent inappropriate diagnosis of obstruction. Inte rmittent or unexplained symptoms, tortuous ureters, malpositioned kidn eys, or previous surgery are indications for provocative positional te sting.