A modified Whitaker test (upper urinary tract videourodynamics) using for evaluating complex upper urinary tract reconstruction surgical effect

BACKGROUND: To evaluate the feasibility and effect of upper urinary tract videourodynamics in complex reconstructed upper urinary tract. METHODS: From January 2016 to December 2018, patients who underwent complex upper urinary tract reconstruction and received upper urinary tract videourodynamics were included in the study. The modified Whitaker test was performed at 3 months after operation. The relative pelvic pressure was defined as the pelvic pressure minus the bladder pressure. Based on the flow rate, the test was divided into physiological phase and high flow phase. The results of pressure and image were classified into 3 types. Successful nephrostomy removal was defined as no symptoms and improved or stable hydronephrosis. RESULTS: A total of 12 patients who underwent complex upper urinary tract reconstruction received modified Whitaker test. All tests were successfully completed without adverse reactions. The relative pelvic pressure of 3 patients kept steady near the baseline throughout the examination and was classified into type 1. The pelvic pressure of 7 patients increased as the perfusion continued, and the relative pressure dropped to relative low level due to the peristalsis of ureter (type 2). The pressure of 2 patients increased along with increasing perfusion speed, and the relative pelvis pressure could easily reach 15 cmH2O. The peristalsis of ureter disappeared or appeared very weakly on the video record (type 3). Patients in type 1 (3 cases) and type 2 (7 cases) groups were allowed to remove the nephrostomy tube immediately. Patients in type 3 group needed to keep the nephrostomy for close follow up, and the tubes were removed 2 weeks and 4 weeks after the examination, respectively. None of the 12 patients received further treatment for recurrent symptoms and exacerbation of hydronephrosis. CONCLUSIONS: The modified Whitaker test is initially safe and feasible in postoperative evaluation of complex upper urinary tract reconstruction surgery. Detailed results can provide more evidence to judge whether nephrostomy tube could be removed safely.