Is Bladder Cycling Useful in the Urodynamic Evaluation previous to Renal Transplantation?

Abstract

Objectives: To evaluate the usefulness of bladder cycling (BC) in differentiating between urodynamic abnormalities due to reversible bladder dysfunction and those due to preexisting lower urinary tract (LUT) abnormalities, and to determine if BC increases the diagnostic yield of urodynamic investigations (UIs) in these patients. Methods: Eleven patients with oligoanuria (<300 ml/day) were evaluated with complete UIs. All cases showed low compliance (mean 6 ml/cm H₂O) and low cystometric capacity (mean 146 ml) and were placed in a BC program. The indications for UIs were LUT symptoms in 2 patients, LUT abnormalities (myelodysplasia or urethral valves) in 3 patients, or the appearance of an extremely small bladder on cystogram (6 patients). BC was performed through a hypogastric catheter in an outpatient setting. UIs were repeated afterwards. Results: After BC, 5 patients (45%) continued to have low compliance (<8 ml/cm H₂O) and 4 patients (36%) had normal UIs. In 2 cases (18%), a previously unrecognized obstruction was diagnosed. No patient with LUT symptoms or abnormalities had a normal UI after BC. Conversely, 4 of 6 patients in whom BC was indicated due to a small bladder on cystogram had normal UIs after BC. Conclusions: BC is useful in explaining whether high bladder pressure is due to dysfunction or to preexisting disorders, and thus indicating the proper surgery for correction. Suprapubic BC significantly increases bladder capacity thus increasing the diagnostic yield of the UI.