MP74-14 INTERNATIONAL CONTINENCE SOCIETY DEFINITION OF DETRUSOR UNDERACTIVITY; ANALYSIS OF CLINICAL PARAMETERS AND COMPARISON WITH CONTRACTILITY GRADING METHODS

Abstract

INTRODUCTION AND OBJECTIVES: Lower urinary tract symptoms (LUTS) experienced by elderly men may be due to bladder outlet obstruction, detrusor underactivity (DU) or a combination of both. The International Continence Society (ICS) defines DU as ‘a contraction of reduced strength and/or duration, resulting in prolonged bladder emptying and/or a failure to achieve complete bladder emptying within a normal time span’. This definition is quantifiable by the following non-invasive urodynamic parameters: voiding time (VT), post void residual (PVR) and voiding efficiency (void%). The best method to determine DU is by pressure flow study. Three parameters to grade detrusor voiding contraction are Schafer pressure/flow nomogram (LinPURR), bladder contractility index (BCI) and maximum Watt Factor (Wmax). The goal of this study was to compare three methods of grading detrusor contraction and to correlate results with noninvasive measurements of DU VT, PVR and void%. METHODS: We evaluated 1420 urodynamic pressure flow studies of men > 50 years of age with LUTS. Patients with abnormal urinalysis, neurological disorders, pelvic or urological surgery, or with evidence of urethral stricture were excluded. We determined VT, PVR and void% of all measurements and graded contractility with LinPURR, BCI and Wmax. Correlation of different grading methods regarding contractility groups was done using either Spearman or Pearson correlation test. A threshold of 80% for void% was chosen as a normal limit. We tested diagnostic values of VT, PVR and void% and combinations of this parameters related to contractility groups by calculating specificity and sensitivity. RESULTS: LinPURR and BCI as well as LinPURR and Wmax contractility groups showed a highly significant correlation (0.975, p<0.000), (0.620, p<0.001) respectively. Sensitivity and specificity of VT, PVR and void% have been calculated for LinPURR contractility. Combining VT and void% showed a sensitivity of 71.0% and a specificity of 62.5%. Combining VT and PVR showed a sensitivity of 38.9% and a specificity of 38.2%. Combining VT and void% diagnosed 35.7% and combining VT and PVR diagnosed 42.8% of the DU as normal contractility in LinPURR contractility grading. CONCLUSIONS: Results of LinPURR, BCI and Wmax contractility grading were highly correlated. Therefore, because of simplicity, we suggest to use LinPURR classification in daily practice. The combination of void% and VT nor PVR and VT is specific in predicting detrusor underactivity.