Detrusor contraction power parameters (BCI and W (max)) rise with increasing bladder outlet obstruction grade in men with lower urinary tract symptoms: results from a urodynamic database analysis

Matthias Oelke*, Kevin L. J. Rademakers, Gommert A. van Koeveringe

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


To investigate to what extent detrusor work during voiding is influenced by bladder outlet obstruction (BOO) in adult men with lower urinary tract symptoms (LUTS). We reviewed data of patients with LUTS suggestive of benign prostatic hyperplasia who received computer-urodynamic investigations as part of their baseline clinical assessment. BOO was defined by the Schafer classification and detrusor work during voiding was quantified by calculation of the bladder contractility index (BCI) and maximum Watt factor (W (max)) obtained by pressure-flow analysis. A total of 786 men with medians of 64 years, IPSS 16 and prostate volume of 35 ml, were included in the study. A total of 462 patients (58.8 %) had BOO (Schafer 2-6). Both detrusor contraction power parameters continuously increased with rising BOO grade. Median BCI increased from 73.3 in Schafer 0 to 188.0 in Schafer 6, whereas W (max) increased from 9.6 to 23.4 W/m(2) (p <0.001). Results of BCI and W (max) correlated well (p <0.001). With increasing BOO grade, there was a significant decrease of voiding efficiency (p <0.001). In adult male LUTS patients, detrusor contraction power parameters-BCI and W (max)-continuously increase with rising BOO grade. According to our results, it is impossible to determine a single threshold value for detrusor contraction power to diagnose detrusor underactivity in a group of LUTS patients with different BOO grades. The study is limited to men with non-neurogenic LUTS. Future studies should evaluate exact threshold values for BCI and W (max) in BOO subgroups to adequately define detrusor underactivity and investigate men with other bladder conditions.
Original languageEnglish
Pages (from-to)1177-1183
JournalWorld Journal of Urology
Issue number5
Publication statusPublished - Oct 2014


  • Detrusor underactivity
  • Detrusor contractility
  • Bladder outlet obstruction
  • Lower urinary tract symptoms
  • Men
  • Urodynamics
  • Pathophysiology

Cite this