Moderated Posters Session 1

3:05 PM - 3:50 PM

Clinical characteristics and useful signs that distinguish detrusor underactivity from bladder outlet obstruction in male patients with non-neurogenic lower urinary tract symptoms

Yoshihisa Matsukawa (1), Tsuyoshi Majima (1), Yasuhito Funahashi (1), Kazuna Matsuo (1), Shohei Ishida (1), Takashi Fujita (1), Tokunori Yamamoto (1), Momokazu Gotoh (1)

(1) Department Of Urology, Nagoya University Graduate School Of Medicine, , Japan


Detrusor underactivity (DU) is a common cause of lower urinary tract symptoms (LUTS) and is present in 9–48% of men undergoing urodynamic evaluation for non-neurogenic LUTS. However, LUTS due to DU is difficult to distinguish from LUTS due to bladder outlet obstruction (BOO); thus, little is known about the clinical characteristics of non-neurogenic DU in men. In this study, we investigated clinical characteristics of non-neurogenic DU in male patients.


The study included 683 treatment-naive men who visited our hospital with a chief complaint of LUTS. All patients underwent subjective and objective evaluations, including a urodynamic study. Patients with neurogenic diseases were excluded. We divided the patients into 2 groups (DU and BOO groups) and investigated the clinical characteristics of non-neurogenic DU. In this study, DU was defined as a bladder contractility index (BCI) of ≤100 and BOO index (BOOI) of ≤40, whereas BOO was defined as a BCI of >100 and BOOI of >40.


Of the 683 cases evaluated, 145 (21.2%) and 273 (40.0%) had confirmed DU and BOO, respectively. Comparisons of the subjective and objective parameters between the two groups revealed that the statistically significant parameters (mean values) in the DU and BOO groups were prostate volume (DU and BOO groups, respectively: 33.6 and 53.3 mL), prostate-specific antigen level (2.15 and 5.08 ng/mL), intravesical prostatic protrusion (IPP; 6.4 and 12.6 mm), international prostate symptom score (IPSS; 20.7 and 18.3), IPSS-voiding subscore (12.3 and 10.3), Qmax (6.6 and 7.7 mL/s), residual urine volume (100 and 55 mL), and voiding efficiency (65% and 79%). A multivariate analysis revealed that the factors that must be classified as DU were IPP, IPSS intermittent stream score, Qmax, and voiding efficiency.


Lower IPP, Qmax and voiding efficiency were considered significant predictors for discriminating DU from BOO in men with non-neurogenic LUTS.