Login to Access Video or Poster Abstract: MP26-13
Sources of Funding: None

Introduction

Little is known about contribution of detrusor contraction duration (DCD) for voiding function in males and initial findings have been contradictory. Our objective was to analyze physiologic factors that influence male DCD to better understand its role. _x000D_

Methods

We retrospectively reviewed urodynamic studies in 148 male patients (2010-2016). 120 patients had measurable voluntary DCD. Independent variables analyzed included voided volume (VV), post void residual (PVR), detrusor pressure at maximum flow (PdetQmax), bladder compliance (BC), maximum flow rate (Qmax), bladder outlet obstruction index (BOOI), and bladder contractility index (BCI). BOOI (PdetQmax - 2 Qmax) was categorized into non-obstructed (BOOI < 20), equivocal (20 ≤ BOOI ≤ 40), and obstructed (BOOI > 40). BCI (PdetQmax + 5 Qmax) was categorized into weak contraction (BCI < 100), normal contraction (100 ≤ BCI ≤ 150), and strong contraction (BCI > 150). Multiple regression analysis determined which variables were related to DCD. Variables dependent upon each other were not analyzed together (i.e. either PdetQmax and Qmax, or BOOI and BCI). _x000D_

Results

Of 120 patients, mean age was 63.4 ± 17 years and mean DCD was 103.6 ± 66.9 sec. Results from multiple regression analysis (DCD as the outcome) are shown in Table 1. Increased Qmax (p<0.05), PdetQmax (p<0.01), and VV (p<0.001) were associated with increased DCD. Regression 1 shows that when Qmax increases by 1 mL/s, DCD decreases by 2.59 ± 1.19 sec, on average. Increase in PdetQmax by 1 cm H2O increases DCD by 0.40 ± 0.15 sec. Increase in 1 mL VV increases DCD by 0.20 ± 0.04 sec. When performing multiple regression analysis using BOOI, BCI, VV, and bladder compliance, only BOOI (obstructed vs non-obstructed, p<0.002) and VV (p<0.001) were significantly associated with prolonged DCD. _x000D_

Conclusions

This is one of the first studies to examine association between DCD and other voiding parameters. In men, longer DCD appears to be influenced by higher PdetQmax, VV, and lower Qmax. Men with outlet obstruction have prolonged DCD compared to men without. Contraction strength did not influence DCD. Further studies are needed to determine clinical significance of these physiologic relationships and utility of DCD._x000D_

Funding

None