Spontaneous voiding is surprisingly recoverable via outlet procedure in men with underactive bladder and documented detrusor underactivity on urodynamics.

Aims: To identify clinical and urodynamic factors leading to spontaneous voiding in men with detrusor underactivity (DU) and suspected bladder outlet obstruction who underwent an outlet de-obstruction procedure.

Methods: We identified 614 men who underwent an outlet procedure at our institution from 2005 to 2014. Men were stratified by bladder contractility index (BCI). The primary outcome was spontaneous voiding after surgery. Data were analyzed in Statistical analysis system software.

Results: Of the 131 men who underwent preoperative urodynamics, 122 (mean age 68 years) had tracings available for review. DU (BCI < 100) was identified in 54% (66 of 122), of whom only 68% (45 of 66) voided spontaneously before surgery, compared with 82% (46 of 56) of men with BCI ≥ 100. At a mean follow-up of 6.4 months postoperatively, 79% (52 of 66) of men with DU were able to void spontaneously, compared with 96% (54 of 56) of men with BCI ≥ 100. In men with a BCI < 100 unable to void before surgery, 57% (12 of 21) recovered spontaneous voiding after surgery. On logistic regression for the outcome postoperative spontaneous voiding, significant preoperative characteristics, and urodynamic factors included preoperative spontaneous voiding (odds ratio [OR] = 9.460; 95% confidence interval [CI] = 2.955-30.289), increased maximum flow rate (Qmax; OR = 1.184; 95% CI = 1.014-1.382), increased detrusor pressure at maximum flow (Pdet@Qmax; OR = 1.032; 95% CI = 1.012-1.052), DU with BCI < 100 (OR = 0.138; 95% CI = 0.030-0.635), and obstruction with bladder outlet obstruction index > 40 (OR = 5.595; 95% CI = 1.685-18.575).

Conclusion: Outlet de-obstruction improves spontaneous voiding in men with DU and may benefit men who do not meet the urodynamic threshold for obstruction.