Can we predict which patients will experience resolution of detrusor overactivity after transurethral resection of the prostate?

Purpose: We determined which clinical and urodynamic variables may be related to persistent detrusor overactivity after transurethral resection of the prostate.

Materials and methods: We studied 46 patients with bladder outlet obstruction due to benign prostatic hyperplasia who were treated with transurethral prostate resection from 2011 to 2012. All patients underwent urodynamic analysis preoperatively and 12 months postoperatively. Clinical and urodynamic variables in the preoperative period were correlated with the resolution of detrusor overactivity postoperatively.

Results: Patients with detrusor overactivity in the preoperative period were older (65.2 vs 61.1 years, p = 0.041) and had a higher I-PSS (International Prostate Symptom Score) (25.2 vs 19, p = 0.014) and higher maximum flow rate (8.6 vs 6.6 ml per second, p = 0.039). Patients with persistent detrusor overactivity were statistically older than those with resolution (69 vs 63 years, p = 0.043). Detrusor overactivity persisted in 63.6% of patients with maximum cystometric capacity less than 250 ml compared to 20% of those with greater than 250 ml (p = 0.024). When analyzing urodynamic variables together, we found a 66.7% chance of persistent detrusor overactivity in patients with maximum cystometric capacity less than 250 ml and detrusor overactivity amplitude greater than 40 cm H2O (p = 0.041). When these characteristics were associated with early detrusor overactivity, the chance of persistent detrusor overactivity was 83.3% (p = 0.013).

Conclusions: Advanced patient age together with low maximum cystometric capacity, and early and high detrusor overactivity amplitude are the most important predictors of persistent detrusor overactivity after relief of bladder outlet obstruction.