Transurethral resection of the prostate (TURP) is still a standard surgical procedure for patients with lower urinary tract symptoms (LUTS) suggestive of benign prostatic obstruction (BPO). According to the Japanese guideline of benign prostatic hyperplasia (BPH), preoperative urodynamics including filling cystometry and pressure-flow study (PFS) are recommended to delineate BPO, detrusor underactivity (DU) and detrusor overactivity (DO). AUA and EAU guideline indicate that PFS is optional if the patient’s condition does not suggest BPO. Several previous studies showed that unfavorable urodynamic factors such as unobstruction, DU or DO before TURP could predict unsuccessful short-term outcome. In this study, we retrospectively examined the long-term outcome after TURP depending on preoperative lower urinary tract function.

We retrospectively collected the data of patients who had undergone TURP before December 2010. Patients who were evaluated by urodynamics and IPSS preoperatively and re-evaluated by IPSS at the minimum 7-year after TURP were included in this study. Patients who received any treatments to improve voiding dysfunction including alpha-adrenergic antagonist, phosphodiesterase 5 inhibitor, 5 alpha-reductase inhibitor, cholinergic agent, re-TURP, intermittent catheterization or placement of urethral catheter during the observation period were defined as the relapse of voiding dysfunction. The Schäfer nomogram was used to judge the obstruction and detrusor contractility. We assessed the change in IPSS over time depending on obstruction (Schäfer grade: 3-6) vs unobstruction (Schäfer grade: 0-2) and normal detrusor contractility (Strong: ST and normal: N) vs DU (weak: W and very weak: VW), and analyzed the relapse rate of voiding dysfunction using the Kaplan-Meier method.

Thirty-nine patients were included. The mean age at TURP was 69.8 years and the mean observation period was 114 months. During the observation period, 8 patients (21%) were categorized as the relapse of voiding dysfunction and the mean time to the relapse was 4.2 years. The patients categorized as unobstruction or DU had a higher recurrence rate of voiding dysfunction with a statistical significance between those with unobstruction vs obstruction (Figure 1). Except for those with relapse of voiding dysfunction, improvement of IPSS was maintained after TURP over 10 years. Improvement of IPSS tended to be worse in the patients with unobstruction or DU compared to those with obstruction or normal contractility (Figure 2).
 Figure 1: Relapse free rate; Kaplan-Meier estimates the relapse free rate between patients with and without BPO (left figure), and patients with ST/N detrusor contractility and with W/VW (right figure). 
 Figure 2: IPSS change after TURP; Comparison of IPSS change over time after TURP between patients with and without BPO (left figure), and patients with ST/N detrusor contractility and with W/VW (right figure).

In the patients with BPO, improvement of LUTS has been maintained during the long-term period after TURP. On the other hand, the patients without BPO or those with DU had a higher recurrence rate of LUTS and were likely to receive any treatments to improve voiding symptoms. The mean time to relapse was 4.2 years, reflecting the good short-term and mid-term outcome even in such patients. Because TURP is a surgical procedure to remove prostatic obstruction and improve voiding symptoms, the benefit of TURP is less anticipated for the patients without BPO. To guarantee the long-term outcome after TURP, it’s necessary to determine the presence of absence of obstruction as described in the guideline of each urological association. The limitation of this study is a small sample size and retrospective nature of the study.

TURP is a good surgical procedure to guarantee a long-term symptomatic outcome in the patients with BPO, while the patients without BPO are likely to have a relapse of voiding dysfunction and need any additional treatments during a long-term after TURP.