This is the first study to investigate the predictive value of preoperative multichannel urodynamic parameters for initial trial without catheter (TWOC) failure following prostate deobstruction surgery. Benign prostatic obstruction (BPO), a major cause of male lower urinary tract symptoms (LUTS), is commonly managed with transurethral resection of the prostate (TURP), GreenLight laser photoselective vaporization (GLPVP), or holmium laser enucleation of the prostate (HoLEP). Despite surgical intervention, some patients still experience postoperative TWOC failure, requiring recatheterization and delaying recovery. Although clinical predictors have been explored, the role of preoperative multichannel urodynamic studies remains unclear. This study aimed to identify urodynamic and clinical predictors of initial TWOC failure after prostate deobstruction surgery.

This retrospective cohort study included male patients who underwent TURP, GLPVP, or HoLEP between 2018 and 2024 at our institution and had preoperative multichannel urodynamic studies within one year prior to surgery. Patients with prior lower urinary tract surgery, prostate or bladder cancer, urethral stricture, or pelvic irradiation were excluded. Baseline characteristics, biochemical data, uroflowmetry, and urodynamic parameters were analyzed. Urodynamic studies followed International Continence Society standards, measuring detrusor pressure at maximum flow (PdetQmax), bladder contractility index (BCI), bladder outlet obstruction index (BOOI), post-void residual volume (PVR), and voiding efficiency. Detrusor underactivity (DU) was defined as BCI < 100, while BOO severity was classified by BOOI (≥40: high, 20–40: equivocal, <20: low). The primary outcome was initial trial without catheter (TWOC) failure, defined as recatheterization within one week. Secondary outcomes included postoperative voiding function and long-term TWOC failure. Logistic regression identified independent predictors, with significance set at P < 0.05. Post hoc power analysis demonstrated 94% power to detect the observed between-group differences in DU and low BOO.

A total of 322 patients were analyzed, the overall initial TWOC failure rate was 12.1%. Postoperative uroflowmetry showed significant improvements in Qmax, PVR, and voiding efficiency across all surgical groups (all P < 0.001). Long-term TWOC failure occurred in 3 patients (7.3%) in the initial TWOC failure group, and none in the success group (P < 0.001). The initial TWOC failure group exhibited lower PdetQmax (P = 0.022), lower BCI (P = 0.007) and higher PVR (P = 0.017) (Table 1). In multivariate analysis, DU (OR: 2.77; P = 0.012) and low BOO (OR: 2.88; P = 0.041) were independently associated with initial TWOC failure (Table 2). Notably, patients presenting with both risk factors had a higher likelihood of initial TWOC failure (OR: 4.56, P = 0.003) (Figure 1). In contrast, patients with no DU and high BOO had a lower likelihood of initial TWOC failure (OR: 0.32, P = 0.003). Among patients with preoperative PVR ≥ 300 mL, those with no DU and high BOO consistently had a reduced risk of initial TWOC failure (OR: 0.11, P = 0.041).

Although postoperative uroflowmetry confirmed significant improvements in voiding parameters across the cohort, 12.1% of patients still experienced initial TWOC failure. DU and low BOO were identified as independent risk factors, while high BOO with preserved detrusor function was protective. These findings suggest that traditional predictors like prostate volume and PVR may be insufficient, and support integrating objective urodynamic measures into preoperative evaluation.

Preoperative multichannel urodynamic studies can enhance risk stratification for initial TWOC failure following prostate deobstruction surgery. Patients with DU and low BOO should be counseled about the increased risk of prolonged catheterization or alternative postoperative plans. In contrast, early catheter removal may be feasible in patients with high BOO but preserved detrusor function, even in the presence of high preoperative PVR. Furthermore, long-term catheter dependence (7.3%) among initial TWOC failure highlights the importance of individualized catheter management.

Zhu, Y., Zhao, Y. R., Zhong, P. et al.: Detrusor underactivity influences the efficacy of TURP in patients with BPO. Int Urol Nephrol, 53: 835, 2021
Elmansy, H., Shabana, W., Ahmad, A. et al.: Factors Predicting Successful Same-Day Trial of Void (TOV) After Laser Vaporization of the Prostate. Urology, 165: 280, 2022