Hypothesis / aims of study
Benign prostatic enlargement (BPE) is a common condition in aging men, frequently causing lower urinary tract symptoms (LUTS). While bladder outlet obstruction (BOO) is often present, some patients experience LUTS without BOO. Although it is a known predictor of surgical success, outcomes in patients without BOO remain underexplored (1,2). This study aims to compare long-term functional outcomes in patients with and without BOO undergoing photovaporization of the prostate (PVP) with GreenLight XPS 180 W and Thulium laser enucleation of the prostate (ThuLEP).
Study design, materials and methods
This secondary analysis of an observational longitudinal study included patients from January 2012 to March 2023 who underwent PVP or ThuLEP for LUTS/BPE with a preoperative urodynamic study (UDS). Exclusion criteria included lack of consent, prior pelvic radiotherapy, neurogenic lower urinary tract dysfunction (NLUTD), previous prostatic intervention, urethral stricture, prostate cancer, or incomplete follow-up data.
Preoperative evaluations comprised medical history, physical examination, International Prostate Symptom Score (IPSS) with a quality-of-life (QoL) question, ultrasonography, and UDS. BOO was defined by the bladder outlet obstruction index (BOOI): detrusor pressure at Qmax - 2 Qmax. Patients were classified as Group 1 (BOOI <20), Group 2 (BOOI 20-40), and Group 3 (BOOI >40). Primary outcomes included IPSS reduction (≥4 points) and QoL improvement (≥1 point). Follow-up ranged from 2-8 years.
A descriptive analysis was conducted based on the nature of each variable. Group differences were evaluated using Kruskal-Wallis test for continuous variables and chi-square (X²) test or Fisher’s exact test for categorical variables, as appropriate (p<0.05 considered significant). Statistical analysis was performed using Jamovi 2.3.21.
Results
A total of 276 patients were included: 20 in Group 1, 57 in Group 2, and 199 in Group 3. Group 3 had significantly higher detrusor pressure at Qmax (74.1 vs. 50.5 vs. 27 cm H2O, p<0.001) and bladder contractility index (107 vs. 88.5 vs. 63, p<0.001), confirming obstruction. Preoperative uroflowmetry showed lower Qmax in Group 3 (p=0.019) and higher post-void residual volume in Groups 1 and 3 (p=0.0156).
Intraoperatively, Group 3 required higher laser energy (300 vs. 136 vs. 172 kJ, p=0.012) and longer surgical time (70 vs. 58.5 vs. 50 min, p=0.026). Hospitalization and catheterization times were comparable (p=0.628, p=0.093). Incidences of urinary retention (p=0.771) and urinary tract infections (p=0.997) were similar across groups.
Median IPSS reduction was 11 in Group 3, 13.5 in Group 2, and 7 in Group 1 (p=0.112). A clinically significant IPSS reduction occurred in 57.9% of Group 1, 91.4% of Group 2, and 87.9% of Group 3 (p<0.001). QoL improved by a median of 3 points in Group 3, 2 in Group 2, and 1 in Group 1, with ≥1-point improvement in 62.1% of Group 2 and 61.3% of Group 3 (p=0.107).
Interpretation of results
All groups experienced symptom relief. However, while most patients in Groups 2 and 3 met the threshold for clinically significant improvement, a significantly lower percentage in Group 1 didn't. This suggests that at least an indeterminate level of obstruction may enhance surgical response and that BOOI alone should not determine success, highlighting the need for additional urodynamic parameters in treatment planning. BOO patients required more energy and longer procedures, but these factors did not yield superior outcomes.
Concluding message
Both BOO and non-BOO patients benefited from surgery, with no significant difference between Groups 2 and 3, though Group 1 had a lower rate of clinically significant IPSS improvement. This supports the benefit of surgery regardless of BOO status, with potentially optimized outcomes in patients with at least indeterminate BOOI. Limitations include selection bias, reliance on a single preoperative UDS, and variable follow-up. Further studies should refine BOO thresholds and incorporate additional parameters to improve surgical decision-making and individualized patient counseling.