Study design, materials and methods
This is a prospective randomized controlled trial executed in two clinical sites in which eligible patients with mild and moderate urinary incontinence after radical prostatectomy were enrolled and randomly divided into two groups: the treatment group and the control group. The patients in treatment group received transurethral Erbium: YAG laser in non-ablative SMOOTH mode. Six laser sessions with 3 weeks interval were performed. The control group received biofeedback and electrostimulation therapy in 30 minutes sessions three times a week for 15 consecutive weeks. The primary outcome measures were the change in a) Incontinence Episodes Frequency in 72 hours (IEF) and b) 1 hour pad test. The secondary outcome measures used to evaluate the therapeutic effect were c) International Consultation on Incontinence Questionnaire–Urinary Incontinence Short Form (ICIQ-UI SF); d) Incontinence Quality of Life Questionnaire (I-QoL); e) Patient Global Impression of Improvement (PGI-I) and urodynamic indicators f) Abdominal Leak Point Pressures (ALPP) and g) Maximum Urethral Closure Pressure (MUCP). The total treatment effectiveness was calculated as a combination of the results of the ICIQ-UI SF and 1 hour pad test and the scores were divided into four categories (Cured / Significant Effect, Effective, Minor Effect and Ineffective). The occurrence of adverse reactions after treatment were observed at each visit and follow-ups. The assessments of outcomes were made before treatment, at 9 weeks of treatment, at the end of treatment (18 weeks), and at 6 months after the end of treatment. The study was executed in accordance with the Declaration of Helsinki for research and was approved by appropriate Ethics Committee and all the patients signed the informed consent.
Results
Between December 2020 and June 2023, a total of 79 patients who met the inclusion criteria were recruited and randomly assigned to treatment (n=42) or control group (n=37). Baseline characteristics in terms of average age, average post-surgery time and urinary incontinence measures between treatment and control group showed no significant difference between groups (p > 0.05). The primary outcome measures the IEF and 1-hour pad test values in the laser group showed larger reduction than control group at all time points and the difference between the two groups was statistically significant (p < 0.01). All secondary outcome measures also showed significant improvement in comparison to the baseline and the results of laser group were significantly better than of control group (p<0.01) in all three time points. After 18 weeks, 76.19% of patients in laser group and 32.43% of patients in control group had PGI-I scores ≤ 3 points ("Very much better" or "Much better" or "A little better"). The total effectiveness of laser group and control group at 6 months follow-up, compared to baseline, were 66.67% and 29.73%, respectively. No adverse reactions such as infection, hematoma, tissue burns, dysuria or new urge incontinence were observed in any of the groups.
Interpretation of results
We show in this study that the transurethral non-ablative Er:YAG laser improves the mild to moderate SUI in post radical prostatectomy patients significantly better than biofeedback and electrostimulation therapy as measured by various objective and subjective measurement tools.