This randomized, prospective study enrolled patients with BPH who underwent HoLEP at a single institution (Tohoku Medical and Pharmaceutical University Hospital) between September 2017 and March 2019. Patients were randomly assigned in a ratio of 1:1 to one of the two groups using a simple randomization procedure (computerized random numbers generated using Microsoft Excel for Windows). Group A included patients who started PFME preoperatively 28 days before HoLEP and continued postoperatively. Group B included patients who started PFME postoperatively only.
The inclusion criteria were males between 50 and 90 years of age with symptoms of dysuria for ≥3 months before study entry. Patients with prostate volumes of ≥30 ml were eligible. Patients who could continue PFME on their own were eligible. We excluded patients who could not continue PFME on their own and those who had severe incontinence before HoLEP due to severe cerebrovascular disorder or spinal cord injuries.
The primary outcome measure was self-reported continence postoperatively. The condition of no incontinence was evaluated by defining complete urinary control as no pad usage. The secondary outcome measure gauged QOL as determined by International Consultation on Incontinence Questionnaire-Short Form (ICIQ-SF) score .
Urinary incontinence was evaluated on the day before surgery; 3 days after HoLEP, which was one day after catheter removal; and 1, 3, and 6 months after HoLEP. ICIQ-SF score was evaluated on the day before surgery and at 1, 3, and 6 months after HoLEP. Patients in group A received sufficient instructions for PFME by urological nurses to start the same 28 days before HoLEP and continue thereafter. Then, on the second day after HoLEP, which was the day of catheter removal, all patients in both groups A and B were instructed regarding PFME by the nurses sufficiently. For all patients, the instructions for PFME included illustrations; all patients were instructed to perform a set of 3 min at least three times a day and record it in a PFME performance table. The table was described by all patients, and the PFME implementation status was confirmed for each outpatient.
The ethical committee of Tohoku Medical and Pharmaceutical University Hospital School of Medicine, Sendai, Japan approved the study protocol. Written informed consent was obtained from all patients prior to participation in this study. This study was registered with the Tohoku Medical and Pharmaceutical University Hospital Medical Research Registry in Japan (Protocol 2017–2-056) on August 22, 2017 and was registered with the University Hospital Medical Information Network Clinical Trials Registry in Japan (UMIN000034713) on October 31, 2018.
The enucleation procedure was performed following the anteroposterior dissection HoLEP method (antegrade separation method), as reported by Endo et al. . The three lobes technique was used in all cases. In this study, all surgeons used the same surgical techniques. We removed the urinary catheter on the second day after HoLEP and confirmed self-urination and degree of urinary incontinence.
Predictive factors for postoperative urinary incontinence
Uni- and multivariate analyses were performed to investigate the predictive factors for postoperative urinary incontinence at 3 days and 1, 3, and 6 months after HoLEP, including potential factors. These factors included age, body mass index (BMI), preoperative international prostate symptom score (IPSS) and overactive bladder symptom score (OABSS), ICIQ-SF score, prostate volume, operation time, enucleate prostate weight, presence or absence of diabetes mellitus, and G8 score . Urodynamic examination, including free uroflowmetry, filling cystometry, and pressure flow studies, was performed before HoLEP. We investigated the maximum detrusor pressure, detrusor overactivity, volume at the first desire to void, maximum cystometric capacity, and residual volume.
Prior to this study, there were about 40% postoperative urinary incontinence 1–3 months after HoLEP at our institute. Therefore, between the study groups, we set a significant difference in the urinary incontinence rate of 16–20% as the threshold for clinical importance. This threshold was derived following discussions between clinicians and the project management group as well as inspection of the urinary incontinence rate reported in previous studies that reviewed the number of men who showed urinary incontinence at 1–3 months after HoLEP [3,4,5]. Using the two-sided test to differentiate between proportions, this study had an ability of 80% to detect a difference of 20% in the proportion of patients remaining incontinent at 1 and 3 months after HoLEP, assuming a total sample size of 70 patients and a type 1 error rate of 0.05.
Patient characteristics are described in terms of mean and standard deviation (SD) or range for continuous variables. We used the JMP version 9.0 (SAS Institute Inc., Cary, NC. USA) for statistical analyses. Intergroup differences were analyzed using Mann–Whitney U test for continuous variables and Fisher exact tests for categorical variables. Multivariate analysis was analyzed using logistic regression analysis. P value of < 0.05 was considered statistically significant.