Wave is an effective treatment for elderly patients with benign prostatic hyperplasia who have multiple complications. In particular, enabling patients with benign prostatic hyperplasia who cannot have their urinary catheters removed to live without a catheter is highly beneficial for them in terms of reducing the risk of infection and improving their quality of life. We examined the factors associated with successful removal of urinary catheters in patients who underwent Water Vapor Energy Therapy (WAVE) at our hospital.

We conducted a statistical analysis of the patient characteristics of those who were able to discontinue postoperative catheter management, focusing on 21 of the 39 WAVE performed at our hospital by six surgeons between July 2023 and February 2024 who had been on catheter management prior to surgery, including the results of preoperative urodynamic study. The patients included in this analysis are those who have undergone at least one catheter removal attempt while taking α-blocker.
All statistical analyses were performed using EZR. The data were analyzed using the Mann-Whitney U test and the chi-square test.

The catheter removal group and non-removal group comprised 16 and 5 patients, respectively. The median age was 77 years (range 64-88) in the catheter-free group and 80 years (range 70-88) in the catheter-dependent group. No complications of grade 3 or higher were observed according to the Clavien-Dindo classification.
 Univariate analysis of patient characteristics revealed a statistically significant difference in Pdet Qmax from the preoperative urodynamic study (P=0.05). No significant differences were observed for other factors such as prostate volume, Schfer classification, or number of waves.

While Pdet Qmax showed a significant difference as a predictor for postoperative catheter removal following WAVE in this study. On the other hand, no statistically significant differences were observed in prostate volume or the number of injections (Figure. 1). One limitation was that we did not take into account the patients’ history of neurogenic bladder or their performance status. In addition, because the number of patients was small in this study, we were unable to perform multivariate analysis.

Since WAVE is a procedure that can be performed quickly, carries virtually no postoperative complications, and is generally safe, the number of procedures is expected to continue to rise as it is considered a useful option for the growing elderly population. Joint studies with other institutions have also reported its efficacy over a five-year postoperative period [1]. It can be performed on cases of mid-urethral prolapse and for prostates of a certain size, and is therefore considered useful for a wide range of cases [2].
Although urodynamic study may be a useful tool for determining whether a urinary catheter can be safely removed prior to WAVE surgery, elderly patients with cognitive impairment are likely to be unable to undergo this test. Furthermore, given the time and human resources required, it is unlikely to be feasible to perform urodynamic study on all patients.
Moving forward, it will be necessary to apply machine learning using the results of multivariate analysis to identify alternative indicators to urodynamic study.

McVary KT, et al : Final 5-Year Outcomes of the Multicenter Randomized Sham-Controlled Trial of a Water Vapor Thermal Therapy for Treatment of Moderate to Severe Lower Urinary Tract Symptoms Secondary to Benign Prostatic Hyperplasia. J Urol 206 : 715-724, 2021
Woo H, et al : Prospective Trial of Water Vapor Thermal Therapy for Treatment of Lower Urinary Tract Symptoms Due to Benign Prostatic Hyperplasia in Subjects with a Large Prostate: 6- and 12-month Outcomes. Eur Urol Open Sci 8 : 64-72,2023