Study on Water Vapor Thermal Therapy

This prospective cohort study aims to evaluate the safety and efficacy of the Rezum procedure, a minimally invasive treatment for benign prostatic hyperplasia (BPH) that utilizes convective water vapor thermal energy. The Rezum procedure was approved by the U.S. FDA in 2015, and recent approval by South Korea's Ministry of Health and Welfare has allowed its use in South Korean patients. Unlike other BPH treatments, Rezum delivers steam at 103°C directly into the prostatic tissue, inducing necrosis and reduction of prostate size through a controlled thermal effect. This process is conducted in a day-surgery setting under local, general, or spinal anesthesia, minimizing patient burden and recovery time.

The study will enroll male patients aged 50 or older with confirmed BPH who meet specific prostate size criteria, measured via transrectal ultrasound. Following a preoperative evaluation, including prostate size, PSA levels, symptom questionnaires, and urodynamic assessment, patients will undergo the Rezum procedure. This involves cystoscope-guided needle insertion into hypertrophic prostate regions, where targeted thermal energy is delivered in short bursts. The procedure is completed within a single hospital visit, and patients are generally discharged on the same day unless complications arise.

After surgery, participants will have routine follow-up visits, including catheter removal and initial voiding assessments within one week. Further follow-up, at a minimum of three months, will include standardized assessments of voiding function, symptom severity (IPSS, IIEF, OAB-q), prostate size, uroflowmetry, and residual urine volume. The safety profile will be assessed by recording adverse events, including infection, hematuria, voiding dysfunction, and the necessity for catheter reinsertion. Complications will be classified according to the Clavien-Dindo classification system.

Data analysis will assess the preoperative and postoperative changes in symptom severity, functional parameters, and prostate measurements. Comparisons of these continuous variables will utilize paired sample t-tests or Wilcoxon signed-rank tests, depending on normality test results. Variables include IPSS, IIEF, OAB-q, prostate size, PSA, maximum flow rate (Qmax), and post-void residual volume (PVR). Additionally, multiple regression analysis will identify factors contributing to the need for postoperative catheter reinsertion. Statistical significance will be set at α=0.05, with p-values below 0.05 indicating significant differences.

This study will address a current gap in research on the Rezum procedure's impact on Korean patients, contributing to the understanding of this minimally invasive approach within different populations and expanding its potential applicability.

Inclusion criteria

• Age 50 or older
• Prostate size between 30cc and 80cc as measured by transrectal ultrasound
• Patients scheduled for Rezum surgery for BPH

Exclusion criteria

• Suspected prostate cancer
• Suspected urinary tract infection
• Inability to complete follow-up
• Patients who do not consent to participate in the study