MISTER Study: Minimally Invasive Steam Therapy - Russian Effectiveness Registry (MISTER)

Rezūm is a minimally invasive procedure that uses water vapor (steam) to treat urinary symptoms caused by an enlarged prostate (benign prostatic hyperplasia, BPH). It has been used in clinical practice since receiving FDA approval in 2015 and is recommended as a treatment option for men with moderate-to-severe urinary symptoms, including those who wish to preserve ejaculatory function. Clinical trials have shown that Rezūm improves urinary symptoms and flow rates, with benefits that last for at least five years, a low reoperation rate, and a low risk of sexual side effects.

Despite this evidence, several important questions remain. It is not well understood which patients are more likely to experience temporary urinary retention after the procedure, need repeat treatment, or develop ejaculatory changes. Standardized criteria for defining overall treatment success are also lacking.

The MISTER study is a multicenter registry designed to evaluate real-world outcomes of Rezūm therapy in patients treated in the Russian Federation. Using data from a large patient cohort, the study aims to identify factors associated with urinary retention after catheter removal, the need for repeat treatment or return to medication, and changes in ejaculatory function. The study will also develop and test combined criteria for defining treatment success.

Study Overview

• Status: Recruiting
• Conditions: LUTS(Lower Urinary Tract Symptoms); Benign Prostate Hypertrophy(BPH)
• Intervention / Treatment: Procedure: Rezūm

• Study Type: Interventional
• Enrollment (Estimated): 1400
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Vladislav Petov; Phone Number: +7 925 351 75 49; Email: pettow@mail.ru

Study Locations

• Russia
  • Moscow, Russia, 119435
    • Recruiting
    • Institute for Urology and Reproductive Health, Sechenov University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria

• Lower urinary tract symptoms (IPSS ≥8 points; QoL ≥3 points) due to BPH
• Prostate volume of 30-150 cm³
• Qmax ≤15 mL/s; post-void residual urine volume <300 mL

Non-Inclusion Criteria

• Prostate cancer
• Acute infections of the urinary tract, prostate, or scrotal organs
• Neurogenic lower urinary tract dysfunction
• Bladder stone(s)
• Urethral stricture
• Prior prostate surgery

Exclusion Criteria

• Patient refusal to allow use of medical data for scientific analysis
• Missing or lost data required for analysis

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Rezūm therapy; Convective water vapor thermal ablation for benign prostatic hyperplasia

Procedure: Rezūm; Rezūm therapy is performed transurethrally by specialists at the study centers in accordance with established clinical practice. The type of anesthesia, the number and location of water vapor injections, treatment of the median lobe, characteristics of the indwelling catheter, and duration of catheterization were determined by the attending physician.; Other Names: convective water vapor thermal ablation; minimally invasive treatment

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of Rezūm therapy failure	Rate of Rezūm therapy failure within 12 months after the intervention, defined as the occurrence of at least one of the following events: Resumption or continuation of medical therapy for LUTS/BPH; Repeat surgical intervention for BPH; Failure to restore voiding	12 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Post-void residual urine volume	14 days	14 days
International Prostate Symptom Score (IPSS)	Mild LUTS (symptom score less than of equal to 7) Moderate LUTS (symptom score range 8-19) Severe LUTS (symptom score range 20-35)	3, 6, and 12 months
Qmax		3, 6, and 12 months
Prostate volume		3, 6, and 12 months
PSA level		3, 6, and 12 months
International Index of Erectile Function (IIEF-5)	severe ED (5-7), moderate ED (8-11), mild to moderate ED (12-16), mild ED (17-21), and no ED (22-25)	3, 6, and 12 months
Rate of de novo retrograde ejaculation		3, 6, and 12 months

Collaborators and Investigators

• Sponsor: Sechenov University
• Collaborators: Russian University of Medicine; N. I. Pirogov Clinic of High Medical Technologies; UGMK-Zdorovie Medical Center; SM-Clinic Multidisciplinary Medical Holding; MEDSI Group of Companies; URO-PRO Clinic; Avicenna Clinical Hospital; Neftyanik Medical and Sanitary Unit; St. Luke's Clinical Hospital; N. A. Semashko Railway Clinical Hospital ("RZD-Meditsina"); Liniya Zhizni LLC; S. P. Botkin Moscow Multidisciplinary Scientific and Clinical Center; European Medical Center; RTH (Real Trans Hair) Medical Center

Publications and helpful links

General Publications

• 1. Sandhu J. S., Bixler B. R., Dahm P. et al. Management of Lower Urinary Tract Symptoms Attributed to Benign Prostatic Hyperplasia (BPH): AUA Guideline Amendment 2023 // The Journal of Urology. - 2024. - Vol. 211, № 1. - P. 11-19. - DOI: 10.1097/JU.0000000000003698. 2. Dixon C. M., Rijo Cedano E., Mynderse L. A., Larson T. R. Transurethral convective water vapor as a treatment for lower urinary tract symptomatology due to benign prostatic hyperplasia using the Rezūm® system: evaluation of acute ablative capabilities in the human prostate // Research and Reports in Urology. - 2015. - Vol. 7. - P. 13-18. - DOI: 10.2147/RRU.S74040. 3. McVary K. T., Gange S. N., Gittelman M. C. et al. Minimally invasive prostate convective water vapor energy ablation: a multicenter, randomized, controlled study for the treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia // The Journal of Urology. - 2016. - Vol. 195, № 5. - P. 1529-1538. - DOI: 10.1016/j.juro.2015.10.181. 4. McVary K. T., Gittelman M. C., Goldberg K. A. 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 // The Journal of Urology. - 2021. - Vol. 206, № 3. - P. 715-724. - DOI: 10.1097/JU.0000000000001778. 5. Akgul B., Aydin A., Cakir O. O. et al. Impact of minimally invasive surgical therapies on sexual function in benign prostatic hyperplasia: a systematic review // Minerva Urology and Nephrology. - 2025. - Vol. 77, № 4. - P. 459-471. - DOI: 10.23736/S2724-6051.25.06374-8. 6. Özkaptan O., Sevinç C., Çanakcı C. et al. Comparison of outcome for holmium laser enucleation prostate and Rezum system in benign prostate hyperplasia: a matched pair analysis // World Journal of Urology. - 2025. - Vol. 43, № 1. - Art. 242. - DOI: 10.1007/s00345-025-05644-y. 7. López Alcina E., Fernández Arjona M., Fernández Guzmán E. et al. Exp

Study record dates

Study Major Dates

• Study Start (Estimated): August 1, 2026
• Primary Completion (Estimated): August 1, 2027
• Study Completion (Estimated): September 1, 2027

Study Registration Dates

• First Submitted: July 20, 2026
• First Submitted That Met QC Criteria: July 20, 2026
• First Posted (Actual): July 23, 2026

Study Record Updates

• Last Update Posted (Actual): July 23, 2026
• Last Update Submitted That Met QC Criteria: July 20, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: LUTS; BPH; minimally invasive treatment; water vapor thermal ablation
• Additional Relevant MeSH Terms: Urogenital Diseases; Genital Diseases; Genital Diseases, Male; Prostatic Diseases; Male Urogenital Diseases; Urological Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Prostatic Hyperplasia; Lower Urinary Tract Symptoms
• Other Study ID Numbers: MISTER_1.0

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No