MISTER Study: Minimally Invasive Steam Therapy - Russian Effectiveness Registry

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.