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

Background: Current guidelines recommend Rezūm water vapor thermal therapy for the treatment of benign prostatic hyperplasia (BPH) for prostate glands ranging in volume from 30 to 80 cm³. Few prospective studies have specifically evaluated the use of Rezūm for larger prostates. Objective: To evaluate the safety and efficacy of water vapor thermal therapy in patients with a prostate gland >80 cm³ and ≤150 cm³. Design, setting, and participants: In this prospective, single-arm study at seven centers in the USA, subjects were males aged >50 yr with symptomatic BPH and prostate volume of >80 cm³ and ≤150 cm³. Intervention: Rezūm was used to deliver sterile water vapor via a transurethral approach to ablate targeted areas of prostate tissue. Outcome measurements and statistical analysis: The primary efficacy outcome was response to therapy, defined on a per-patient basis as a ≥30% improvement in International Prostate Symptom Score (IPSS) from baseline to 6 mo. The primary safety outcome was a composite of serious device-related safety events. Secondary outcomes included catheterization for device-related retention. IPSS outcomes over time were analyzed via generalized estimating equations. Results and limitations: Among 47 eligible patients, prostate volume ranged from 80.8 to 148.1 cm³. All patients completed 6-mo follow-up, and 40/47completed 12-mo follow-up. At 6 mo, 83% were treatment responders according to the primary efficacy endpoint. The mean IPSS improvement at 6 mo was 11.9 ± 7.5 points, reflecting significant improvement. The primary safety outcome was met, with no occurrence of device-related composite safety events. The study is limited by the nonrandomized design and early termination, unrelated to safety or effectiveness. Conclusions: Our results are consistent with previous findings for prostate glands of up to 80 cm³, and indicate the safety and efficacy of Rezūm for BPH in patients with a larger prostate. Patient summary: Rezūm therapy, in which water vapor is used to treat targeted areas of the prostate, is currently recommended for patients with benign enlargement of the prostate and a prostate size of up to 80 cm³. We found that this treatment was also effective and safe in patients with a larger prostate of 80–150 cm³.