Efficacy and Safety of Rezūm Water Vapor Thermal Ablation in Large and Small Prostates: A Multicenter Comparative Analysis of 2,725 Patients

Background: Rezūm water vapor therapy is well established for benign prostatic hyperplasia in prostates <80 cc; however, evidence in larger glands remains limited despite increasing demand for minimally invasive alternatives to conventional surgery. We compared outcomes after Rezūm therapy in patients with large versus small prostates. Study Design: In this multicenter retrospective study, 2,725 patients undergoing Rezūm therapy across 5 centers were stratified by prostate volume: large prostate (LP, ≥80 cc; n=993) and small prostate (SP, <80 cc; n=1,732). Primary outcomes were 6-month changes in International Prostate Symptom Score (IPSS), IPSS Quality of Life (QoL), peak urinary flow rate (Qmax), and post-void residual (PVR). Secondary outcomes included Sexual Health Inventory for Men (SHIM) scores, complications, and retreatment rates. Results: At 6 months, LP and SP cohorts achieved comparable improvements in IPSS (41.4% vs 41.9%; p=0.958), QoL (50.0% vs 50.0%; p=0.394), and Qmax (122.2% vs 118.2%; p=0.62). LP patients experienced greater reduction in PVR (68.8% vs 24.0%; p<0.001). SHIM scores remained stable in both groups despite a significant between-group difference. Complication rates were similar (5.0% vs 4.9%; p=0.559). Over a median follow-up of 41 months, LP patients had lower surgical retreatment rates than SP patients (3.6% vs 7.2%; p<0.001). Conclusions: In this large multicenter cohort, Rezūm therapy provided comparable symptomatic and flow-rate improvement in prostates ≥80 cc and <80 cc, with greater improvement in bladder emptying and lower long-term surgical retreatment rates among larger glands. These findings support the safety, effectiveness, and durability of Rezūm therapy in appropriately selected patients with prostates ≥80 cc.