Minimally invasive surgical therapies (MIST) have gained increasing popularity in the treatment of benign prostatic hyperplasia (BPH). Among these, REZUM, a convective water vapor thermal therapy, is recommended by current guidelines for symptomatic BPH patients with a prostate volume (PV) between 30–80 g. However, limited studies have investigated postoperative complications associated with REZUM. This study aims to evaluate the impact of prostate volume, using a 50 ml threshold, on perioperative and postoperative outcomes.

We retrospectively reviewed patients who underwent REZUM therapy at our institution between January 16, 2024, and January 22, 2025. All procedures were performed as outpatient same-day surgeries, with Foley catheters removed at the first postoperative clinic visit. A total of 64 patients were initially included. After excluding patients with missing data or loss to follow-up, a final cohort of 41 patients was included for analysis. Collected data included age, comorbidities, preoperative PSA, baseline IPSS score, and urodynamic study results (e.g., Qmax, post-void residual (PVR), bladder voiding efficiency). Patients were allocated to two groups based on prostate volume (<50 ml vs. ≥50 ml). The categorical variables are calculated using Pearson’s chi-square or fisher’s exact test and continuous variables are estimated using Mann-Whitney U test.

As shown in Table 1., baseline characteristics between the two groups showed no significant differences except for PSA, which was higher in the PV ≥50 ml group (3.34 vs. 1.06 ng/mL, p = 0.0003). Patients with PV ≥50 ml required significantly more punctures (median: 4.5 vs. 3.0, p = 0.0125) and had a larger field of view(FOV) from the bladder neck to the verumontanum (p = 0.0002). In Table 2., postoperative hematuria (12.5% vs. 8.0%, p = 0.6366) and urinary tract infection (UTI) (18.75% vs. 4.00%, p = 0.2811) were more frequent in the PV ≥50 ml group, though not statistically significant. Notably, TWOC failure at the first attempt was observed increased in the PV ≥50 ml group (18.75% vs. 0.0%, p = 0.0525). While median Foley indwelling days were slightly longer in the PV ≥50 ml group (9.5 vs. 9.0 days, p = 0.0783), the difference was not statistically significant.

Our findings suggest that PV ≥50 ml does not significantly impact the overall incidence of postoperative complications following REZUM therapy. However, larger prostates were associated with a trend toward higher TWOC failure and slightly longer catheterization duration. These findings suggest that delaying catheter removal or closer monitoring after TWOC might be considered in those with larger PV. Further studies with larger sample sizes are warranted to validate these observations and optimize postoperative protocols for patients undergoing REZUM therapy.