Introduction: Traditional treatment approach for Rezum utilizes injections based on prostate volume. Recent literature with short-term follow-up has shown that improvements in lower urinary tract symptoms (LUTS) can be achieved with less injections. We assessed the long-term durability of Rezum outcomes in relationship to the number of injections utilized during treatment. Methods: A single office, retrospective study was conducted on men with moderate to severe LUTS who were treated with Rezum. Men were stratified into four cohorts based on the number of injections received per lateral prostatic lobe: 1, 2, 3, or 4 injections. International Prostate Symptom Score (IPSS), quality of life (QoL), maximum urinary flow rate (Qmax), postvoid residual (PVR), and adverse events (AEs) were collected at baseline, 1-, 3-, 6-, 12- and/or 48-months postoperatively. The impact of the number of injections on urinary outcomes and AEs were assessed using multivariate linear regression and logistic regression models, respectively, after adjusting for confounders at baseline. Results: A total of 179 men were included: 58, 91, 22, and 8 men in the 1, 2, 3, and 4 injections cohorts, respectively. Compared to baseline, at 3-months, all cohorts saw significant mean changes in IPSS (-9.7 ± 7.9, p<0.001) and QoL (-1.9 ± 1.9, p<0.001), and improvements remained durable to 48-months (IPSS -10.8 ± 9.0, p<0.001; QoL -2.7 ± 1.9, p<0.001). The 2 injections cohort saw a significantly greater mean change in Qmax at 6-months (10.2 ± 10.1 ml/s) when compared to the 1 injection cohort (0.6 ± 4.6 ml/s, p=0.02). There were no significant differences in mean changes in IPSS, QoL, and PVR between the cohorts at any follow-up (p>0.05). The most common AE was gross hematuria (69.8%), followed by penile burning (65.8%). By 48-months, reoperation rate was 9.2%, with no significant difference in reoperation rates between the cohorts (p>0.05). Multivariate logistic regression showed that for each additional injection, the odds of gross hematuria, penile burning, penile pain, and dysuria increased by 3.8 (95% CI 1.7, 9.1), 2.6 (95% CI 1.2, 5.9), 2.2 (95% CI 1.1, 4.9), and 3.0 (95% CI 1.3, 7.5), respectively. Multivariate linear regression showed that the number of injections was not significantly associated with changes in IPSS, QoL, and PVR at any follow-up (p>0.05) but significantly associated with change in Qmax at 3-months (ß=5.7, p=0.02). Conclusions: Utilizing less lateral lobe injections during Rezum treatment is a safer treatment approach that can still achieve long-term durable relief in LUTS. SOURCE OF Funding: None.
