Four-year outcomes of water vapor thermal therapy for benign prostatic hyperplasia

Abstract

Background

The Rezūm system offers a minimally invasive treatment option for alleviating lower urinary tract symptoms associated with benign prostatic hyperplasia. We report the 48-month outcomes from a single tertiary center.

Materials and methods

A retrospective study was conducted to review Rezūm therapy from 2021 to 2025 at our tertiary hospital. Maximum urinary flow rate, International Prostate Symptom Score, quality of life, post-void residual, prostate volume, and adverse events were actively monitored. Analyses were performed at baseline and at follow-up intervals of 3, 12, 24, 36, and 48 months.

Results

Eighty-six patients (mean age of 66.7 ± 7.3 years) were assessed in our study, of whom eleven were catheter-dependent. The mean preoperative prostate size was (71.4 ± 15.6 cc). A statistically significant improvement was recorded in all voiding parameters at 3 months, including maximum urinary flow rate, International Prostate Symptom Score, quality of life, and post-void residual (P < 0.001), with sustained benefits at 48 months. Adverse events were mostly Clavien grade 1 and 2, including urinary retention (11.6%). Two patients (2.3%) required endoscopic intervention for clot retention, representing grade 3B complications. No sexually related adverse events were recorded in our study. The retreatment rate increased at 48 months, with 41.8% requiring medical therapy and 19.7% undergoing surgical retreatment.

Conclusion

Rezūm therapy demonstrates both safety and efficacy in managing benign prostatic hyperplasia-related lower urinary tract symptoms, offering maximum benefit within the first 2 years after treatment. Patient selection and counseling regarding the potential need for future medical or surgical retreatment are recommended to optimize long-term outcomes and patients’ satisfaction.

1. Introduction

Benign prostatic hyperplasia (BPH) represents the most common etiology of male lower urinary tract symptoms (LUTS), which progressively worsens with advancing age and significantly impairs quality of life (QoL).^{1, 2, 3}

The initial treatment for LUTS due to BPH involves medical management, while surgery is reserved for failure of medical therapy. Transurethral resection of the prostate (TURP) is widely accepted as a definitive surgical approach. However, it is associated with ejaculatory dysfunction that affects the QoL in sexually active men.^{4, 5, 6}

Water vapor thermal therapy (WVTT) such as the Rezūm system, employs convective thermal energy to achieve zonal ablation of the hyperplastic prostatic tissue using water vapor. This treatment modality improves urinary symptoms with a negligible risk of sexual dysfunction.⁷

The 2025 American Urological Association (AUA) guidelines recommend Rezūm as a surgical option for men experiencing LUTS due to BPH, particularly for prostate volumes between 30–80 cc, with a moderate strength of recommendations.^8,9 In contrast, the European Association of Urology guidelines highlight the ongoing uncertainties regarding Rezūm's outcomes. A Cochrane network meta-analysis found insufficient evidence to determine its effects on retreatment rates.¹⁰

Despite recommendations from several clinical studies on the effectiveness of Rezūm therapy, evidence for long-term outcomes and durability remains limited, with few studies evaluating therapy for extended periods.^{11, 12, 13}

Additional studies with long-term duration are essential to validate the mid- to long-term durability of WVTT. Our study aimed to assess the long-term outcome, durability, and retreatment rate of Rezūm therapy in patients with BPH over a four-year duration.

2. Materials and methods

We conducted a retrospective cohort study at our tertiary center including patients who underwent WVTT using the Rezūm system and had available follow-up data for up to four years. Following ethical approval from the institutional review board, we enrolled patients aged >40 years who had LUTS secondary to BPH. The International Prostate Symptom Score (IPSS) for the included patients was 13 or more. All participants provided documented informed consent, allowing the use of their anonymized clinical data without breach of their confidentiality. All participants were screened and treated for urinary tract infections before the procedure. Exclusion criteria included urinary bladder stones, urethral stricture, neurological disease, or urological malignancy.

Preoperative medical history, IPSS, QoL, maximum urinary flow rate (Qmax), postvoiding residual urine (PVR), prostate volume by transrectal ultrasound, International Index of Erectile Function (IIEF-5), and prostate-specific antigen (PSA) were documented. Patients with urinary retention were involved in our study.

The WVTT was performed using the Rezūm system under sedation or general anesthesia. Injections were delivered 1 cm distal to the bladder neck, at the 3 and 9 o'clock positions, up to the verumontanum's proximal edge. The total injection count was recorded for each patient. The number of injections per patient was recorded and in cases with a median lobe, 1-2 extra injections were administered.

Following the procedure, patients underwent same-day discharge with an indwelling urinary catheter. The catheter removal schedule was proportional to prostate size (1 day per 10 grams of prostate). Patients who were taking alpha-blockers, 5-alpha reductase inhibitors (5-ARIs), were advised to continue these medications until re-evaluation at the 3-month follow-up.

Follow-up assessments were conducted at catheter removal and at 3, 12, 24, 36, and 48 months postoperatively. Primary outcomes included changes in prostate volume, PVR, Qmax, IPSS, QoL, and IIEF-5 score compared to baseline. Secondary outcomes encompassed procedure-related adverse events and retreatment rates over the 4-year follow-up period.

2.1. Statistical analysis

Data were analyzed using the Statistical Package for the Social Sciences (SPSS, version 21; IBM Corp., Armonk, NY, USA). Continuous variables with normal distribution were expressed as mean ± standard deviation (SD), while categorical variables were summarized as frequencies and percentages. A comparison between qualitative variables was made by using the Chi-square test, while the analysis of variance (ANOVA) test was used to compare normally distributed quantitative variables between groups. A P value <0.05 was considered statistically significant.

3. Results

Eighty-six patients were finally evaluated in our study. The baseline demographic data showed a mean age of 66.7 ± 7.3 years, prostate volume of 71.4 ± 15.6 cc, IPSS of 21.3 ± 5.2, QoL score of 4.7 ± 0.74, Qmax of 8.8 ± 0.6 mL/s, and PVR of 82.6 ± 40.6 mL, PSA level of 2.6 ± 1.03 ng/mL, and IIEF-5 score of 20.2 ± 3.2. A median prostate lobe was identified in 27.9% of patients; 87.2% were on BPH medications for at least 6 months with significant bothersome symptom based on IPSS evaluation, and 12.7% were catheter-dependent at baseline Table 1.

Table 1.

Distribution of demographic data

Parameters		Total No. = 86
Age (yr)		Mean ± SD: 66.74 ± 7.3	Range: (53-79)
Prostate volume (cc)	Total population	Mean ± SD: 71.4 ± 15.6	Range: (50-120)
	30–80 cc	67 patients	(77.9%)
	>80 cc	19 patients	(22.1%)
Presence of median lobe by TRUS		24 patients	(27.9%)
IPSS	Total population	Mean ± SD: 21.3 ± 5.28	Range: (13– 34)
	Moderate	29 patients	(33.7%)
	Severe	46 patients	(53.4%)
QoL		Mean ± SD: 4.7 ± 0.74	Range: (4 – 6)
Qmax		Mean ± SD: 8.8 ± 0.6	Range: (7 – 10)
PVR		Mean ± SD: 82.6 ± 40.6	Range: (10 – 200)
PSA		Mean ± SD: 2.6 ± 1.03	Range: (0.8 – 5)
IIEF		Mean ± SD: 20.2 ± 3.2	Range: (13 – 25)
Charlson comorbidity index	0-1	28 patients	(32.5%)
	2-3	53 patients	(61.6%)
	≥4	5 patients	(5.8%)
Catheter dependent		11 patients	(12.7%)

IIEF, International Index of Erectile Function; IPSS, International Prostate Symptom Score; PSA, prostate-specific antigen; PVR, post-void residual; Qmax, maximum urinary flow rate; QoL, quality of life.

The perioperative data in Table 2 showed a mean operative time of 4.96 ± 1.5 minutes and a mean of 6.15 ± 1.7 injections per procedure. Intravenous sedation was the preferred anesthesia method (83.7%), while general anesthesia was used in 16.2% of cases. The mean catheter retrieval time was 7.11 ± 1.6 days, and patients resumed daily activities within 9.17 ± 1.6 days postoperatively. Complications were documented using the Clavien–Dindo classification as shown in Table 2. Urinary retention occurred in 11.6% post-catheter removal but resolved with extended catheterization for another 2 weeks, with a successful second trial of micturition. Two patients (2.3%) experienced grade 3B complications (severe hematuria and clot retention requiring cystoscopy and transurethral resection of the prostate).

Table 2.

Perioperative date

		Total No. = 86
Operative time		Mean ± SD: 4.96 ± 1.5	Range: (3-8)
Anesthesia	Sedation	72 patients	(83.7%)
	General anesthesia	14 patients	(16.2%)
Number of injections		Mean ± SD: 6.15 ± 1.7	Range: (4-10)
Catheter removal time (d)		Mean ± SD: 7.11 ± 1.6	Range: (5-12)
Return to daily activity (d)		Mean ± SD: 9.17 ± 1.6	Range: (7-14)
Complications	Grade 1	24 patients (27.9%)	Hematuria (n = 10)
			Urine retention (n = 10)
			Painful ejaculation (n = 4)
	Grade 2	5 patients (5.8%)	UTI (n = 4)
			Epididymo-orchitis (n = 1)
	Grade 3A	0 patients (0.0%)	--------
	Grade 3B	2 patients (2.3%)	Clot retention (n = 2)
	Total	31 patients (36%)	---------

SD, standard deviation.

Postoperative voiding function showed significant improvement in all parameters as shown in Fig. 1. Following Rezūm therapy, medication use declined sharply to 20.9% by 3 months, demonstrating early symptom improvement, and was fully discontinued by 6 months. However, retreatment rates increased progressively to 11.6%, 29.1%, and 41.8% at 24, 36, and 48 months, respectively, predominantly involving alpha-blockers and/or 5-ARIs. Surgical retreatment was uncommon in the early postoperative period, with only two cases requiring TURP for severe hematuria and clot retention. The need for surgical intervention re-emerged at 36 months (2.3%) and rose significantly to 19.7% by 48 months. Over the 4-year follow-up, 17 patients underwent reoperation (13 opted for TURP and 4 for WVTT), primarily due to severe LUTS (n = 11) or urinary retention (n = 6) Fig. 2.

Fig. 1.

Distribution of voiding and sexual outcomes over time.

Fig. 2.

surgical and medical retreatment rate over time.

Over four years, Rezūm therapy demonstrated a significant prostate volume reduction of −29.7 % at 3 months (P < 0.001), which declined at −4.7% at 48 months (P = 0.1). PVR dropped sharply by −73.8% at 3 months (P < 0.001), diminishing to −33.0% at 48 months (P < 0.001). Qmax improved by 78.7% at 3 months (P < 0.001) and remained significant at 48 months (48.2 %, P < 0.001). IPSS scores showed a significant reduction by (−58.4 % at 3 months, P < 0.001), and (−27.3 % by 48 months, P < 0.001). QoL score improved significantly higher than baseline at 48 months. The IIEF-5 score showed no changes postoperatively with a gradual decline over time, which may represent an age-related effect on erectile function. The degree of change in parameters over time is demonstrated in Table 3.

Table 3.

Distribution of voiding and sexual outcomes over time.

Prostate volume	Baseline	3 mo	12 mo	24 mo	36 mo	48 mo
No	86	84	84	84	82	67
Follow-up	71.5 ± 15.4	50.3 ± 11.9	53.3 ± 12.2	57.3 ± 12.7	61.3 ± 12.8	65.1 ± 11.5
Change	----	−21.1 ± 3.7	−18.1 ± 3.4	−14.1 ± 2.9	−9.5 ± 2.4	−3.3 ± 1.2
% Change	-----	−29.7%	−25.3 %	−19.6%	−13.2%	−4.7%
P value	-----	<0.001	<0.001	<0.001	<0.001	0.1
PV residual urine	Baseline	3 mo	12 mo	24 mo	36 mo	48 mo
No	75	84	84	74	59	48
Follow-up	82.6 ± 40.6	24.8 ± 18.4	28.2 ± 19.6	33.4 ± 22.1	38.9 ± 22.8	46.5 ± 25
Change	-----	−57.8 ± 22.2	−58.4 ± 21	−48.9 ± 18.1	−40.1 ± 18.3	−27 ± 15.9
% Change	-----	−73.77%	−69.53%	−63.1%	−51.8%	−33.04%
P value	-----	<0.001	<0.001	<0.001	<0.001	<0.001
Qmax	Baseline	3 mo	12 mo	24 mo	36 mo	48 mo
No	75	84	84	74	59	48
Follow-up	8.8 ± 0.6	15.6 ± 1.3	14.8 ± 1.3	14.8 ± 0.9	14.2 ± 0.7	13.3 ± 0.5
Change	----	6.8 ± 0.7	6 ± 0.7	6 ± 0.3	5.3 ± 0.1	4.2 ± 0.1
% change	-----	78.7%	69.4%	67.7%	60.1%	48.2%
P value	-----	<0.001	<0.001	<0.001	<0.001	<0.001
PSA	Baseline	3 mo	12 mo	24 mo	36 mo	48 mo
No	86	84	84	84	79	76
Follow-up	2.6 ± 1.1	1.7 ± 0.8	1.8 ± 0.8	2 ± 0.8	2.2 ± 0.9	2.5 ± 0.9
Change	----	−0.9 ± 0.2	−0.8 ± 0.2	−0.6 ± 0.2	−0.4 ± 0.1	−0.1 ± 0.1
% Change	-----	−36.2%	−32.3%	−24.5%	−14.8%	−0.18%
P value	-----	<0.001	<0.001	<0.001	<0.001	1
IPSS	Baseline	3 mo	12 mo	24 mo	36 mo	48 mo
No	75	84	84	74	59	48
Follow-up	21.3 ± 5.2	8.7 ± 2.6	9.5 ± 3	10.5 ± 2.9	11.1 ± 2.1	12.9 ± 1.6
Change	----	−12.6 ± 2.6	−11.8 ± 2.2	−9.4 ± 1	−7.7 ± 1.2	−5.4 ± 1.8
% Change	-----	−58.4%	−54.7%	−46.7%	−39.6%	−27.3%
P value	-----	<0.001	<0.001	<0.001	<0.001	<0.001
QoL	Baseline	3 mo	12 mo	24 mo	36 mo	48 mo
No	86	84	84	74	59	48
Follow-up	4.7 ± 0.6	1.49 ± 0.6	1.5 ± 0.61	1.6 ± 0.6	1.8 ± 0.7	2.17 ± 0.69
Change	----	−3.2 ± 0.1	−3.2 ± 0.1	−3.1 ± 0.1	−2.6 ± 0.2	−2.1 ± 0.2
% Change	-----	−69.6%	−69.3%	−65.1%	−57.6%	−50.1%
P value	-----	<0.001	<0.001	<0.001	<0.001	<0.001
IIEF	Baseline	3 mo	12 mo	24 mo	36 mo	48 mo
No	77	75	75	75	71	66
Follow-up	20.1 ± 3.3	20.4 ± 3.4	20.1 ± 3.7	19 ± 3.9	18.2 ± 3.8	17.6 ± 4.4
Change	----	0.2 ± 0.2	−0.1 ± 0.5	−1.2 ± 0.7	−2 ± 0.6	−2.6 ± 1.2
% Change	-----	1.3%	−0.69%	−6.2%	−10.6%	−13.8%
P value	-----	<0.6	0.8	0.030	<0.001	<0.001

IIEF, International Index of Erectile Function; IPSS, International Prostate Symptom Score; PSA, prostate-specific antigen; PV, prostate volume; Qmax, maximum urinary flow rate; QoL, quality of life.

4. Discussion

Minimally invasive surgical therapies (MISTs) such as WVTT are increasingly gaining popularity as effective modalities for the management of LUTS due to BPH. The Rezūm system as a form of WVTT, has been shown to provide symptom relief with minimal comorbidities, especially in sexually related outcomes. The need for long-term data reporting the durability of such treatment modality has been emphasized to enhance clinical decision-making and patient counseling.^10,14

Our study adds to this evidence by reporting real-world, patient-centered outcomes following Rezūm therapy over four years in a retrospective manner. Those patients presented with different prostate sizes moderate to severe LUTS, were either on medical therapy, or presented with refractory retention. This diversity reflects everyday urological practice and enhances the generalizability of our findings regarding the long-term effectiveness of WVTT in BPH management.

The average prostate volume reduction was −29.7% compared to baseline within the first 3 months. Other studies reported comparable size reduction.^11,13 After 4 years, our study demonstrated a size reduction by −4.7% compared to the baseline; this result was lower compared to Babar et al after 3 years of follow-up.¹³ Wolters et al, reported a decrease by one-third in prostate volume after therapy,¹⁵ Mollengarden et al showed a 17% reduction in prostate volume,¹⁶ while Elterman et al reported a prostate volume reduction of 34% after 12 months.¹⁷

Improvement in voiding parameters was observed in our study population, including patients who were catheter-dependent. Maximum improvement was noted between 3 and 12 months postintervention. The BPH medication use was reduced by 79.1% at 3 months postoperatively. After 48 months, 41.8% of patients required medical retreatment. Walters et al demonstrated that 80% of patients with prostate size 30 to 80 ceased their medication following Rezūm therapy, and 32.6% had returned to medication after 48 months,¹⁵ while Mollengarden et al reported that 89.5% of patients with a mean PV of 52.6 cc ceased pharmacological management.¹⁶

Our study showed improvements in IPSS and QoL scores of−58.4% and −69.6%, respectively, in the first 3 months postoperatively, with sustained improvements of−27.3% and −50% at 48 months. In agreement with previously reported trials, Wolters et al reported improvements of 46% and 41% improvements in IPSS and IPSS-QoL, respectively.¹⁵ McVary et al reported similar 46% and 41% improvements over 5 years of follow-up.¹¹ Mooney et al recorded maximum improvements after 12 months (64.8% and 61%) and remained durable for 4 years (54.7% and 59.2%).¹⁸

Qmax improvement in our study was 78.7% initially and 48.2% at 48 months, comparable to the 49.5% and 38% improvements reported by McVary et al and Wolters et al, respectively.^11,15 A PVR reduction of 73.8% was seen at 3 months, with a gradual decline in the magnitude of improvement but sustained benefits 33% over 48 months. Babar et al reported a significant reduction in PVR of 75.5% at 3 months and continued positive effects throughout a 4-year follow-up.¹³ Furthermore, McVary et al. reported a sustained reduction in PVR of 38% over 5 years,¹¹ while Mooney et al. reported a more modest improvement in PVR 17.6% at 3 months and 11% at 4 years.¹⁸

Postoperative complications are either Grade 1 or 2 according to the Clavien–Dindo classification system, with comparable results to previous trials.^11,15,18 Grade 3B complication occurred in two patients (2.3%) who developed clot retention and underwent cystoscopy and transurethral resection of the prostate. Postoperative urine retention was seen in 11.6% of our patients (10 patients) who needed catheterization and another trial of micturition after 2 weeks; all subsequently voided successfully. Barbar et al reported a higher incidence of urine retention at the initial trial of micturition, representing 51% of the study population, attributing this to the high PVR, prostatic edema, and inflammation, and therefore recommended delaying the first trial of micturition for at least two weeks.¹³ We did not report cases of urethral stricture or erectile dysfunction in our study, unlike Mooney et al, who reported a surgical intervention for urethral stricture (2.4%) and erectile dysfunction (2.4%).¹⁸ We assessed sexual function using the IIEF-5 questionnaire, with no negative impact on sexual function initially. However, a decline was noticed at 48 months, which may be an age-related change rather than a procedure-related event. McVary et al reported no change in the IIEF-5 over 5 years, unlike Darson et al, who found that Rezūm had a minimal impact on sexual and ejaculatory function.^11,19

In contrast to most of the existing literature, our study demonstrated a surgical retreatment rate of 19.7% after 4 years of follow-up. This is higher than the rates reported by McVary et al (4.4% at 5 years) and Mooney et al (3.4% at 4 years). Notably, our study population included catheter-dependent patients, patients with moderate-to-severe LUTS or high PVR, or those with a large median lobe or prostate size more than 80 cc, aiming to reflect real-world clinical practice.^11,18

Our findings further support the effectiveness of WVTT in the treatment of LUTS due to BPH.^11,13,15,18 However, the generalization of these data in the healthcare system is still under consideration. A Cochrane network meta-analysis reported inconclusive evidence regarding Rezūm's effect on retreatment rates compared to sham treatment at 3 months, with very low certainty of evidence.²⁰

4.1. Limitations

First, this is a retrospective, single-arm study without a head-to-head comparison with other treatment modalities for BPH. However, the large number of treated patients and the extended follow-up period provided meaningful data to draft our conclusions. Additionally, we were unable to assess risk factors for those who were more likely to need either surgical or medical retreatment.

5. Conclusion

WVTT demonstrates both safety and efficacy in managing benign prostatic hyperplasia-related LUTS. It has demonstrated a sustained improvement in voiding parameters and prostate volume, particularly during the first 2 years of follow-up, with a gradual decline thereafter. A considerable retreatment rate was noted at the four-year follow-up, highlighting the need for pharmacological treatment or surgical intervention, which underscores the importance of long-term monitoring and proper patient selection and counseling.

Authors’ contributions

A. Higazy: Drafting the protocol and discussion section.

M. Zaza: Final revision and discussion writing.

M.H. Ali: Final revision.

M. Elshahawy: Protocol design, Statistics, and data collection.

T. Salem: Final revision.

S. Azazy: Introduction and protocol design.

M. Soliman: Results section and discussion writing.

Consent for participation

Written consent was obtained from all patients before participation.

Ethical consideration

This study was approved by the ethical committee of the Faculty of Medicine, the Helwan University ID (30-2023). Also, registered at the National Library of Medicine. The study was registered on clinicaltrials.gov with a registration number: NCT05982444.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Funding

No fund was received for our study.

Conflicts of interest

All authors have no conflict of interest to declare.