What are the considerations for a male patient with Benign Prostatic Hyperplasia (BPH) undergoing an injection of water vapor into the prostate?

Water Vapor Thermal Therapy (Rezūm) for Benign Prostatic Hyperplasia

Water vapor thermal therapy is an appropriate minimally invasive option for men with BPH and prostate volume <80g who prioritize preservation of sexual function, though patients must understand it provides less symptom improvement than TURP and requires acceptance of transient irritative symptoms. 1

Patient Selection Criteria

Prostate Volume Requirements

• Eligibility is strictly limited to prostate volume <80g per AUA guidelines 1
• Recent evidence suggests the procedure may be safe and effective for prostates 80-150cc, with 83% achieving ≥30% IPSS improvement at 6 months, though this exceeds current guideline recommendations 2
• Medium (38.5-55.6cc) and large (>55.6cc) prostates may achieve faster symptom improvement compared to small prostates (≤38.5cc), with median time to 25% IPSS reduction of 12.3 and 13.8 months respectively versus 16.1 months for small glands 3

Ideal Candidate Profile

• Men with moderate-to-severe LUTS (IPSS ≥13) who desire preservation of erectile and ejaculatory function 4, 5
• Patients willing to accept less robust symptom improvement compared to TURP in exchange for sexual function preservation 4
• Men who can tolerate transient irritative urinary symptoms lasting several weeks post-procedure 6, 5

Medical Comorbidities

• Patients with diabetes should be counseled that they may experience 3.67 points higher IPSS at 3 months post-procedure compared to non-diabetics 3

Expected Efficacy Outcomes

Symptom Improvement

• Mean IPSS improvement of 11.2 points at 3 months (50% reduction from baseline of 22), significantly superior to sham control (4.3 points) 5
• Symptom improvement is durable, with sustained 50% or greater IPSS reduction maintained through 12 months 5, 7
• Response rate (≥30% IPSS improvement) is 74% at 3 months versus 31% for sham 4

Urinary Flow Rates

• Peak flow rate (Qmax) increases by 6.2 mL/sec at 3 months and remains sustained through 12 months 5
• At 12 months, Qmax improvement represents an 87% increase from baseline 7

Quality of Life

• Quality of life scores improve by 61% at 12 months 7
• Mean QOL improvement of 1.2 points on IPSS-QOL scale (0-6 scale) at 3 months 4

Sexual Function Preservation

This is the primary advantage of water vapor therapy over TURP and should be emphasized for appropriate candidates. 4

• No de novo erectile dysfunction reported in any published trials 4, 5
• Ejaculatory function is completely preserved with no significant changes from baseline 4, 5
• This represents a critical distinction from TURP, which causes retrograde ejaculation in 65.4% of patients 1

Safety Profile and Adverse Events

Transient Irritative Symptoms

• Patients should expect a significantly higher incidence of minor adverse events (Clavien-Dindo Grade I-II) compared to sham: 434 per 1000 men versus baseline 6
• Irritative urinary symptoms (dysuria, frequency, urgency) are common but typically resolve within weeks 1, 5

Catheterization Requirements

• The procedure greatly increases the rate of requiring indwelling urinary catheters post-operatively (RR 35.58) 6
• This is a temporary measure and should be anticipated in counseling 6

Major Adverse Events

• Evidence regarding major adverse events (Clavien-Dindo Grade III-V) is very uncertain, though no serious device-related composite safety events occurred in the largest prospective trial 6, 2

Retreatment Rates

• Evidence on retreatment rates remains poorly defined with very low certainty 6
• The procedure can be performed in office or hospital settings using oral pain medication 5

Comparison to Alternative Therapies

Versus TURP

• TURP remains the benchmark surgical therapy with superior symptom reduction and flow rate improvement 1
• Water vapor therapy provides less robust outcomes but avoids the sexual dysfunction associated with TURP 4, 5

Versus Prostatic Urethral Lift (PUL)

• Both procedures preserve sexual function 4, 8
• PUL is limited to prostates <70-80g with no middle lobe obstruction, while water vapor therapy can treat median lobe tissue 1, 8, 5
• PUL has a defined 5-year retreatment rate of 13.6%, while water vapor therapy data remains limited 8

Procedural Considerations

Technical Requirements

• The procedure requires specialized equipment (Rezūm System) and training, which may limit availability 4
• Treatment involves transurethral delivery of sterile water vapor to the transition zone and median lobe as needed 5
• Can be performed under oral pain medication without general anesthesia 5

Critical Caveats

Evidence Limitations

• The AUA provides only a conditional recommendation (Grade C evidence) for water vapor therapy, reflecting limited long-term data beyond 12 months 4
• Most evidence comes from industry-sponsored trials with relatively short follow-up 6, 5
• No head-to-head comparisons exist between water vapor therapy and TURP or other minimally invasive procedures 6

Patient Counseling Priorities

• Patients must understand this is a trade-off: accepting less symptom improvement in exchange for sexual function preservation 4
• The transient period of irritative symptoms and potential catheterization must be clearly communicated 6, 5
• Long-term durability and retreatment rates remain incompletely defined compared to established procedures 6