Rezum Water Vapour Therapy

Water vapour or steam therapy is a new minimally invasive day stay procedure used for the treatment of men with bothersome urinary symptoms due to benign enlargement of the prostate gland. Steam therapy provides a rapid and durable relief of symptoms with preservation of sexual function. It is an alternative to the long term use of drugs and avoids the potential side effects of prostate surgery.

How is it performed?

The procedure is performed as a day stay procedure under sedation or a brief general anaesthetic. A telescope with the attached steam delivery device is inserted into the urethra. A needle deployed from the device is inserted into the prostate. Steam is delivered along the needle in 9 second injections. The total number of injections (typically between 2 and 10) is determined by the size of the prostate gland. The treatment takes approximately 30 minutes. A catheter is left in the bladder for 3-7 days afterwards. The catheter allows for easy bladder emptying during the period of prostate swelling.

How does it work?

Steam at a temperature of 103 degrees Celsius passes into the prostate gland. This causes instant cell death within the 1-2cm zone around each needle injection site. The steam is contained within the prostate gland and does not cause any heating of tissues outside of the gland. The average reduction in prostate volume after treatment is approximately 30%.

What beneficial effects can I expect?

All studies have shown a significant improvement in clinical outcomes including a 50% improvement in the international prostate symptoms score (IPSS), a 50% improvement in maximum flow rate and a 30% reduction in the volume of urine left in the bladder after voiding. The improvement seen with steam therapy is not as great as is typical for prostate surgery however the beneficial effects occur sooner and there is a lower risk of side effects.

How long will it take for the beneficial effects to be experienced?

Compared to prostate surgery, steam therapy leads to a more rapid relief of urinary symptoms - from as early as two weeks after treatment.

Are there any sexual side effects?

A key strength of steam therapy lies in its ability to preserve sexual function. No significant changes in erectile function have been reported. A change in ejaculatory volume is noticed in <5% of men.

What is the evidence for its safety and efficacy?

The principles of steam therapy have been investigated in a series of investigations including clinical trial studies reported in peer reviewed journals. (Ref 1). The benefits of steam therapy have been shown to be durable out to 4 years.

The Rezum system received US Food and Drug Administration approval in 2015.

What side effects can I expect?

It is common to  experience mild to moderate urinary irritation afterwards. Typically men may notice some stinging with urination (20%), urgency (6%), and blood in the urine. (12%) These side effects resolve within a few days to 4 weeks.

What are the risks?

Transient irritative urinary symptoms, blood in the urine and ejaculate. Urinary infection. Urinary retention requiring placement of  a temporary urinary catheter for longer than the usual 3-7 days. Reduction in ejaculation volume in <5% of men. The surgical retreatment rate is 4% over 3 years.

Who is it appropriate for?

Men in treated in the clinical trial of steam therapy were >= 50 years of age with moderate to severe urinary symptoms. The prostate volume was between 30-80 cc, maximum flow rate <=15ml/s and post voiding residual urine volume <250mL. An enlarged median lobe of the prostate is not a restriction to use of steam therapy.

Men in urinary retention, those with very large prostates (>120cc) or those with associated conditions such as bladder stones or prior prostate radiotherapy are not ideal for steam therapy.

Is it covered by insurance?

Most insurance companies do not yet cover this treatment. We can give you a quote for the full cost of the procedure.


McVary KT, Gange SN, Gittelman MC, et al. Minimally invasive prostate convective water vapor energy (WAVE) ablation: a multicentre, randomized, controlled study for treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia. J Urol. 2016; 195(5): 1529-1538.