Enlarged prostate (BPH)
What the published trials say about symptom relief, durability, catheters, prostate size and sexual side effects when comparing prostate artery embolization with Rezum water vapor therapy.
Editorially updated October 21, 2026. This educational article was prepared by SoCal Interventional using the cited primary and authoritative sources. It does not replace an individualized medical evaluation.
Quick answer: Prostate artery embolization (PAE) and Rezum both treat an enlarged prostate by shrinking tissue rather than cutting it out, and both are designed to preserve sexual function. The differences are the route and the recovery. Rezum injects steam into the prostate through the urethra in a urology office; in its randomized sham-controlled trial of prostates between 30 and 80 mL, the symptom score fell by about 48% from baseline and held through 5 years, with a 4.4% surgical retreatment rate, and a urinary catheter for several days afterward is standard. PAE is performed through an artery with no instrument in the urethra, usually needs no catheter, and has no upper limit on prostate size; in its own sham-controlled trial it improved the symptom score by about 13 points more than a sham procedure at 6 months. No trial has compared the two directly. Men with a small-to-medium prostate who want a short office procedure and accept a catheter lean toward Rezum; men with a large prostate, a prominent median lobe, blood-thinner use, or a strong wish to avoid a urethral instrument and catheter lean toward PAE.
PAE is offered at our Fountain Valley office in Orange County as well as in Van Nuys and Tarzana. Rezum is a urology procedure that we do not perform; this article is meant to help you ask better questions of both specialists.
Rezum and PAE both shrink prostate tissue instead of cutting it out, by different routes. Rezum delivers nine-second bursts of steam into the prostate through the urethra in a urology office, and a catheter follows while the swelling settles. PAE blocks the prostate’s arteries with microscopic particles through a wrist or groin puncture under sedation, with nothing in the urethra and usually no catheter.
Rezum (water vapor thermal therapy). A urologist passes a small device through the urethra and delivers nine-second injections of sterile water vapor into the obstructing prostate tissue. The thermal energy destroys the targeted cells, and over the following weeks the body reabsorbs that tissue, so the urinary channel gradually widens. In the pivotal trial the number of vapor treatments per lobe was set by the length of the prostatic urethra, and the middle lobe was treated at the physician’s discretion. It is usually done with local anesthesia, sometimes light sedation, in an office or outpatient suite, and a catheter is placed afterward while the swelling settles.
Prostate artery embolization. An interventional radiologist threads a catheter from the wrist or groin into the small arteries that feed the prostate and injects microscopic particles that block them. With less blood supply the whole gland softens and shrinks over the following weeks, easing pressure on the urethra from the outside in. Nothing is passed through the urethra, moderate sedation rather than general anesthesia is used, and most men go home the same day without a urinary catheter. Improvement is gradual, usually becoming noticeable over two to six weeks (see our PAE recovery timeline).
The two procedures have never been randomized against each other. Each, unusually among BPH procedures, has been tested against a sham procedure in a blinded trial, and PAE has also been randomized against TURP. The numbers below therefore come from different trials with different patients and different follow-up lengths; read them as context for a conversation, not as a direct contest.
| Measure | Rezum (sham-controlled trial, 5-year follow-up) | PAE (sham-controlled trial, 6 months; TURP trial, 12 weeks) |
|---|---|---|
| Trials | McVary et al., J Urol 2021: 197 men over 50 with IPSS of 13 or more, peak flow of 15 mL/s or less and prostates of 30 to 80 mL; 136 treated vs 61 sham, with 53 sham patients crossing over to treatment at 3 months | Pisco et al., Eur Urol 2020: 80 men aged 45 or older with severe symptoms unresponsive to medication, randomized 1:1 to PAE or sham after a prostatic artery had been catheterized. Abt et al., BMJ 2018: 103 men, 51 PAE vs 52 TURP |
| Symptom score (IPSS) | Baseline about 22; mean reduction 11.3 points (about 48%) at 5 years; crossover group similar | 13.2 points more improvement than sham at 6 months (95% CI 10.2 to 16.2); the sham group improved 13.6 points after crossing over to PAE. Against TURP: 9.23 points at 12 weeks vs 10.77 after TURP |
| Quality of life (IPSS QoL) | From 4.4 at baseline to 2.2 at 5 years (about 45% better) | 2.13 points better than sham at 6 months (95% CI 1.57 to 2.68) |
| Peak urinary flow (Qmax) | From 9.9 to 14.0 mL/s at 5 years (about 44% improvement) | Not reported on the sham-trial abstract. Against TURP: +5.19 mL/s vs +15.34 after TURP |
| Need for further treatment | Surgical retreatment 4.4% through 5 years | No treatment failures within the 12-month trial; in the largest long-term PAE series roughly one man in five needed another treatment by 5 years (see how long does PAE last) |
| Sexual function | No device- or procedure-related sexual dysfunction and no sustained new erectile dysfunction reported through 5 years | Against TURP: some ejaculatory dysfunction in 56% (14 of 25 assessed) vs 84% (21 of 25) after TURP |
| Catheter afterward | Standard for several days (a 211-patient university series used a routine 5-day catheter; 92.4% catheter-free after a median of 5 days) | Usually none; nothing is placed in the urethra |
| Adverse events | Not detailed in the 5-year abstract; the university series reported low 30-day complication rates and no bleeding complications | Sham trial: 14 events (35.0%) after PAE vs 13 (32.5%) after sham. TURP trial: 36 treatment-related events after PAE vs 70 after TURP |
Two cautions when reading the table. First, the Rezum trial excluded prostates above 80 mL and the PAE sham trial enrolled only men with severe symptoms who had already failed medication, so each trial’s population would have been partly ineligible for the other. Second, percentage changes and point changes are not interchangeable: a 48% reduction from a baseline score of 22 is about 11 points, which is in the same range as the roughly 9 to 13 points reported for PAE in its randomized trials. Neither figure predicts an individual man’s result.
Prostate size is the first filter. Rezum’s randomized evidence covers prostates of 30 to 80 mL, the range most urologists treat, although a Swiss series included larger glands. PAE has no upper size limit because the particles reach the whole gland through its blood supply, so very large prostates and prominent median lobes are common reasons for referral to embolization.
Size is the most common reason one of these procedures is ruled out before anything else is discussed. Rezum’s randomized evidence covers prostates of 30 to 80 mL, and that remains the range in which most urologists offer it. Real-world practice stretches further: in the Swiss university series of 211 men treated between 2014 and 2022, about one in five (19.9%) had a prostate of 80 mL or more and 38.4% had a median lobe, with the symptom score falling 54.3% by 2 months. PAE has no upper size limit, because the particles reach every part of the gland through its blood supply; very large prostates are among the most common referrals for embolization, often after a man has been told that the office procedures are not an option for him.
Shape matters as well. A median lobe that protrudes into the bladder can be treated with Rezum at the physician’s discretion, as it was in 31% of the trial patients, but a large median lobe is a reason some urologists favor a different approach. Because PAE works through the arteries rather than the urethra, lobe anatomy affects the technical plan less, though the arteries themselves must be reachable, which is one of the things imaging and the consultation establish (see our PAE candidacy page).
Rezum requires a urinary catheter for several days (routinely five in a 211-patient series) plus a few weeks of burning and urgency while the treated tissue is reabsorbed. PAE usually needs no catheter; expect several days of pelvic discomfort, mild burning, occasional blood in the urine or semen and low-grade fever, managed with oral medication, with improvement building over weeks.
This is the difference men notice most. Rezum deliberately injures prostate tissue, so swelling follows, and a catheter is placed while it settles: routinely 5 days in the Swiss series, with 92.4% of men catheter-free after a median of 5 days (interquartile range 5 to 7). Urinary burning and urgency while the treated tissue is reabsorbed are expected for a few weeks. After PAE a catheter is usually unnecessary. The typical after-effects are several days of pelvic or perineal discomfort, mild urinary burning, occasional small amounts of blood in the urine or semen and low-grade fever, collectively called post-embolization syndrome, which is managed with oral medication. Most men return to desk work within a few days, and symptom improvement builds over the following weeks rather than arriving at once.
Rezum has the stronger long-term trial data: its 3-month improvements held at 5 years with a 4.4% surgical retreatment rate. PAE’s durability comes from large single-center series rather than trials: symptom scores stayed improved for most men, but roughly one in five needed another treatment by 5 years and more than half by 10 years.
The Rezum trial’s 5-year data are its strongest card: the symptom, quality-of-life and flow improvements measured at 3 months were still present at 5 years, and only 4.4% of men had surgery for BPH in that time. The real-world Swiss series reported a 5.7% reoperation rate at a median of 407 days. PAE’s randomized trials are shorter, so its long-term picture comes from large single-center series rather than trials. Our review of that evidence, how long does PAE last, summarizes the largest series (1,072 men followed for an average of about 4.4 years): symptom scores stayed improved for most men, but roughly one in five needed another treatment by 5 years and more than half by 10 years. A repeat embolization is possible when the arteries can still be reached, and a prior PAE does not prevent Rezum or surgery later.
Both procedures preserve sexual function far better than TURP. The 5-year Rezum trial reported no procedure-related sexual dysfunction and no sustained new erectile dysfunction. PAE preserves erections and ejaculation for most men, but 56% of the men assessed in the randomized trial against TURP reported some ejaculatory change, versus 84% after TURP, so it is not entirely free of effects.
Both procedures were developed in part to avoid the retrograde ejaculation that follows TURP in most men. The 5-year Rezum trial reported no device- or procedure-related sexual dysfunction and no sustained new erectile dysfunction. PAE preserves erections and ejaculation for most men, but the randomized trial against TURP shows it is not free of ejaculatory effects: 56% of the men assessed reported some change after PAE versus 84% after TURP. If preserving ejaculation is a top priority, say so at both consultations and ask what each physician’s own patients report.
The AUA guideline lists both water vapor thermal therapy and PAE among the procedural options for BPH, frames the choice as shared decision-making, and expects PAE to be performed by clinicians trained in the interventional radiology technique; the Society of Interventional Radiology’s multisociety statement describes PAE as a safe and effective option for appropriately selected men.
The American Urological Association’s guideline on lower urinary tract symptoms attributed to BPH lists both water vapor thermal therapy and prostatic artery embolization among the procedural options, frames the choice as shared decision-making, and expects PAE to be performed by clinicians trained in the interventional radiology technique. The full statements now sit behind the AUA’s member login, so we link to the guideline page and to the trials themselves rather than quoting the current wording. The Society of Interventional Radiology’s multisociety position statement describes PAE as a safe and effective option for appropriately selected men. Our five-way comparison of PAE, UroLift, Rezum, Aquablation and TURP places both procedures alongside the other options.
Rezum tends to suit men with a small-to-medium prostate (30 to 80 mL) who want a short office procedure without general anesthesia, who can tolerate a catheter for several days and a few weeks of urinary irritation, and who want the reassurance of 5-year randomized data with a low surgical retreatment rate.
PAE tends to suit men with a large or very large prostate, a prominent median lobe, or urinary retention; men on blood thinners or with heart or lung conditions that make urethral instrumentation and anesthesia less attractive; men who strongly prefer to avoid a catheter; and men who accept a gradual improvement and a real chance of needing a further treatment in later years in exchange for a same-day outpatient procedure with nothing passed through the urethra. Our PAE candidacy page describes the evaluation, and our PAE vs Aquablation and PAE vs TURP articles cover the tissue-removing alternatives.
Neither has been shown better in a head-to-head trial, because none exists. Each was tested against a sham procedure in its own randomized trial: Rezum reduced the symptom score by about 48% from baseline at 5 years with a 4.4% surgical retreatment rate, and PAE improved the symptom score by about 13 points more than sham at 6 months. The trials enrolled different men (Rezum: prostates of 30 to 80 mL; PAE: severe symptoms that had not responded to medication), so the figures are context, not a contest. The right choice depends on prostate size and shape, your tolerance for a catheter, anesthesia risk and what you most want to avoid.
The Rezum randomized trial enrolled prostates of 30 to 80 mL, and that is the range most urologists treat; a real-world Swiss series did include men above 80 mL (about one in five of its 211 patients). PAE has no upper size limit, and large glands are one of the most common reasons men are referred for it. For a prostate well above 80 mL, PAE and the tissue-removing operations are usually the realistic options.
After Rezum a urinary catheter for several days is standard: in a 211-patient university series the routine catheter time was 5 days, and 92.4% of men were catheter-free after a median of 5 days. After PAE most men need no catheter, because nothing is passed through the urethra; the common after-effects are several days of pelvic discomfort, urinary burning and low-grade fever, known as post-embolization syndrome.
Both are designed to preserve ejaculation and erections. The 5-year Rezum trial reported no device- or procedure-related sexual dysfunction and no sustained new erectile dysfunction. For PAE, the randomized trial against TURP found some ejaculatory change in 56% of the men assessed after PAE versus 84% after TURP, so PAE is not entirely free of ejaculatory effects, and this should be discussed before either procedure.
Neither requires general anesthesia. Rezum is performed through the urethra in a urology office or outpatient suite, usually with local anesthesia and sometimes light sedation. PAE is performed by an interventional radiologist through a small puncture in the wrist or groin under moderate sedation, and most patients go home the same day.
Neither procedure closes the door on the other. In the Rezum trial, 4.4% of men had a surgical retreatment within 5 years; in the largest long-term PAE series, roughly one man in five needed another treatment by 5 years. After PAE, options include medication adjustment, repeat embolization when the arteries can still be reached, or a tissue-removing procedure such as TURP, HoLEP or Aquablation; after Rezum, PAE and the operations remain available.
Call (310) 929-0026 or request a consultation. Orange County patients are seen at our Fountain Valley office, 10900 Warner Ave, Suite 101A, Fountain Valley, CA 92708; Los Angeles patients are seen in Van Nuys and Tarzana. Bring any prostate imaging, PSA results and your current medication list, and tell us if a urologist has already discussed Rezum with you so the two options can be weighed together.
Medical disclaimer: This article provides general education and cannot tell an individual man which procedure is right for him. The figures above are averages from separate trials and series with different patients and were not measured head to head; your own candidacy, likely benefit and alternatives require an in-person evaluation.
Explore more: Read the complete prostate artery embolization treatment guide, PAE vs UroLift, Rezum, Aquablation and TURP, the PAE Patient Resource Center, and our Medical Editorial Policy.
Medical content reviewed by Nathanael Sabbah, MD, interventional radiologist. Last reviewed: October 2026.