Long-term results of Rezum therapy for patients with large prostates

Patients with large prostates (LP), defined as greater than 80 grams, are generally limited to certain procedures such as a prostatectomy or transurethral resection of the prostate (TURP) when surgery is required. In most instances, these procedures require general anesthesia and admission. In more recent years, however, investigators are introducing alternative therapies to men with LP with less invasive options for treatment.

In a study presented at the 2021 American Urological Association Annual Meeting,¹ Michael Palese, MD, Evan Garden and co-authors estimate the long-term outcomes of Rezum water vapor therapy in treating men with LP (greater than or equal to 80 grams) who have benign prostatic hyperplasia (BPH). Dr. Palese is the Chair of the Department of Urology at Mount Sinai Downtown & Beth Israel Medical Center and Evan Garden is a fourth-year medical student at the Icahn School of Medicine at Mount Sinai, New York, New York.

Please discuss the background for this study.

Palese: The reason that we started looking at using this procedure, called Rezum or water vapor treatment, for this particular population of men was that there aren't many options for men with very large gland prostates. So, in men with prostates that are 80 grams or larger, you really either need to do a TURP - and again there's only so large of a TURP that you can do - or you're looking at doing a prostatectomy. The traditional approach for prostatectomy would be an open approach where you make an incision to remove the prostate. Nowadays, we're doing these robotically and laparoscopically. But again, this still requires general anesthesia. There is also a potential for higher complications. Patients need to remain in the hospital at least 1 night, if not 2 nights, so we were looking for an alternative for avoiding general anesthesia and more invasive surgery.

The Rezum became very interesting to us because it had the potential to do that. We had some excellent success with our initial patients, who have prostates between 20 and 80 grams. We started to look at this with an IRB approved study to see if we could do this in men with larger glands and hopefully push the envelope a little bit. We presented our data at the American Urologic Association meeting this year. We have also published our preliminary data.2 We have had some interesting findings that I think are very promising. We'd love to see if others can recreate it and see if they have the same, or hopefully better, outcomes than we did. That's the main reason why we chose to look at this as an alternative treatment for large gland prostates.

What were some of the notable findings? Were any of them surprising to you and your co-authors?

Garden: We divided our outcomes into a number of different categories: whether they were functional outcomes related to patients' urinary function, proxies for the severity of disease, self-reported symptom scores, reliance on medications, and the safety profile of the procedure for this subset of patients with prostates greater than 80 grams. We also compared the rates of certain post-procedural complications to patients who’ve had prostates less than 80 grams. Regarding functional outcomes and disease-related outcomes, we found that both groups of men, with greater than and less than 80 grams-sized prostates, had significant improvements in urinary function as demonstrated by Uroflow and post void residual. We also found that they had improvements in AUA symptom score, and we found that both groups had significantly decreased reliance on alpha blockers, which is one of the primary categories of medications used to provide symptomatic relief for patients with BPH. These are medications like tamsulosin, silodosin, etc.

And then in terms of the clinical side effects of the procedure, we found that largely the clinical side effect profile demonstrated by the 2 groups were comparable. No statistically significant differences in rates of urinary tract infection, hematuria retention, emergency room visits or post-operative hospitalizations. The only difference was that men with larger prostates reported significantly increased rates of post-operative urgency compared to men with smaller prostates.

The other significant finding that we found was those men with large prostates greater than 80 grams were surgically retreated at a significantly higher rate. So, the retreatment rate for our small prostate cohort was 4.4%, which is in line with the results demonstrated from the original WATER clinical trial,3 which also had a retreatment rate of 4.4%. For our large prostate cohort, this subset of patients had a retreatment rate of 18.4%, so a little less than one in five patients required subsequent procedural intervention for BPH related symptoms.

Palese: The significant finding is that we are dealing with a larger gland, which means more tissue needs to be ablated. It is therefore not surprising that we would have found it to be a much higher retreatment rate than with smaller glands. But a 1 in 5 retreatment rate is clinically not terrible. It does give men another option, and so I think that's really what we're focusing on here. Giving the option to avoid general anesthesia and to avoid a more invasive surgery, with the intent that if we don't have success that we're looking for, we still can go back and do one of the more traditional approaches.

What is your patient selection process like for treating BPH?

Palese: One of the most important things about this procedure is setting up patient expectations. When patients come to see us, we want to provide the information that they require to make an informed decision and informed consent about what they're doing, and that their expectations are in line with what they're seeking. For the Rezum, one of the reasons that a lot of men will seek it out is because it tends to have minimal sexual side effects compared to many of the other procedures available. A lot of my younger patients will request to do a Rezum procedure, knowing that they'll probably need some type of retreatment or some other type of treatment in the future, anywhere from 3 to 5 years. We keep that in mind when we're recommending treatments, like Rezum. We want to make sure that patients understand what they're signing up for, what their expectations are and what they hope they can achieve by doing this procedure.

What is the take-home message for the practicing urologist?

Palese: The main goal here is to provide another alternative for the large gland prostate group. It's certainly not something that I believe a urologist who's just starting out doing Rezum should be undertaking. I think you do need to get some experience with the traditional 20-to-80-gram group. There's no question that there is a learning curve. It important to understand how to counsel the patients as well because they do have more irritative symptoms afterwards. There's more inflammation and they tend to keep the catheter a little bit longer than with the other smaller gland prostates. I think these are all things that need to be addressed with a patient upfront, and they need to understand that there are going to be some differences. The main take-home message here for the urologist is that this is another alternative. It doesn't always work with an 18% retreatment rate but it is another option.

Is there anything else you feel our audience should know about the findings?

Garden: It's always important to understand the context in which this research is done. There are some limitations to our findings. This was a retrospective, not a prospective, study. So, while this study does offer a lot of promise for the treatment options that we can offer to these patients, it does also highlight the need for further prospective trials to evaluate the efficacy of this treatment for this population, as well as the efficacy of all the different surgical options available to patients who are suffering from BPH. We hope that this can contribute to the existing body of literature to better inform urologists and patients alike.


1. Garden E, Ravivarapu K, Levy M, et al. Rezum for men with large prostates ≥80 cc versus small prostates <80 cc: Updates outcomes and long-term results. Paper presented at: 2021 American Urological Association Annual Meeting; September 10-13, 2021; virtual. Abstract MP09-05

2. Garden EB, Shukla D, Ravivarapu KT, et al. Rezum therapy for patients with large prostates (≥80 g): Initial clinical experience and postoperative outcomes. Published online January 3, 2021. World J Urol. doi:10.1007/s00345-020-03548-7

3. McVary K, Roehrborn C. Five year results of the prospective, randomized controlled trial of water vapor thermal therapy for treatment of lower urinary tracts symptoms due to benign prostatic hyperplasa. Published online April 1, 2020. J Urol. doi:10.1097/JU.0000000000000946.06