3-year Aquablation study results show favorable outcomes in BPH

Kevin Zorn, MD, FRCSC, FACS

Aquablation is a new surgical technique used to treat patients with symptomatic benign prostatic hyperplasia (BPH). Although it has not been around as long as transurethral resection of the prostate (TURP), prostatic urethral lift, Rezum, and other popular treatment options, early studies suggest high rates of safety and efficacy.

In a presentation at the 2021 American Urological Association Annual Meeting,¹ Kevin Zorn, MD, FRCSC, FACS, reported 3-year results assessing the efficacy of robot-assisted Aquablation procedures in treating men with large prostates. Zorn is an associate professor of urology at the University of Montreal, Canada.

Please provide an overview of the Aquablation system and its use in treating BPH.

The Aquablation system by PROCEPT BioRobotics is a novel new technology which marries conventional ultrasound imaging we are all familiar with (for prostate volume assessment as well as for surgical mapping/planning of transition zone treatment) with robotic surgical execution—an ultra-precise, automated robot that does the treatment with a high-pressure, athermal water jet that will treat up to a 2.4 cm radius of tissue on each pass. As such, compared to other BPH treatments, this is a very fast, reproducible technology that could democratize how all urologists perform BPH surgery and harmonize outcomes and complications.

What are the advantages of Aquablation compared with other treatments for BPH?

There's a few of them, the first being reliability and reproducibility. In other words, be it myself, who performs high volume Aquablation procedures, or a community urologist in Boston or someone else around the world, we would all be doing the same standardized procedure. Procept Aquablation system universalizes the way we define our visual treatment margins of where we will want to treat, and the actual treatment itself is the robot. It's an automated delivery treatment robot that actually conducts the hydro-dissection procedure.

The other huge advantage is speed. As urologists, we all treat very large prostates—well over 50- 80 grams. These larger glands take longer and unfortunately, have higher potential retreatment rates since with conventional TURP we don't remove enough tissue. Other than offering HOLEP, open/robotic simple prostatectomy, which require significant learning curves and long OR time, the WATER2 study data demonstrates safety, efficacy and a huge OR advantage. Hence with Aquablation, we finally have a technology to treat any-size prostate in under an hour.

The third advantage of Aquablation that is unique to any of the other surgical treatments, is that it has the strong ability to preserve antegrade ejaculation. Surgical mapping and preservation of the apical tissue with the precise, heat-free Aquablation apical butterfly dissection explain this maintenance of sexual function.

What are some of the notable findings from this study, and were any of them surprising to you and your co-authors?

This is our single-series outcomes of 101 men with large-sized prostates, called the WATER II trial (NCT03123250). It's a prospective, ongoing study up to 5 years, and the 3-year data have very similar outcomes to what we saw for the WATER randomized trial (NCT02505919). The notable findings here were the fact that we had similar reductions in International Prostate Symptom Score (IPSS) and marked improvements in the quality of life, Qmax voiding speed, and postvoid residual bladder volume post Aquablation. As such, not only is the technology effective, but it's also durable up to 3 years. That's really the novel new message we're delivering from this year's AUA abstract. It's not just something that lasts a short period of time. We're at 3 years and the results are comparable to the 3-month data. The plan at present in to continue assessment to at least 5 years. So far, this seems to be a very durable treatment for these large prostates—men with 80 to 150 CCs.

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

The take-home message is that Aquablation is safe. It's efficacious, especially in these large prostates. We know right now that the 2021 AUA BPH guidelines position this as a technology to be considered for 30- 80 grams (based on the WATER1 RTC in 30-80cc porstates). However, our study provides strong evidence to support the use of Aquablation in larger prostates. With the primary end points being safety and efficacy being achieved at 3 months and maintained up to 3 years, this is reassuring that what we're offering to our patients is something that can be quick, efficacious, and durable (with a very low surgical retreatment rate).

Is further research on this topic planned? If so, what will the focus be?

I think the WATER and WATER II studies were the initial pivotal studies to demonstrate efficacy, (IPSS reduction), and safety (preservation of sexual function and Clavien-Dindo complications). And we're seeing this out to 3 years, so is there further research? Yes, we're going to be continuing to watch this out till 5 years, maybe even further. That's really the focus—to show the durability in these larger prostates, which as we know, tend to have a very high retreatment rate. As we see with other technologies, there may be an up-front benefit, but at year 3 or 5, a lot of patients drop out, go back on medications, or have another surgery. At least in the 3-year results, we know that 94% of these 101 men are free from any BPH medication, and 97% are free from any surgical reintervention. Those are the key elements of our outcomes at 3 years.

Is there anything else you feel our audience should know about this research?

There's a lot more traction and buzz toward Aquablation. I think the key elements that you should know about Aquablation if you are treating BPH, in consideration for your patients and care, especially those who are looking for a more durable response and to maintain their ejaculation: This is a therapy that should be part of the urological BPH armamentarium and discussed as part of the informed consent counseling of your patient.

Reference

1. Zorn K, Bidair M, Bhojani N. Aquablation for benign prostatic hyperplasia in large prostates (80-150CC): 3-year results. Paper presented at 2021 American Urological Association Annual Meeting; September 10-13; virtual. Abstract PD18-06.