Zenflow Spring System shows promise in BPH

Use of the Zenflow Spring System led to immediate and significant symptom improvement in patients with benign prostatic hyperplasia (BPH), according to results from the ZEST CAN study presented at the 2023 AUA Annual Meeting.¹

Regarding next steps, Elterman said the results are now being validated in the large, prospective BREEZE trial.

At 12 months, the treatment led to 46% improvement in IPSS from baseline and a 56% improvement in IPSS-QOL from baseline. Qmax also improved by 45% from baseline. Additionally, patients did not experience any sexual dysfunction.

Explaining the mechanism of Zenflow, lead author Dean Elterman, MD, a urologist at University Urology Associates and a faculty member in the University of Toronto's Division of Urology, said “Zenflow is a novel minimally invasive surgical therapy (MIST) that delivers a nitinol device into the prostatic urethra displacing the lateral lobes for improved urinary flow.”

The prospective, single-arm ZEST CAN study (NCT04309695) included 10 patients with BPH who received the device at 3 centers in Canada. The average patient age was 68.4 years, the mean prostate volume at baseline was 43.9 cc (range 31.4-62.9), and the average prostatic urethral length, which was used to select the size of the implant, was 31.8 mm (range, 26.0-38.0).

After the Zenflow implant was placed, “Patients were discharged within 2 hours of the procedure with no acute adverse events reported during the procedure,” said Elterman, “Adverse events post procedure were typically mild and transient and common to events reported in similar MIST procedures.”

The investigators used IPSS and IPSS-QOL to measure symptom improvement. Functional improvement was measured by peak urinary flow rate (Qmax).

At 12 months, patients had a significant reduction in IPSS from baseline, with the score lowering from 21.2 to 11.4 (P <.01). IPSS-QOL was also significantly reduced at 12 months, lowering from 5.4 at baseline to 2.4 (P <.010). And Qmax went from 9.7 mL/sec at baseline to 14.0 mL/sec at 12 months (P <.05).

“There was no change in erectile function (SHIM), and a 45% improvement to ejaculatory function bother score (MSHQ-EjD),” said Elterman.

Regarding next steps, Elterman said the results are now being validated in the large, prospective BREEZE trial.

Following his presentation, Elterman was asked to explain, “Given that there are several novel stent devices such as Zenflow emerging for BPH, how will practicing urologists choose among them?”

In response, Elterman said, “You know, I think we've entered into a new era of stents. Certainly the material has improved. And not all nitinols are the same; some of them are actually quite thin and others are a little bit more rigid and robust. Some stents are designed to be left in permanently, while some are designed to be left in semi-permanently.

“Other key factors will be whether it’s easy to place the stent, whether it’s easy to remove, and of course, issues with migration and encrustation.

“So, time may tell eventually as these stents come to market, in terms of urologist preference. We have 3 FDA-approved MISTS right now: Rezum, UroLift, and iTind. And each one has, I would say, advantages and disadvantages to certain prostates. And it's really up to the urologist to figure out for this particular phenotype, I may prefer A, B, or C.”

References

1. Elterman D, Matsumoto ED, Zorn KC. 12-month outcomes from the first North American study of the Zenflow Spring System for the treatment of benign prostatic hyperplasia (BPH). Presented at 2023 AUA Annual Meeting. April 27-May 1, 2023; Chicago, IL. Abstract PD41-02. doi:10.1097/JU.0000000000003346.02