First-in-man Safety and Efficacy of the ClearRing Implant for the Treatment of Benign Prostatic Hyperplasia

Egils Vjaters, David Nitsan, Michael Mullerad, Dov Engelstein, Ilan Leibovitch, Yair Feld*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Background: Although effective for benign prostatic hyperplasia (BPH), transurethral resection of the prostate (TURP) can be associated with side effects including prolonged recovery, storage and voiding symptoms, and a risk of acute urinary retention. Objective: To test a new minimally invasive device for the treatment of lower urinary tract symptoms (LUTS) due to BPH, involving implantation of a C-shaped nitinol ring (ClearRing) in a circular incision in the prostatic tissue using an electrocuting blade over a dilatation balloon. Design, setting, and participants: This was a multicenter single-arm clinical trial involving 29 men with severe symptomatic BPH. Intervention: Implantation of a ClearRing device under regional anesthesia. Outcome measurements and statistical analysis: Effectiveness in alleviating LUTS was assessed in terms of International Prostate Symptom Score (IPSS) at baseline and 3, 6, and 12 mo after the procedure. To evaluate changes from baseline, a general estimating equation model was fitted to IPSS, the Quality of Life (QOL) scale, Benign Prostatic Hyperplasia Impact Index, maximum flow rate (Qmax), and postvoid residual volume. Statistical significance was defined as p < 0.05. Results and limitations: The average age was 71.4 yr, prostate size was 35–50 cm3, and IPSS was 21.6. All procedures were successfully completed with one implant in 28 patients and two implants in one patient. No serious complications occurred. Patients experienced symptom relief by 3 mo that was sustained to 12 mo. Mean IPSS, QOL, and Qmax improved by 45%, 41%, and 40% by 3 mo, and 53%, 52%, and 49% by 12 mo, respectively (p < 0.05). Adverse events were mild and transient. There were no reports of loss of antegrade ejaculation or any effects on erectile function. Implantation positioning failed in 11/29 patients, who then underwent uneventful TURP. After modification of the delivery device, the success rate for implant positioning improved from 5/13 patients to 13/16 patients. Study limitations include the single-arm nature and the low patient number. Conclusions: We demonstrated preliminary feasibility of the ClearRing device for minimally invasive treatment of BPH in men. Further studies are needed to confirm the safety and efficacy of this approach. Patient summary: In this study we tested outcomes after implantation of a ClearRing device in patients with benign prostatic hyperplasia. We found that the device was safe and effective. However, there was a high rate of implantation failure due to malpositioning, which was significantly improved following modification of the delivery device.

Original languageEnglish
Pages (from-to)131-136
Number of pages6
JournalEuropean Urology Focus
Issue number1
StatePublished - 15 Jan 2020
Externally publishedYes


FundersFunder number
ProArc Medical


    • Benign prostatic hyperplasia
    • Endoscopy
    • Surgical devices


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