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

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 (Q_max), 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 Q_max 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.