Safety and Effectiveness Study of the Zenflow Spring System

Evaluate the safety and effectiveness of the Zenflow Spring System in relieving LUTS associated with BPH.

Prospective, multi-center, multinational, 2:1 randomized, single-blinded, controlled clinical trial of the Zenflow Spring System.

Patients randomized to the treatment group will undergo Zenflow Spring placement.

Patients randomized to the control group will undergo a Sham procedure. Patients and site personnel administering follow-up assessments will be blinded to the randomized treatment through completion of the 3-month follow-up visit. Once a patient has completed their 3-month follow-up assessments, they will be unblinded. Following unblinding, patients who received a Sham procedure may elect to receive treatment with the Zenflow Spring System or alternatively they may exit the study.

The duration of study participation is 60 months for patients who receive a Spring Implant and 3 months for subjects in the Control Arm.

Eligibility Criteria:
Inclusion Criteria:

1. Subject is able and willing to comply with all the assessments of the study,
2. Subject or subject's legal representative has been informed of the nature of the study, agrees to participate and has signed the informed consent form,
3. ≥ 45 years of age,
4. Baseline IPSS score ≥ 13; ≥ 1 in the IPSS voiding to storage sub-score ratio (IPSS-V/S),
5. Prostate volume 25 - 80 cc by transrectal ultrasound (TRUS), measured within 120 days post study consent,
6. Prostatic urethral length between 25 and 45 mm, as measured by cystoscopic pull-back,
7. Failed, intolerant, or subject choice to not take a medication regimen for the treatment of LUTS.

Exclusion Criteria:

1. Obstructive intravesical median prostatic lobe as determined by ultrasound (i.e., more than 10 mm intravesical prostatic protrusion on sagittal mid-prostate plane via abdominal ultrasound),
2. High bladder neck with the absence of lateral lobe encroachment indicating a high likelihood of primary bladder neck obstruction as determined by the Investigator,
3. Urethral stricture, meatal stenosis, or bladder neck stricture - either current or recurrent,
4. Anatomical anomalies that will not accommodate the Implant, as determined by cystoscopy (e.g., prostatic urethral length to height geometry),
5. Requires indwelling catheter or intermittent catheterization to void,
6. Baseline PSA \> 10 ng/mL or confirmed or suspected prostate cancer (Subjects with a PSA level above 2.5 ng/mL, or age specific, or local reference ranges should have prostate cancer excluded to the Investigator's satisfaction),
7. One of the following baseline test results, taken from a single uroflowmetry reading:

   1. Urinary volume void ≤ 125mL (pre-bladder urinary volume of ≥ 150 mL required),
   2. Peak urinary flow rate (Qmax) of ≤ 5 ml/second or \> 15 mL/second,
   3. Post- void residual volume (PVR) \> 250 mL
8. History of other diseases causing voiding dysfunction including urinary retention (e.g., uncontrolled diabetes, diagnosis of neurogenic bladder, Parkinson's disease, multiple sclerosis, etc.),
9. Subjects with overactive bladder in the absence of benign prostatic obstruction,
10. Acute urinary tract infection (UTI) or finding of asymptomatic bacteriuria (Note: subject can be enrolled if the UTI is treated and followed with a negative urine test result), or subjects with history of recurrent UTIs (defined as \> 3 UTIs in the past 12 months),
11. Concomitant bladder stones,
12. Previous pelvic irradiation or radical pelvic surgery,
13. Previous prostate surgery, including: enucleation, resection, vaporization, thermotherapy, ablation, stenting or prostatic urethral lift,
14. Chronic prostatitis, recurrent prostatitis, chronic pelvic pain syndrome (CPPS), or painful bladder syndrome within the past 12 months
15. Known allergy to nickel,
16. Life expectancy less than 60 months,
17. Use of concomitant medications (e.g., anticholinergics, antispasmodics or tricyclic antidepressants) affecting bladder function,
18. Inability to stop taking anticoagulants and/or antiplatelets for at least 3 days prior to the procedure or coumadin for at least 5 days prior to the procedure (Note: low dose aspirin therapy (81 mg) is permitted),
19. Taking 5-alpha-reductase inhibitors within 3 months of baseline evaluation,
20. Taking one of the following within 2 weeks of baseline evaluation:

    1. alpha-blockers,
    2. imipramine,
    3. anticholinergics,
    4. cholinergic gonadotropin releasing hormonal analogues,
    5. Phosphodiesterase-5 Enzyme Inhibitors (Tadalafil) in doses for BPH,
    6. Beta-3 adrenergic receptor agonist (Mirabegron),
21. Taking androgens, unless eugonadal state for at least 3 months or greater as documented by the Investigator,
22. Taking one of the following within 24 hours of pre-treatment (baseline) evaluation:

    1. phenylephrine, or,
    2. pseudoephedrine,
23. Future fertility concerns, or,
24. In the Investigator's opinion, the subject has a physical, psychological, or medical impairment that might prevent study completion or would confound study results (including subject questionnaires).