Zenflow Spring SystemThe Zenflow Spring System Safety and Performance Study (ZEST CAN)

Inclusion Criteria:

1. Patient is able and willing to comply with all the assessments of the study
2. Patient or patient'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
5. Prostate volume 25 - 80 cc and prostatic urethral length between 2.5-4.5 cm measured within the past 90 days
6. Failed, intolerant, or patient choice to not take a medication regimen for the treatment of LUTS

Exclusion Criteria:

1. Obstructive intravesical median prostatic lobe which in the opinion of the operator would not benefit from treatment
2. Urethral stricture, meatal stenosis, or bladder neck obstruction - either current, or recurrent requiring 2 or more dilations as reported in the patient's history
3. Requiring self-catheterization to void.
4. Baseline PSA > 10 ng/mL or confirmed or suspected prostate cancer
5. Any of the following, taken from a single uroflowmetry reading:

1. Post-void residual volume (PVR) > 250 ml
2. Peak urinary flow rate of > 15 ml/second
3. < 125 ml urinary volume voided at baseline (pre-bladder urinary volume of ≥150 ml required)
6. Other condition or disease that might cause urinary retention
7. History of other diseases causing voiding dysfunction
8. Concomitant Urinary Tract Infection (UTI) (subject can be enrolled following successful treatment of UTI and a clean urine test), or subjects who have a history of recurrent or chronic UTIs (defined as 2 or more UTIs in the past 12 months)
9. Concomitant bladder stones
10. Previous pelvic irradiation or radical pelvic surgery
11. Previous prostate surgery, stent implantations, laser prostatectomy, hyperthermia or another invasive treatment to the prostate
12. Chronic prostatitis, or recurring prostatitis within the past 12 months
13. Known allergy to nickel
14. Life expectancy less than 24 months
15. Use of concomitant medications (e.g., anticholinergics, antispasmodics or tricyclic antidepressants) affecting bladder function
16. 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 (low dose aspirin therapy not prohibited).
17. Taking 5-alpha-reductase inhibitors within 3 months of pre-treatment (baseline) evaluation
18. Taking one of the following within 2 weeks of pre-treatment (baseline) evaluation:

1. alpha-blockers,
2. imipramine,
3. anticholinergics, or
4. cholinergic medication gonadotropin releasing hormonal analogs
19. Taking androgens, unless evidence of eugonadal state for at least 6 months.
20. Taking one of the following within 24 hours of pre-treatment (baseline) evaluation:

1. phenylephrine, or
2. pseudoephedrine
21. Future fertility concerns
22. Any concurrent medical condition or illness that might prevent study completion or would confound study results