The objectives of the trial are to demonstrate the safety and performance of the Zenflow Spring System in relieving the symptoms of obstructive Benign Prostatic Hyperplasia (BPH).

The purpose of the Zenflow Study (ZEST CAN) is to evaluate the safety, performance and effectiveness of the Zenflow Spring System for the treatment of Lower Urinary Tract Symptoms (LUTS) that arise due to bladder outlet obstruction (BOO), secondary to the presence of Benign Prostatic Hyperplasia (BPH). It is intended that the features of the Zenflow Spring will provide an effective office-based treatment and management therapy for BPH with little or no side effects.

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