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

  • End date
    Jan 1, 2026
  • participants needed
  • sponsor
    Zenflow, Inc.
Updated on 30 July 2021
benign prostatic hypertrophy
lower urinary tract symptoms
bladder outlet obstruction
benign prostatic hyperplasia


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.

Condition Prostate Disorders, Benign prostatic hypertrophy, Prostatic disorder, Benign Prostatic Hyperplasia (Enlarged Prostate), benign prostatic hyperplasia
Treatment Zenflow Spring System
Clinical Study IdentifierNCT04309695
SponsorZenflow, Inc.
Last Modified on30 July 2021


Yes No Not Sure

Inclusion Criteria

Patient is able and willing to comply with all the assessments of the study
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
45 years of age
Baseline IPSS score > 13
Prostate volume 25 - 80 cc and prostatic urethral length between 2.5-4.5 cm measured within the past 90 days
Failed, intolerant, or patient choice to not take a medication regimen for the treatment of LUTS

Exclusion Criteria

Obstructive intravesical median prostatic lobe which in the opinion of the operator would not benefit from treatment
Urethral stricture, meatal stenosis, or bladder neck obstruction - either current, or recurrent requiring 2 or more dilations as reported in the patient's history
Requiring self-catheterization to void
Baseline PSA > 10 ng/mL or confirmed or suspected prostate cancer
Any of the following, taken from a single uroflowmetry reading
Post-void residual volume (PVR) > 250 ml
Peak urinary flow rate of > 15 ml/second
< 125 ml urinary volume voided at baseline (pre-bladder urinary volume of 150 ml required)
Other condition or disease that might cause urinary retention
History of other diseases causing voiding dysfunction
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)
Concomitant bladder stones
Previous pelvic irradiation or radical pelvic surgery
Previous prostate surgery, stent implantations, laser prostatectomy, hyperthermia or another invasive treatment to the prostate
Chronic prostatitis, or recurring prostatitis within the past 12 months
Known allergy to nickel
Life expectancy less than 24 months
Use of concomitant medications (e.g., anticholinergics, antispasmodics or tricyclic antidepressants) affecting bladder function
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)
Taking 5-alpha-reductase inhibitors within 3 months of pre-treatment (baseline) evaluation
Taking one of the following within 2 weeks of pre-treatment (baseline) evaluation
anticholinergics, or
cholinergic medication gonadotropin releasing hormonal analogs
Taking androgens, unless evidence of eugonadal state for at least 6 months
Taking one of the following within 24 hours of pre-treatment (baseline) evaluation
phenylephrine, or
Future fertility concerns
Any concurrent medical condition or illness that might prevent study completion or would confound study results
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