Waterjet Ablation Therapy for Endoscopic Resection of Prostate Tissue (WATER)

Inclusion criteria

• Subject has diagnosis of lower urinary tract symptoms due to benign prostatic enlargement causing bladder outlet obstruction.
• Age from 45 to 80 years.
• Subject has medical record documentation of a prostate volume between 30mL and 80mL (inclusive) by transrectal ultrasound (TRUS). (If TRUS testing documentation is available from less than 180 days prior to the informed consent date and the prostate volume is between 30mL and 80mL, it may be used for the inclusion/exclusion criteria.)
• Subject has an International Prostate Symptom Score (IPSS) score greater than or equal to 12 measured at the baseline visit.
• Subject has medical record documentation of a maximum urinary flow rate (Qmax) less than 15mL/s. (If uroflow testing documentation is available within 90 days prior to the informed consent date, and the sample is greater than or equal to 125mL, and the Qmax is less than 15mL/s it may be used for the inclusion/exclusion criteria.)
• Subject has a serum creatinine that is within the normal range for the laboratory at the study center (or documentation of clinical insignificance in the subject's medical record by the investigator if outside the normal range) and measured ≤ 30 days prior to the date of surgery.
• History of inadequate response, contraindication, or refusal to medical therapy.

Exclusion criteria

• Body Mass Index (BMI) ≥ 42.
• History of prostate cancer or current/suspected bladder cancer.
• Prostate cancer should be ruled out before participation to the satisfaction of the investigator if Prostate-Specific Antigen (PSA) is above acceptable thresholds.
• Subjects with a history of actively treated bladder cancer within the past two (2) years.
• Bladder calculus or clinically significant bladder diverticulum (e.g., pouch size >20% of full bladder size).
• Active infection, including urinary tract infection.
• Prostatitis treated with antibiotics within 1 year of enrollment.
• Ever been diagnosed with a urethral stricture, meatal stenosis, or bladder neck contracture.
• Subject has damage to external urinary sphincter .
• Subject has diagnosis of stress urinary incontinence that requires treatment or daily pad or device use.
• Post-Void Residual (PVR) > 300 mL.
• Urinary retention at time of enrollment or subject has been catheterized in the 14 days prior to the surgical procedure.
• Subject has a history of intermittent self-catheterization.
• Previous prostate surgery or history of other lower urinary tract surgery such as e.g. urinary diversion, artificial urinary sphincter or penile prosthesis.
• Subjects on anticoagulants (if medication cannot be stopped before and after procedure) or known coagulopathy (except aspirin below 100mg/d).
• Any severe illness that would prevent complete study participation or confound study results.
• Participants using systematic immune-suppressants including corticosteroids; unable to withhold non-steroidal anti-inflammatory agents (Nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin) for 3-5 days prior to treatment except for low dose aspirin (e.g. less than or equal to 100mg).
• Participants using anticholinergics specifically for bladder problems. Use of medications with anticholinergic properties is allowable provided the patient does not have documented adverse urinary side effects from these medications.
• Contraindication to general or spinal anesthesia.
• Subject has any other disease or condition(s) that would interfere with completion of the study and follow up assessments, would increase risks of the procedure, or in the judgment of the investigator would potentially interfere with compliance to this study or would adversely affect outcomes.
• Subject is unwilling to accept a transfusion should one be required.