Patient description: The patient is a 63-year-old man presenting to the Emergency Department with a history of acute urinary retention in the past 2 days. Abdominopelvic CT scan revealed a large prostate and a bladder filled with urine. He is a candidate for urethral catheterization and TURP. Further evaluation revealed: Post-void residual: 71 mL Prostate volume (TRUS): 63 mL Prostate-specific antigen (PSA) level: 3.5 ng/mL His recent blood chemistry (3 days ago) was normal: Hgb: 13.6 g/dl WBC: 133000 /mm3 Plt: 370000 /ml PT: 12 second PTT: 34 second INR: 0.9 Creatinine: 0.5 mg/dl BUN: 10 mg/dl U/A: Color: yellow Appearance: cloudy PH: 5.3 Specific gravity: 1.010 Glc: 100 Nitrite: negative Ketone: none Leukocyte esterase: negative RBC: negative WBC: 2 WBCs/hpf U/C: negative

Clinical trial eligibility criteria: eligible ages (years): 50.0-999.0,  Prostatic Hyperplasia Patient is aged 50 years or older. 2. Patient has signed informed consent 3. Patient has experienced lower urinary tract symptoms (LUTS) for at least 6 months prior to study enrollment 4. Patient has a prostate size larger than 40g as measured by MRI or CT (if MR not possible) 5. Patient has an IPSS score greater than or equal to 13 6. Patient either: i. Refuses surgical treatment ii. Is considered high risk for surgical treatment 7. Patient is either: i. Refractory to medical treatment ii. Contraindicated for medical treatment 8. Patient must meet ONE of the following Baseline PSA ≤ 2.5ng/mL Baseline PSA > 2.5 ng/mL and ≤ 10 ng/mL AND free PSA ≥ 25% of total PSA (no biopsy required) Baseline PSA > 2.5 ng/mL and ≤ 10 ng/mL AND free PSA < 25% of total PSA AND negative prostate biopsy result (minimum of 12 core biopsy) within 12 months Baseline PSA >10 ng/mL AND negative prostate biopsy result (minimum of 12 core biopsy) within 12 months 9. Patient has a peak urine flow rate < 12ml/sec  Active prostatitis or urinary tract infection 2. History of prostate or bladder cancer, or currently being evaluated for cancer 3. Bladder atonia, neurogenic bladder disorder or other neurological disorder that is impacting bladder function. 4. Urethral stricture, bladder neck contracture, other potentially confounding bladder pathology, bladder disease, or confounding urethral pathology 5. Patient has taken beta blockers, antihistamines, anticonvulsants, or antispasomodics within 1 week of study treatment AND has not been on the same drug dosage for 6 months with a stable voiding pattern. 6. Patient has taken antidepressant, anticholinergics, androgens or gonadotropin-releasing hormonal analogues within 2 months of study treatment AND has not been on the same drug dosage for at least 3 months with a stable voiding pattern. 7. Patient has taken alpha blockers within 4 weeks of study treatment AND has not been on the same drug dosage for at least 3 months with a stable voiding pattern. 8. Patient has taken 5-alpha reductase inhibitors within 3 months of study treatment AND has not been on the same drug for at least 6 months with a stable voiding pattern 9. History of open prostate surgery, radiofrequency, or microwave therapy 10. Previous open bladder or rectosigmoid colon surgery 11. Acute urinary retention requiring an indwelling catheter 12. Cystolithiasis within the past 3 months 13. Coagulation disturbances not normalized by medical treatment 14. Iodinated contrast allergy not controlled with 24-hour steroid preparation 15. History of pelvic irradiation 16. History of severe peripheral vascular disease or known major iliac arterial occlusive disease 17. Interest in future fertility 18. Significant cardiac or respiratory disease that the Investigator believes puts the patient at risk for a complication during the procedure 19. Acute urinary retention requiring an indwelling catheter 20. Life expectancy less than 6 months 21. History of rectal disease 22. Known immunosuppression either pathological or pharmacological 23. Presence of collateral vessel pathways potentially endangering normal anatomy during embolization that cannot be bypassed with the microcatheter 24. History of any illness or surgery that might confound the results of the study, by producing symptoms which may be confused with those of the disease process under consideration (e.g., Parkinson's, multiple Sclerosis), or which pose an additional risk to the patient