To measure intra-prostatic temperatures and evaluate the shape and size of necrotic lesions achieved under the standard treatment protocol in men with benign prostatic hyperplasia (BPH).

The Wallterm System provides minimally invasive treatment of benign prostatic hyperplasia (BPH) via a high temperature, liquid filled, balloon thermotherapy. The catheter is composed of a silicone positioning balloon which anchors the catheter against the bladder neck. The multi-layer silicone treatment balloon may be adjusted to fit short (20-35mm) and long (40-55mm) prostates and is inflated (to approximately 650-700 mmHg / 20-22mm diameter) to ensure tight tissue contact and reduced blood perfusion. The handle contains the heating element and the liquid circulation mechanisms

Inclusion Criteria:

• Men with symptomatic BPH requiring treatment,
• IPSS score > 15
• Age > 50 years
• Prostate size of 25 g or greater
• Prostatic urethra length between 2.0 cm and 5.5 cm,
• Ability to understand and consent to participate in this investigation,
• Willingness and ability to participate in all required follow-up evaluations.

Exclusion Criteria:

• Allergy towards Silicone,
• Peak Urinary Flow > 15 mL/s,
• Penile or urinary sphincter implant,
• Patients with active urinary tract infection indicated by a positive urinary culture >105 CFU (Note: These patients may be treated after successful treatment of the infection.)
• Clinical (historical), paraclinical (i.e. PSA> 10ng/mL) or histological evidence of prostatic cancer or bladder cancer,
• Evidence of a non-symmetric prostatic median lobe enlargement, or a prostatic lobe which is prominent with an obstructing "ball valve", as determined by cystoscopy or ultrasound,
• Patients with any previous prostate surgery, procedure for BPH, or any other invasive treatment to the prostate (such as TUR-P).
• Previous rectal surgery (Exception: hemorrhoid surgery), radical pelvic surgery or pelvic irradiation.
• Patients with confirmed or suspected bladder cancer.
• Patients with a history of cystolithiasis or bladder pathology, or who have experienced relapsing bacterial prostatitis within the last 6 months.
• Patients with gross haematuria. (Note: These patients may be eligible for this investigation if the results of a careful workup for cancer, including an X-ray study, cystoscopy and cytology, are found to be negative.)
• Patients with a history of bladder neck contracture.
• Patients who presently have urethral strictures, which prevent the passage of a 20 Fr endoscope (these patients may be treated after successful treatment of the stricture).
• Patients with neurogenic bladder dysfunction (neurogenic detrusor hypo- or hyperactivity).
• Patients interested in future fertility.
• Patients who have chronic catheter drainage due to urinary retention (these patients may be treated if a CMG demonstrates that the patient has a contractile bladder).
• Patients with bleeding disorders, or other systemic disorder contraindication minimally invasive surgical therapies.
• Any condition (ie: vascular clips) which would preclude an MRI from being performed, or otherwise confound this investigation.
• Patients with compromised renal function (i.e. serum creatinine >150 mls/l), renal or upper tract dilatation.

Men with BPH