AquaTherm uses hot water that is circulated through a specially designed treatment balloon encased in a single-use, closed-loop catheter and positioned via urethral catheterization into the prostatic urethra.

The catheter is made up of the urinary drainage lumen, which allows urine to drain during the procedure; the positioning balloon; the treatment balloon, which is available in 9 lengths ranging from 2–6 cm; and the insulated shaft.

The system is attached to a computer console that heats water to 60° C (140° F) to ablate obstructive prostatic tissue and precisely controls the water temperature during the procedure. Heat is transmitted to targeted tissue through the treatment balloon.

WIT is performed in an outpatient setting using topical anesthetic. The procedure is completed in one 45-minute session. Mild discomfort, including distal penile burning, may occur during the procedure.

AquaTherm may be indicated in the following patients:

  • Clinical diagnosis of symptomatic BPH
  • Failed drug treatment or drug intolerance
  • International Prostate Symptom Score (IPSS) of 13 or higher
  • Peak urinary flow rate of 12 mL/second or lower with volume of 125 mL or greater
  • Prostatic urethra is a suitable length (2–6 cm; determined by cystoscopy)

The procedure is not typically used in patients with the following:

  • Compromised renal function (serum creatinine >1.8 mg/dL)
  • Confirmed or suspected prostate cancer
  • Desire to remain fertile
  • Hematuria or bladder stones within the past 3 months
  • History of prostate, rectal (other than hemorrhoidectomy), or radical pelvic surgery or radiation to the pelvis
  • Large prostate or median prostatic lobe that protrudes into the bladder
  • Postvoid residual urine >250 mL (determined by ultrasound)
  • PSA level >10 ng/mL
  • Sphincter abnormalities due to Parkinson's disease, multiple sclerosis, stroke, or diabetes
  • Urethral strictures, bladder neck contracture, or prostatitis
  • Urinary tract infection, urinary retention, neurogenic bladder
  • Upper tract disease

After the procedure, the AquaTherm prostatic catheter is removed and a Foley catheter is inserted, usually for 4–17 days. Patients are released immediately following treatment and antibiotics are prescribed.

Side effects are usually mild and include hematuria, urinary tract infection, and urinary urgency. Over time, destroyed prostatic tissue is sloughed off or resorbed by the body, improving BPH symptoms.

Publication Review By: the Editorial Staff at

Published: 04 Oct 2003

Last Modified: 31 Aug 2015