BERKELEY, CA (UroToday Inc.) - Interstitial cystitis (IC) is a chronic and debilitating bladder syndrome, primarily affecting women. It is characterized by pelvic pain associated with urinary urgency and frequency, and sterile, cytologically normal urine. Despite a large number of purported therapeutic approaches, the treatment of IC remains sub-optimal and the majority of those treatment modalities lack efficacy.

Hyperbaric oxygen therapy (HBO) has been used extensively and successfully in the treatment of chronic radiation cystitis, which shows similarities with interstitial cystitis regarding symptoms, various histologic alterations and therapeutic approaches. Symptoms commonly associated with both bladder diseases include urinary frequency, urgency, incontinence and pelvic pain. The encouraging results of HBO treatment in the treatment of radiation cystitis have stimulated a prospective observational pilot study to examine the role of hyperbaric therapy in interstitial cystitis patients.

A series of six patients with the diagnosis of interstitial cystitis by the strictest criteria underwent 30 treatments of 100% oxygen inhalation in a hyperbaric chamber and were followed for 15 months. The study was conducted by A. van Ophoven et al., from Bonn, Germany and the results reported in the July 2004 issue of European Urology. Mean age of patients was 51.5 years, with 1 man and 5 women comprising the study group. Mean duration of symptoms prior to treatment was 5.1 years and all had failed multiple prior conservative medical treatments.

The endpoints of the study were changes in pain and urgency (via visual analog scales), alteration in the patient?s assessment of overall change in well being (Patient Global Assessment Form), and changes in frequency and functional bladder capacity (48-hour voiding diary).

Results showed that four patients rated the therapeutic result as either excellent or good and assessed their well being after HBO as improved. Two patients reported only short-term improvement of some of their symptoms. At 12 months, the baseline functional bladder capacity had increased from 37-161 ml (range) to 160-200 ml in the responder group. The 24-hour voiding frequency decreased from 15-27 to 6-11 voids per day, a pain scale improvement from 20-97 mm at baseline to 3-30 mm at 12 months follow-up and an urgency scale improvement from 53-92 mm to 3-40 mm, respectively was observed at 12-month follow-up. The symptom and pain index score decreased from 23-35 at baseline (max 35) to 3-17 at 12-month follow-up. No significant adverse events were observed with the treatment.

Hyperbaric oxygen therapy appears to be effective to treat interstitial cystitis patients in this small pilot study. The treatment was well tolerated and resulted in a sustained decrease of pelvic pain and urgency, improvement of voiding patterns and an increase of functional bladder capacity for at least 12 months. A randomized, placebo-controlled study is currently being performed to provide evidence-based data on the efficacy of this novel therapeutic approach to IC.

Eur Urol. 2004; 46(1):108-13