Measurement of luminal nitric oxide in bladder inflammation using a silicon balloon catheter: A novel minimally invasive method

Objectives. Nitric oxide (NO) measured in the gaseous phase has been shown to be a marker of inflammation in the urinary bladder. The NO content of air incubated in the bladder can be measured in an NO analyzer. The aim of our study was threefold: to evaluate whether NO can be measured in air incubated in a catheter balloon, to determine the optimal time of incubation, and to find the most suitable type of catheter. Methods. The NO concentration in air introduced directly into the bladder and into the catheter balloon was measured in patients with and without bladder infections. The air was incubated for 5 to 60 minutes. NO concentration in the bladder of patients with interstitial cystitis was also analyzed. The diffusion rate of NO through silicon and latex catheters was studied. Results. Elevated NO levels were detected in the urinary bladder in patients with bladder inflammation due to infection or interstitial cystitis. A marked increase in NO concentration was found after just 5 minutes of incubation and continued to rise for up to 20 minutes, both in air taken directly from the bladder and from the catheter balloon. The NO diffusion rate into the balloons of silicon catheters was high; the recovery rate in latex catheters was poor. Conclusions. Measurement of NO concentration in a silicon balloon catheter inserted into the urinary bladder is a fast, convenient, and reliable method to detect inflammation.