Recording urethral pressure profile: comparison of methods and clinical implications.

Urodynamic evaluation of urethral sphincter efficiency can be carried out by constant carbon dioxide perfusion, constant water perfusion, or the use of membrane catheters. A comparison of these three techniques was made in in vitro and in vivo experiments. Results, and advantages and disadvantages of each method are discussed. From all factors considered in this study--responsiveness to pressure changes sensitivity to pressures at various levels along the urethra, and reproducibility and accuracy of the profile--the membrane catheter system was by far superior to either of the flow systems.