Five meters of H2O: The pressure at the urinary bladder neck during human ejaculation

BACKGROUND. There are no data in the literature on pressure changes in the prostatic urethra during Ejaculation. In healthy men, it has always been po stulated that there must be a pressure gradient in order to prevent retrogr ade ejaculation, but scientific proof for that is pending. METHODS. In five healthy male volunteers, the pressure profile in the prost atic urethra was registered during ejaculation, using a 10 French balloon c atheter with 16 pressure channels. The channels were arranged in pairs at 5 -mm intervals, beginning just below the balloon at the bladder neck and ext ending down to the external urethral sphincter. RESULTS. In the proximal part of the prostatic urethra, a pressure of up to 500 cm of H2O was measured in all subjects. Contrary to that, pressures di d not exceed 400 cm of H2O distally to the verumontanum. CONCLUSIONS. A novel method to register the pressure profile in the lower u rinary tract during ejaculation (ejaculomanometry) is presented. This study adds to the knowledge of the normal physiology of reproductive function an d may be useful in the evaluation of male sexual and reproductive disorders . (C) 2000 Wiley-Liss, Inc.