A STUDY OF URODYNAMICS

XI-2 The Response of Urethral Pressure to Phentolamine and the Damage of the Pelvic Plexus after a Radical Hysterectomy

Abstract

Urodynamic features of the disturbance of micturition were studied precisely in sixty-eight patients who had radical hysterectomy, and an assessment was made about the relation between the degree of impairment of the pelvic plexus and the response of urethral pressure to α-blocker (phentolamine).
The patients consisted of two groups. One was a thirty patient group of radical hysterectomy with preservation of the pelvic plexus (preserved group). The other was a thirty-eight patient group of the operation with transection of the bilateral pelvic plexus (transected group). The performed urodynamic examinations included exteroceptive sensation of the bladder, CO₂ gas cystometry with electromyography of external anal sphincter, uroflowmetry and urethral pressure profilometry with and without an intravenous injection of 5mg phentolamine. The examinations were performed prior to the operation and at 1-3, 4-6, 7-12 months, 2-3 years and more than 3 years after the operation.
The maximum urethral closure pressure (cPura) was 77cmH₂O and declined by 43 per cent after injection of 5mg phentolamine prior to the operation in both groups. The cPura fell to 69 cmH₂O and responded by 31 per cent to phentolamine in the preserved group and to 53cmH₂O and by 18 per cent in the transected group more than six months after the operation. The fall of cPura and its poor response to phentolamine were due to damage of the pelvic plexus.
The phentolamine test in the urethral pressure profile is a method which is useful in the diagnosis of the degree of impairment of not only the sympathetic nerves but also the pelvic nerves in the neurogenic bladder of radical hysterectomy, since these nerves were damaged simultaneously by transection of the pelvic plexus.