[Urethral instability: diagnosis and clinical significance].

Simultaneous urethrocystometry, the advantages of which are outlined, enabled us to diagnose 27 cases of pure urethral instability (male and female) and 16 cases of mixed instability (urethral and bladder instability). We analysed the relationship between the main symptom, this urethral dysfunction and the competence of the bladder neck. Definition, characteristics and frequency of urethral instability are discussed. It is responsible of: frequency or urgency, in the absence of bladder instability, when the bladder neck is closed, intermittent sphincteric incontinence, in the presence of a normal closure pressure on the urethral pressure profile, when the bladder neck is incompetent, enuresis, particularly in case of stable bladder; a new treatment is proposed for this entity. The clinical interest of this diagnosis is stressed in these three situations.