Maximum urethral closure pressure and sphincter volume in women with urinary retention.

PURPOSE: In 1988 a syndrome of isolated urinary retention in young women that is associated with electromyographic abnormality of the striated urethral sphincter was described. It was hypothesised that urinary retention resulted from a failure of sphincter relaxation. The electromyographic abnormality causes overactivity of the muscle and may induce changes of work hypertrophy. If the hypothesis that the electromyographic abnormality is the cause of urinary retention is correct, we would expect the urethral sphincter to be enlarged and the urethral pressure profile to be increased in these women. We evaluated the role of static urethral pressure profilometry and transvaginal ultrasound in women in urinary retention. MATERIALS AND METHODS: A total of 66 women in complete or partial urinary retention underwent electromyography of the striated urethral sphincter using a concentric needle electrode, followed by urethral pressure profile and/or urethral sphincter volume measurement by transvaginal ultrasound. RESULTS: Maximum urethral closure pressure plus or minus standard deviation was significantly increased in patients with versus without the electromyographic abnormality (103 +/- 26.4 versus 76.7 +/- 18.4 cm. water, p <0.001). Maximum urethral sphincter volume was also increased in women with versus without the abnormality (2.29 +/- 0.64 versus 1.62 +/- 0.32 cm.3, p <0.001). CONCLUSIONS: The results of this study are consistent with the hypothesis that a local sphincter abnormality is the cause of urinary retention in a subgroup of women. Urethral pressure profilometry and sphincter volume measurement are useful for assessing these cases, especially when sphincter electromyography is not readily available.

The cause and natural history of isolated urinary retention in young women.

PURPOSE: Using a questionnaire mailed to patients we evaluated the course and natural history of urinary retention in women, of which the cause is attributed to electromyography abnormality of the striated urethral sphincter. Previously urinary retention in young women has often been considered to be due to multiple sclerosis or a manifestation of a psychogenic disorder. MATERIALS AND METHODS: A questionnaire was mailed to 216 women with abnormal sphincter electromyography and urinary retention. Of the 112 responses we analyzed the 91 from those who had been in complete urinary retention. RESULTS: Mean patient age at the onset of complete retention was 27.7 years (range 10 to 50). No patients had neurological features indicating a cauda equina lesion or central demyelination and none had progressed to features of a general neurological disorder. Mean maximum bladder capacity at the initial episode of complete retention was 1,208 ml. Of the women 65% reported an event that had apparently precipitated urinary retention, most commonly a gynecologic surgical procedure using general anesthesia. Sacral neuromodulation was the only therapeutic intervention that restored voiding. CONCLUSIONS: The concept of an organic cause of urinary retention in otherwise healthy young women has considerable importance in terms of correct management. Neurological investigation in these women does not reveal underlying neurological disease. It is thought that this disorder is due to a primary failure of relaxation of the striated urethral sphincter.