The open bladder neck: a significant finding?

Women with lower urinary tract symptoms were retrospectively studied. They were all investigated using a urinary symptoms questionnaire, a frequency-volume chart and videocystourethrography. An open bladder neck was recorded at maximum cystometric capacity with the patient standing in the left lateral position, if contrast medium entered the proximal urethra at rest in the absence of a detrusor contraction or an increase in intra-abdominal pressure. Women with neurological disorders were excluded. Of 4500 women, 2,593 (57.6%) had a single urodynamics diagnosis and were included in the study: 1207 (46.5%) had urodynamics diagnosis of urodynamic stress incontinence, 558 (21.5%) had detrusor overactivity, 118 (4.6%) had sensory urgency, and 710 (27.4%) had a normal urodynamic study. Out of the 2,593 women included, 776 women (29.9%) had an open bladder neck at rest while 1817 (70.1%) had a closed bladder neck at rest. Only 45% (542/1207) of women with urodynamic stress incontinence had an open bladder neck at rest. Seventy percent (542/776) of women with an open bladder neck had a diagnosis of urodynamic stress incontinence whilst 73% of women with detrusor overactivity and 93% of those with sensory urgency had a closed bladder neck. An open bladder neck at rest is not diagnostic of urethral sphincter incompetence but is associated with urodynamic stress incontinence. It is not associated with urgency as few women with sensory urgency and detrusor overactivity were found to have an open bladder neck. Imaging the bladder neck at rest has questionable value.