Overflow incontinence occurs when the bladder becomes overdistended because it cannot empty properly. Overflow incontinence is usually caused by interference with normal neurologic control of the bladder. Patients report that they void small quantities of urine and afterwards still feel that their bladder is full.
Although overflow incontinence can be caused by medical conditions such as multiple sclerosis, diabetic neuropathy, and trauma, in patients with breast cancer it is important to rule out metastatic lesions in the lumbar spine or sacrum. Patients with such lesions will often report loss of bowel continence and neuropathy-typically a loss of S1 nerve root sensation on the soles of the feet. Cystoscopic and neurologic assessment will establish the diagnosis. Appropriate radiologic studies, including bone scans and magnetic resonance imaging studies of the lumbar spine and sacrum, are necessary to identify metastatic sites that could be causing neurogenic bladder.
Diagnosis and Management
Because each type of incontinence presents with characteristic symptoms and findings, the history is the most important factor in the diagnostic work-up. The work-up should also include a culture of the urine, which may reveal a bladder infection, and a pelvic examination, which will often provide valuable information on the type of incontinence and may also reveal a causative factor, such as a pelvic mass. If there is vaginal atrophy or a cystocele, these should be revealed on the pelvic examination. During the pelvic examination, the patient should cough while the speculum is in place. Excessive urethral movement or loss of urine as a result of coughing should be noted.
In patients who have a cystocele identified on pelvic examination, an anterior colporrhaphy with bladder neck plication is appropriate. In patients with symptoms of urge incontinence, if physical examination does not reveal a causative factor, a short course of a detrusor inhibitor such as oxybutynin hydrochloride extended-release can be offered. In addition, detrusor instability can be improved with bladder retraining and scheduled voiding.
Patients with symptoms of stress incontinence should be taught how to perform isometric Kegel exercises to strengthen the levator ani and pubococcygeal muscles. These exercises are effective in more than 60% of patients with mild stress incontinence. If conservative measures do not help in a patient with stress urinary incontinence, surgical approaches are available for cure. These include abdominal approaches that involve elevation of the paravaginal tissue near the urethra in the space of Retzius and suturing of this tissue to the pubic symphysis or to Cooper’s ligament. When properly performed, these procedures are associated with a long-term cure rate of greater than 80%. In addition, there is now a vaginal surgical procedure in which a tension-free mesh is placed under the urethra. This is performed as an outpatient procedure and does not require placement of a Foley catheter after surgery. While this is a newer procedure, data from use of the procedure over 7 years also show a greater than 80% cure rate.
It is not uncommon for women to have coexisting stress incontinence and urge incontinence; thus, proper evaluation using urodynamics is essential for successful management of incontinence. Indications for urodynamic testing include uncertain diagnosis, symptoms of both stress incontinence and urge incontinence, and failure to respond to intervention.
In patients who do not respond to initial treatment, referral to a urogynecologist may be necessary.
Elizabeth R. Keeler, Pedro T. Ramirez, and Ralph S. Freedman
Committee on Gynecological Practice, the American College of Obstetricians and Gynecologists. Obstet Gynecol 2007