It is advisable to follow a stepwise approach in treating urinary incontinence in postmenopausal women. Behavioural therapy is initially attempted and if unsuccessful pharmacological treatment is indicated.
Urological problems are common in postmenopausal women. This article will discuss some successful interventions for varieties of pathologies, including urgency incontinence (UI), stress incontinence (SI), recurrent urinary tract infections (UTIs) and neurogenic (atonic) bladder.
Urinary incontinence is the involuntary leakage of urine. In a study of postmenopausal women, about 56% reported this problem at least weekly.1 There are six different subtypes of urinary incontinence: stress incontinence (most common type in postmenopausal women), urgency incontinence, mixed incontinence combining features of the aforementioned two types, overflow incontinence, functional incontinence and lastly true incontinence usually related to a postoperative vesicovaginal or ureterovaginal fistula.
There is some evidence that pharmacological treatment with antimuscarinic agents, eg. darifenacin, fesoterodine, oxybutynin, solifenacin, tolterodine, trospium, improved UI compared to placebo with NNT (number needed to treat) to improve symptoms ranging from six to 10 patients. They may achieve continence and improve quality of life. Side effects of antimuscarinic agents include urinary retention, dry mouth, constipation, nausea, blurred vision, tachycardia and confusion. They are contraindicated in patients with narrow angle glaucoma. Agents that do not cross the blood brain barrier, eg. trospium, are preferred in the elderly. Moderate quality evidence showed that the B3 agonist, mirabegron achieved continence and improved UI more than placebo.4 B3 agonists are associated with hypertension, arrhythmias.
Neuromodulation is based on the pain gate control theory published for the first time in 1965.5 This theory, despite its flaws, asserts that stimulation of thick myelinated fibers, eg. A-beta fibers, is able to suppress painful stimuli conveyed by smaller unmyelinated fibers, eg. C fibers.
It is postulated that neuromodulation of sacral nerves at a specific frequency can inhibit afferent nociceptive fibers from the urinary bladder and hence suppress the urgency. Modalities to treat UI include sacral neuromodulation and percutaneous tibial nerve stimulation.
Sacral neuromodulation has been approved to treat UI. After ruling out treatable causes of UI, eg. stones, interstitial cystitis, tumour, the patient receives a temporary external pulse generator connected via wire leads to S3. After one to two weeks, if the patient’s symptoms improve by >50%, a permanent stimulator is implanted in the hip area in the subcutaneous tissue. The programming of the stimulator can be adjusted to improve symptoms. Age doesn’t appear to affect efficacy of the procedure.
Percutaneous tibial nerve stimulation is an office procedure where a needle electrode is inserted 5cm above the medial malleolus for 30 minutes weekly for a total of 12 weeks. According to some studies, response rate is about 54%6 in patients with UI who failed antimuscarinic drug and complete recovery was maintained in 42% of those patients at one year.
Chemodenervation using intravesical injection of Botulinum toxin acts by inhibiting presynaptic release of Acetylcholine. A recent study7 showed that chemodenervation was superior to sacral neuromodulation in decreasing the number of daily incontinence episodes and in complete symptom resolution at six months. However, the Botulinum toxin group has higher rate of UTI compared to neuromodulation group at six months (35% versus 11%) and a greater need for self-catheterisation (8% of patients in chemodenervation group at one month, 4% at three month and 2% at six month). Intravesical injection of the toxin usually needs to be repeated every nine months.
Recurrent UTI is the most common bacterial infection in postmenopausal women. At least two RCTs showed that intravaginal oestrogen reduces the incidence of UTI in this patient group by one third to three quarters.9 If topical application is not feasible, women can use a estradiol vaginal ring, which can be replaced every three months. Lactobacillus, taken orally10 or applied as vaginal suppositories,11 showed a trend towards fewer UTI. Cranberry data regarding that indication are mixed.
Bladder augmentation involves enlarging the bladder storage capacity using intestinal sections. It is associated with a number of complications and requires adequate risk-benefit assessment before being undertaken.
In summary, it is advisable to follow a stepwise approach in treating urinary incontinence in postmenopausal women. Behavioural therapy is initially attempted and if unsuccessful pharmacological treatment is indicated. If the patient did not control her symptoms or did develop side effects related to pharmacotherapy, other approaches as outlined above can be attempted.
Emad E. Shoukr, Assistant Professor of Medicine, Division of Geriatrics, University of North Texas, Fort Worth.
3. Qaseem A, Dallas P, Forciea MA, Starkey M, Denberg TD, et al. Nonsurgical management of urinary incontinence in women: a clinical practice guideline from the American College of Physicians. Ann Inter Med 2010; 161: 429–40.
5. Melzack R, Wall PD (1965) Pain mechanisms: a new theory. Science 150.
6. Nuhoglu B, Fidan V, Ayyıldız A, et al. Stoller afferent nerve stimulation in woman with therapy resistant over active bladder; a 1-year follow up. Int Urogynecol J Pelvic Floor Dysf 2006; 17: 204–207.
9. Perrotta C, Aznar M, Mejia R, Albert X, Ng CW (2008) Oestrogens for preventing recurrent urinary tract infection in postmenopausal women. Cochrane Database Syst Rev.