MIXED INCONTINENCE

Mixed  incontinence - Definition
Involuntary urinary leakage associated with urgency, and also with exertion, effort, sneezing, or coughing (UUI + SUI). 30 50% of women with SUI also have symptoms of frequency, urgency, or UUI. Underlying aetiologies and evaluation remain the same as for SUI and UUI.

SUI component
Risk factors for women include childbirth (increased with forceps delivery); ageing; oestrogen withdrawal; previous pelvic surgery; and obesity. There also appears to be an intrinsic loss of urethral strength, often associated with urethral hypermobility. In men, damage occurs to the external sphincter from pelvic fractures and after prostatectomy. Neurological disorders (SCI, MS, spina bifida) also cause sphincter weakness.

Investigation
This mixed UI patient group needs further investigation to rule out pathologies such as bladder cancer, stones, and interstitial cystitis. Voiding records and urodynamic studies are most useful.
Women: stress test; Q-tip test; examine for pelvic organ prolapse. Elevation of an existing cystocele will unmask any occult sphincter incompetence in those who are continent with the prolapse.
The Q-tip angle is a measure of urethral mobility in women. With the bladder comfortably full in the lithotomy position, the patient is asked to cough or strain in an attempt to reproduce the incontinence.
The Q-tip test is performed by inserting a well-lubricated sterile cotton-tipped applicator gently through the urethra into the bladder. Once in the bladder, the applicator is withdrawn to the point of resistance, which is at the level of the bladder neck. The resting angle from the horizontal is recorded. The patient is then asked to strain and the degree of rotation is assessed. Hypermobility is defined as a resting or straining angle of greater than 30° from the horizontal.
Men: examine for a palpable bladder and penile abnormalities. Assess prostate size; flow rate; PVR; consider imaging of upper tracts.

Management
When SUI appears to be the predominant symptom, initially start with conservative methods, and then review.
- Behavioural and pelvic floor exercises with vaginal weights (Kegel's exercises) are important, and can improve symptoms in 30% of women with mild SUI.
- Biofeedback is the technique by which information on ability and strength of pelvic floor muscle contraction is presented back to the patient as a visual, auditory, or tactile signal. Patients may also be helped by the perineometer, which measures pelvic floor contraction.
- Extracorporal magnetic innervation involves sitting the patient in a chair, and using a pulsed magnetic field to stimulate the nerves of the sphincter and pelvic floor.
- High-frequency electrical stimulation (50 100Hz) can be used to treat SUI by directly stimulating a bladder contraction. In mixed UI, this can be used alternatively with low-frequency therapy (5 20Hz) which acts on inhibitory nerves to reduce bladder overactivity, which can alleviate the urge and UUI component.
- Correct pelvic organ prolapse with a pessary.

Surgery
When stress symptoms predominate, surgical repair can alleviate remaining symptoms. However, if UUI is the most marked symptom, surgery will be less helpful, and behavioural therapy with pharmacotherapy should be used first.
Surgical procedures for SUI in women include colposuspension, vagino-obturator shelf procedure, slings for bladder neck support, and tension-free vaginal tape (TVT). Urethral bulking agents and artificial urinary sphincters can be used in both sexes.