HOW TO TREAT 33
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HOW TO TREAT 33
Figure 4 . Urethral opening with and without bulking agent . Figure 5 . Sacral nerve stimulation .
The dose for idiopathic OAB is 100 units , and up to 300 units for neurogenic OAB . There is significant improvement in 60-90 % of patients , with up to 66 % achieving full continence . 46
Side effects include UTI and urinary retention ( 10-20 %), so alert patients to the need for intermittent self-catheterisation in the event of retention . 46 Self-catheterisation is often required in patients with neurogenic conditions . Contraindications include neuromuscular disorders , pregnancy / breastfeeding , the use of gentamicin and the use of botulinum toxin at other sites , as the total dose should not exceed 360 units over a three-month period .
Sacral nerve stimulation Sacral nerve stimulation ( SNS , see figure 5 ) most commonly stimulates S3 , which alters the somatic afferent inputs that modulate the sensory processing and micturition reflex pathways of the spinal cord and above . Success rates range from 60-90 % with cure rates of 30-50 %. 47 This is less effective for a neurogenic bladder or in patients with progressive neurological conditions .
Indications include frequency urgency , refractory urinary urge incontinence and non-obstructive high residual volumes . Side effects include infection and lead migration .
Contraindications include patients who are likely to require MRI ( MRI-friendly devices are under development ), those aged under 18 , acute neurological infection or disease , pregnancy and obstructive urinary retention .
Percutaneous tibial nerve stimulation This alters bladder innervation by
Table 3 . Advanced investigations and their indications Investigation Purpose Indications
Urodynamic studies • Provides systematic functional information • Severe UI of any type
• Before surgery or other irreversible treatment
• With very straightforward SUI , simply a cough stress test may be performed 33
• Mixed SUI and OAB particularly if severe and refractory to fluid management and pelvic floor therapy
• Concomitant high residual volumes or outright urinary retention
• Risk assessment for the upper urinary tract in spinal pathology
• Failure of conservative treatment 34
Fluoroscopy
Cystoscopy +/ - examination under anaesthetic
Transvaginal ultrasound
stimulation of the posterior tibial nerve through a fine needle inserted behind the medial malleolus ( see figure 6 ). It is generally administered in weekly 30-minute sessions over 12 weeks and then monthly thereafter for 12 months , and possibly lifelong . Implantable devices may prove to be more user friendly but are not yet available . This treatment is indicated
• To distinguish between urethral and bladder causes of severe incontinence ; this is important in the presence of high grade trabeculation , high pressure vesico-ureteric reflux and spinning top urethra from loss of urethral co-ordination during detrusor overactivity . These features suggest a neurological condition
• Permits delineation of site of obstruction , if present , eg , previous sling surgery or urethral stricture
• Demonstrates bladder base conditions such cystocele or SUI associated with urethral hypermobility and / or ISD
• An endoscopic examination of the urethra and bladder
• Cystoscopy is not required as part of the standard work up for mild stress urinary incontinence or OAB
• Trans-labial or transvaginal ultrasound +/ - 3D imaging permits delineation of the urethra and vaginal wall
• This is a developing area and in specialist hands is a useful modality for detecting sub-urethral mesh and its position , which may be too close to the bladder neck causing obstruction and secondary OAB
• Recurrent urinary tract infections , especially urosepsis
• Persistent sterile pyuria
• Suspected transitional cell carcinoma with haematuria and LUTD
• Persistent bladder pain
MRI pelvis • Limited role in female UI • Can be useful in complex evaluations when symptoms are refractory to previous SUI or POP surgery
• Useful for characterisation of a urethral pelvic mass or where a diverticulum is suspected
Table 4 . Behavioural and lifestyle modification Aspect
Continence management products
Weight loss
Detail
Reduces the impact of leakage on QOL while awaiting results of other treatments
• Weight loss from an effective strategy in women with a BMI greater than 25kgm 2 can result in a significant reduction in the symptoms of SUI 35
Fluid management Reducing fluid intake reduces the number of episodes of incontinence . Principles include :
• Urine output of 1-2 litres / day
• Avoid drinking after mid evening if nocturia is an issue
• Reduce caffeine , alcohol and carbonated drinks
• Empty bladder before sleep if nocturia an issue
Figure 6 . Percutaneous tibial nerve stimulation .
Bladder retraining
Pelvic floor muscle training ( PFMT )
The use of scheduled voiding techniques , urge suppression and behavioural strategies to alter the response to inappropriate behaviour triggers Encourage :
• Regular voiding every 2-3 hours
• Appropriate toileting position to assist in emptying
• Avoidance of straining to empty the bladder Physiotherapists ( and continence nurses ) are often well trained to implement these measures , as well as a pelvic floor exercise program
Active contraction of pelvic floor muscles may improve bladder neck support because repeated activation of the pelvic floor muscle at the onset of urge can dampen urge intensity and shortens the detrusor contraction ; this provides continence control and time to reach the toilet
Supervised intensive PFMT is first line therapy for women with SUI or mixed UI ; this should be provided for three months or longer and should be as intense as possible 36