Bladder problems in general are common and can affect men and women of all ages. It is estimated that, in the UK, 14 million people live with bladder problems, which also affect 900 000 children and young people (NHS England, 2018).
Many suffer in silence because embarrassment makes them reluctant to discuss their condition with family members or to seek medical care. Consequently, because bladder dysfunction is such an emotive condition that has both physical and psychological effects, it can have a profoundly negative effect on the individual and family. Patients who suffer from bladder overactivity are often preoccupied and concerned with constantly locating the nearest toilet, looking for aisle seating and estimating the amount of time until their next break (Kinsey et al, 2016). It impairs psychological and emotional wellbeing and is linked with high rates of anxiety and depression, while affecting daily activities, sexual function and work productivity (Rigby, 2014).
In addition, patients with an overactive bladder often have other comorbidities, such as recurrent urinary tract infections, skin infections, vulvovaginitis, falls, fractures, and cardiovascular and central nervous system pathologies. Chronic constipation and faecal incontinence can also be a feature.
Economic burden
The results of a survey carried out in 2005 in Canada, Germany, Italy, Spain, Sweden and the UK suggested that the sum total costs of overactive bladder with urge urinary incontinence for patients aged 18 years and older amounted to about €2.1 billion per year, with nursing homes additionally incurring costs of €4.7 billion. The approximate sum total costs across these countries of overactive bladder, without urge urinary leakage, were estimated to be €1.8 billion per year (Irwin et al, 2009).
By the end of 2020, the total annual cost of overactive bladder to health care in Germany, Italy, Spain, Sweden and the UK is expected to reach €5.2 billion, assuming that the number of people with an overactive bladder will have reached 25.5 million in the five countries (Reeves et al, 2006).
Overactive bladder
This is a common condition where there is a frequent feeling of needing to urinate to such a degree that it negatively affects an individual's life. Eapen and Radomski (2016) reviewed the epidemiology of overactive bladder and reported a prevalence of 11.8%. The symptoms of an overactive bladder include:
Idiopathic chronic non-obstructive urinary retention (voiding dysfunction)
This is the inability to empty the urinary bladder with no physical obstruction to the flow of urine. It can be idiopathic or occur as a result of neurological disorders such as multiple sclerosis. In young women, it can be caused by a rare disorder in which the urethral sphincter fails to relax to allow urine to be passed normally (Fowler's syndrome). Chronic non-obstructive urinary retention can cause complications such as chronic kidney disease and recurrent urinary tract infections.
Sacral neuromodulation and how it works
Sacral neuromodulation or sacral nerve stimulation involves applying an electric current to one of the sacral nerves (usually S3) via an electrode (thin wire), which is placed through the corresponding sacral foramen (Figure 1). The electrode is attached to an implanted pulse generator (similar to a pacemaker), which stimulates the nerves associated with bladder function. The aim is to restore the ability of the bladder to empty voluntarily, removing the need for catheterisation or, in the case of bladder overactivity, to work in a more controllable way by reducing urinary frequency, urgency and urge urinary leakage.
Sacral neuromodulation occurs in two stages several weeks apart, involving an evaluation phase to help the patient and the clinician decide whether long-term stimulation therapy will be beneficial and tolerated. The evaluation also includes assessment of the integrity of the sacral nerves and identifying the optimal lead location.
Two main techniques are used for the test phase (stage 1), both of which involve an implantation procedure using fluoroscopic guidance with the patient under general or local anaesthesia. The conventional technique involves percutaneously placing a temporary lead with a unipolar electrode alongside a sacral nerve (usually S3) and taping it to the skin surface.
In some instances a newer two-stage technique is used. This involves implanting a permanent tined lead, with a quadripolar electrode, on the sacral nerve, usually through the third sacral foramen. When the lead is correctly positioned, an extension cable is tunnelled to the proposed site for the neurostimulator, usually in the upper buttock.
In both techniques, the leads are attached to a small external generator and the level of stimulation is adjusted to achieve normal bladder function without causing discomfort for the patient.
The length of the evaluation period varies, but it is usually 2 weeks with the temporary lead and 4 weeks if a permanent lead is used. At the end of the evaluation period, it is decided whether or not the patient has gained sufficient benefit for the sacral neurostimulator to be implanted under general anaesthetic.
The neurostimulator is inserted into a subcutaneous pocket through a small incision in the upper buttock. If a permanent lead was used it is connected to the neurostimulator. If a temporary lead was used, it is replaced by a permanent lead placed in approximately the same position and connected to the neurostimulator. The electrical current generated by the neurostimulator and delivered by the lead modifies sacral nerve activity. This electrical current can be increased or decreased by the patient using a hand-held programmer and turned on and off.
Patient suitability for sacral nerve stimulation is determined following assessment and counselling. It should not be used for:
Efficacy and popularity
Key efficacy outcomes include reduction in frequencyurgency, urge leakage, improved ability to void spontaneously, lower residual urine volume and reduced need for clean intermittent self-catheterisation, ie reduced need for catheters and/or medication. In addition, perhaps more importantly, it brings improved quality of life and general health status.
Following a review of current evidence on the safety and efficacy of sacral nerve stimulation, the National Institute for Health and Care Excellence (NICE) (2004; 2015) recommended the use of sacral neuromodulation therapy. The literature demonstrates that there are sustained long-term efficacy and quality-of-life benefits.
With regard to urinary urge incontinence, the guidance (NICE, 2004; 2015) highlighted two randomised controlled trials, which showed that 50% and 80% of patients respectively returned to normal or showed good improvement. With regard to urgency frequency, more than 50% of patients demonstrated a reduction in symptoms. In addition, the guidance reports a case series of 93 patients with idiopathic urinary retention having a success rate of 73%; in the case of patients with Fowler's syndrome the cure rate (100% success) was 63% and for those with non-Fowler's idiopathic urinary retention it was 54%.
These statistics are in keeping with the Queen Elizabeth Hospital's outcomes, where 70% of patients who have had a trial of sacral neuromodulation go on to have a permanent implant (currently 169 patients), reporting a 60-100% reduction in symptoms. When reviewing patients, commentaries report consistent benefits and substantial improvements in quality of life.
Case histories
Case history 1: male patient aged 20 years
The patient was referred by his GP in October 2016 with a history of infrequent twice-daily voiding since childhood. He went into urinary retention in February 2016 with a 2 L residual urine. He was treated at another local hospital, where he failed three trials without a catheter. He had a normal MRI scan and cystoscopy findings. Urodynamic investigations demonstrated an inability to generate detrusor pressure on command to void. He was diagnosed with a hypocontractile bladder and managed with a suprapubic catheter with FLIP-FLO catheter valve because he declined on several occasions to be taught clean intermittent self-catheterisation (ISC). He found the thought of performing the procedure too distressing.
He was consequently referred by his GP for a second opinion and had a first-stage primary percutaneous nerve evaluation (PNE) test in August 2018. His left S3 was cannulated, with a good motor response. Over the 2-week test phase he started to void spontaneously to completion. He went on to have a permanent implant in September 2018 and his suprapubic catheter was removed one month later. He continues to be delighted with his response to sacral nerve stimulation and is leading a normal active life.
Case history 2: female patient aged 17 years
This patient was a tertiary referral, following an admission to her local hospital with abdominal pain and urinary retention. She had a laparoscopy and appendicectomy, but failed two trials without catheter postoperatively. She was unable to perform clean ISC due to pain and found indwelling urethral catheters intolerable for the same reason. She was therefore managed with a suprapubic catheter. In addition to her urological history, she was under the care of the mental health team for anorexia nervosa. She had a normal MRI scan.
Video urodynamic and urethral pressure profile studies demonstrated generation of minimal detrusor pressure with high urethral closure pressure.
She had a positive PNE test evaluation, voiding spontaneously to completion in September 2013. She proceeded to have a permanent implant in January 2014 and her suprapubic catheter was removed. A revision procedure was performed in 2018 due to lead migration following a fall.
She has been living a full and active life and has enjoyed travelling extensively around the world.
Case history 3: female patient aged 59 years
This patient was a tertiary referral following a 15-year history of bladder overactivity symptoms post-hysterectomy. She reported daytime urinary frequency of several times in an hour, urgency with leakage, and six episodes of nocturia, despite trying medication and botulinum A toxin, which is an acetylcholine release inhibitor and neuromuscular blocking agent. It works by relaxing the bladder muscle temporarily—usually 3–9 months after which the muscle returns to its normal strength. The patient wore four moderately absorbent containment pads over each 24-hour period.
In November 2018, she had a positive PNE test evaluation, and her voiding pattern was reduced to 3-4 hourly, with no nocturia and no urge-urinary leakage. She therefore stopped using containment products and she proceeded to a permanent implant in January 2019. She continues to feel that her quality of life has been significantly improved and that she has ‘been given her life back’.
Lifestyle limitations
Although sacral nerve stimulation is becoming an increasingly used option for managing bladder dysfunctions, with potentially long-term enduring benefits, it is not for everyone. Patients who have an implanted sacral neuromodulator may lead a relatively normal life, but lifestyle choices do have to be made. For example, to avoid lead displacement or breakage the following activities should be avoided: body-contact sports, horse riding, skiing and extreme activities, such as bungy jumping and theme-park rides. Sometimes, therefore, a patient may decide that they would prefer to continue with their bladder symptoms rather than change their lifestyle.
Precautions
It is recommended that, whenever the individual visits doctors and dentists, they inform the health professional that they have a device implanted and show them their medical card. The battery life of the neurostimulator is 5–7 years and it has to be changed surgically, unless the patient has opted for the newly available rechargeable battery. Additional precautions are necessary under the following circumstances:
Pregnancy
The device must be switched off immediately a female patient discovers that she is pregnant, and it should remain switched off for the duration of the pregnancy. This is because the effect of sacral nerve stimulation on a foetus is unknown and it would be unethical to continue using it.
Medical procedures
Some medical procedures and equipment may affect the individual and their neuromodulator adversely if adjustments are not made. This is due to heat energy from the required medical equipment during treatment being transferred through the implanted system, which causes tissue damage at the location of the implanted electrodes, resulting in severe injury and, in extreme circumstances, death. It applies to the following devices and procedures:
Diving
This is considered safe, but not below a depth of 10 m of water.
Hyperbaric chambers
Hyperbaric chambers with pressures above 2.0 ATA (atmospheres) (202.65 kiliopascals). These chambers are used to treat breathing disorders or carbon monoxide poisoning, with the prescribed pressures dependent on need for treatment and the patient's condition.
Screening devices
Screening systems, such as those found at airports and some shop entrances, can cause neurostimulators to be turned on or off. It is recommended that screening devices are bypassed, if possible, or, if this is not possible, that the sacral neurostimulator is switched off and the screening gate is approached centrally.
Cremation
The device will need to be removed before cremation, because there is a danger that it may explode.
Reasons for device removal
Daniels (2010) identified that explants for infection were significantly higher in patients with diabetes:
Role of the nurse specialist
To achieve successful sacral nerve stimulation outcomes good patient selection is vital, and the role of the urology nurse specialist lends itself well to this. The group of patients to whom this therapy is offered are often greatly affected emotionally as a consequence of their embarrassing and distressing bladder condition. In addition, sacral nerve stimulation can appear very technical and daunting to individuals lacking in confidence with operating medical devices.
There is a wealth of evidence demonstrating positive impacts on patient outcomes when nurse specialists are involved in their care. Specialist nurses hold specialist knowledge, skills, communicators. Randomised controlled trials have also shown favourable comparison to doctors in relevant settings with patients reporting higher levels of satisfaction with nurse-managed care (Royal College of Nursing, 2009).
As a urology nurse specialist supporting this group of patients I counsel, empathise and support them; I also programme the sacral neuromodulators and evaluate symptom control while driving safety and quality of care to improve patient outcomes. My role is complementary to the consultant urologist and our holistic approach to the selection and care of the patient is very much an integrated multidisciplinary one.
Conclusion
Sacral neuromodulation can restore continence and improve quality of life significantly. It is a safe long-lasting therapy that can also contribute to a reduction of the economic burden consequential to this debilitating condition. It improves patients' quality of life, enabling them to return to work and follow normal lifestyles, and leads to a reduction in the use of drugs and containment products. In my experience, 95% of patients would recommend this therapy.