Pelvic floor pacemaker
Pelvic floor pacemaker (also neuromodulator ) or sacral neuromodulation is abbreviated as SNM . It is used synonymously with Sacral Neurostimulation , SNS and Interstim II .
definition
Sacral neuromodulation is a scientifically based empirical therapy for functional disorders in the lower abdomen, small pelvis and pelvic floor . What is meant are pathological, often very stressful disorders without a clear organ-related injury (e.g. sphincter muscle tear ) or anatomically visible disease (e.g. lower bladder, bowel prolapse ). The cause of such a disorder can seldom be clarified, e.g. B. in patients with multiple sclerosis .
With the neuromodulator (pelvic floor pacemaker) the so-called sacral nerves, which control the function of the pelvic floor, bladder and rectum , are modulated by electrical impulses in order to improve the biological reflex arcs and processes. By modulating these nerves, both overactivity and underactivity of the bladder or bowel can be improved.
The method should most correctly be called sacral neuromodulation, users often speak of sacral nerve stimulation, or SNS for short. Patients and relatives often speak of their pelvic floor pacemaker, bladder pacemaker or also say SNS.
Medico-historical development
Sacral neurostimulation has been used in Europe for more than 20 years to treat dysfunction of the bladder or rectum. It was first used in urology in 1988, when it was still an experimental procedure.
Sacred neuromodulation has been officially approved in Europe since 1994. More than 300,000 patients worldwide have now been treated with this method. Statistically speaking, depending on the diagnosis, 60–85% of patients implanted with a pacemaker are permanently satisfied. However, a 100% disappearance of the symptoms should not be expected; the device aims to improve function and thus quality of life. On the other hand, it is considered certain that there will be no long-term damage even after decades of use with the method.
Anatomy and physiology
To understand the procedure, it is necessary to know the anatomy of the pelvis.
Continence
The ability to hold urine and stool in order to later, at a socially appropriate time, to empty oneself satisfactorily without suffering, defines continence .
Continence performance
This achievement is only possible through an extremely complicated harmonious interplay of psyche, mental abilities, cerebrum, spinal cord, sacral nerves, hollow organ (intestine or bladder), pelvic floor muscles, sphincter muscles.
Sensory technology, information processing, muscle activation and muscle relaxation must work together in a well-dosed manner in precise time sequences.
A complex neural network ( hypogastric nerve and sacral plexus ) lies between the sacral nerves and the target organs . The malfunction can be counteracted here.
The sacral nerves go from the back into the small pelvis, where the bladder and rectum lie, and run through openings in the sacrum , called the neuroforamina (sing. Neuroforamen). At this point the nerves lie under the skin and can be easily reached. The electrodes are placed in a neuroforamen. In this way, the hypogastric nerve / sacral plexus can be gently stimulated.
indication
When is the procedure suitable?
The patient should go to a specialist ( gynecologist , proctologist , urologist ) who is experienced with the method. There are few centers with a focus on neurourology, urogynecology or coloproctology , and even fewer are recognized by Medtronic as training centers.
- Exclusion of anatomical causes: First, the doctor must rule out or remedy correctable causes (e.g. incident, perineal tear ...). Often a lowering of the bladder is raised, an intestinal prolapse is stretched or removed, or a lowering of the pelvic floor is fixed. Sometimes functional complaints remain afterwards despite a successful operation, or no anatomical changes can be determined.
- Conservative therapy: Therapy options without surgery (= conservative) should have been tried without success or are not satisfactory or are not feasible.
As a rule, the patient has to keep a stool or urination diary for three to four weeks.
For whom and for which diagnoses is the procedure suitable?
Suffering
Although functional disorders are not an emergency and can rarely be dangerous, the suffering of those affected is often very high.
Any age group and both sexes can be affected. Many patients hardly dare to leave the house out of fear. All activities are based on the presence of a toilet. It is not uncommon for the affected patients to withdraw completely from social life.
Diagnoses
There are five main causes of discomfort that can make using a pelvic floor pacemaker useful.
It is not uncommon for the bladder and rectum to be doubly impaired - for example in patients with neurological disorders such as multiple sclerosis or after spinal surgery. Then both diseases can be treated with one and the same method.
- With irritable bladder (urge incontinence, overactive bladder ).
- The affected patients suffer from a very strong urge to urinate and sometimes have to urinate very frequently, sometimes more than 20 times a day. A satisfactory improvement can be achieved by the SNS in approximately 70% of the SNS tests.
- With sphincter weakness (sphincter insufficiency)
- These patients are particularly exposed to stress because they cannot adequately control or postpone their bowel movements or intestinal gases. Faecal incontinence is the best indication for sacral neuromodulation; success is achieved in over 80% of the tests.
- With flaccid bladder (bladder atony ) : Patients with flaccid bladder have high amounts of residual urine and typically have to undergo sterile self-catheterization several times a day. If the corresponding nerve tracts are reactivated and modulated, these patients can also be treated well in approx. 70% of cases.
- In the case of bowel evacuation disorder ( constipation ), a slow transit disorder is present in 20% of cases. It is a neurological disorder of the functioning of the myenteric plexus, which can be improved by modulating the sacral nerves in an average of 40% of cases.
- Chronic pelvic floor pain due to pathological nerve conduction can be successful in some cases. Unfortunately, there are no reliable statistics on the success rates of SNS testing.
How does the therapy work?
Ultimately, it is not fully understood how the process works. It is clear that the light stimulation currents in the right amount and in the right place recruit nerve fibers, nerve cells and muscle cells; in addition, the body's own nerve impulses are strengthened or calmed . This effect is basically demonstrable, provided that the disturbed brain-sacral plexus-pelvic floor system is still completely present. This explains why the procedure is unsuitable for complete paraplegia : the chain from the brain to the pelvic floor must be at least partially preserved. In the case of incomplete paraplegia, however, the procedure can help.
The effect
The effect of the procedure can basically be measured on the target organs: more strength, better conduction of stimuli ... This effect does not necessarily have to be sufficient for the success of the treatment.
There is no such thing as an “on-off system”. The patient will not urinate "at the push of a button", but will notice in a very natural way that he has urged, needs to go to the toilet and can empty himself there normally by relaxing. The SNS system supports this "normal" natural cycle, the patient does not need to do anything else.
Successful testing / therapy
A success of the therapy is a sufficient improvement of the complained complaint for the patient. Therefore, the method is first tested (tried) on the patient with a temporary stimulator for two to three weeks. A definitive implantation is only carried out if the patient is sufficiently satisfied during the test phase.
The surgically simple and less stressful testing and the implantation (minimally invasive) are gentle and reversible, i. that is, it can be easily undone.
The electrode is inserted through a 3-4 mm mini-prick under image intensifier control. No changes are made to the spine, spinal cord or pelvic floor and no surgical risks are taken. The greatest advantage of the procedure is that no complications are to be expected for the patient.
The almost unlimited possibilities of electrical stimulation settings on the sacral nerves enable desired changes in bowel and bladder function to be achieved:
- better emptying,
- better sensitivity
- more power.
Components of the system
Tined lead electrode
It is an insulated electrode wire with four combinable contact surfaces and four soft rubber barbs for fastening in the neuroforamen. The best possible placement of the tined lead electrode is the most important therapeutic step for the success of the method.
Neuromodulator (Interstim II)
In terms of technology, it is structurally identical to the long-known cardiac pacemakers - but the programming is completely different.
External Test Neuromodulator (Verify)
This small housing (51 mm × 43 mm × 15 mm) with an AAAA battery is worn by the patient on a belt provided with them - it is connected to the tine lead electrode via a wire extension for the test phase.
The N'Vision doctor programmer
The programming device is a portable device for programming, function checks and measurements of the implanted neuromodulator.
The programming device has a touchscreen display for data entry, a telemetry head for connecting to the implanted Interstim II and an infrared interface for connecting to the patient control device icon.
The control device for the patient (icon)
It's a little remote control for the patient. The telemetry takes place on skin contact directly over the place where the neuromodulator was implanted. The patient is trained in the application.
Process of sacral neuromodulation
SNS test under anesthesia: acute testing
The patient is tested under anesthesia: fine neuroelectrodes are inserted and pelvic function is tested.
Certain muscle twitches in the pelvic floor can tell the doctor that the function is adequate and that the electrodes are correctly positioned.
The test electrodes are implanted using a 3–4 mm long prick.
Outpatient SNS test phase: chronic testing
If the pelvic floor has a successful "response" in the acute test, the effectiveness is likely.
Success is now to be tested for patient satisfaction: The electrodes that have already been implanted are connected to an external test pacemaker that the patient wears on a small belt.
The settings and switching off are easily possible via one control.
After programming / setting in the test phase, the patient does not need to do anything else in everyday life.
The stool diaries / micturition diaries are kept for two to three weeks; success can be documented compared to the course before the test.
Definitive implantation
With at least 50% improvement / satisfaction of the patient, the definitive miniaturized nerve stimulator (Interstim II) is implanted under the skin of the buttocks.
If this is unsuccessful, the test electrodes are removed (explantation).
After the implantation, the patient is resilient again, without any particular restrictions in the long term. He no longer needs to manipulate any controls or make any more settings; the nervous system then continues to function “optimized”, of course. The device can be switched off at any time. The pacemaker is not visible from the outside.
Results of sacral neuromodulation
The results of the neuromodulation for the indicated indications have been confirmed and can be found in the current guidelines of the AWMF .
There is a significant improvement in quality of life in cases of urination disorder and fecal incontinence .
The incontinence has completely disappeared in 50 to 70% of patients. In 60 to 100% of patients there is an improvement of more than 50% in continence performance: It means at least a halving of the frequency of incontinence episodes.
There are no known short or long-term side effects.
Complications and Cons
Complications
A major advantage of the SNS is the low rate of complications (rare events) and harmlessness (no dangerous complications).
Infections
Infections can rarely develop at the site of the implantation, mostly during wound healing. Late infections are extremely rare.
Pain
Sometimes the patients feel unpleasant sensations at the electrode penetration points, and very rarely they feel pain.
Electrode break / material defect
In a few cases electrode breaks have been described, e.g. B. in the context of martial arts by targeted kicks on the housing of the device.
Overall, the procedure is very safe from a medical point of view, in the event of a break or infection it can simply be removed, and six months later it can be re-implanted.
disadvantage
The main disadvantage for those affected is that they carry a foreign body for their entire life and have to have the battery changed every three to ten years through a minor operation. Otherwise his movement and quality of life are not restricted.
Magnetic resonance imaging (MRI) for SNS users
According to the manufacturer, MRIs ( magnetic resonance imaging ) should not be performed on pacemaker wearers. However, there are more and more case studies in which imaging was performed without any further problems. This restriction was relaxed by Medtronic in 2015, brain MRIs are now allowed. Presumably the risks of the MRI with 1.5 Tesla are only physical-theoretical and have no relevant consequences for the patient.
costs
The process is expensive and technically complex: a neuromodulator costs over 6,000 euros , a Tine-lead electrode costs over 2,000 euros. Comparisons were made with the costs caused by incontinence, which could impressively show that the SNS are more cost-effective in the long term than the so-called aids with a significantly better quality of life for the patients.
Microwave therapy (orthopedics)
Here, microwaves are applied to the body, and the development of heat should produce a therapeutic effect. With metallic implants in the irradiation area, there is a high level of damaging heat development in the implant (electrode, housing). This is the only absolute contraindication to the procedure. This does not mean the use of “normal” microwaves from a commercially available microwave oven.
Web links
- http://beckenbodenschrittmacher.de
- What is Sacred Neuromodulation?
- Continence and Pelvic Floor Center Stuttgart
Individual evidence
- ↑ J Urol Urogynäkol 2007; 14 (1): 32-35. Sacral Neurostimulation, KD Sievert, B. Amend, J. Pannek, H. John, A. Stenzl (PDF file)
- ↑ a b Sacral neuromodulation - last hope for therapy-refractory bladder dysfunction and chronic pelvic pain syndrome? Thomas M. Kessler, Fiona C. Burkhard, Urs E. Studer Switzerland Med Forum 2005; 5: 540–545 (PDF file)
- ↑ Frequently asked questions
- ↑ Topographical Anatomy: Retrositus: Pelvis: Outer Genitale - Wikibooks
- ↑ Test stimulation (PDF file)
- ↑ a b Entry - HUK - Vivantes
- ↑ Treating Incontinence Correctly - Sacral Neuromodulation for Overactive Bladder (PDF file)
- ↑ What is InterStim ™ Therapy? ( Memento of the original from September 16, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ Sacral neuromodulation (Interstim Therapy) - Medtronic
- ↑ AWMF: Current guidelines
- ↑ KE Matzel, MA Kamm, M. Stösser, CG Baeten, J. Christiansen, R. Madoff, A. Mellgren, RJ Nicholls, J. Rius, H. Rosen: Sacral spinal nerve stimulation for faecal incontinence: multicentre study. In: Lancet. Volume 363, Number 9417, April 2004, pp. 1270-1276, doi : 10.1016 / S0140-6736 (04) 15999-0 , PMID 15094271 .
