Faecal incontinence is a common problem, but is still a strong taboo. A small microchip, implanted above the sacral bone, promises to make sufferers’ lives a lot easier. Sacral nerve stimulation (SNS) not only restores patients’ ability to control defaecation, but also provides new insights into the innervation and physiology of the bowel and the pelvic floor.
There are quite a few diseases that sufferers do not really like to talk about. Faecal incontinence is undoubtedly one of these. People suffering from this disease are no longer able to consciously control defaecation due to a functional disorder of the anal muscle or the pelvic floor. Sufferers experience involuntary bowel evacuations, which can cause huge stress in everyday life. There are around two million people in Germany who suffer from this disorder. “However, I believe that the actual number is a lot higher because many people are too ashamed to seek help from their doctor,” said Dr. med. Dirk Weimann, senior physician at the Ludwigsburg Hospital. The disorder mainly affects elderly women, but it can affect all age groups. The causes of disease range from birth trauma, tumour diseases and neurological diseases such as multiple sclerosis or Parkinson’s disease.
Sacral nerve stimulation (SNS), which was originally developed for the treatment of urinary incontinence, is now also used for the treatment of faecal incontinence. A small pulse generator is surgically implanted in the buttocks. The device sends electrical impulses to the nerves that run from the sacral area and control the muscles in the pelvic area (including the pelvic floor, urethral sphincters, bladder, anal sphincter muscles, rectal muscles, leg muscles, genital function) by way of a thin electrode.
“Surgeons who implant pulse generators of this kind need to be very experienced in order to be able to find the right position for the electrode to ensure that it only stimulates the nerves associated with the regulation of continence,” explained Weimann who is one of the most experienced SNS specialists in Germany. The SNS principle has already proven effective in the treatment of urinary incontinence. “I am convinced that this method will become the method of choice for treating faecal incontinence in future,” said the surgeon highlighting that conservative and other surgical interventions do not often lead to a satisfactory long-term outcome.
These days, SNS has a success rate of around 80 per cent. Once the pulse generator has been implanted, the majority of patients regain complete control over their defaecation. Other patients benefit from a small technical trick that allows them to deactivate the microchip before going to the toilet using a small remote control. “Patients can then empty their bowel in just a couple of minutes,” said Weimann, who is head of the “Pelvic Floor Centre” at the Ludwigsburg Hospital. Although the method is relatively successful, the negative aspect is that it is relatively costly, with treatment amounting to around 10,000 euros per patient. “However, if we also take into account improvements in quality of life or care of the elderly, then the intervention is definitely worth the money,” said Weimann.
As promising as the new method is in clinical application, the accurate mechanism underlying the stimulation of the sacral nerves is not yet understood in detail. It has long been assumed that the direct electrical stimulation of the motor part of the sacral nerves and the resulting contraction of the sphincter (a circular muscle that controls the exit of faeces from the body) leads to an improvement of the symptoms. “This is why the method was originally only used for the treatment of patients with a structurally intact sphincter,” said Weimann. However, several studies have since shown that people with a defective sphincter – for example as a result of an anal fistula, surgical intervention or birth trauma – can also benefit from SNS. “It seems that motor and other effects play a decisive role in the maintenance of faecal continence,” said Weimann. SNS improves the sufferers’ sensory perception of the strongly innerved anal canal as well as the rectal wall, which considerably increases the stool storage capacity of the rectum. “Moreover, the implant improves the blood circulation of the intestinal mucosa and the peristaltic of the bowel,” said the Weimann going on to add “this suggests that the vegetative nervous system is also directly affected”.
This complex interplay might also explain the paradoxical observation that SNS not only markedly improves faecal incontinence symptoms, but that it also improves symptoms associated with chronic constipation. “It seems that SNS has a modulating effect on several sensomotoric control circuits affecting the bowel and the pelvic floor, both on the level of the spinal marrow as well as on the central level,” said Weimann who believes that the application of SNS will in future be expanded considerably to other areas. The use of SNS has also shown a promising outcome in the treatment of chronic pelvic pain and in the treatment of defective sexual function.
Further information:Dr. med. Dirk WeimannDepartment of General and Visceral SurgeryLudwigsburg HospitalPosilipostraße 471640 LudwigsburgTel.: +49 (0)7141/ 99-94224Fax: +49 (0)7141/ 99- 66519E-mail: Dirk.Weimann(at)kliniken-lb.de