Surgery for faecal incontinence
Faecal incontinence is usually treated surgically if conservative treatment options have been exhausted. Depending on the cause and the severity of the faecal incontinence, different surgical procedures will be used. Repair of the sphincter muscle (sphincter repair), sacral nerve stimulation and sacral injection are some of the more common procedures. If this does not have the desired success, procedures to replace the sphincter muscle will be used. They include muscle implantation (dynamic gracilis muscle plasty) and the artificial sphincter muscle system with a balloon sleeve.
Faecal incontinence is treated surgically if conservative treatment options have not been completely effective. There can be different reasons for faecal incontinence. Sometimes perineal tears which occur during childbirth can result in injury to and weakness of the anal sphincter muscle. Another well-known cause of faecal incontinence is pelvic floor weakness. This can cause prolapse of the bowel (rectal prolapse) or weakness of the sphincter muscle.
Depending on the cause, different surgical procedures are used. If there is an injury to or a defect in the sphincter muscle, it will be surgically repaired (sphincter repair). A silicone injection is an alternative to repair. This method is used primarily to address mild incontinence. If the patient is suffering from incontinence due to a weakness of the sphincter muscle, sacral nerve stimulation is a tried and tested treatment.
If this procedure is not successful, final options are a procedure involving replacement of the sphincter muscle (dynamic gracilis muscle plasty) and an artificial sphincter muscle. In rare cases, an artificial anus must be created if these operations are inadequate. This technique is discussed in the chapter entitled [Colon surgery].
Procedures to remedy pelvic floor weakness and rectal prolapse are described in the chapter entitled Surgery to remedy pelvic floor weakness.
What preparations are carried out before the procedure?
Different examinations are carried out to identify the cause of the faecal incontinence. They include rectoscopy, anal ultrasound examination, anal pressure measurement (manometry) and MRI examination of the pelvic floor. Sometimes, defaecography (radiological imaging of the defecation process) or MRI defaecography is also carried out. It is an MRI examination which is carried out during the bowel movement. Tests are often carried out on the nerve impulses of the anal sphincter muscle to examine whether the patient has a weakness in their pelvic floor (electromyography).
All the usual pre-operative assessments are required, such as a blood test, blood pressure measurement and an ECG. All blood-thinning medication must be discontinued prior to surgery. The bowel is usually cleaned out before the procedure. The patient should have an empty stomach for the surgery. Depending on the surgery used, the procedure will either undertaken under general or regional anaesthetic.
How is the operation performed?
This surgical procedure is mainly used when childbirth damages the sphincter muscle. Repair of the sphincter muscle (sphincterotomy) is usually carried out under general anaesthetic. Defects in the ring-shaped sphincter muscle are repaired with an overlapping suture. If necessary, the sphincter muscle will also be shortened or narrowed.
Silicone injection is a method to increase the volume of the sphincter and thus to strengthen the function of the sphincter muscle. A ring-shaped piece of silicon is injected between the inner and outer sphincter muscle under local anaesthetic. It is a simple, newer procedure but there are still no long-term results available.
Sacral nerve stimulation
Sacral nerve stimulation involves stimulating every nerve which leads to the pelvic floor and the sphincter muscle of the anus electrically from outside the body. A device similar to a cardiac pacemaker is then implanted under the skin via the sacral vertebra. The device provides electrically-controlled impulses from outside the body which provide targeted stimulation to the pelvic floor muscles. This procedure is suitable for patients who only have minor defects in the sphincter and intact pelvic floor nerves. The procedure is carried out in two phases. First, the probe is only implanted to stimulate the nerves and tested with a wearable control device in an approx. 3-week test phase. If the procedure is successful, the device is implanted permanently under the skin in a second step. Both procedures take place under local anaesthetic.
Dynamic gracilis plasty
Dynamic gracilis muscle plasty is used when standard surgical procedures are unsuccessful. During this operation, the delicate gracilis muscle on the inner side of the thigh is exposed and looped around the anus as a replacement sphincter muscle. The transplanted muscle must be stimulated with a special pacemaker. This is implanted in the lower part of the stomach under the skin. The procedure generally takes place under general anaesthetic.
Artificial sphincter muscle replacement
Artificial sphincter muscle replacement is a newly preferred alternative to dynamic gracilis muscle plasty. In the process, a sleeve-like balloon is laid around the anal channel. The balloon is connected to a pump and a fluid reservoir. In this way, it can be filled or emptied as necessary. The entire artificial sphincter muscle system is transplanted under the skin. The operation is usually performed under general anaesthetic.
What is the success rate of this procedure?
The success rates of the different procedures depend on the cause of the incontinence. Repair of the sphincter muscle after injury is generally very successful. Approx. 85% of patients who undergo sacral nerve stimulation are successfully cured. The success rates of the other surgical procedures are between 50% and 70%. Basically, incontinence is always treated with the simplest surgical procedure, and serious procedures are only used if no other options are available.
What are the possible complications and risks of this procedure?
As with all surgery, the operation may occasionally lead to post-operative bleeding, nerve damage or infections. Patients who undergo anal surgery may temporarily need to defecate more frequently.
What happens after the operation?
The follow-up treatment is based on the surgery which has been carried out. Silicone injections and sacral nerve stimulation are usually carried out on an outpatient basis. After repair of the sphincter or sphincter muscle replacement, the patient must remain in hospital for two to three days. He or she must go through a certain learning and familiarisation phase, which can vary in length, after nerve stimulation therapy or sphincter muscle replacement.