Medical and Economic Evaluation of a Magnetic Anal Sphincter for Patients With Severe Anal Incontinence

The purpose of this study is to compare 2 surgical treatments of severe fecal incontinence (defined as more than a major leak per week). The hypothesis of this "non-inferiority" trial is that magnetic anal sphincter is clinically as effective as SNS, but more cost-effective in managing fecal incontinence

Severe anal incontinence, defined as the uncontrolled passing of stool at least once a week, is a problem that has a serious impact on the quality of life. In the event of failure of conservative treatments, surgery can help improve continence problems in a significant number of cases.

Sacral nerve stimulation is currently the standard surgical treatment for severe anal incontinence when sphincter repair (sphincteroplasty) is not recommended.

A new method of treatment based on sphincter reinforcement through the implanting of a band of magnetic beads\*, has proved to be reliable and efficient on a small series of cases, particularly after the failure of sacral nerve stimulation.

The aim of our trial, which compares the "magnetic anal sphincter\* and sacral nerve stimulation" in a homogeneous population of patients affected by severe anal incontinence is to define the position of this new approach in the treatment algorithm of this functional disorder, determining its clinical and medical/economic advantages compared to those of the current standard treatment.

\* FenixTM (Torax Medical)

Eligibility Criteria:
Inclusion Criteria:

* Adult patient (male or female) of 18 to 75 years of age
* Affected by severe anal incontinence (SAI)\*.
* Documented failure of conservative treatment (reeducation and medical treatment)
* With functional anal sphincter\*\*
* Agrees to take part in the study and has signed the informed consent form
* Agrees to undergo post-operative surveillance for a period of one (1) year
* Covered by National Insurance

  * Defined as follows: at least one involuntary passing of stool per week measured by collecting data on incontinence accidents on a 3-week stool record chart, with the continence problem developing over more than 6 months. \*\*Defined as follows: external sphincter intact (without injury or after sphincter repair) or external sphincter altered, with an injury of a size that does not justify sphincter repair.

Internal sphincter injuries not taken into account (by professional consensus).

Exclusion Criteria:

* Anorectal or pelvic malformations
* Local conditions incompatible with the proposed sizes of the MAS (extreme obesity, thickness of the tissue in the anorectal area)
* Sequelae of rectal resections - presence of cancer of the rectum or anus
* Rectal prolapse and/or major pelvic floor disorders
* Major chronic disorder of the intestinal motility, irritable bowel syndrome, repeated faecalomas, megarectum
* Extensive sphincter degeneration
* Consequences of radiation-induced rectitis and chronic inflammatory diseases of the bowel (Crohn's disease)
* Neurological disorders or systemic diseases (multiple sclerosis, scleroderma, paraplegia)
* Festering sores of the perineal and/or anorectal regions
* Known or suspected risks of allergy to titanium
* Active pelvic infection
* Contraindications to SNS:

  * Cardiac stimulator or defibrillator implant
  * Malformation of the sacrum
  * Patient exposed to Magnetic Resonance Imaging
  * Skin diseases exposing the patient to the risk of infection (at the investigator's discretion)
  * Patient scheduled for diathermy or ablation by radiofrequency
* Pregnant women
* Adults under guardianship
* Patients involved in a mobility project in the year following the operation
* Patient already subjected to one or other of the therapeutic approaches (MAS or SNS) Please note: coagulation problems (including anti-aggregant or anti-coagulant treatments) are not a contraindication if these problems can be corrected during the perioperative period.