Anastomose iléo-anale : état des lieux

The search for an alternative to a stoma for patients with ulcerative colitis (UC)or familial adenomatous polyposis (FAP) is not recent, however it is only in the last 30 years that restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) has evolved into the surgical treatment of choice for most patients. In 1933 Nissen described a 10-year-old child with on whom he performed an IPAA in three stages, with satisfactory early results. Fourteen years later, Ravitch and Sabiston performed a series of animal experiments and later operated on 11 patients. The functional outcomes were poor and the technique did not gain widespread acceptance. In 1977 Martin, published the results of IAA in a series of 17 children operated for UC with successful outcome in 15.This renewed interest in restoring continence following proctocolectomy. However, in adults the functional results of direct IAA were not satisfactory and it became clear that stool frequency was related to the ‘neorectal’ reservoir capacity. In 1978 Parks and Nicholls described an ileal pouch reservoir in an S configuration that was handsewn to the anus following distal rectal
mucosectomy. Utsunomiya devised a simple J pouch which has since become the standard configuration. Physiological investigations confirmed the relationship between capacity of the pouch reservoir and functional outcomes. Thus IPAA became the
standard operation for most patients with UC or FAP.
Crohn’s disease is generally considered a contraindication to IPAA owing to increased postoperative complications and long-term failure. IPAA is usually successful in patients with indeterminate colitis but approximately 30 per cent will manifest overt Crohn’s disease within 10 years of operation. Use in patients with Crohn’s colitis, severe constipation or Hirschprung’s disease is controversial and is contraindicated in patients with multifocal Crohn’s disease or pre-existing continence difficulties.
Most questions regarding operative technique have been addressed in large prospective series and meta-analyses. Continence outcomes are superior if the anal transitional zone is preserved and a stapled anastomosis is performed. Mucosal proctectomy remains indicated when dysplasia is present in the rectum. It is usual to defunction with a loop ileostomy, however it may be avoided in highly selected individuals. Laparoscopic techniques offer less intra-operative blood loss and shorter hospital stay but at
the cost of significantly longer surgery.
Long term outcome data are now available with up to 28 year follow-up. Functional outcomes are reasonable and quality of life is generally improved. Males have better continence and quality of life outcomes than females. Adverse effects on female fertility and mode of childbirth remain significant issues for women in child bearing years. Salvage surgery may be attempted in patients with poor functional outcomes. Depending on the cause, satisfactory outcomes can be achieved in 50%.
Construction of an ileal pouch reservoir has significant effects on bacterial ecology of the distal ileum. Morphological changes occur in ileal pouch mucosa and up to 40% of patients develop inflammation of the pouch known as pouchitis. In the majority, this responds to antibiotic treatment however in a small minority pouchitis is intractable. There is considerable interest in pouchitis as a model of inflammatory bowel disease given a genetic susceptibility and morphological and bacteriological changes observed. There are substantial data to support a role for sulphate reducing bacteria in the pathogenesis of pouchitis.
In 30 years since its introduction, IPAA has changed not only surgery for IBD but also has influenced operative techniques used for
rectal cancer. Most of the technical difficulties have been overcome so that IPAA is now the treatment of choice in the majority of
patients.