Cancer arising from the remnant mucosa of the ileoanal anastomosis leading to pouchectomy

Incidence and Risk Factors of Cancer in the Anal Transitional Zone and Ileal Pouch following Surgery for Ulcerative Colitis and Familial Adenomatous Polyposis

Proctocolectomy with ileal pouch-anal anastomosis is the intervention of choice for ulcerative colitis and familial adenomatous polyposis requiring surgery. One of the long-term complications is pouch cancer, having a poor prognosis. The risk of high-grade dysplasia and cancer in the anal transitional zone and ileal pouch after 20 years is estimated to be 2 to 4.5% and 3 to 10% in ulcerative colitis and familial polyposis, respectively. The risk factors for ulcerative colitis are the presence of pre-operative dysplasia or cancer, disease duration > 10 years and severe villous atrophy. For familial polyposis, the risk factors are the number of pre-operative polyps > 1000, surgery with stapled anastomosis and the duration of follow-up. In the case of ulcerative colitis, a pouchoscopy should be performed annually if one of the following is present: dysplasia and cancer at surgery, primary sclerosing cholangitis, villous atrophy and active pouchitis (every 5 years without any of these factors). In the case of familial polyposis, endoscopy is recommended every year including chromoendoscopy. Even if anal transitional zone and ileal pouch cancers seldom occur following proctectomy for ulcerative colitis and familial adenomatous polyposis, the high mortality rate associated with this complication warrants endoscopic monitoring.

[Surgical strategy to save ileoanal pouch reconstruction]

Restorative proctocolectomy under formation of an ileoanal/ileorectal J‑pouch has become the procedure of choice in the therapy of ulcerative colitis. Although patients experience a dramatic improvement of their quality of life, surgery is not successful in about 5-10% of all treated patients. The reasons for failure are chronic pouchitis, incontinence, delayed diagnosis of Crohn's disease, fistula, surgical complications, too long remnant rectal stump, chronic abscess, and surgical technical errors. Some of the reasons do not always prevent the loss of a well-functioning ileoanal pouch. In many cases, correction, closure of fistulas or even a complete reconstruction of the ileoanal pouch are possible. Based on a review of the literature and our own experience, we show in 887 patients a success rate of 75% with acceptable pouch function. Indications, technics, and results are presented.

The mesentery: structure, function, and role in disease

Systematic study of the mesentery is now possible because of clarification of its structure. Although this area of science is in an early phase, important advances have already been made and opportunities uncovered. For example, distinctive anatomical and functional features have been revealed that justify designation of the mesentery as an organ. Accordingly, the mesentery should be subjected to the same investigatory focus that is applied to other organs and systems. In this Review, we summarise the findings of scientific investigations of the mesentery so far and explore its role in human disease. We aim to provide a platform from which to direct future scientific investigation of the human mesentery in health and disease.