Background and study aims  Restorative proctocolectomy has become the most common surgical option for patients with familial adenomatous polyposis (FAP). However, adenomas and even carcinomas may develop in the ileal pouch over time. The aim of this study was to evaluate the long-term incidence and nature of ileal pouch or distal ileal adenomas and carcinomas in patients with FAP. Patients and methods  This was a retrospective study of 47 FAP patients with Kock's continent ileostomy (Kock) (n = 8), ileorectal anastomosis (IRA) (n = 13), and ileal pouch-anal anastomosis (IPAA) (n = 26). Patients were followed with a standardized protocol including chromoendoscopy and biopsies of visible polyps in the ileal pouch, distal ileum, and rectum every 6 to 12 months. Results  Median follow-up was 21.0 years. Overall risk of adenoma development was significantly higher in IRA patients, with incidence rates of 85 % and 100 % at 5 and 10 years' follow-up, respectively, compared to pouch patients (Kock + IPAA) ( P  < 0.001). However, there was also a high frequency of adenomas in the ileal pouch mucosa, with rates of 12 %, 33 %, and 68 %, at 5, 10, and 20 years of follow-up, respectively. Maximum size of ileal pouch adenomas was significantly related to time since surgery ( P  = 0.0214). Six cases of advanced adenomas including two cases of adenocarcinomas developed in the ileal pouch mucosa. Conclusions  There is a significant incidence of adenoma(s) in the ileal pouch of FAP patients on long-term follow-up. Regular endoscopic surveillance is recommended, not only in IRA patients, but also in pouch patients after proctocolectomy.

Restorative proctocolectomy has become the most common surgical option for patients with familial adenomatous polyposis (FAP). However, adenomas may develop in the ileal pouch mucosa over time, and even carcinoma in the pouch has been reported. Our aim was to evaluate the prevalence, nature, and etiology of ileal pouch and nonpouch adenomas and carcinoma in patients with FAP.

This was a retrospective study of 31 FAP patients with Kock's continent ileostomy (Kock; n = 8), ileorectal anastomosis (IRA; n = 7), and ileal pouch-anal anastomosis (IPAA) (n = 16). All patients were followed with a standardized protocol including chromoendoscopy and biopsies of visible polyps in the ileal pouch and nonpouch mucosa.

Sixteen of 24 pouch patients (Kock and IPAA) developed adenomas in the ileal pouch mucosa, and all patients with IRA developed adenomas in the rectal mucosa. The prevalence of ileal adenomas was significantly higher in pouch patients than in IRA patients (P = 0.002). Only one patient with Kock showed adenoma in the prepouch area. Two cases of adenocarcinomas and one case of advanced adenoma were found in the ileal pouch mucosa.

Our results show a high frequency of adenomas in the ileal pouch mucosa, with evolution into carcinoma in some patients. Regular endoscopic surveillance of the pouch is recommended at a frequency similar to that for the rectal mucosa after IRA in pouch patients with FAP.

Since restorative proctocolectomy (RPC) with ileal-pouch anal anastomosis (IPAA) removes the entire diseased mucosa, it has become firmly established as the standard operative procedure of choice for familial adenomatous polyposis (FAP). Many technical controversies still persist, such as mesenteric lengthening techniques, close rectal wall proctectomy, endoanal mucosectomy vs. double stapled anastomosis, loop ileostomy omission and a laparoscopic approach. Despite the complexity of the operation, IPAA is safe (mortality: 0.5-1%), it carries an acceptable risk of non-life-threatening complications (10-25%), and it achieves good long-term functional outcome with excellent patient satisfaction (over 95%). In contrast to the high incidence in patients operated for ulcerative colitis (UC) (15-20%), the occurrence of pouchitis after IPAA seems to be rare in FAP patients (0-11%). Even after IPAA, FAP patients are still at risk of developing adenomas (and occasional adenocarcinomas), either in the anal canal (10-31%) or in the ileal pouch itself (8-62%), thus requiring lifelong endoscopic monitoring. IPAA operation does not jeopardise pregnancy and childbirth, but it does impair female fecundity and has a low risk of impairment of erection and ejaculation in young males. The latter can almost completely be avoided by a careful "close rectal wall" proctectomy technique. Some argue that low risk patients (e.g. <5 rectal polyps) can be identified where ileorectal anastomosis (IRA) might be reasonable. We feel that the risk of rectal cancer after IRA means that IPAA should be recommended for the vast majority of FAP patients. We accept that in some very selected cases, based on clinical and genetics data (and perhaps influenced by patient choice regarding female fecundity), a stepwise surgical strategy with a primary IPA followed at a later age by a secondary proctectomy with IPAA could be proposed.

The aim of this study was to establish the prevalence of adenomatous polyps in the ileal pouch of patients with familial adenomatous polyposis.

Forty-three patients who had an ileal pouch for familial adenomatous polyposis were invited to have a careful endoscopic examination of their pouch, including dye spraying. The number of polyps was recorded, and up to ten were biopsied. In addition, four random biopsy specimens were taken from the proximal and four from the distal pouch.

Thirty-three patients with a median age of 36 (range, 14-63) years who had a pouch (5 Kock and 28 pelvic) for a median of 7 (range, 1-19) years accepted the invitation. Twenty-one patients (64 percent) had endoscopically identified polyps, the number of polyps ranging from 1 to 100 (median, 10) and varying in size from 1 to 3 mm. Fourteen patients (42 percent) had adenomatous polyps and 4 of these also had microadenomas on random biopsies. Nine of the 14 patients with adenomas also had lymphoid polyps. Seven patients had lymphoid polyps only and two of these patients had a microadenoma on random biopsy. Four of 12 patients with no visible polyps had microadenomas in their random biopsies. The presence of adenomatous polyps (Pearson's correlation; P < 0.01) increased with the age of the pouch. In total, 20 of 33 (60 percent) patients had adenomas and or microadenomas.

Adenomatous polyps occur frequently in ileal pouches. These findings are of concern, and therefore, regular surveillance seems warranted until the natural history of these adenomatous polyps is determined.

To determine the prevalence of adenomas in ileal pouches from patients with familial adenomatous polyposis (FAP) and to determine whether a correlation exists between the presence of pouch adenomas and duodenal adenomas and the site of the adenomatous polyposis coli gene mutation.

Restorative proctocolectomy can markedly reduce the risk of colorectal adenocarcinoma in FAP patients. However, adenomas with the potential to progress to adenocarcinoma can develop in the duodenum, ileum, and continent ileostomy after restorative proctocolectomy. More recently, adenomas have been described in the ileal pouch after ileoanal anastomosis.

Pouch endoscopy was offered to 167 patients with FAP who had undergone restorative proctocolectomy between January 1984 and December 1996.

Adenomas were found in 35% of the 85 ileal pouches examined. No invasive carcinomas were noted. The risk of developing one or more adenomas at 5, 10, and 15 years was 7%, 35%, and 75%, respectively. Patients with adenomas were more likely to have duodenal and ampullary adenomas. No correlation was detected between adenoma development and the site of the adenomatous polyposis coli mutation.

Adenomas are frequently found in the ileal pouch of patients after restorative proctocolectomy for FAP. Regular endoscopic surveillance of the pouch is recommended at a frequency similar to that of upper gastrointestinal endoscopy.

Microadenomas or aberrant crypt foci (ACFs) are regarded as early neoplastic lesions that precede the development of macroscopic adenomas. The aim of this study was to characterize surface features of ileal microadenomas in patients with familial adenomatous polyposis (FAP). Magnifying ileoscopy was performed in 19 patients with FAP. A histologically verified adenomatous tubule, the existence of which was suggested by magnified observation, was regarded as a microadenoma. Magnifying ileoscopy detected microadenoma in five patients. In four of the five cases, the ileal microadenomas were identified as areas with tiny crypt openings or serrated surfaces, which were distinctive of nonneoplastic, diminutive protrusions. Magnifying ileoscopy seems to be useful in the detection of ileal microadenomas.

Although adenomatous polyps and even adenocarcinomas have been found in the terminal ileum of patients with familial adenomatous polyposis, the prevalence of neoplastic changes in the pouches of patients who have undergone restorative proctocolectomy is unknown. The objective of this study was to determine the frequency of pelvic pouch neoplasia in familial adenomatous polyposis patients after restorative proctocolectomy.

Patients in a polyposis registry who had undergone restorative proctocolectomy were recruited. Demographic, surgical, pathologic, and endoscopic data were obtained from patient records. Video pouchoscopy was done after two enemas and representative biopsies were taken.

Of 102 eligible patients, 26 (17 males and 9 females) participated. Median age at ileal pouch-anal anastomosis was 31 (range, 12-58) years. Median follow-up period was 66 (11-156) months. Adenomas were found in the pouch of 11 (42 percent) patients, in the terminal ileum above the pouch in 1 patient, and in the anal canal of 4 patients. Among patients with pouch polyps, three patients had one lesion, three patients had two lesions, and five patients had more than ten lesions. The incidence of polyps increased steadily with time from restorative proctocolectomy. There was no relation between the incidence of pouch polyposis and the severity of colonic or duodenal disease.

Proctocolectomy and ileal pouch-anal anastomosis is associated with a significant risk of pouch neoplasia in familial adenomatous polyposis patients. The severity of pouch adenomas was not related either to the severity of colonic or duodenal disease. The pelvic pouches of all patients with familial adenomatous polyposis who have undergone restorative proctocolectomy should be examined periodically.

Little data are available on the type and prevalence of mucosal changes involved in the development of ileal adenomas in patients with familial adenomatous polyposis who have undergone colectomy. However, colonic metaplasia of the ileal epithelium is thought to be an important step in the development of such adenomas.

Retrograde endoscopy and biopsy of the distal ileum were performed in 17 affected patients who underwent total colectomy or proctocolectomy 3-184.1 months (mean, 80.3 +/- 13.9 months) before the study.

Macroscopic ileal polyps were identified in 14 (82.4%) patients. All polyps were sessile and 1-5 mm in size. Histological analysis showed adenomas in 9 (52.9%) patients and lymphoid hyperplasia or inflammation in the others. In 1 patient, an area of colonic-type metaplasia of the ileal mucosa was found close to an adenoma. However, in 5 (29.4%) patients, random biopsy specimens of the normal-appearing mucosa showed foci of abnormal crypts in the absence of metaplasia, with histological appearance similar to the findings described in dysplastic aberrant crypt foci of the colon. Such lesions, previously observed only in colorectal mucosa and referred to as microadenomas or oligocryptal adenomas, are considered putative preneoplastic abnormalities.

Although the hypothesized sequence normal ileal mucosa leading to colonic-type metaplasia leading to adenoma cannot be excluded, our findings support the sequence normal ileal mucosa leading to microadenoma leading to gross adenoma and possibly cancer as the main histogenetic pathway, as already suggested for the large bowel.

Most small bowel polyps in familial adenomatous polyposis (FAP) occur in the peri-ampullary region, and distal small bowel adenomas and carcinomas are comparatively less common. As standard therapy in FAP consists of proctocolectomy with ileal pouch anal anastomosis, or ileorectal anastomosis, it is essential to be aware of the potential for adenomatous polyp formation in the terminal ileum and rectum. Ileal adenomas are found in 9-20% of patients with FAP, and new polyps may develop after colectomy. Ileal lymphoid hyperplasia and polyps are 2-4 times more common than adenomas, may be indistinguishable from adenomas on examination (requiring biopsy for diagnosis), and tend to regress after colectomy. Adenomas may arise in pouches, usually after an interval of several years, and have been documented to occur in the terminal ileum up to 25 years after colectomy. At pouch construction, rectal mucosectomy may theoretically fail to remove all mucosa at risk. Small islets of rectal mucosa may remain after this technically difficult operation, and the late development of cancer, up to 20 years postoperation has been noted. A stapled anastomosis may arguably have a better physiological result, but a greater amount of residual rectal mucosa may increase late cancer risk. Annual endoscopic follow-up of pouches is recommended. All polyps or suspicious lesions should be biopsied, excised or destroyed, preserving a sample for histology. After ileorectal anastomosis, cancer risk in the rectal stump increases with chronological age, with risk ranging from 5-10% at age 50 years, to 14-29% at age 60 years. Surveillance of the rectal stump in FAP is recommended every 4-6 months. There may be a role for prostaglandin synthesis inhibitors in some patients.

In view of the rarity of small-bowel epithelial neoplasms as compared with the case for the large bowel, evidence for an adenoma-carcinoma sequence in the small bowel was studied based on a search for data in the medical literature for the years 1927 through 1986. Sufficiently defined data were found for comparison of 185 benign adenomas, 76 adenoma-with-carcinomas, and 1333 carcinomas in patients without familial polyposis disease and for 63, five, and 30, respectively, in patients with disease. For patients without polyposis, it was found that (1) 29.8% of all small-bowel adenomas (33.6% if those at Vater's ampulla are excluded) showed malignancy; (2) the mean and median ages were lower for benign adenoma than for adenoma-with-carcinoma and carcinoma, although the ratios by sex were the same; (3) there is a nearly identical spatial distribution of the three types of epithelial neoplasms within the small bowel; and (4) both the frequency of finding adenomatous residues existing in continuity with carcinoma and the life history of the adenoma-carcinoma sequence are similar in the small bowel as in the large. In comparing these results with those from patients with familial polyposis disease, it was particularly noted that (1) the only difference was that adenomas in familial polyposis occurred earlier and multiply, and (2) the spatial distributions of adenomas and carcinomas for both cases were closely similar. It is therefore postulated that the adenoma-carcinoma sequence is as significant in the small bowels as in the large. A hypothesis regarding the relationship of epithelial neoplasms in people with and without familial polyposis disease is suggested.

A new type of ileostomy was constructed in rats using an interposed ileal (I-I) segment functioning as a neocolon. The effects of this operation in these rats were compared with a control group undergoing conventional ileostomy (I). Rats in the I group lost weight throughout follow-up, whereas rats in the I-I group regained weight and were significantly heavier four weeks after surgery. Transit time from the stomach to the stoma was significantly prolonged in the I-I group (187 +/- 29 minutes) when compared with the I group (141 +/- 17 minutes, P less than 0.01). Serum analysis revealed no significant differences in total protein, lipids, electrolytes (Na, Cl, CO2), and osmolarity between the groups. Biliary bile salt concentration, normalized bile flow, and normalized bile acid output in the I-I group were not different from those in unoperated control rats, suggesting unimpaired bile acid metabolism. These data suggest this operative procedure has the beneficial effects of slowing intestinal transit and promoting postoperative recovery without impairing distal ileal function.

Endoscopy and biopsy of the terminal ileum were performed in 18 patients with familial adenomatosis coli/Gardner's syndrome. All had undergone total colectomy with ileoproctostomy 7 to 249 months (average, 79.7 months) before the study. In all of these patients, endoscopic studies revealed multiple or innumerable small (less than 4 mm in diameter) polypoid lesions, all recognizable as whitish, sessile elevations. Histologic findings of the biopsy specimens from the polypoid lesions showed tubular adenoma, with or without lymphoid hyperplasia, in nine (50 percent), but only lymphoid hyperplasia in the other nine patients. Colonic metaplasia was present in the adjacent ileal mucosa in 3 patients with ileal adenomas. The incidence (83 percent) of ileal adenomas detected 113 to 249 months after colectomy was higher than that (33 percent) found 7 to 90 months after surgery. In view of these results, endoscopy and biopsy of the terminal ileum, as well as the retained rectum, should be done periodically for postcolectomy patients with this disease.

A patient with familial adenomatous polyposis was treated with colectomy, mucosal proctectomy, and a straight ileoanal anastomosis in 1962. Thirteen to 21 years later recurrent adenomas developed at the ileoanal anastomosis, and 25 years after the operation multiple adenomas were found in the terminal ileum up to 12 cm from the ileoanal anastomosis. It is concluded that colectomy and mucosal proctectomy, with or without an ileoanal reservoir, does not eliminate the future risk of adenoma formation. Thus, this method should be used only in selected polyposis patients.

The outcome of mucosal proctectomy with ileoanal anastomosis in patients with polyposis coli has not been well studied. A series of 25 patients with polyposis treated at the Mount Sinai Hospital over a period of ten years is reported. The mean age of the patients was 23 years. Early postoperative complications were present in seven patients and consisted of thrombophlebitis (three), pelvic sepsis (three), and retraction of the anastomosis (one). Intestinal obstruction requiring laparotomy occurred in another five patients. Twenty-three patients were followed for a mean of 47 months after closure of the ileostomy. Ninety-one percent are satisfied with the operative results. The mean number of bowel movements per 24 hours is 6.0. All patients are continent, but eight have occasional episodes of rectal seepage at night. Nearly 50 percent require some antidiarrheal medication. New adenomatous polyps have developed just above the dentate line in four patients. Patients with polyposis coli seem to have fewer serious complications requiring excision of the ileoanal anastomosis than patients with ulcerative colitis. They also should have lifelong surveillance of the entire gastrointestinal tract even after total colectomy with ileoanal anastomosis.

In a 29-year-old man who presented with leakage from a continent ileostomy after proctocolectomy, endoscopic evaluation of the reservoir revealed extensive adenomatous polyposis. The polyps were not present at the time of revision of the reservoir 4 years earlier. Because it was not possible to fashion an adequate nipple valve in the presence of so many polyps and the concern over possible malignant transformation, the reservoir was excised. This is the second reported case of polyposis involving a continent reservoir ileostomy. Patients with a continent ileostomy constructed after proctocolectomy for polyposis coli should be evaluated endoscopically at regular intervals.