Stricture of ileo-anal J pouch anastomosis increased the intensity of pouchitis in an experimental rat model

Diagnosis and Medical Treatment of Acute and Chronic Idiopathic Pouchitis in Inflammatory Bowel Disease

Despite the decreased rates in inflammatory bowel disease (IBD) colectomies due to high advances in therapeutic options, a significant number of patients still require proctocolectomy with ileal pouch-anal anastomosis (IPPA) for ulcerative colitis (UC). Pouchitis is the most common complication in these patients, where up to 60% develop one episode of pouchitis in the first two years after UC surgery with IPAA with severe negative impact on their quality of life. Acute cases usually respond well to antibiotics, but 15% of patients will still develop a refractory disease that requires the initiation of advanced immunosuppressive therapies. For chronic idiopathic pouchitis, current recommendations suggest using the same therapeutic options as for IBD in terms of biologics and small molecules. However, the available data are limited regarding the effectiveness of different biologics or small molecules for the management of this condition, and all evidences arise from case series and small studies. Vedolizumab is the only biologic agent that has received approval for the treatment of adult patients with moderately to severely active chronic refractory pouchitis. Despite the fact that IBD treatment is rapidly evolving with the development of novel molecules, the presence of pouchitis represents an exclusion criterion in these trials. Recommendations for the approach of these conditions range from low to very low certainty of evidence, resulting from small randomized controlled trials and case series studies. The current review focuses on the therapeutic management of idiopathic pouchitis.

Normal Ileal Mucus Is Inadequate for Epithelial Protection in Ileal Pouch Mucosa

BACKGROUND

Clinical, nonspecific pouchitis is common after restorative proctocolectomy for ulcerative colitis, but its cause is unknown. A possible lack of protection for the ileal mucosa in its role as a reservoir for colonic-type bacteria may be the missing piece in defining the causes of pouchitis.

OBJECTIVE

The study aimed to review the causes of pouchitis and introduce the hypothesis that inadequate mucus protection in the pouch, combined with a predisposition to abnormal inflammation, is the most common cause of nonspecific pouchitis.

DATA SOURCES

Review of PubMed and MEDLINE for articles discussing pouchitis and intestinal mucus.

STUDY SELECTION

Studies published from 1960 to 2023. The main search terms were "pouchitis," and "intestinal mucus," whereas Boolean operators were used with multiple other terms to refine the search. Duplicates and case reports were excluded.

MAIN OUTCOME MEASURES

Current theories about the cause of pouchitis, descriptions of the role of mucus in the physiology of intestinal protection, and evidence of the effects of lack of mucus on mucosal inflammation.

RESULTS

The crossreference of "intestinal mucus" with "pouchitis" produced 9 references, none of which discussed the role of mucus in the development of pouchitis. Crossing "intestinal mucus" with "pouch" resulted in 32 articles, combining "pouchitis" with "barrier function" yielded 37 articles, and "pouchitis" with "permeability" yielded only 8 articles. No article discussed the mucus coat as a barrier to bacterial invasion of the epithelium or mentioned inadequate mucus as a factor in pouchitis. However, an ileal pouch produces a colonic environment in the small bowel, and the ileum lacks the mucus protection needed for this sort of environment. This predisposes pouch mucosa to bacterial invasion and chronic microscopic inflammation that may promote clinical pouchitis in patients prone to an autoimmune response.

LIMITATIONS

No prior studies address inadequate mucus protection and the origin of proctitis. There is no objective way of measuring the autoimmune tendency in patients with ulcerative colitis.

CONCLUSIONS

Studies of intestinal mucus in the ileal pouch and its association with pouchitis are warranted.

Diagnosis and classification of ileal pouch disorders: consensus guidelines from the International Ileal Pouch Consortium

Restorative proctocolectomy with ileal pouch-anal anastomosis is an option for most patients with ulcerative colitis or familial adenomatous polyposis who require colectomy. Although the construction of an ileal pouch substantially improves patients' health-related quality of life, the surgery is, directly or indirectly, associated with various structural, inflammatory, and functional adverse sequelae. Furthermore, the surgical procedure does not completely abolish the risk for neoplasia. Patients with ileal pouches often present with extraintestinal, systemic inflammatory conditions. The International Ileal Pouch Consortium was established to create this consensus document on the diagnosis and classification of ileal pouch disorders using available evidence and the panellists' expertise. In a given individual, the condition of the pouch can change over time. Therefore, close monitoring of the activity and progression of the disease is essential to make accurate modifications in the diagnosis and classification in a timely manner.

Clinical value of surveillance pouchoscopy in asymptomatic ileal pouch patients with underlying inflammatory bowel disease

BACKGROUND

There is no consensus on the need for and the interval of surveillance pouchoscopy in asymptomatic ileal pouch patients with underlying ulcerative colitis (UC). The purpose of this study was to evaluate the likelihood of finding dysplasia or incidental ileal pouch disorders in asymptomatic patients undergoing surveillance pouchoscopy.

METHODS

This study included all eligible consecutive asymptomatic UC patients undergoing surveillance pouchoscopy to our subspecialty Pouchitis Clinic from 2002 to 2011. Univariable and multivariable analyses were performed.

RESULTS

A total of 138 patients met the inclusion criteria, with 72 (52.2 %) being male. The mean age at pouch construction was 45.4 ± 15.0 years, and the mean interval from ileostomy closure to the inception of first surveillance pouchoscopy was 89.4 ± 78.8 months. One patient was found to have indefinite for dysplasia on pouch body mucosal biopsy (0.7 %), and two patients had non-caseating granulomas, suggesting Crohn's disease (CD) of the pouch. Of the 138 patients, 69 (50 %) had abnormal endoscopic findings, 102 (73.9 %) had acute and/or chronic inflammation on histology, and 62 (44.9 %) had both abnormal endoscopy and histology. The abnormal endoscopic findings included isolated pouch ulcer (n = 29, 21 %), active pouchitis (n = 31, 22.5 %), inflammatory polyps (n = 10, 7.2 %), strictures at the anastomosis (n = 5, 3.6 %), inlet (n = 10, 7.2 %) or outlet (n = 2, 1.4 %). Thirteen patients (13/17, 76.5 %) with pouch strictures underwent endoscopic balloon dilatation therapy and nine had (9/10, 90 %) endoscopic polypectomy. Multivariable analysis showed that patients with a preoperative diagnosis of CD and concomitant extraintestinal manifestations had a higher risk for abnormal pouch endoscopic findings with odds ratios of 2.552 (95 % confidence interval [CI] 1.108-16.545, p = 0.035) and 4.281 (95 % CI 1.204-5.409, p = 0.014), respectively.

CONCLUSIONS

Dysplasia was rare in asymptomatic patients with restorative proctocolectomy who underwent surveillance pouchoscopy in this cross-sectional study. However, "incidental" abnormal endoscopic and/or histologic findings were common, which often needed endoscopic therapeutic intervention.