Pouchitis: extracolonic manifestation of ulcerative colitis?

Prevalence of pouchitis in both ulcerative colitis and familial adenomatous polyposis: A systematic review and meta-analysis

AIM

Pouchitis is a clinically significant complication of ileal pouch-anal anastomosis with its prevalence varying in the literature. Pouchitis is thought to occur more commonly in patients with ulcerative colitis (UC) than in patients with familial adenomatous polyposis (FAP). We conducted a systematic review with meta-analysis of all published literature to report the prevalence of pouchitis in all pouch patients as well as specifically in UC and FAP. We also investigated the prevalence of acute and chronic pouchitis in UC and FAP.

METHODS

A meta-analysis was conducted by searching the Embase, Embase Classic and PubMed databases between 1978 and 2021 exploring the prevalence of pouchitis in UC and FAP. We then performed a random effects model in order to find the pooled prevalence of pouchitis and used odds ratios to report differences in the prevalence of pouchitis in UC and FAP.

RESULTS

Fifty-nine full papers and conference abstracts were included in the meta-analysis comprising 18 117 patients with UC and 860 with FAP. The prevalence of pouchitis in UC was 0.32 (95% CI 0.27-0.37) and in FAP was found to be 0.06 (95% CI 0.03-0.15). The odds ratio of pouchitis in UC patients compared with FAP patients was 4.95 (95% CI 3.17-7.72, P < 0.0001).

CONCLUSIONS

Our findings support the consensus that the prevalence of pouchitis is higher in UC than in FAP. More significantly our findings suggest that the true prevalence of pouchitis is higher than commonly reported in the literature. This literature may help counsel patients prior to undergoing restorative proctocolectomy.

Meta-analysis of the association of extraintestinal manifestations with the development of pouchitis in patients with ulcerative colitis

Background

The presence of extraintestinal manifestations may be associated with the development of pouchitis in patients with ulcerative colitis after ileal pouch–anal anastomosis. The aim of this study was to assess this correlation.

Methods

A systematic literature search was performed using MEDLINE and the Cochrane Library. Studies published in English up to 22 May 2017 investigating the association between extraintestinal manifestations and development of pouchitis in adults with ulcerative colitis were included. Case reports were excluded. The association of extraintestinal manifestations with the development of overall and chronic pouchitis was investigated using a random‐effects model.

Results

Of 1010 citations identified, 22 observational studies comprising 5128 patients were selected for analysis. The presence of extraintestinal manifestations was significantly associated with both chronic pouchitis (odds ratio 2·28, 95 per cent c.i. 1·57 to 3·32; P = 0·001) and overall pouchitis (odds ratio 1·96, 1·49 to 2·57; P < 0·001).

Conclusion

The presence of extraintestinal manifestations is associated with development of pouchitis after ileal pouch–anal anastomosis.

Review article: the pathogenesis of pouchitis

BACKGROUND

A total proctocolectomy followed by ileal pouch-anal anastomosis is a potentially curative surgery for ulcerative colitis or familial adenomatous polyposis. About 5-35% of patients with ulcerative colitis and 0-11% of patients with familial adenomatous polyposis develop subsequent inflammation of the ileal pouch termed pouchitis.

AIM

To provide a comprehensive analysis of the research studying the possible pathogenesis of pouchitis. The goals were to identify promising areas of investigation, to help focus clinicians, researchers and patients on how to better understand and then potentially manage ileal pouchitis, and to provide avenues for future research investigations.

METHODS

This review examined manuscripts from 1981 to 2015 that discussed and/or proposed hypotheses with supportive evidence for the potential underlying pathogenic mechanism for pouchitis.

RESULTS

The pathogenesis of pouchitis is not definitively understood, but various hypotheses have been proposed, including (i) recurrence of ulcerative colitis, (ii) dysbiosis of the ileal pouch microbiota, (iii) deprivation of nutritional short-chain fatty acids, (iv) mucosal ischaemia and oxygen-free radical injury, (v) host genetic susceptibility and (vi) immune dysregulation. However, none of these alone are able to fully explain pouchitis pathogenesis.

CONCLUSIONS

Pouchitis, similar to inflammatory bowel disease, is a complex disorder that is not caused by any one single factor. More likely, pouchitis occurs through a combination of both dysregulated host inflammatory mechanisms and interaction with luminal microbiota.

Frequency, Clinical Features and Factors Associated with Pouchitis after Proctocolectomy with Ileo-Pouch-Anal Anastomosis in Patients with Ulcerative Colitis: A Latin-American Country Retrospective-Cohort Study

BACKGROUND

Pouchitis is the most common complication of proctocolectomy with ileo-pouch-anal anastomosis (IPAA) for ulcerative colitis (UC). No previous study in Mexico has evaluated this issue; our aim was to evaluate its frequency, clinical characteristics and factors associated with its presence in Mexican patients with UC and IPAA.

METHODS

Retrospective-cohort study including 70 patients with histopathological diagnosis of UC and IPAA between 1983 and 2014 from inflammatory bowel disease clinic of a tertiary care center. The statistical analysis used descriptive statistics, chi-square and Fisher's exact test for categorical variables and Student's t test for numeric variables. Univariate analysis was performed to identify the factors associated.

RESULTS

Patients presenting with pouchitis accounted for 48.6%. From the 34 cases, 12 (35.3%) had inactive pouchitis; 7 (20.6%) active acute pouchitis; 15 (44.1%) chronic active pouchitis. On average, pouchitis occurred 5.37 years after IPPA. Factors probably associated with its occurrence were the presence of autoimmune concomitant diseases (ACDs; p = 0.06, OR 4.40, 95% CI 0.84-22.9) and extra-intestinal manifestations (EIMs; p = 0.05, OR 2.53, 95% CI 0.96-6.64), which was also probably associated with chronic active pouchitis (p = 0.06, OR 0.31, 95% CI 0.07-1.31).

CONCLUSIONS

The frequency of pouchitis is high in Mexican UC patients after IPAA. ACDs and EIMs were probably associated with its development.

Histopathological evaluation and risk factors related to the development of pouchitis in patients with ileal pouches for ulcerative colitis

OBJECTIVE

Many changes in mucosal morphology are observed following ileal pouch construction, including colonic metaplasia and dysplasia. Additionally, one rare but potential complication is the development of adenocarcinoma of the reservoir. The aim of this study was to evaluate the most frequently observed histopathological changes in ileal pouches and to correlate these changes with potential risk factors for complications.

METHODS

A total of 41 patients were enrolled in the study and divided into the following three groups: a non-pouchitis group (group 1) (n = 20; 8 males; mean age: 47.5 years) demonstrating optimal outcome; a pouchitis without antibiotics group (group 2) (n = 14; 4 males; mean age: 47 years), containing individuals with pouchitis who did not receive treatment with antibiotics; and a pouchitis plus antibiotics group (group 3) (n = 7; 3 males; mean age: 41 years), containing those patients with pouchitis who were administered antibiotics. Ileal pouch endoscopy was performed, and tissue biopsy samples were collected for histopathological analysis.

RESULTS

Colonic metaplasia was found in 15 (36.6%) of the 41 patients evaluated; of these, five (25%) were from group 1, eight (57.1%) were from group 2, and two (28.6%) were from group 3. However, no correlation was established between the presence of metaplasia and pouchitis (p = 0.17). and no differences in mucosal atrophy or the degree of chronic or acute inflammation were observed between groups 1, 2, and 3 (p>0.45). Moreover, no dysplasia or neoplastic changes were detected. However, the degree of mucosal atrophy correlated well with the time of postoperative follow-up (p = 0.05).

CONCLUSIONS

The degree of mucosal atrophy, the presence of colonic metaplasia, and the degree of acute or chronic inflammation do not appear to constitute risk factors for the development of pouchitis. Moreover, we observed that longer postoperative follow-up times were associated with greater degrees of mucosal atrophy.

Pathogenesis of and unifying hypothesis for idiopathic pouchitis

Ileal pouch-anal anastomosis is the procedure of choice in the surgical management of refractory ulcerative colitis. Pouchitis affects up to 60% of patients following ileal pouch-anal anastomosis for ulcerative colitis. It overlaps significantly with ulcerative colitis such that improvements in our understanding of one will impact considerably on the other. The symptoms are distressing and impinge significantly on patients' quality of life. Despite 30 years of scientific and clinical investigation, the pathogenesis of pouchitis is unknown; however, recent advances in molecular and cell biology make a synergistic hypothesis possible. This hypothesis links interaction between epithelial metaplasia, changes in luminal bacteria (in particular sulfate-reducing bacteria), and altered mucosal immunity. Specifically, colonic metaplasia supports colonization by sulfate-reducing bacteria that produce hydrogen sulfide. This causes mucosal depletion and subsequent inflammation. Although in most cases antibiotics lead to bacterial clearance and symptom resolution, immunogenetic subpopulations can develop a chronic refractory variant of pouchitis. The aims of this paper are to discuss proposed pathogenic mechanisms and to describe a novel mechanism that combines many hypotheses and explains several aspects of pouchitis. The implications for the management of both pouchitis and ulcerative colitis are discussed.

Pouchitis: an evolving clinical enigma--a review

While the overall incidence of pouchitis is low, extensive research continues at clinical and experimental levels in attempts to unravel its etiology. The ileal pouch and pouchitis together represent a unique in vivo opportunity to study mucosal adaptation and inflammation in depth. In the recent past, molecular data relating to pouchitis has significantly expanded. These data provide invaluable insight into intracellular and extracellular events that underpin mucosal adaptation and inflammation. Advances in classification, risk factor evaluation, and prevention have meant that a review of this data, as well as its relationship to our current understanding of pouchitis, is both timely and warranted. Therefore, the aim of this review is to summarize recent data in the context of the established literature.

Portal vein thrombi after ileal pouch-anal anastomosis: its incidence and association with pouchitis

PURPOSE

Portal vein thrombi (PVT) have recently been linked to ileal pouch-anal anastomosis (IPAA). We assessed the rate of PVT in patients who underwent IPAA and attempted to identify the associated features.

METHODS

We reviewed all patients who underwent IPAA at our hospital between 1997 and 2002, noting demographic, operative, and clinical data. Computed tomography (CT) scans were independently re-reviewed by two radiologists blinded to patient data. Scans were designated as positive, negative, or indeterminate for PVT.

RESULTS

A total of 112 patients underwent IPAA for ulcerative colitis, 28 (25%) of whom had a CT scan done within 8 weeks postoperatively. The indications for CT included prolonged ileus (32.1%), abdominal pain (28.6%), and fever (17.9%). On examining the CT scans, 39% were positive, 14% were indeterminate, and 46% were negative for PVT. There was no association between PVT and pelvic sepsis. Within a mean follow-up of 36.2 months, 15.4% patients without PVT had suffered pouchitis compared with 25% of those with indeterminate scans and 45.5% of those with PVT.

CONCLUSIONS

Portal vein thrombi are a common finding in the subset of patients who require a CT scan after IPAA. Patients who suffer PVT have a higher incidence of postoperative pouchitis. Thus a prospective evaluation of the risk of PVT and its association with pouchitis is warranted.

Diagnostic difficulties in inflammatory bowel disease pathology

This review summarizes some of the common diagnostic problems encountered by pathologists when evaluating patients with chronic colitis and in whom inflammatory bowel disease (IBD) is either suspected or within the differential diagnosis. Both ulcerative colitis (UC) and Crohn's disease (CD) show characteristic, but non-specific, pathological features that may overlap and result in a diagnosis of 'indeterminate colitis' (IC). However, other reasons why pathologists may entertain a diagnosis of IC include failure to recognize or accept certain 'hardcore' histological features as indicative of CD, an attempt to classify cases of chronic colitis based on mucosal biopsy material or in the absence of adequate clinical and radiographic information, and the presence of other disease processes that mask, or mimic, IBD. In addition, some cases of UC may show unusual CD-like features, such as discontinuous or patchy disease, ileal inflammation, extracolonic inflammation, granulomatous inflammation in response to ruptured crypts, aphthous ulcers, or transmural inflammation. Furthermore, other forms of colitis, such as microscopic colitis, diverticulitis and diversion colitis may, on occasion, also show IBD-like changes. The clinical and pathological features that aid in the distinction between these entities, and others, are covered in detail in this review.

Pouchitis-associated pyoderma gangrenosum following restorative proctocolectomy for ulcerative colitis

A 43-year-old female with ulcerative colitis treated by proctocolectomy and ileal pouch--anal anastomosis developed acute pouchitis. Although no extra-intestinal manifestations were present before the surgical procedure, pyoderma gangrenosum developed concomitantly with the appearance of acute pouchitis. Both conditions completely resolved with oral metronidazole only. This is the first report of acute pouchitis-related pyoderma gangrenosum. This association suggests that pouchitis may represent a recurrent ulcerative colitis-like syndrome within the novel environment of the pouch.

Histologic predictors of pouchitis in patients with chronic ulcerative colitis

Inflammation of ileal reservoir mucosa ("pouchitis") is a common sequelae in ulcerative colitis (UC) patients who have had a colectomy with ileal pouch anal-anastomosis (IPAA). Although several clinical, genetic, and laboratory parameters have been evaluated, reliable pathologic predictors for the development of pouchitis are lacking. The purpose of this case-control study was to determine whether there are any pathologic features in UC colectomy specimens that may help predict the subsequent development of pouchitis after an IPAA procedure. The study group consisted of 39 UC patients (male/female ratio: 21/18, mean age: 35 years), who had at least 1 episode of pouchitis after an IPAA procedure during the follow-up period (mean: 57 months, range: 12-121 months). There were 26 control patients (male/female ratio: 11/15, mean age: 37 years), all of whom also underwent a total colectomy and IPAA procedure for UC, but did not develop pouchitis during the follow-up period (mean: 78 months, range: 14-223 months). Routinely processed tissues from each colectomy specimen were evaluated for a variety of histologic features, such as extent of colitis, severity of colitis, extent of severe colitis, type and extent of ulceration, presence and severity of appendiceal inflammation, and the presence of active ileitis, and compared between the study and control patients. Pathologic features that were associated with the subsequent development of pouchitis included the presence of severe colitis that extended into the cecum (severe pancolitis), which was present in 7/39 (18%) pouchitis patients, but in none (0%) of the control patients (P = 0.03), early fissuring ulcers [9/39 (23%) pouchitis cases versus 1/26 (4%) controls (P = 0.04)], active inflammation of the appendix [20/32 (63%) pouchitis patients versus 7/19 (31%) controls (P = 0.03)], and appendiceal ulceration [13/32 (41%) pouchitis patients versus none (0%) of the controls (P = 0.002)]. No significant differences in patient gender or age, depth or extent of ulceration, or the presence or absence of "backwash ileitis" were identified between the 2 groups. In conclusion, there are several histologic features in colectomy specimens from UC patients who have undergone an IPAA procedure that may help predict the subsequent development of pouchitis. Of these features, appendiceal ulceration is highly associated with pouchitis.

Pouchitis

Pouchitis is one of the commonest and most debilitating complications of a restorative proctocolectomy. The cause remains elusive, though a number of approaches have been shown to alleviate the condition. This review outlines current evidence relating to pouchitis, obtained from randomised and nonrandomised studies. Medline, the Bath Information Data Service (BIDS) and PubMed were searched using the keywords 'pouchitis' and 'inflammatory bowel disease'. In addition, articles were cross-referenced, and the abstracts of recent colorectal meetings studied.

Short- and long-term outcomes of ileal pouch-anal anastomosis for ulcerative colitis

Ileal pouch-anal anastomosis was an important advancement in the treatment of ulcerative colitis. The aim of this study was to determine whether early complications of ileal pouch-anal anastomosis in patients with ulcerative colitis are associated with poor late functional results.

PATIENTS AND METHODS

Eighty patients were operated on from 1986 to 2000, 62 patients with ileostomy and 18 without. The early and late complications were recorded. Specific emphasis has been placed on the incidence of pouchitis with prolonged follow-up.

RESULTS

The ileostomy was closed an average of 9.2 months after the first operation. Fourteen patients were excluded from the long-term evaluation; 6 patients were lost to regular follow-up, 4 died, and 4 patients still have the ileostomy. Of the 4 patients that died, 1 died from surgical complications. Early complications after operation (41) occurred in 34 patients (42.5%). Late complications (29) occurred in 25 patients as follows: 16 had pouchitis, 3 associated with stenosis and 1 with sexual dysfunction; 5 had stenosis; and there was 1 case each of incisional hernia, ileoanal fistula, hepatic cancer, and endometriosis. Pouchitis occurred in 6 patients (9.8%) 1 year after ileal pouch-anal anastomosis, 9 (14.8%) after 3 years, 13 (21.3%) after 5 years, and 16 (26.2%) after more than 6 years. The mean daily stool frequency was 12 before and 5.8 after operation. One pouch was removed because of fistulas that appeared 2 years later.

CONCLUSIONS

Ileal pouch-anal anastomosis is associated with a considerable number of early complications. There was no correlation between pouchitis and severe disease, operation with or without ileostomy, or early postoperative complications. The incidence of pouchitis was directly proportional to duration of time of follow-up.