Postoperative Endoscopic Recurrence on the Neoterminal Ileum But Not on the Anastomosis Is Mainly Driving Long-Term Outcomes in Crohn's Disease

Long-term risk of delayed postoperative Crohn's disease recurrence in patients with no or mild endoscopic recurrence at first assessment

BACKGROUND

Early endoscopic evaluation is recommended for assessment of postoperative recurrence (POR) of Crohn's disease (CD) but no further monitoring recommendations are available.

AIM

To evaluate the long-term outcome of patients without endoscopic POR at first endoscopic assessment.

METHODS

Retrospective four-centre study including consecutive CD patients with ileocolonic resection (ICR) without endoscopic POR (Rutgeerts score i0-i1) at first endoscopic assessment performed within 18 months from ICR. All patients had a clinical follow-up ≥24 months and at least one further endoscopic assessment. Main outcomes were endoscopic, clinical and surgical POR, need for rescue therapy and "delayed POR" (any need for rescue therapy or clinical or surgical POR) during follow-up.

RESULTS

Overall, 183 patients were included (79% with risk factors for POR, 44% without postoperative prophylaxis). Endoscopic POR was observed in 42% of patients. Clinical POR-free survival was 89.4% and 81.5% at 3 and 5 years, and delayed POR-free survival was 76.9% and 63.4% at 5 and 10 years, respectively. In multivariate analysis, postoperative prophylaxis (HR .55; 95% CI .325-.942) and active smoking (HR 1.72; 95%CI 1.003-2.962) were independent risk factors for clinical POR, whereas presence of mild endoscopic lesions at index ileocolonoscopy (i1) was the only risk factor for delayed POR (HR 1.824; 95% CI 1.108-3.002).

CONCLUSIONS

Long-term risk of POR among patients with no or mild endoscopic lesions at first ileocolonoscopy after surgery is steadily low, being higher among smokers, in the absence of postoperative prophylaxis and when mild endoscopic lesions are observed in the first endoscopic assessment.

Outcomes and Endpoints of Postoperative Recurrence in Crohn's Disease: Systematic Review and Consensus Conference

BACKGROUND

Outcomes after ileocolonic resection in Crohn's disease [CD] are heterogeneous, and a clear definition of postoperative recurrence remains to be determined. Our Endpoints Working Group of the International Organization for the study of Inflammatory Bowel Disease [IOIBD] aimed to standardise postoperative outcomes, to discuss which endpoints should be used for postoperative clinical trials, and to define those which could be used in trials or registries.

METHODS

Based on a systematic review of the literature, recommendations and statements were drafted and sent to all IOIBD members for a first round of voting. Recommendations and statements were revised based on the voters' comments during a consensus hybrid conference open to all IOIBD members. If no agreement was reached after two rounds of voting, the statement was excluded.

RESULTS

In the systematic review, 3071 manuscripts were screened of which 434 were included. Sixteen recommendations were identified, of which 11 were endorsed. Recommendations and statements include that endoscopy remains the gold standard and should be used as a short-term primary endpoint in both observational cohorts and randomised controlled trials. Clinical symptoms classically used in clinical trials for luminal CD are not reliable in this specific situation. For that reason, longer-term endpoints should be based on the evidence of macroscopic inflammation assessed by imaging techniques, endoscopy, or as reflected by the presence of complications.

CONCLUSIONS

Agencies recommend the use of clinical evaluations, as in the case of luminal CD, and do not recognise primary endpoints based solely on endoscopy. This consensus has led to agreement on the need to define postoperative endoscopy-based and/or imaging-based endpoints.

Diagnostic value of MR and CT enterography in post-operative recurrence of Crohn's disease: a systematic review and meta-analysis

Post-operative recurrence is a critical issue in the surveillance of Crohn's disease after ileocecal resection. This meta-analysis aims to assess the diagnostic yield of enterography techniques in post-operative recurrence of Crohn's disease. A systematic electronic bibliographic databases search was conducted. The inclusion criteria of original articles were: Utilized MR enterography or CT enterography after ileocolonic resection; Documented recurrence by ileo-colonoscopy (Rutgeerts' score ≥ i2); Provided crude data of diagnostic performance. A random-effect method was used for analysis. Relative risk and diagnostic value of each imaging feature were calculated. Eleven studies (11 populations and 589 patients) were included (4 CTE and 7 MRE with 248 and 341 patients, respectively). The pooled sensitivity and specificity of the enterography were 91% (95% CI: 0.85-0.95) and 75% (95% CI: 0.56-0.87), respectively. The pooled sensitivity and specificity of CTE were 93% (95% CI: 0.87-0.96) and 67% (95% CI: 0.35-0.90), respectively. MRE revealed pooled sensitivity and specificity of 90% (95% CI: 0.78-0.96) and 78% (95% CI: 0.57-0.90), respectively. The inter-study heterogeneity was low for sensitivity (I2 = 29%, p-value = 0.17) and high for specificity (I2 = 85%, p-value < 0.01). Wall enhancement, anastomosis wall thickening, anastomosis stenosis, pre-anastomotic dilatation, penetrating lesion, comb sign, and perivisceral edema were significantly higher in POR patients. Wall thickening and penetrating lesion were the most sensitive (81%) and specific (97%) findings, respectively. MRE and CTE exhibit high sensitivity and acceptable specificity (especially MRE) for detection of recurrence in Crohn's disease which makes them an effective initial screening tool and reserves ileo-colonoscopy for those patients with inconclusive enterography results.

Postoperative small bowel Crohn's disease: how to diagnose, manage and treat

PURPOSE OF REVIEW

Crohn's disease is a relapsing inflammatory condition and disease recurrence after surgery is common. Significant variation in clinical practice remains despite progress in management of postoperative Crohn's disease. In this review, we summarise current management strategies and guidelines, unmet needs, and research progress in this field.

RECENT FINDINGS

There has been real progress in risk stratifying individuals' postsurgery and tailoring therapies based on their risk; this has been incorporated into current management guidelines in the USA, UK, and Europe. Furthermore, novel noninvasive monitoring tools such as intestinal ultrasound have shown high sensitivity and specificity at detecting disease recurrence and are an attractive point-of-care test. Recent studies are also investigating multiomic biomarkers to prognosticate postoperative Crohn's disease. However, given the heterogeneity within this condition, large multicentre clinical validation across all age groups is needed for clinical translation in the future.

SUMMARY

Ongoing progress in research and the development of novel prognostic and noninvasive disease monitoring tools offers hope for personalised therapy tailored to individual recurrence risk in postoperative Crohn's disease.

Clinical Predictors of Early and Late Endoscopic Recurrence Following Ileocolonic Resection in Crohn's Disease

BACKGROUND AND AIMS

Multiple factors are suggested to place Crohn's disease patients at risk of recurrence after ileocolic resection with conflicting associations. We aimed to identify clinical predictors of recurrence at first [early] and further [late] postoperative colonoscopy.

METHODS

Crohn's disease patients undergoing ileocolic resection were prospectively recruited at six North American centres. Clinical data were collected and endoscopic recurrence was defined as Rutgeerts score ≥i2. A multivariable model was fitted to analyse variables independently associated with recurrence.

RESULTS

A total of 365 patients undergoing 674 postoperative colonoscopies were included with a median age of 32 years, 189 [51.8%] were male, and 37 [10.1%] were non-Whites. Postoperatively, 133 [36.4%] used anti-tumour necrosis factor [anti-TNF] and 30 [8.2%] were smokers. At first colonoscopy, 109 [29.9%] had recurrence. Male gender (odds ratio [OR] = 1.95, 95% confidence interval [CI] 1.12-3.40), non-White ethnicity [OR = 2.48, 95% CI 1.09-5.63], longer interval between surgery and colonoscopy [OR = 1.09, 95% CI 1.002-1.18], and postoperative smoking [OR = 2.78, 95% CI 1.16-6.67] were associated with recurrence, while prophylactic anti-TNF reduced the risk [OR = 0.28, 95% CI 0.14-0.55]. Postoperative anti-TNF prophylaxis had a protective effect on anti-TNF experienced patients but not on anti-TNF naïve patients. Among patients without recurrence at first colonoscopy, Rutgeerts score i1 was associated with subsequent recurrence [OR = 4.43, 95% CI 1.73-11.35].

CONCLUSIONS

We identified independent clinical predictors of early and late Crohn's disease postoperative endoscopic recurrence. Clinical factors traditionally used for risk stratification failed to predict recurrence and need to be revised.

How Reliable Is Endoscopic Scoring of Postoperative Recurrence in Crohn Disease?: A Systematic Review and Meta-Analysis

Objective

Guidelines advise to perform endoscopic surveillance following ileocolic resection (ICR) in Crohn disease (CD) for timely diagnosis of recurrence. This study aims to assess the variation in endoscopic recurrence (ER) rates in patients after ICR for CD using the most commonly used classification systems, the Rutgeerts score (RS) and modified Rutgeerts score (mRS) classifications.

Methods

A systematic literature search using MEDLINE, Embase, and the Cochrane Library was performed. Randomized controlled trials and cohort studies describing ER < 12 months after an ICR for CD were included. Animal studies, reviews, case reports (<30 included patients), pediatric studies, and letters were excluded. The Newcastle-Ottawa Quality Assessment Scale and Cochrane Collaboration's tool were used to assess risk of bias. Main outcome was the range of ER rates within 12 months postoperatively, defined as RS ≥ i2 and/or mRS ≥ i2b. A proportional meta-analysis was performed. The final search was performed on January 4, 2022. The study was registered at PROSPERO, CRD42022363208.

Results

Seventy-six studies comprising 7751 patients were included. The weighted mean of ER rates in all included studies was 44.0% (95% confidence interval, 43.56-44.43). The overall range was 5.0% to 93.0% [interquartile range (IQR), 29.2-59.0]. The weighted means for RS and mRS were 44.0% and 41.1%, respectively. The variation in ER rates for RS and mRS were 5.0% to 93.0% (IQR, 29.0-59.5) and 19.8% to 62.9% (IQR, 37.3-46.5), respectively. Within studies reporting both RS and mRS, the weighted means for ER were 61.3% and 40.6%, respectively.

Conclusions

This study demonstrates a major variation in ER rates after ICR for CD, suggesting a high likelihood of inadequate diagnosis of disease recurrence, with potentially impact on quality of life and health care consumption. Therefore, there is an important need to improve endoscopic scoring of recurrent disease.

Optimising surgical anastomosis in ileocolic resection for Crohn's disease with respect to recurrence and functionality: two international parallel randomized controlled trials comparing handsewn (END-to-end or Kono-S) to stapled anastomosis (HAND2END and the End2End STUDIES)

BACKGROUND

The most common intestinal operation in Crohn's disease (CD) is an ileocolic resection. Despite optimal surgical and medical management, recurrent disease after surgery is common. Different types of anastomoses with respect to configuration and construction can be made after resection for example, handsewn (end-to-end and Kono-S) and stapled (side-to-side). The various types of anastomoses might affect endoscopic recurrence and its assessment, the functional outcome, and costs. The objective of the present study is to compare the three types of anastomoses with respect to endoscopic recurrence at 6 months, gastrointestinal function, and health care consumption.

METHODS

This is a randomized controlled multicentre superiority trial, allocating patients either to side-to-side stapled anastomosis as advised in current guidelines or a handsewn anastomoses (an end-to-end or Kono-S). It is hypothesized that handsewn anastomoses do better than stapled, and end-to-end perform better than the saccular Kono-S. Two international studies with a similar setup will be conducted mainly in the Netherlands (End2End) and Italy (HAND2END). Patients diagnosed with CD, aged over 16 years in the Netherlands and 18 years in Italy requiring (re)resection of the (neo)terminal ileum are eligible. The first part of the study compares the two handsewn anastomoses with the stapled anastomosis. To detect a clinically relevant difference of 25% in endoscopic recurrence, a total of 165 patients will be needed in the Netherlands and 189 patients in Italy. Primary outcome is postoperative endoscopic recurrence (defined as Rutgeerts score ≥ i2b) at 6 months. Secondary outcomes are postoperative morbidity, gastrointestinal function, quality of life (QoL) and costs.

DISCUSSION

The research question addresses a knowledge gap within the general practice elucidating which type of anastomosis is superior in terms of endoscopic and clinical recurrence, functionality, QoL and health care consumption. The results of the proposed study might change current practice in contrast to what is advised by the guidelines.

TRIAL REGISTRATION

NCT05246917 for HAND2END and NCT05578235 for End2End ( http://www.

CLINICALTRIALS

gov/ ).

Prognostic Value of the Modified Rutgeerts Score for Long-Term Outcomes After Primary Ileocecal Resection in Crohn's Disease

INTRODUCTION

The prognostic value of the modified Rutgeerts score (mRS) in patients with Crohn's disease (CD) needs to be further elucidated. This study assessed the prognostic value of the mRS for long-term outcomes after primary ileocecal resection in patients with CD.

METHODS

Patients with CD after primary ileocecal resection with an available mRS at first postoperative ileocolonoscopy (index mRS) were retrospectively included. The primary outcome was surgical recurrence. Secondary outcomes were clinical recurrence and progression to severe endoscopic recurrence (≥i3). Cox proportional hazard models were used to assess the association between index mRS and outcomes.

RESULTS

Six hundred fifty-two patients were included (mean follow-up: 6.4 years, SD: 4.6). Surgical recurrence rates were 7.7%, 5.3%, 12.9%, 19.1%, 28.8%, 47.8% for index mRS i0, i1, i2a, i2b, i3, and i4, respectively. Clinical recurrence occurred in 42.2% (i0), 53.7% (i1), 58.5% (i2a), 80.2% (i2b), 79.4% (i3), and 95.3% (i4) of patients. Progression to severe endoscopic recurrence occurred in 21.1% (i0), 33.9% (i1), 26.8% (i2a), and 33.3% (i2b) of patients. An index mRS of i2b (adjusted hazard ratio [aHR] 3.0; 1.5-5.6), i3 (aHR 4.0; 2.0-7.9) and i4 (aHR 8.0; 4.0-16.0) were associated with surgical recurrence. An index mRS of i1 (aHR 1.7; 1.2-2.4), i2a (aHR 1.7; 1.2-2.4), i2b (aHR 4.4; 3.2-6.0), i3 (aHR 3.6; 2.5-5.2), and i4 (aHR 7.3; 4.8-10.9) were associated with clinical recurrence. An index mRS of i1 (aHR 2.0; 1.1-3.7) or i2b (aHR 2.5; 1.4-4.6) was associated with progression to severe endoscopic recurrence.

DISCUSSION

The increasing mRS corresponds closely with the risk of surgical and clinical recurrence. An index mRS ≥ i2b is associated with surgical recurrence, an index mRS ≥ i1 is associated with clinical recurrence, and i1 or i2b with progression to severe endoscopic recurrence. These results support tight monitoring of disease activity and treatment optimization in patients with ileal lesions and a more conservative management in patients with anastomotic lesions.

Clinical Update on the Prevention and Management of Postoperative Crohn's Disease Recurrence

PURPOSE OF REVIEW

Despite advances in therapeutics, a significant portion of patients with Crohn's disease still require surgical management. In this article, we present updates to the natural history, prognostication and postoperative monitoring, and novel therapeutics in the prevention and treatment of postoperative Crohn's disease recurrence.

RECENT FINDINGS

Clinical risk factors have been associated with higher rates of postoperative recurrence (POR), and in recent studies demonstrate an increased cumulative risk with presence of additional risk factors. Additional novel clinical, histologic, and "-omic" risk factors for recurrence have recently been elucidated, including the role of the mesentery on recurrence and perioperative intraabdominal septic complications. High-risk patients benefit most from medical prophylaxis, including anti-TNF with or without immunomodulator therapy to prevent recurrence. New biologics such as vedolizumab and ustekinumab have emerging evidence in the use of prophylaxis, especially with recent REPREVIO trial data. Non-invasive disease monitoring, such as cross-sectional enterography, intestinal ultrasound, and fecal calprotectin, have been validated against ileocolonoscopy. Recent advances in the prediction, prevention, and monitoring algorithms of postoperative Crohn's disease may be leading to a reduction in postoperative recurrence. Ongoing trials will help determine optimal monitoring and management strategies for this at-risk population.

Endoscopic Lesions of Postoperative Anastomotic Area in Patients With Crohn's Disease in the Biologic Era: A Japanese Multi-Centre Nationwide Cohort Study

BACKGROUND AND AIMS

Many patients have endoscopic evidence of recurrent Crohn's disease [CD] at 1 year after intestinal resection. These lesions predict future clinical recurrence. We endoscopically evaluated postoperative anastomotic lesions in CD patients from a large cohort of postoperative CD patients.

METHODS

We retrospectively enrolled CD patients who underwent surgical resection between 2008 and 2013 at 19 inflammatory bowel disease [IBD]-specialist institutions. The initial analyses included patients who underwent ileocolonoscopy ~1 year after intestinal resection. Follow-up analyses assessed any changes in the endoscopic findings over time. We evaluated the postoperative endoscopic findings, which were classified into four categories [no lesion, mild, intermediate, severe] at the sites of the anastomotic line and peri-anastomosis.

RESULTS

In total, 267 CD patients underwent postoperative ileocolonoscopy. Postoperative anastomotic lesions were widely detected in index ileocolonoscopy [61.0%] and were more frequently detected in follow-up ileocolonoscopy [74.9%]. Endoscopic severity also increased. Patients with intermediate or severe peri-anastomotic or anastomotic line lesions at the index ileocolonoscopy required significantly more interventions, including endoscopic dilatation or surgery, than patients with mild lesions or no lesions.

CONCLUSIONS

Frequent anastomotic lesions were observed at the postoperative index ileocolonoscopy. These gradually increased for subsequent ileocolonoscopy, even in the biologic era. Regarding lesions on the anastomotic line, intermediate lesions on the anastomotic line [e.g. irregular or deep ulcers] might be considered recurrent disease, and mild lesions [e.g. linear superficial ulcers] might be considered non-recurrent disease. Prospective studies are needed to resolve this issue, including treatment enhancement.

The Management of Postoperative Recurrence in Crohn's Disease

Crohn's disease (CD) is a chronic inflammatory bowel disease with different phenotypes of presentation, inflammatory, penetrating, or stricturing disease, that significantly impacts patient well-being and quality of life. Despite advances in medical therapy, surgery sometimes represents the only treatment to address complications, such as strictures, fistulas, or abscesses. Minimizing postoperative recurrence (POR) remains a major challenge for both clinicians and patients; consequently, various therapeutic strategies have been developed to prevent or delay POR. The current review outlines an updated overview of POR management. We focused on diagnostic assessment, which included endoscopic examination, biochemical analyses, and cross-sectional imaging techniques, all crucial tools used to accurately diagnose this condition. Additionally, we delved into the associated risk factors contributing to POR development. Furthermore, we examined recent advances in the prophylaxis and treatment of POR in CD.

Rates of Endoscopic Recurrence In Postoperative Crohn's Disease Based on Anastomotic Techniques: A Systematic Review And Meta-Analysis

BACKGROUND

Patients with Crohn's disease (CD) after ileocolic resection may develop an endoscopic postoperative recurrence (ePOR) that reaches 40% to 70% of incidence within 6 months. Recently, there has been growing interest in the potential effect of anastomotic configurations on ePOR. Kono-S anastomosis has been proposed for reducing the risk of clinical and ePOR. Most studies have assessed the association of ileocolonic anastomosis and ePOR individually, while there is currently limited data simultaneously comparing several types of anastomosis. Therefore, we performed a systematic review and meta-analysis to assess the impact of different ileocolonic anastomosis on ePOR in CD.

METHODS

We searched PubMed and Embase from inception to January 2023 for eligible studies reporting the types of anastomoses and, based on these, the rate of endoscopic recurrence at ≥6 months. Studies were grouped by conventional anastomosis, including side-to-side, end-to-end, and end-to-side vs Kono-S, and comparisons were made between these groups. Pooled incidence rates of ePOR were computed using random-effect modelling.

RESULTS

Seventeen studies, with 2087 patients who underwent ileocolic resection for CD were included. Among these patients, 369 (17,7%) Kono-S anastomoses were performed, while 1690 (81,0%) were conventional ileocolic anastomosis. Endoscopic postoperative recurrence at ≥6 months showed a pooled incidence of 37.2% (95% CI, 27.7-47.2) with significant heterogeneity among the studies (P < .0001). In detail, patients receiving a Kono-S anastomosis had a pooled incidence of ePOR of 24.7% (95% CI, 6.8%-49.4%), while patients receiving a conventional anastomosis had an ePOR of 42.6% (95% CI, 32.2%-53.4%).

CONCLUSIONS

Kono-S ileocolic anastomosis was more likely to decrease the risk of ePOR at ≥6 months compared with conventional anastomosis. Our findings highlight the need to implement the use of Kono-S anastomosis, particularly for difficult to treat patients. However, results from larger randomized controlled trials are needed to confirm these data.

Results of the Eighth Scientific Workshop of ECCO: Diagnosing Postoperative Recurrence of Crohn's Disease After an Ileocolonic Resection With Ileocolonic Anastomosis

Despite the introduction of potent biologic therapies, many patients with Crohn's disease [CD] still require an ileocolonic resection [ICR] during the course of their disease. Furthermore, the need of redo ICR has not decreased over the past few decades, highlighting the need for better strategies to prevent and treat postoperative recurrence [POR]. The first step to develop such a strategy would be to define and standardise the description of POR with adequate diagnostic instruments. In this article, we will describe the different methodologies used to report POR [endoscopic, histological, radiological, biochemical, clinical, and surgical], and review their potential benefits and limitations, as well as the optimal timing of evaluation.

A nomogram incorporating ileal and anastomotic lesions separately to predict the long-term outcome of Crohn's disease after ileocolonic resection

Background

The Rutgeerts score (RS) is widely used to predict postoperative recurrence after ileocolonic resection for Crohn's disease (CD) based on the severity of lesions at the neoterminal ileum and anastomosis (RS i0-i4). However, the value of anastomotic ulcers remains controversial.

Objectives

Our aim was to establish a nomogram model incorporating ileal and anastomotic lesions separately to predict the long-term outcomes of CD after ileal or ileocolonic resection.

Design

A total of 136 patients with CD were included in this retrospective cohort study.

Methods

Consecutive CD patients who underwent ileal or ileocolonic resections with postoperative ileocolonoscopy evaluation within 1 year after the surgery were included. The primary endpoint was postoperative clinical relapse (CR). An endoscopic classification separating ileal and anastomotic lesions was applied (Ix for neoterminal ileum lesions; Ax for anastomotic lesions). A nomogram was constructed to predict CR. The performance of the model was evaluated by the receiver-operating characteristic (ROC) curve and decision curve analysis (DCA).

Results

CR was observed in 47.1% (n = 64) of patients within a median follow-up of 26.9 (interquartile range, 11.4-55.2) months. The risk of CR was significantly higher in patients with an RS ⩾ i2 assessed by the first postoperative endoscopy compared with patients with an RS ⩽ i1 (p < 0.001). Moreover, the cumulative rate of CR was significantly higher in patients with ileal lesions (I1-4) compared with patients without (I0) (p < 0.001). Besides, patients with anastomotic lesions (A1-3) had significantly higher rates of CR than patients without (A0) (p = 0.002). A nomogram, incorporating scores of postoperative ileal or anastomotic lesions, sex, L2-subtype and perianal disease, was established. The DCA analysis indicated that the nomogram had a higher benefit for CR, especially at the timeframe of 24-60 months after index endoscopy, compared to the traditional RS score.

Conclusion

A nomogram incorporating postoperative ileal and anastomotic lesions separately was developed to predict CR in CD patients, which may serve as a practical tool to identify high-risk patients who need timely postoperative intervention.

Stemming the tide with ileocecal Crohn's disease: when is pharmacotherapy enough?

INTRODUCTION

Crohn's disease (CD) mostly affects the terminal ileum and ileocecal region and up to 80% of patients end up requiring surgery. Previously reserved for complicated or refractory forms, surgery is now considered as an alternative to medical treatment in localized ileocecal disease.

AREAS COVERED

This review examines factors associated with response to medical treatment and those associated with the need for surgery in ileocecal CD to identify the patients' profile for whom pharmacotherapy might be enough. Factors associated with the recurrence and the postoperative complications are also reviewed to help the clinician identify patients for whom medical therapy might be preferred.

EXPERT’S OPINION

LIR!C study long-term follow-up data show that 38% of infliximab-treated patients were still treated with infliximab at the end of their follow-up, while 14% had switched to another biologic or had received immunomodulator or corticosteroid and 48% had CD-related surgery. Only the combination with an immunomodulator was associated with a greater likelihood of continuing infliximab. Patients with ileocecal CD for whom pharmacotherapy might be sufficient are probably those with no risk factors for CD-related surgery.In addition, patients with high risk of recurrence or of post-operative complications may benefit more from medical treatment than from surgery.

Increased Primary Bile Acids with Ileocolonic Resection Impact Ileal Inflammation and Gut Microbiota in Inflammatory Bowel Disease

BACKGROUND

Most Crohn's disease [CD] patients require surgery. Ileitis recurs after most ileocolectomies and is a critical determinant for outcomes. The impacts of ileocolectomy-induced bile acid [BA] perturbations on intestinal microbiota and inflammation are unknown. We characterized the relationships between ileocolectomy, stool BAs, microbiota and intestinal inflammation in inflammatory bowel disease [IBD].

METHODS

Validated IBD clinical and endoscopic assessments were prospectively collected. Stool primary and secondary BA concentrations were compared based on ileocolectomy and ileitis status. Primary BA thresholds for ileitis were evaluated. Metagenomic sequencing was use to profile microbial composition and function. Relationships between ileocolectomy, BAs and microbiota were assessed.

RESULTS

In 166 patients, elevated primary and secondary BAs existed with ileocolectomy. With ileitis, only primary BAs [795 vs 398 nmol/g, p = 0.009] were higher compared to without ileitis. The optimal primary BA threshold [≥228 nmol/g] identified ileitis on multivariable analysis [odds ratio = 2.3, p = 0.04]. Microbial diversity, Faecalibacterium prausnitzii and O-acetylhomoserine aminocarboxypropyltransferase [MetY] were decreased with elevated primary BAs. Amongst ileocolectomy patients, only those with elevated primary BAs had diversity, F. prausnitzii and MetY reductions. Those with both ileocolectomy and intermediate [p = 0.002] or high [≥228 nmol/g, p = 9.1e-11]] primary BA concentrations had reduced F. prausnitzii compared to without ileocolectomy. Those with ileocolectomy and low [<29.2 nmol/g] primary BA concentrations had similar F. prausnitzii to those without ileocolectomy [p = 0.13]. MetY was reduced with ileitis [p = 0.02].

CONCLUSIONS

Elevated primary BAs were associated with ileitis, and reduced microbial diversity, F. prausnitzii abundance and enzymatic abundance of MetY [acetate and l-methionine-producing enzyme expressed by F. prausnitzii], and were the only factors associated with these findings after ileocolectomy.

Comparison of the Risk of Crohn's Disease Postoperative Recurrence Between Modified Rutgeerts Score i2a and i2b Categories: An Individual Patient Data Meta-analysis

BACKGROUND

The modified Rutgeerts' score [RS] differentiates i2a-lesions confined to the anastomosis-and i2b-more than five aphthous ulcers in the neoterminal ileum with normal intervening mucosa, with or without anastomotic lesions-categories. Its relevance for the therapeutic management of Crohn's disease [CD] patients after ileocolic resection is still debated. Our objective was to compare the postoperative recurrence risk in patients with an i2a or i2b score, using an individual patient data meta-analysis.

METHODS

We conducted a systematic literature search until July 2020, to identify all relevant studies reporting the i2a/i2b status in the year following ileocolic resection and clinical and/or surgical postoperative CD recurrence in their follow-up. Individual patient-level data were obtained from the corresponding authors. The association between the modified RS and time-to-event was evaluated using a mixed Cox model with the centre as the random effect.

RESULTS

Seven studies published between 2008 and 2019 were included, corresponding to 400 patients: 189 [47%] i2a and 211 [53%] i2b. Median [interquartile range, IQR] time from ileocolic resection to ileocolonoscopy was 6.2 [5.5, 7.9] months and median [IQR] follow-up time after ileocolonoscopy was 4.5 [2.9, 7.3] years. The risk of clinical postoperative recurrence at 1 and 3 years was 11% [6-15%], and 25% [18-32%] in the i2a group versus 9% [5-13%] and 33% [26-41%] in the i2b group [p = 0.63 and p = 0.12, respectively]. No significant difference was observed in terms of time to clinical postoperative recurrence [p = 0.16] or surgical postoperative recurrence [p = 0.87]. Results did not change after excluding patients having initiated an immunosuppressant or a biologic in the 3 months after endoscopy [remaining cohort, n = 361].

CONCLUSIONS

In this individual patient data meta-analysis, no difference was observed between i2a and i2b subcategories with regards to clinical or surgical postoperative recurrence. As we wait for prospective trials, the same treatment strategy could be applied to all patients classified as i2 on the Rutgeerts score.

Prophylactic Medication for the Prevention of Endoscopic Recurrence in Crohn's Disease: a Prospective Study Based on Clinical Risk Stratification

BACKGROUND

To prevent recurrence after ileocolonic resection [ICR] in Crohn's disease [CD], postoperative prophylaxis based on risk stratification is recommended in international guidelines. This study aimed to evaluate postoperative CD recurrence after implementation of a clinical management algorithm and to determine the predictive value of clinical and histological risk factors [RFs].

METHODS

In this multicentre, prospective cohort study, CD patients [≥16 years] scheduled for ICR were included. The algorithm advised no postoperative medication for low-risk patients, and treatment with prophylaxis [immunosuppressant/biological] for high-risk patients [≥1 RF: active smoking, penetrating disease, prior ICR]. Clinical and histological RFs [active inflammation, granulomas, plexitis in resection margins] for endoscopic recurrence [Rutgeerts' score ≥i2b at 6 months] were assessed using logistic regression and ROC curves based on predicted probabilities.

RESULTS

In total, 213 CD patients after ICR were included [age 34.5 years; 65% women] (93 [44%] low-risk; 120 [56%] high-risk: 45 [38%] smoking; 51 [43%] penetrating disease; 51 [43%] prior ICR). Adherence to the algorithm was 82% in low-risk [no prophylaxis] and 51% in high-risk patients [prophylaxis]. Endoscopic recurrence was higher in patients treated without prophylaxis than with prophylaxis in both low [45% vs 16%, p = 0.012] and high-risk patients [49% vs 26%, p = 0.019]. Clinical risk stratification including the prescription of prophylaxis corresponded to an area under the curve [AUC] of 0.70 (95% confidence interval [CI] 0.61-0.79). Clinical RFs combined with histological RFs increased the AUC to 0.73 [95% CI 0.64-0.81].

CONCLUSION

Adherence to this management algorithm is 65%. Prophylactic medication after ICR prevents endoscopic recurrence in low- and high-risk patients. Clinical risk stratification has an acceptable predictive value, but further refinement is needed.

Neutrophil-to-lymphocyte ratio for predicting postoperative recurrence in Crohn's disease patients with isolated anastomotic lesions

Background

Patients with isolated anastomotic lesions (iAL) are common in postoperative Crohn's disease (CD) and have heterogeneous prognosis.

Objectives

To investigate the prognostic value of neutrophil-to-lymphocyte ratio (NLR) in CD patients with iAL.

Design

A bicenter retrospective cohort study.

Methods

CD patients who received ileocolonic resection from 2013 and 2020 and had a modified Rutgeerts score of i2a were recruited. NLR was determined within 1 week around the initial endoscopy after ileocolectomy. The primary outcome was clinical recurrence. Kaplan-Meier method and Cox hazard regression analysis were utilized to assess the association between candidate variables and outcomes of interest.

Results

In total, 411 postoperative CD patients were preliminarily reviewed and 83 patients were eligible. In total, 36 (48.6%) patients experienced clinical recurrence with a median follow-up time of 16.3 (interquartile range, 9.7-26.3) months. NLR > 2.45 and age at surgery >45 years had higher cumulative incidence of clinical recurrence in the Kaplan-Meier analysis. After adjusted for potential confounders, NLR > 2.45 was the only independent risk factor for clinical recurrence, with an adjusted hazard ratio (HR) of 2.88 [95% confidence interval (CI), 1.39-6.00; p = 0.005]. Furthermore, a risk score based on NLR and age at surgery were built to further stratify patients. Compared to those who scored 0, patients with a score of 1 and 2 had an adjusted HR of 2.48 (95% CI, 1.22-5.02) and 6.97 (95% CI, 2.19-22.16) for developing clinical recurrence, respectively.

Conclusions

NLR is a promising prognostic biomarker for CD patients with iAL. The utilization of NLR and the risk score to stratify patients may facilitate the personalized management in patients with iAL.

Post-operative prevention and monitoring of Crohn's disease recurrence

Crohn's disease (CD) and ulcerative colitis (UC) are relapsing and remitting chronic inflammatory diseases of the gastrointestinal tract. Although surgery for UC can provide a cure, surgery for CD is rarely curative. In the past few decades, research has identified risk factors for postsurgical CD recurrence, enabling patient risk stratification to guide monitoring and prophylactic treatment to prevent CD recurrence. A MEDLINE literature review identified articles regarding post-operative monitoring of CD recurrence after resection surgery. In this review, we discuss the evidence on risk factors for post-operative CD recurrence as well as suggestions on post-operative management.

Contemporary Management of Postoperative Crohn's Disease after Ileocolonic Resection

Surgery remains an important treatment modality in the multidisciplinary management of patients with Crohn's disease (CD). To illustrate the recent advances in the management of postoperative CD we outline the contemporary approach to treatment: diagnosing disease recurrence using endoscopy or noninvasive methods and risk stratification underlying decisions to institute treatment. Endoscopic scoring indices are being refined to guide treatment decisions by accurately estimating the risk of recurrence based on endoscopic appearance. The original Rutgeerts score has been modified to separate anastomotic lesions from lesions in the neoterminal ileum. Two further indices, the REMIND score and the POCER index, were recently developed with the same intention. Noninvasive monitoring for recurrence using a method with high negative predictive value has the potential to simplify management algorithms and only perform ileocolonoscopy in a subset of patients. Fecal calprotectin, intestinal ultrasound, and magnetic resonance enterography are all being evaluated for this purpose. The use of infliximab for the prevention of postoperative recurrence is well supported by data, but management decisions are fraught with uncertainty for patients with previous exposure to biologics. Data on the use of ustekinumab and vedolizumab for postoperative CD are emerging, but controlled studies are lacking.

Prevention of post-operative recurrence of Crohn's disease among patients with prior anti-TNFα failure: A retrospective multicenter study

BACKGROUND

Anti-TNFα are recommended for preventing Crohn's disease (CD) postoperative recurrence (POR) in patients with risk factors. However, few data exploring anti-TNFα efficacy in patients with preoperative anti-TNFα failure are available so far.

AIMS

The aim of the present study was to compare the efficacy of anti-TNFα with other biologics and immunosuppressants to prevent POR in this setting.

METHODS

Consecutive CD patients who underwent bowel resection between January 2010 and December 2019 after failure of at least one anti-TNFα were retrospectively included among three tertiary centers if they started a postoperative medical prophylaxis within the three months after index surgery. The main outcome was to compare rates of objective recurrence (endoscopic or radiological recurrence in absence of colonoscopy) between patients treated with an anti-TNFα agent or another treatment as prevention of POR.

RESULTS

Among the 119 patients included, 71 patients received an anti-TNFα (26 infliximab, 45 adalimumab) and 48 another treatment (18 ustekinumab, 7 vedolizumab, 20 azathioprine and 3 methotrexate) to prevent POR. Rates of objective recurrence at two years were 23.9% in patients treated with anti-TNFα and 44.9% in the others (p = 0.011).

CONCLUSION

Anti-TNFα remained an effective option to prevent POR for patients operated upon with previous anti-TNFα failure.

Benefit of risk-stratified prophylactic treatment on clinical outcome in post-operative Crohn's disease

BACKGROUND AND AIMS

While immediate post-operative treatment has shown effectiveness in reducing endoscopic post-operative recurrence (POR), evidence regarding the clinical benefit is limited. We compared rates of clinical POR in Crohn's disease (CD) patients receiving immediate prophylactic treatment with patients receiving endoscopy-driven treatment.

METHODS

We retrospectively collected data from 376 consecutive CD patients that underwent an ileocecal resection with anastomosis between 2007 and 2018 with at least 3 years of follow-up at 3 sites. Subsequently, high- and low-risk patients categorized by established guidelines who underwent endoscopy within 12 months postoperatively were grouped according to a prophylactic- or endoscopy-driven approach and compared for incidence and time till endoscopic- and clinical POR.

RESULTS

Prophylactic treatment reduced rates of- and time till endoscopic POR within 1 year in high-risk (HR 0.48, 95% CI 0.27-0.86, p=0.04, NNT=5) but not low-risk (HR 0.90, 95%CI 0.32-2.56, p=0.85) patients. Conversely, no significant differences in clinical POR within 3 years between prophylactic- and endoscopy-driven low-risk (HR 1.17, 95%CI 0.41-3.29, p=0.75) and high-risk patients were observed (HR 1.06, 95%CI 0.63-1.79, p=0.82, NNT=22). However, a large numerical albeit not statistical significant difference in 3 year clinical POR (28.6% vs. 62.5%, p=0.11) in a subset of high-risk patients with ≥3 or more ECCO-defined risk factors was observed, indicating a cumulative effect of having multiple risk factors.

CONCLUSION

Our observations favor step-up treatment guided by early endoscopic evaluation with prophylactic treatment reserved for carefully selected high-risk patients in order to avoid potential overtreatment of a significant number of patients.

Recommendations for Standardizing Clinical Trial Design and Endoscopic Assessment in Postoperative Crohn's Disease

BACKGROUND

The lack of standardized methods for clinical trial design and disease activity assessment has contributed to an absence of approved medical therapies for the prevention of postoperative Crohn's disease (CD). We developed recommendations for regulatory trial design for this indication and for endoscopic assessment of postoperative CD activity.

METHODS

An international panel of 19 gastroenterologists was assembled. Modified Research and Development/University of California Los Angeles methodology was used to rate the appropriateness of 196 statements using a 9-point Likert scale in 2 rounds of voting. Results were reviewed and discussed between rounds.

RESULTS

Inclusion of patients with a history of completely resected ileocolonic CD in regulatory clinical trials for the prevention of postoperative recurrence was appropriate. Given the absence of approved medical therapies, a placebo-controlled design with a primary end point of endoscopic remission at 52 weeks was appropriate for drug development for this indication; however, there was uncertainty regarding the appropriateness of a coprimary end point of symptomatic and endoscopic remission and the use of currently available patient-reported outcome measures. The modified Rutgeerts Score, endoscopic assessment of the anastomosis, and a minimum of 5cm of neoterminal ileum were also appropriate; although the appropriateness of other indices including the Simple Endoscopic Score for CD for endoscopic assessment of postoperative CD activity was uncertain.

CONCLUSIONS

A framework for regulatory trial design for the prevention of postoperative CD recurrence and endoscopic assessment of disease activity has been developed. Research to empirically validate end points for these trials is needed.

Identification of Gene Expression Profiles Associated with an Increased Risk of Post-Operative Recurrence in Crohn's Disease

BACKGROUND AND AIMS

Ileocolonic resection is frequently needed in the course of Crohn's disease [CD] treatment and post-operative recurrence is extremely common. Our main objective was to analyse gene expression in the mucosa of CD patients at the time of surgery and at post-operative endoscopy, in order to identify predictors and mechanisms of early endoscopic recurrence.

METHODS

We conducted transcriptome analyses on ileal mucosa samples collected from inflamed sections of the surgical specimens [n = 200], from ileal resection margins [n = 149] and in the neo-terminal ileum 6 months after surgery [n = 122]; these were compared with non-inflammatory bowel disease controls [n = 25]. The primary endpoint was post-operative endoscopic recurrence at 6 months. We applied regression models to identify gene signatures predicting endoscopic recurrence.

RESULTS

Chronic inflammation was associated with strong expression of inflammatory genes [IL-6, IL-8, IL-1B] and decreased expression of genes involved in metabolic processes, but with a high inter-individual heterogeneity. Gene signatures associated with early endoscopic recurrence were mainly characterized by upregulation of TNFα, IFNγ, IL23A and IL17A. Pathway analyses showed that upregulation of mitochondrial dysfunction within the inflamed sections and JAK/STAT at the ileal margin were predictive of post-operative recurrence. A combined model integrating these top pathway signatures improved the prediction of endoscopic recurrence [area under the curve of 0.79]. STAT3 phosphorylation at the surgical ileal margin was associated with severe recurrence at 6 months.

CONCLUSION

We identified several biological pathways in surgical ileal mucosa specimens associated with an increased risk of disease recurrence. Integration of the JAK/STAT and mitochondrial dysfunction pathways in the clinical model improved the prediction of post-operative recurrence.

Mild neoterminal ileal post-operative recurrence of Crohn's disease conveys higher risk for severe endoscopic disease progression than isolated anastomotic lesions

There are conflicting data assessing the impact of isolated post-operative anastomotic inflammation on future disease progression. The aim of this study was to determine the relative risk of severe disease progression in post-operative Crohn's disease (CD) patients with isolated anastomotic disease.

METHODS

Retrospective cohort study of adult CD patients undergoing ileocolonic resection between 2009 and 2020. Patients with a post-operative ileocolonoscopy ≤18 months from surgery and ≥1 subsequent ileocolonoscopy were included. Disease activity was assessed using the modified Rutgeerts' score (RS). Primary outcome was severe endoscopic progression, defined as i3 or i4 disease, on immediate subsequent ileocolonoscopy and during entire post-operative follow-up. Secondary outcome was surgical recurrence.

RESULTS

One hundred and ninety-nine CD patients had an ileocolonoscopy ≤18 months from surgery, index RS of i0-i2b and ≥1 subsequent ileocolonoscopy. At index ileocolonoscopy, 34.7% had i0 disease, 16.1% i1, 24.6% i2a and 24.6% i2b. On multivariable logistic regression, i2b disease was associated with severe endoscopic progression compared to i0 or i1 (aOR 5.53; P < 0.001) and i2a disease patients (aOR 2.63; P = 0.03). However, i2a disease did not confer increased risk compared to i0 or i1 disease (P = 0.09). Furthermore, i2b patients experienced severe endoscopic progression significantly earlier than i0 or i1 disease (aHR 4.68; P < 0.001), whereas i2a disease did not differ from i0 or i1 disease (P = 0.25). Surgical recurrence was not associated with index RS i0-i2b (P = 0.86).

CONCLUSION

Post-operative ileal disease recurrence, not isolated anastomotic inflammation, confers increased risk for severe endoscopic disease progression. Location of CD recurrence may impact optimal management strategies.

What's New in the Postoperative Management of Crohn's Disease?

Patients with Crohn's disease (CD) often require surgical resection due to complications, such as strictures and abscesses, or disease refractory to medical therapy. To understand the evolving management of patients with CD after surgery, we outline the risk factors for postoperative recurrence, advances in postoperative endoscopic evaluation and characterization of recurrence, noninvasive methods of assessing postoperative recurrence, use of postoperative prophylactic medical therapy including newer biologics, and novel surgical methods to reduce postoperative recurrence. The Rutgeerts score (RS) was developed to predict progression of disease based on endoscopic appearance postoperatively and to guide medical therapy. However, this scoring system groups ileal and anastomotic lesions into the same category. A modified RS was developed to separate lesions isolated to the anastomosis and those in the neo-terminal ileum to further understand the role of anastomotic lesions in CD progression. Additional scoring systems have also been evaluated to better understand these differences. In addition, noninvasive diagnostic methods, such as small bowel ultrasound, have high sensitivity and specificity for the detection of postoperative recurrence and are being evaluated as independent methods of assessment. Studies have also shown a reduction in endoscopic recurrence with postoperative anti-TNFα therapy. However, preoperative exposure to anti-TNFα therapy may impact postoperative response to these medications, and therefore, determining optimal postoperative prophylaxis strategy for biologic-experienced patients requires further exploration. Lastly, new surgical modalities to reduce postoperative recurrence are currently being investigated with preliminary data suggesting that an antimesenteric functional end-to-end anastomosis (Kono-S) may decrease postoperative recurrence.

Split stoma with delayed anastomosis may be preferred for 2-stage surgical resection in high-risk patients with Crohn's disease

BACKGROUND

Fecal diversion after bowel resection is a safe and effective procedure in high-risk patients with Crohn's disease, but the better approach between primary anastomosis with protective stoma and split stoma with delayed anastomosis has not yet been investigated. This study aimed to compare the outcomes of these approaches in high-risk patients with Crohn's disease.

METHODS

A retrospective investigation on consecutive high-risk patients with Crohn's disease was conducted at a tertiary referral hospital from August 2009 to March 2019. The primary outcomes were the overall early postoperative complications and overall anastomosis-related adverse events in an intention-to-treat approach.

RESULTS

A total of 118 consecutive patients who underwent 121 surgeries (35 procedures with a protective stoma and 86 procedures with a split stoma) were enrolled. After a median follow-up period of 659 days and 728 days, respectively, 25 patients underwent a stoma-reversal procedure in the protective-stoma group, and 54 patients underwent delayed anastomosis in the split stoma group. Overall, early 30-day surgical morbidity and anastomosis-related adverse events were observed in more patients in the protective-stoma group than in the split-stoma group (51.4% [18/35] vs 30.2% [26/86]; P = .028 and 37.1% [13/35] vs 2.3% [2/86]; P < .001, respectively; intention-to-treat analysis). Similar results were found in the per-protocol analysis (44.0% [11/25] vs 20.4% [11/54]; P = .029 and 36.0% [12/25] vs 3.7% [2/54]; P < .001, respectively.) CONCLUSION: Split stoma with delayed anastomosis is associated with a reduction in anastomotic adverse events and overall early surgical complications and thus may be a better surgical option for high-risk patients with Crohn's disease.

Positive histologic margins is a risk factor of recurrence after ileocaecal resection in Crohn's disease

INTRODUCTION

Surgical resection is not curative in Crohn's disease (CD) and, recurrence after surgery is a common situation. The identification of patients at high risk of recurrence remains disappointing in clinical practice.

OBJECTIVE

To evaluate the impact of residual microscopic disease on margins on the risk of recurrence after ileocaecal resection in CD.

PATIENTS AND METHODS

All patients who underwent ileocaecal resection between January 1992 and December 2016 were prospectively identified. Demographic data, clinical, surgical and histological variables were retrospectively collected. Positive histologic margin was assessed prospectively and defined by the presence of acute inflammatory lesions on margins: erosion, ulceration, chorion infiltration by neutrophils, cryptic abscesses or cryptitis.

RESULTS

One hundred twenty five patients were included, with a median follow-up of 8 years (Interquartile Range (IQR), 4.3-15.2). Half (49.6%, n = 62) were women, and the median age at surgery was 33 years (IQR, 24-42). Fifty-six (44.8%) had positive inflammatory margins. Five years after surgery, respectively 29 (51%) and 23 (34%) patients with positive and negative margins had clinical recurrence (p = 0.034). At the end of the follow-up, respectively 60% (n = 34) and 47% (n = 33) patients had clinical recurrence (p = 0.07). CD-related hospitalizations were observed in respectively 37.5% (n = 21) and 18.8% (n = 13) with positive and negative margins (p = 0.02). Fourteen patients (25%) with positive intestinal margins had surgical recurrence at the end of the follow-up compared to 5 patients (7%) with negative margins (p = 0.04). Multivariate analysis confirmed that positive intestinal margin was independently associated with surgical recurrence (OR, 4.7 (CI95%, 1.4-15.3), p = 0.01).

CONCLUSION

Positive histologic margin was associated with an increased risk of clinical and surgical recurrence after ileocaecal resection for Crohn's disease.

Anti -TNFα agents in preventing the postoperative recurrence of Crohn's disease: Do they still play a role in the biological era?

BACKGROUND

Approximately half of patients with Crohn's disease (CD) may inevitably receive surgical intervention as the disease progress. However, about 75% of CD patients will experience postoperative recurrence (POR). Biologics are appealing alternatives for the prevention of POR; however, it is still unclear which biological agents are more efficient. This meta-analysis aimed to investigate the efficacy of biologics for POR prevention and to compare the superiority of different biologics.

METHODS

We conducted a thorough search of online databases and screened for studies on the efficacy of biologics in preventing POR (clinical, endoscopic, or histological) that were published until January 2021. The results were presented as forest plots and odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

We included 26 studies with 2,136 participants. Overall, biologics were more efficient over non-biological treatments in preventing endoscopic, severe endoscopic, and clinical POR without increasing the frequency of adverse events. Among the various types of biologics, anti-TNFα agents were better than vedolizumab in preventing endoscopic POR. Moreover, infliximab had a similar curative effect to adalimumab in preventing endoscopic, severe endoscopic, and clinical recurrence.

CONCLUSION

Biologics, especially anti-TNFα agents, still play a vital role in preventing POR in the biological era.

Endoscopic Evaluation and Therapeutic Considerations of Small Bowel Crohn’s Disease

Small bowel evaluation is warranted in all newly diagnosed cases of Crohn’s disease (CD) as small bowel is involved in two-thirds of CD patients at diagnosis and the involvement can be discontinuous. Endoscopic evaluation of the small bowel in suspected or established CD can be done by video capsule endoscopy (VCE), device assisted enteroscopy (DAE) (which includes single and double balloon enteroscopy, novel motorized spiral enteroscopy (NMSE) and balloon guided endoscopy (BGE)) and intra-operative enteroscopy (IOE). In suspected CD with a negative ileo-colonoscopy, VCE is the preferred initial diagnostic modality in the absence of obstructive symptoms or known stenosis. VCE should be preceded by cross-sectional imaging or patency capsule testing if obstruction is suspected given with high retention risk. In established cases, small bowel cross-sectional imaging (magnetic resonance or computed tomography enterography) is preferred over VCE as it can assess transmural and extra-luminal involvement. VCE is indicated subsequently if necessary to assess disease extent, unexplained symptoms (e.g., anemia, malnutrition) or mucosal healing. Pan-enteric capsule endoscopy (PCE) and the use of artificial intelligence are the recent developments with VCE. DAE with small bowel biopsy can provide definitive evidence of CD including the extent and severity. A final diagnosis of CD is based on the constellation of clinical, radiologic, histologic and endoscopic features. Newer technologies like NMSE and BGE can help with deeper and faster small bowel evaluation. DAE has also allowed endoscopic treatment of small bowel strictures, small bowel bleeding and retrieval of retained capsule or foreign bodies. Endoscopic balloon dilation (EBD), endoscopic electro-incision, strictureplasty and stenting have shown promising results in CD related small bowel strictures. In conclusion, endoscopic evaluation of the small bowel is rapidly evolving field that has a major role in diagnosis and management of small bowel CD and can alter treatment outcomes in properly selected patients.

Endoscopic evaluation of surgically altered bowel in inflammatory bowel disease: a consensus guideline from the Global Interventional Inflammatory Bowel Disease Group

The majority of patients with Crohn's disease and a proportion of patients with ulcerative colitis will ultimately require surgical treatment despite advances in diagnosis, therapy, and endoscopic interventions. The surgical procedures that are most commonly done include bowel resection with anastomosis, strictureplasty, faecal diversion, and ileal pouch. These surgical treatment modalities result in substantial alterations in bowel anatomy. In patients with inflammatory bowel disease, endoscopy plays a key role in the assessment of disease activity, disease recurrence, treatment response, dysplasia surveillance, and delivery of endoscopic therapy. Endoscopic evaluation and management of surgically altered bowel can be challenging. This consensus guideline delineates anatomical landmarks and endoscopic assessment of these landmarks in diseased and surgically altered bowel.