Association Between Microscopic Lesions at Ileal Resection Margin and Recurrence After Surgery in Patients With Crohn's Disease

Use of Intraoperative Ultrasonography of the Small Bowel to Reduce Histologically Positive Margins in Crohn's Disease Surgery: A Pilot Study

Background/Objectives: The histological involvement of surgical resection margins in Crohn's disease (CD) is an important risk factor for postoperative recurrence. The aim of this study was to evaluate the usefulness of intraoperative ultrasonography (IOUS) of the small bowel to best identify the surgical site of resection and reduce the rate of the histological involvement of margins. Methods: Consecutive patients who underwent ileocolic surgery for CD were prospectively enrolled (IOUS group) and underwent IOUS to fix the resection site. A control historical group of patients undergoing the same surgical procedures was considered and a 1:1 propensity score matching for location of disease and repeated surgery was performed. The primary endpoint was the histological involvement of resection margins. The secondary endpoint was to assess the feasibility of the method. Results: Twenty-seven patients were enrolled in the IOUS group and twenty-seven were enrolled in the non-IOUS group. The two groups were homogeneous in terms of gender, age, smoking, BMI, behavior of disease, and surgical technique. The IOUS group presented a lower rate of histological positive margins (18.5% vs. 48.1%; p = 0.021). No significant differences were found in terms of mean duration of surgery (IOUS: 254.2 min vs. non-IOUS: 225 min [SD = 49.3-77.8]; p = 0.11) or in terms of mean length of surgical specimen (IOUS: 24.1 cm vs. non-IOUS: 34.1 cm [SD = 13.5-23.1]; p = 0.058). Conclusions: IOUS of the small bowel appears to be a useful tool to obtain a lower rate of histologically positive margins with a comparable duration of surgery and no significant difference in the intestinal specimen length.

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.

Systematic review: Patient-related, microbial, surgical, and histopathological risk factors for endoscopic post-operative recurrence in patients with Crohn's disease

BACKGROUND

Risk stratification for endoscopic post-operative recurrence (ePOR) in Crohn's disease (CD) is required to identify patients who would benefit most from initiation of prophylactic medication and intensive monitoring of recurrence.

AIMS

To assess the current evidence on patient-related, microbial, surgical and histopathological risk factors for ePOR in patients with CD after ileocolic (re-)resection.

METHODS

Multiple online databases (Embase, MEDLINE, Web of Science and Cochrane Library) were searched up to March 2024. Studies with reported associations of patient-related, microbial, surgical and/or histopathological factors for ePOR (i.e., Rutgeerts' score ≥i2 or modified Rutgeerts' score ≥i2a) were included. The risk of bias was assessed with the Newcastle-Ottawa Scale for observational cohort studies and case-control studies.

RESULTS

In total, 47 studies were included (four RCTs, 29 cohort studies, 12 case-control studies, one cross-sectional study and one individual participant data meta-analysis) including 6006 patients (median sample size 87 patients [interquartile range 46-170]). Risk of bias assessment revealed a poor quality in 41% of the studies. An association was reported in multiple studies of ePOR with active smoking at and post-surgery, male sex and prior bowel resection. A heterogeneous association with ePOR was reported for other risk factors included in the current guidelines (penetrating disease, perianal disease, younger age, extensive small bowel disease and presence of granulomas in the resection specimen or myenteric plexitis in the resection margin), and other patient-related, microbial, surgical and histopathological factors.

CONCLUSION

Risk factors for ePOR in international guidelines are not consistently reported as risk factors in current literature except for active smoking and prior bowel resection. To develop evidence-based, personalised strategies, large prospective studies are warranted to identify risk factors for ePOR. Validation studies of promising (bio)markers are also required.

Mechanical stress-induced connective tissue growth factor plays a critical role in intestinal fibrosis in Crohn's-like colitis

Crohn's disease (CD) is an inflammatory bowel disease characterized by transmural inflammation and intestinal fibrosis. Mechanisms of fibrosis in CD are not well understood. Transmural inflammation is associated with inflammatory cell infiltration, stenosis, and distention, which present mechanical stress (MS) to the bowel wall. We hypothesize that MS induces gene expression of profibrotic mediators such as connective tissue growth factor (CTGF), which may contribute to fibrosis in CD. A rodent model of CD was induced by intracolonic instillation of TNBS to the distal colon. TNBS instillation induced a localized transmural inflammation (site I), with a distended colon segment (site P) proximal to site I. We detected significant fibrosis and collagen content not only in site I but also in site P in CD rats by day 7. CTGF expression increased significantly in sites P and I, but not in the segment distal to the inflammation site. Increased CTGF expression was detected mainly in the smooth muscle cells (SMCs). When rats were fed exclusively with clear liquid diet to prevent mechanical distention in colitis, expression of CTGF in sites P and I was blocked. Direct stretch led to robust expression of CTGF in colonic SMC. Treatment of CD rats with anti-CTGF antibody FG-3149 reduced fibrosis and collagen content in both sites P and I and exhibited consistent trends toward normalizing expression of collagen mRNAs. In conclusion, our studies suggest that mechanical stress, by upregulating profibrotic mediators, i.e., CTGF, may play a critical role in fibrosis in CD.NEW & NOTEWORTHY We found that CTGF expression increased significantly not only in the inflammation site but in the distended segment proximal to inflammation in a rodent model of CD-like colitis. Release of mechanical distention prevented CTGF expression in CD rats, whereas direct stretch induced CTGF expression. Treatment with anti-CTGF antibody reduced fibrosis and collagen contents in CD rats. Thus, mechanical stress, via upregulating profibrotic mediators, i.e., CTGF, may play a critical role in fibrosis in CD.

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.

Children with Localized Crohn's Disease Benefit from Early Ileocecal Resection and Perioperative Anti-Tumor Necrosis Factor Therapy

INTRODUCTION

 In pediatric Crohn's disease ileocecal resection is performed reluctantly as postoperative recurrence is frequent. Anti-tumor necrosis factor (TNF) therapy reduces postoperative recurrence rates but increases the risk for infections.

MATERIALS AND METHODS

 We retrospectively reviewed pediatric Crohn's disease patients who underwent ileocecal resection in our center. We compared disease activity and z-scores for height, weight, and body mass index of patients, who continuously received perioperative anti-TNF therapy (TNF + ), with those who did not (TNF-).

RESULTS

 Of 29 patients (48% females), 13 and 16 were grouped to TNF+ and TNF-, respectively. Patients' characteristics did not differ between groups, except a longer follow-up time in TNF-. We saw significant postoperative improvement but no normalization in z-scores for weight (1.78 vs. 0.77, p < 0.001), body mass index (1.08 vs. 0.22, p < 0.001), and height (0.88 vs. 0.66, p < 0.001). Disease activity improved significantly more in patients receiving anti-TNF therapy (moderate improvement in 83% vs. 31%, p = 0.02). Endoscopic recurrence was more frequent in patients without anti-TNF therapy (80% vs. 20%; p = 0.023), but endoscopic follow-up was incomplete. There was no increase of infections under perioperative anti-TNF therapy (1 patient each; p = 1.000).

CONCLUSION

 In patients with localized Crohn's disease an ileocecal resection leads to short-term postoperative improvement of disease activity, body mass index, weight, and growth. For relevant catch-up growth an earlier intervention is necessary. Continuous perioperative anti-TNF therapy had no increased risk of perioperative infections.

Positive resection margins in Crohn's disease are a relevant risk factor for postoperative disease recurrence

Postoperative disease recurrence in Crohn's disease represents a relevant issue despite recent advancements in surgical and medical therapies. Additional criteria are necessary to improve the identification of patients at risk and to enable selective therapeutic approaches. The role of resection margins on disease recurrence remains unclear and general recommendations are lacking. A single-center retrospective analysis was performed including all patients who received ileocecal resection due to Crohn's disease. Resection margins were analyzed by two independent pathologists and defined by histopathological criteria based on previous consensus reports. 158 patients were included for analysis with a median follow up of 35 months. While postoperative morbidity was not affected, positive resection margins resulted in significantly increased rates of severe endoscopic recurrence at 6 months (2.0% versus 15.6%, p = 0.02) and overall (4.2% versus 19.6%, p = 0.001), which resulted in significantly increased numbers of surgical recurrence (0% versus 4.5%, p = 0.04). Additionally, positive margins were identified as independent risk factor for severe endoscopic disease recurrence in a multivariate analysis. Based on that, positive margins represent an independent risk factor for postoperative endoscopic and surgical disease recurrence. Prospective studies are required to determine whether extended resection or postoperative medical prophylaxis is beneficial for patients with positive resection margins.

Management of Post-Operative Crohn's Disease: Knowns and Unknowns

Crohn's disease (CD) is a chronic inflammatory disorder of the gastrointestinal tract characterized by relapsing-remission phases. CD often requires surgical intervention during its course, mainly ileo-cecal/ileo-colonic resection. However, surgery in CD is not curative and post-operative recurrence (POR) can happen. The management of CD after surgery presents challenges. Ensuring timely, effective, and safe therapy to prevent POR is essential but difficult, considering that approximately 20-30% of subjects may not experience endoscopic POR and that 40-50% will only exhibit intermediate lesions, which carry a low risk of mid- and long-term clinical and surgical POR. Currently, there are two accepted intervention strategies: early post-operative prophylactic therapy (systematically or based on the patient's risk of recurrence) or starting therapy after confirming endoscopic POR 6-12 months after surgery (endoscopy-driven prophylactic therapy). The risk of overtreatment lies in exposing patients to undesired adverse events, along with the costs associated with medications. Conversely, undertreatment may lead to missed opportunities to prevent bowel damage and the necessity for additional surgery. This article aims to perform a comprehensive review regarding the optimal strategy to reduce the risk of POR in CD patients and the current therapeutic options.

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/ ).

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.

Positive margins and plexitis increase the risk of recurrence after ileocecal resection: A systematic review and meta-analysis

INTRODUCTION

There is debate over the impact of residual microscopic disease after ileocecal resection in Crohn's disease (CD) to predict recurrence. We conducted a meta-analysis to evaluate the impact of positive histological margins and plexitis after ileocecal resection on the risk of postoperative recurrence.

METHODS

Using a systematic search, we identified. 30 studies evaluating the impact of inflammatory margins on CD recurrence. The primary outcome was the postoperative clinical recurrence and secondary outcomes were surgical, and endoscopic recurrence. We performed random-effects meta-analysis and estimated odds ratio (OR) and 95% CIs.

RESULTS

Thirty studies were analyzed, seven focused on myenteric plexitis, six on submucosal plexitis and twenty-three on positive margins. Inflammatory margins were associated with a higher rate of clinical and surgical recurrences: respectively 14 studies - OR 2.38; 95% CI, 1.54 - 3.68- I2 = 68.2%, Q test-p = 0.0003 and 8 studies - OR, 1.52; 95% CI, 1.07-2.16 - I2 =0%; Q test-p = 0.43. The presence of myenteric plexitis was associated with a higher rate of clinical recurrence (4 studies- OR, 1.60; 95%CI, 1.12-2.29; I2= 0%, Q-test-p = 0.61), and of endoscopic recurrence (4 studies - OR, 4.25; 95%CI; 2.06-8.76; I2= 0%, Q test-p = 0.97). Submucosal plexitis was not associated with an increased risk of endoscopic recurrence (4 studies - OR, 0.94; 95%CI; 0.58-1.52; I2= 0%, Q test-p = 0.79).

CONCLUSION

Inflammatory margins and/or plexitis were associated with postoperative recurrence after ileocecal resection for CD. These elements should be taken into account in future algorithm for prevention of postoperative recurrence.

Results of the Eighth Scientific Workshop of ECCO: Pathophysiology and Risk Factors of Postoperative Crohn's Disease Recurrence after an Ileocolonic Resection

Postoperative recurrence [POR] after an ileocolonic resection with ileocolonic anastomosis is frequently encountered in patients with Crohn's disease. The 8th Scientific Workshop of ECCO reviewed the available evidence on the pathophysiology and risk factors for POR. In this paper, we discuss published data on the role of the microbiome, the mesentery, the immune system and the genetic background. In addition to investigating the causative mechanisms of POR, identification of risk factors is essential to tailor preventive strategies. Potential clinical, surgical and histological risk factors are presented along with their limitations. Emphasis is placed on unanswered research questions, guiding prevention of POR based on individual patient profiles.

Identification of Potential Genes and Critical Pathways in Postoperative Recurrence of Crohn's Disease by Machine Learning And WGCNA Network Analysis

Background

Crohn's disease (CD) is a chronic idiopathic inflammatory bowel disease affecting the entire gastrointestinal tract from the mouth to the anus. These patients often experience a period of symptomatic relapse and remission. A 20 - 30% symptomatic recurrence rate is reported in the first year after surgery, with a 10% increase each subsequent year. Thus, surgery is done only to relieve symptoms and not for the complete cure of the disease. The determinants and the genetic factors of this disease recurrence are also not well-defined. Therefore, enhanced diagnostic efficiency and prognostic outcome are critical for confronting CD recurrence.

Methods

We analysed ileal mucosa samples collected from neo-terminal ileum six months after surgery (M6=121 samples) from Crohn's disease dataset (GSE186582). The primary aim of this study is to identify the potential genes and critical pathways in post-operative recurrence of Crohn's disease. We combined the differential gene expression analysis with Recursive feature elimination (RFE), a machine learning approach to get five critical genes for the postoperative recurrence of Crohn's disease. The features (genes) selected by different methods were validated using five binary classifiers for recurrence and remission samples: Logistic Regression (LR), Decision tree classifier (DT), Support Vector Machine (SVM), Random Forest classifier (RF), and K-nearest neighbor (KNN) with 10-fold cross-validation. We also performed weighted gene co-expression network analysis (WGCNA) to select specific modules and feature genes associated with Crohn's disease postoperative recurrence, smoking, and biological sex. Combined with other biological interpretations, including Gene Ontology (GO) analysis, pathway enrichment, and protein-protein interaction (PPI) network analysis, our current study sheds light on the in-depth research of CD diagnosis and prognosis in postoperative recurrence.

Results

PLOD2, ZNF165, BOK, CX3CR1, and ARMCX4, are the important genes identified from the machine learning approach. These genes are reported to be involved in the viral protein interaction with cytokine and cytokine receptors, lysine degradation, and apoptosis. They are also linked with various cellular and molecular functions such as Peptidyl-lysine hydroxylation, Central nervous system maturation, G protein-coupled chemoattractant receptor activity, BCL-2 homology (BH) domain binding, Gliogenesis and negative regulation of mitochondrial depolarization. WGCNA identified a gene co-expression module that was primarily involved in mitochondrial translational elongation, mitochondrial translational termination, mitochondrial translation, mitochondrial respiratory chain complex, mRNA splicing via spliceosome pathways, etc.; Both the analysis result emphasizes that the mitochondrial depolarization pathway is linked with CD recurrence leading to oxidative stress in promoting inflammation in CD patients.

Conclusion

These key genes serve as the novel diagnostic biomarker for the postoperative recurrence of Crohn's disease. Thus, among other treatment options present until now, these biomarkers would provide success in both diagnosis and prognosis, aiming for a long-lasting remission to prevent further complications in CD.

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.

Effect of anastomotic configuration on Crohn's disease recurrence after primary ileocolic resection: a comparative monocentric study of end-to-end versus side-to-side anastomosis

There is ongoing debate whether the type of anastomosis following intestinal resection for Crohn's disease (CD) can impact on complications and postoperative recurrence. The aim of the present study is to describe the outcomes of side-to-side (S-S) vs end-to-end (E-E) anastomosis after ileocecal resection for CD. A retrospective comparative study was conducted in consecutive CD patients who underwent primary ileocecal resection between 2005 and 2013. All patients underwent colonoscopy 6 months postoperatively to assess endoscopic recurrence, defined as Rutgeerts' score (RS) ≥ i2. Surgical recurrence implied reoperation due to CD activity at the anastomotic site. Modified surgical recurrence was defined as the need for reoperation or balloon-dilation. Perioperative factors related to recurrence were evaluated. Of the 127 patients included, 51 (40.2%) received an E-E anastomosis. Median follow-up was longer in the E-E group (8.62 vs 13.68 years). Apart from the microscopic resection margins, patient, disease and surgical characteristics were similar between both groups. Anastomotic complications were comparable (S-S 5.3% vs E-E 5.8%, p = 1.00)0. Postoperatively, biologicals were used in 55.3% and 62.7% (p = 0.47) in S-S and E-E patients, respectively. Endoscopic recurrence did not differ between S-S and E-E patients (78.9 vs 72.9%, p = 0.37), with no significant difference in RS values between both groups (p = 0.87). Throughout follow-up, a higher surgical (p = 0.04) and modified surgical recurrence (p = 0.002) rate was observed in the E-E anastomosis group. Type of anastomosis was an independent risk factor for modified surgical recurrence. The type of anastomosis did not influence endoscopic recurrence and immediate postoperative disease complications. However, the wide diameter and the morphologic characteristic of the stapled S-S anastomosis resulted in a significant reduced risk for surgical and endoscopic reintervention on the long term.

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.

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.

Predictive Factors of Surgical Recurrence in Patients with Crohn's Disease on Long-Term Follow-Up: A Focus on Histology

In patients with Crohn’s disease (CD) that underwent surgery, predictive factors of surgical recurrence have been only partially identified. The aim of our study was to identify potential factors associated with an increased risk of surgical recurrence. A monocentric retrospective observational study was conducted including patients diagnosed with CD, according to ECCO criteria who received their first ileocolic resection. Overall, 162 patients were enrolled in our study; 54 of them were excluded due to a lack of sufficient data. The median follow-up was 136.5 months, IQR 91.5−176.5, and the surgical recurrence rate after the median follow-up was 21.3%. In the multivariate analysis, an age ≤ 28 years at the first surgical resection (aHR = 16.44, p < 0.001), current smoking (aHR = 15.84, p < 0.001), female sex (aHR = 7.58, p < 0.001), presence of granulomas at local lymph nodes (aHR = 12.19, p < 0.001), and treatment with systemic corticosteroids after the first surgical resection (aHR = 7.52, p = 0.002) were factors significantly associated with a risk of surgical recurrence, while cryptitis resulted in a protective factor (aHR = 0.02, p < 0.001). In conclusion, the heterogeneous spectrum of factors associated to the risk of surgical recurrence in patients with CD that underwent ileocolic resection supports the need of a personalized follow-up taking into account different clinical, surgical, and histologic features.

State-of-the-art surgery for Crohn's disease: Part I-small intestine/ileal disease

The management of Crohn's disease has evolved significantly over the past 20 years. The arrival of biologic therapies has altered not only the management and outcomes but also rates for refractory disease requiring surgery. New surgical techniques have paralleled these medical advances, and this article will provide an overview of these new modalities as well as their outcomes. This is the first of a three-part series and will focus on terminal ileal and ileocolic disease.

The Revival of Surgery in Crohn's Disease-Early Intestinal Resection as a Reasonable Alternative in Localized Ileitis

Crohn's disease (CD) represents a heterogeneous and complex disease with no curative therapeutic option available to date. Current therapy is mainly antibody-based focusing on the immune system while other treatment alternatives such as surgery are considered to be "last options". However, medical therapy for CD results in mild to severe side effects in a relevant amount of patients and some patients do not respond to the medication. Following that, quality of life is often significantly reduced in this patient cohort, thus, therapeutic alternatives are urgently needed. Updated evidence has revealed that surgery such as ileocecal resection (ICR) might be a potential therapeutic option in case of localized terminal ileitis since resection at early time points improves quality of life and significantly reduces the postoperative need for immunosuppressive medication with low rates of morbidity. In addition, new surgical approaches such as Kono-S anastomosis or inclusion of the mesentery result in significantly reduced rates of disease recurrence and reoperation. Based on the new evidence, the goal of this review is to provide an update on the role of surgery as a reasonable alternative to medical therapy in the interdisciplinary treatment of patients with CD.

The Relationship Between Endoscopic and Clinical Recurrence in Postoperative Crohn's Disease: A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

We aimed to quantify the magnitude of the association between endoscopic recurrence and clinical recurrence [symptom relapse] in patients with postoperative Crohn's disease.

METHODS

Databases were searched to October 2, 2020, for randomised controlled trials [RCTs] and cohort studies of adult patients with Crohn's disease with ileocolonic resection and anastomosis. Summary effect estimates for the association between clinical recurrence and endoscopic recurrence were quantified by risk ratios [RR] and 95% confidence intervals [95% CI]. Mixed-effects meta-regression evaluated the role of confounders. Spearman correlation coefficients were calculated to assess the relationship between these outcomes as endpoints in RCTs. An exploratory mixed-effects meta-regression model with the logit of the rate of clinical recurrence as the outcome and the rate of endoscopic recurrence as a predictor was also evaluated.

RESULTS

In all, 37 studies [N = 4053] were included. For eight RCTs with available data, the RR for clinical recurrence for patients who experienced endoscopic recurrence was 10.77 [95% CI 4.08 to 28.40; GRADE moderate certainty evidence]; the corresponding estimate from 11 cohort studies was 21.33 [95% CI 9.55 to 47.66; GRADE low certainty evidence]. A single cohort study showed a linear relationship between Rutgeerts score and clinical recurrence risk. There was a strong correlation between endoscopic recurrence and clinical recurrence treatment effect estimates as trial outcomes [weighted Spearman correlation coefficient 0.51].

CONCLUSIONS

The associations between endoscopic recurrence and subsequent clinical recurrence lend support to the choice of endoscopic recurrence to monitor postoperative disease activity and as a primary endpoint in clinical trials of postoperative Crohn's disease.

Active Margins, Plexitis, and Granulomas Increase Postoperative Crohn's Recurrence: Systematic Review and Meta-analysis

BACKGROUND & AIMS

Rates of postoperative Crohn's disease recurrence remain high, although the ability to predict this risk of recurrence remains limited. As such, we aimed to determine the association of histologic features at the time of resection with postoperative recurrence.

METHODS

Electronic databases were searched through February 2020 for studies that reported risk of clinical, endoscopic, or surgical postoperative recurrence in patients with positive resection margins, plexitis, or granulomas in the index specimen. Pooled risk ratios (RRs) with 95% CIs were calculated for this risk in patients with and without these histologic features.

RESULTS

Twenty-one studies (2481 patients) assessed positive resection margins, 10 studies (808 patients) assessed plexitis, and 19 studies (1777 patients) assessed granulomas. Positive resection margins increased the risk of clinical (RR, 1.26; 95% CI, 1.06-1.49; I2 = 41%) and surgical (RR, 1.87; 95% CI, 1.14-3.08; I2 = 71%) recurrence, with a trend toward endoscopic recurrence (RR, 1.56; 95% CI, 0.79-3.05; I2 = 85%). Granulomas increased the risk of clinical (RR, 1.31; 95% CI, 1.05-1.64; I2 = 36%) and endoscopic (RR, 1.37; 95% CI, 1.00-1.87; I2 = 49%) recurrence, with a trend toward surgical recurrence (RR, 1.58; 95% CI, 0.89-2.80; I2 = 75%). Plexitis increased the risk of endoscopic recurrence (RR, 1.31; 95% CI, 1.00-1.72; I2 = 20%), with a trend toward clinical recurrence (RR, 1.34; 95% CI, 0.95-1.91; I2 = 46%).

CONCLUSIONS

Positive resection margins, granulomas, and plexitis are predictive of postoperative Crohn's disease recurrence and should be recorded at the time of index resection.

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

INTRODUCTION

Early ileocolonoscopy within the first year after surgery is the gold standard to evaluate recurrence after ileocolonic resection for Crohn's disease (CD). The aim of the study was to evaluate the association between the presence and severity of anastomotic and ileal lesions at early postoperative ileocolonoscopy and long-term outcomes.

METHODS

The REMIND group conducted a prospective multicenter study. Patients operated for ileal or ileocolonic CD were included. An ileocolonoscopy was performed 6 months after surgery. An endoscopic score describing separately the anastomotic and ileal lesions was built. Clinical relapse was defined by the CD-related symptoms, confirmed by imaging, endoscopy or therapeutic intensification; CD-related complications; or subsequent surgery.

RESULTS

Among 225 included patients, long-term follow-up was available in 193 (median follow-up: 3.82 years [interquartile range: 2.56-5.41]). Median clinical recurrence-free survival was 47.6 months. Clinical recurrence-free survival was significantly shorter in patients with ileal lesions at early postoperative endoscopy whatever their severity was (I(1) or I(2,3,4)) as compared to patients without ileal lesions (I(0)) (I(0) vs I(2,3,4): P = 0.0003; I(0) vs I(1): P = 0.0008 and I(1) vs I(2,3,4): P = 0.43). Patients with exclusively ileal lesions (A(0)I(1,2,3,4)) had poorer clinical long-term outcomes than patients with exclusively anastomotic lesions (A(1,2,3)I(0)) (P = 0.009).

DISCUSSION

A score describing separately the anastomotic and ileal lesions might be more appropriate to define postoperative endoscopic recurrence. Our data suggest that patients with ileal lesions, including mild ones (I(1)), could beneficiate from treatment step-up to improve long-term outcomes.

Pharmacological Prevention and Management of Postoperative Relapse in Pediatric Crohn's Disease

Pediatric Crohn's disease (CD) is characterized by an aggressive course that commonly requires more intensive pharmacological and surgical treatments. In spite of the therapeutic advances in monitoring and management, including the widespread use of biologic therapy, the cumulative incidence of surgery in children with CD is still high. However, surgery is usually not curative and disease recurrence after small bowel resection is common. Gastrointestinal endoscopy is currently the gold standard to evaluate disease progression after surgery, but other non-invasive methods have been suggested. Although the efficacy of several drugs as medical prophylaxis to reduce the rate of disease recurrence following intestinal resection has been evaluated, selecting the most appropriate preventive therapeutic intervention remains a challenge. The current recommendations, mostly based on adult studies due to limited pediatric data, state that treatment should be guided by risk for recurrence. Low-risk patients may be given no prophylaxis or only 5-ASA. Maintenance enteral nutrition may also be considered. Thiopurines may be used in moderate risk of CD recurrence. In high risk patients for postoperative recurrence (extensive disease, short disease duration from diagnosis to surgery, recurrent surgery, long resected segment, surgery for fistulizing disease, disease complications, perianal disease, smoking), prophylactic treatment with anti-TNFα is recommended. subsequently, therapy should be guided by repeated measurement of objective measures including endoscopic re-evaluation at 6-12 months following surgery.