Inclusion of the Mesentery in Ileocolic Resection for Crohn's Disease is Associated With Reduced Surgical Recurrence

Prophylaxis of Crohn's disease recurrence: A surgeon's perspective

Management of inflammatory bowel disease has evolved extensively in the last three decades. We have learnt a lot about the pathophysiology and natural history of the disease. New effective classes of drugs with the associated potential morbidity have been introduced. New surgical techniques have been popularized leading to a better understanding of the optimal timing of surgery. The result is a very complex subspecialty of gastroenterology and colorectal surgery called the "IBDologist." Only if we manage these complex patients in the context of a multi-disciplinary team will we be able to obtain outstanding outcomes, specifically with high and sustained remission rates for these patients.

Perioperative management of ileocecal Crohn's disease in the current era

INTRODUCTION

The ileocecal region is most commonly involved in patients with Crohn's disease (CD).

AREAS COVERED

In the management of ileocecal CD, this review discusses the underlying clinical issues with perioperative management and surgical intervention.

EXPERT OPINION

Despite advances in medical treatments, surgery is required in a proportion of patients. Preoperative optimization including weaning of corticosteroids, initiation of enteral feeds, venous thromboembolism prophylaxis and smoking cessation may lead to improved postoperative outcomes. Several surgical approaches regarding anastomotic technique and range of mesentery division are now attempted to reduce the incidence of postoperative recurrence. Disease recurrence is common after surgery for CD. Early endoscopic assessment and subsequent treatment adjustment are optimal strategies for the prevention of recurrence after ileocolonic resection.

Anatomical Variation in Mesenteric Macrophage Phenotypes in Crohn's Disease

INTRODUCTION

Clinical trials are currently investigating whether an extended mesenteric resection for ileocecal resections could reduce postoperative recurrence in Crohn's disease. Resection of the mesorectum, which contains proinflammatory macrophages, during proct(ocol)ectomy, is associated with reduced recurrent inflammation and improved wound healing. We aimed to characterize the macrophages in the ileocecal mesentery, which were compared with those in the mesorectum, to provide a biological rationale for the ongoing trials.

METHODS

In 13 patients with Crohn's disease and 4 control patients undergoing a proctectomy, tissue specimens were sampled at 3 locations from the mesorectum: distal (rectum), middle, and proximal (sigmoid). In 38 patients with Crohn's disease and 7 control patients undergoing ileocecal resections, tissue specimens also obtained from 3 locations: adjacent to the inflamed terminal ileum, adjacent to the noninflamed ileal resection margin, and centrally along the ileocolic artery. Immune cells from these tissue specimens were analyzed by flow cytometry for expression of CD206 to determine their inflammatory status.

RESULTS

In the mesorectum, a gradient from proinflammatory to regulatory macrophages from distal to proximal was observed, corresponding to the adjacent inflammation of the intestine. By contrast, the ileocecal mesentery did not contain high amounts of proinflammatory macrophages adjacent to the inflamed tissue, and a gradient toward a more proinflammatory phenotype was seen in the central mesenteric area.

DISCUSSION

Although the mesentery is a continuous structure, the mesorectum and the ileocecal mesentery show different immunological characteristics. Therefore, currently, there is no basis to perform an extended ileocecal resection in patients with Crohn's disease.

Surgical Prevention of Anastomotic Recurrence by Excluding Mesentery in Crohn's Disease: The SuPREMe-CD Study - A Randomized Clinical Trial

OBJECTIVE

This trial aimed to provide randomized controlled data comparing Kono-S anastomosis and stapled ileocolic side-to-side anastomosis.

BACKGROUND

Recently, a new antimesenteric, functional, end-to-end, hand-sewn ileocolic anastomosis (Kono-S) has shown a significant reduction in endoscopic recurrence score and surgical recurrence rate in Crohn disease (CD).

METHODS

Randomized controlled trial (RCT) at a tertiary referral institution. Primary endpoint: endoscopic recurrence (ER) (Rutgeerts score ≥i2) after 6 months. Secondary endpoints: clinical recurrence (CR) after 12 and 24 months, ER after 18 months, and surgical recurrence (SR) after 24 months.

RESULTS

In all, 79 ileocolic CD patients were randomized in Kono group (36) and Conventional group (43). After 6 months, 22.2% in the Kono group and 62.8% in the Conventional group presented an ER [P < 0.001, odds ratio (OR) 5.91]. A severe postoperative ER (Rutgeerts score ≥i3) was found in 13.8% of Kono versus 34.8% of Conventional group patients (P = 0.03, OR 3.32). CR rate was 8% in the Kono group versus 18% in the Conventional group after 12 months (P = 0.2), and 18% versus 30.2% after 24 months (P = 0.04, OR 3.47). SR rate after 24 months was 0% in the Kono group versus 4.6% in the Conventional group (P = 0.3). Patients with Kono-S anastomosis presented a longer time until CR than patients with side-to-side anastomosis (hazard ratio 0.36, P = 0.037). On binary logistic regression analysis, the Kono-S anastomosis was the only variable significantly associated with a reduced risk of ER (OR 0.19, P < 0.001). There were no differences in postoperative outcomes.

CONCLUSIONS

This is the first RCT comparing Kono-S anastomosis and standard anastomosis in CD. The results demonstrate a significant reduction in postoperative endoscopic and clinical recurrence rate for patients who underwent Kono-S anastomosis, and no safety issues.ClinicalTrials.gov ID NCT02631967.

Microbial Signature in Adipose Tissue of Crohn's Disease Patients

Crohn’s disease (CD) is characterized by compromised immune tolerance to the intestinal commensal microbiota, intestinal barrier inflammation, and hyperplasia of creeping fat (CF) and mesenteric adipose tissue (AT), which seems to be directly related to disease activity. Gut microbiota dysbiosis might be a determining factor in CD etiology, manifesting as a low microbial diversity and a high abundance of potentially pathogenic bacteria. We tested the hypothesis that CF is a reservoir of bacteria through 16S-rRNA sequencing of several AT depots of patients with active and inactive disease and controls. We found a microbiome signature within CF and mesenteric AT from patients, but not in subcutaneous fat. We failed to detect bacterial DNA in any fat depot of controls. Proteobacteria was the most abundant phylum in both CF and mesenteric AT, and positively correlated with fecal calprotectin/C-reactive protein. Notably, the clinical status of patients seemed to be related to the microbiome signature, as those with the inactive disease showed a reduction in the abundance of pathogenic bacteria. Predictive functional profiling revealed many metabolic pathways including lipopolysaccharide biosynthesis and sulfur metabolism overrepresented in active CD relative to that in inactive CD. Our findings demonstrate that microbiota dysbiosis associated with CD pathophysiology is reflected in AT and might contribute to disease severity.

Crohn's versus Cancer: Comparison of Functional and Surgical Outcomes after Right-Sided Resections

BACKGROUND

The objective of this study was to compare functional and surgical outcomes of patients undergoing ileocecal resection for Crohn's disease (CD) to patients undergoing oncological right colectomy.

METHODS

Retrospective single-center cohort study including consecutive patients undergoing right colectomy for adenocarcinoma (oncological resection) or CD (mesentery-sparing resection) between July 2011 and November 2017. Outcome measures were pathological details (lymph node yield), postoperative recovery (pain levels, return to flatus and stool, intake of fluids, weight change, and mobilization), and early (30-day) outcomes (surgical/medical complications, hospital stay, readmissions).

RESULTS

A total of 195 patients (153 [78%] with cancer and 42 [22%] with CD) were included. Overall compliance with the institutional enhanced recovery protocol was comparable between the 2 groups (compliance ≥70%: 60% in CD patients vs. 62% in cancer, p = 0.458). The adenocarcinoma group had a larger lymph node yield than the CD group (26 ± 13 vs. 2.4 ± 5, respectively, p < 0.001). While the CD group experienced significantly more pain (3.7 ± 1.9/10 vs. 2.8 ± 2.5/10, p = 0.007, patients requiring opioids: 65 vs. 28%, p = 0.001), return of flatus (2.3 ± 1.2 days vs. 2.4 ± 2.8 days, p = 0.642) and stool (4.1 ± 6.0 vs. 3.0 ± 1.8 days, p = 0.292) was no different in both groups. No difference was observed regarding postoperative complications, length of stay, and readmission rate.

CONCLUSION

This study revealed no differences in both functional and surgical outcomes in CD and cancer patients undergoing mesentery-sparing or formal oncological right colectomy, respectively.

Small bowel adenocarcinoma in Crohn's disease: a rare but devastating complication

BACKGROUND

Small bowel adenocarcinoma (SBA) remains a rare entity but occurs at increased frequency in the setting of chronic Crohn's disease (CD). Our aim was to study the presentation, diagnosis and prognosis of SBA in patients undergoing surgery for CD at a single institution.

METHODS

We reviewed the medical records of all patients with CD complicated by adenocarcinoma of the small bowel from 2000 to 2017. Descriptive statistics and Kaplan-Meier overall survival estimates were calculated.

RESULTS

In total, 22 patients (14 males) with CD (median duration of Crohn's diagnosis 32 years) were diagnosed with SBA and underwent surgical resection (8 isolated small bowel resections, 12 ileocolic resections, and 2 total proctocolectomies). The median patient age at the time of diagnosis was 54 years (range 22-82 years). A total of 17 patients (77%) underwent cross-sectional CT imaging within 3 months of surgery, a cancer diagnosis was suggested in only one patient. In one other patient, SBA was diagnosed preoperatively on endoscopic biopsy of the terminal ileum. The remaining patients were operated on for obstruction (n = 17), abscess or fistulizing disease (n = 2), and sigmoid cancer (n = 1). For these 20 (90%) patients not suspected to have SBA on preoperative assessment, 5 (25%) were diagnosed intraoperatively on frozen section and 15 (75%) were unexpectedly diagnosed postoperatively on final pathology. T staging was characterized by more advanced tumors (T4: 59%, T3: 27%, T2: 9%, and T1: 5%). Nine patients (41%) had nodal involvement and five patients (23%) had hepatic and/or peritoneal carcinomatosis. The 1-, 3-, and 5-year survival estimates for our cohort were 84%, 30%, and 10%, respectively. Median survival was 30.5 months with median follow-up of 23 months (range 6-84 months).

CONCLUSIONS

SBA in the setting of CD is most commonly found incidentally after surgical resection for benign indications. As such, any suspicious finding at the time of surgery in a patient with chronic CD should warrant careful investigation with frozen section and/or resection. Prognosis for CD complicated by SBA remains poor even in the modern era.

Surgical treatment of intestinal stricture in inflammatory bowel disease

Fibroblast infiltration and collagen deposition result in structural changes in the bowel wall, and lead to strictures in intestinal inflammatory disease. While strictures can also occur in other contexts, such as malignancy, this review focuses on the surgical treatment of stricture secondary to inflammatory bowel disease. Distinguishing between predominantly inflammation vs established fibrosis as the cause of a stricture can be challenging. While inflammatory strictures may be responsive to medication, predominantly fibrotic strictures usually need surgical intervention. Both endoluminal and extraluminal approaches are described in this review. Endoscopic dilatation of strictures is suitable for short-segment isolated small bowel strictures. Other options are to divide the stricture surgically but preserve the length, performing a strictureplasty or resecting the strictured segment. The mesentery is increasingly recognized as playing a role in stricture recurrence. In a relapsing-remitting disease such as Crohn's disease, the preservation of intestinal length is essential and balance is needed between this and a complete resection to reduce the risk of recurrence. Pre- and postoperative involvement of the multidisciplinary team is essential to improve outcomes in this challenging clinical scenario.

Kono-S anastomosis after intestinal resection for Crohn's disease

BACKGROUND

Kono-S anastomosis was described for the first time in 2011 and it showed a lower surgical recurrence rate in patients with Crohn's disease when compared to the standard technique. The aim of this review is to assess the safety and effectiveness of this surgical procedure by analyzing the data existing in the literature.

MATERIALS AND METHODS

Pubmed, EMBASE and Scopus databases were used as data sources for a systematic comprehensive search of all studies where Kono-S anastomosis was performed in patients with Crohn's disease. Perioperative data and clinical outcomes were measured.

RESULTS

Five studies described the use of Kono technique to restore intestinal continuity. Postoperative complications rates seem to be acceptable, with the exception of one case regarding the surgical site infection and bowel obstruction rates of one of the studies compared to the others. Surgical recurrence rate ranges from 0 to 3.4% with significant differences between Kono-S anastomosis and other techniques in the only two existing comparative studies.

CONCLUSION

Kono's anastomosis seems to be a safe procedure with encouraging results on the reduction of the need for reoperation due to relapse, but the few existing studies do not allow to draw final conclusions. Further comparative, randomized studies, with appropriate sample size, follow up and endoscopic evaluation are necessary to establish the real benefits in the use of this hand-sewn antimesenteric anastomosis compared to a stapled wide lumen side-to-side anastomosis.

Crohn's disease associated adenocarcinoma of ileocaecal region: a miscalculated approach

Adenocarcinoma of the bowel is a dreadful sequelae of inflammatory bowel disease that can be difficult to diagnose and has been shown to have poor prognosis. The diagnosis is often made on histopathological examination of the resected specimen for what is suspected to be an exacerbation of the underlying intestinal Crohn's. A 39-year-old woman who was being treated for small bowel Crohn's disease for 4 years presented with features of intermittent intestinal obstruction that was refractory to medical therapy. A contrast CT of the abdomen was suggestive of ileocaecal Crohn's disease, and colonoscopy revealed a stricture at proximal transverse colon with multiple superficial ulcers. She underwent a mesentery sparing right hemicolectomy and had an uneventful recovery. The biopsy, however, was reported to be moderately differentiated adenocarcinoma stage T3N0 with a harvest of four pericolic nodes. Adjuvant chemotherapy was advised, which she deferred. Ten months later, she presented to the emergency room with features of intestinal obstruction. Contrast CT of the abdomen showed thickening at the anastomotic site with intestinal obstruction. On exploratory laparotomy, tumour recurrence was noted at the site of the anastomosis and diffuse peritoneal metastasis. A palliative diversion ileostomy was done due to inoperable obstructing disease. She was then given palliative therapy and subsequently succumbed to the illness. The inclusion of mesentery with the resected specimen in Crohn's disease has been a debate over many years. Since the preoperative diagnosis of carcinoma of the bowel in Crohn's disease is challenging, all ileocolic resections should be radical as done in oncological resections. This would yield better oncological safety and may improve survival rates.

Adipose stem cells from patients with Crohn's disease show a distinctive DNA methylation pattern

Background

Crohn’s disease (CD) is characterized by persistent inflammation and ulceration of the small or large bowel, and expansion of mesenteric adipose tissue, termed creeping fat (CF). We previously demonstrated that human adipose-derived stem cells (hASCs) from CF of patients with CD exhibit dysfunctional phenotypes, including a pro-inflammatory profile, high phagocytic capacity, and weak immunosuppressive properties. Importantly, these phenotypes persist in patients in remission and are found in all adipose depots explored including subcutaneous fat. We hypothesized that changes in hASCs are a consequence of epigenetic modifications.

Methods

We applied epigenome-wide profiling with a methylation array (Illumina EPIC/850k array) and gene expression analysis to explore the impact of CD on the methylation signature of hASCs isolated from the subcutaneous fat of patients with CD and healthy controls (n = 7 and 5, respectively; cohort I). Differentially methylated positions (p value cutoff < 1 × 10⁻⁴ and ten or more DMPs per gene) and regions (inclusion threshold 0.2, p value cutoff < 1 × 10⁻² and more than 2 DMRs per gene) were identified using dmpfinder and Bumphunter (minfi), respectively. Changes in the expression of differentially methylated genes in hASCs were validated in a second cohort (n = 10/10 inactive and active CD and 10 controls; including patients from cohort I) and also in peripheral blood mononuclear cells (PBMCs) of patients with active/inactive CD and of healthy controls (cohort III; n = 30 independent subjects).

Results

We found a distinct DNA methylation landscape in hASCs from patients with CD, leading to changes in the expression of differentially methylated genes involved in immune response, metabolic, cell differentiation, and development processes. Notably, the expression of several of these genes in hASCs and PBMCs such as tumor necrosis factor alpha (TNFA) and PR domain zinc finger protein 16 (PRDM16) were not restored to normal (healthy) levels after disease remission.

Conclusions

hASCs of patients with CD exhibit a unique DNA methylation and gene expression profile, but the expression of several genes are only partially restored in patients with inactive CD, both in hASCs and PBMCs. Understanding how CD shapes the functionality of hASCs is critical for investigating the complex pathophysiology of this disease, as well as for the success of cell-based therapies.

Graphical abstract

Human adipose-stem cells isolated from subcutaneous fat of patients with Crohn’s disease exhibit an altered DNA methylation pattern and gene expression profile compared with those isolated from healthy individuals, with immune system, cell differentiation, metabolic and development processes identified as the main pathways affected. Interestingly, the gene expression of several genes involved in these pathways is only partially restored to control levels in patients with inactive Crohn’s disease, both in human adipose-stem cells and peripheral blood mononuclear cells. Understanding how Crohn’s disease shapes the functionality of human adipose-stem cells is critical for investigating the complex pathophysiology of this disease, as well as for the success of cell-based therapies.

Video-laparoscopic assessment of the small bowel in Crohn's disease: a comparative study to evaluate surgeons' inter-observer variability

BACKGROUND

Assessment of the entire small bowel is advocated during Crohn's disease (CD) surgery, as intraoperative detection of new lesions may lead to change in the planned procedure. The aim of this study was to evaluate the inter-observer variability in the assessment of extent and severity of CD at the small bowel laparoscopic "walkthrough".

METHODS

A survey on laparoscopic assessment of the small bowel in patients with CD, including items adapted from the MREnterography or ultrasound in Crohn's disease (METRIC) study and from the classification of severity of mesenteric disease was developed by an invited committee of colorectal surgeons. Anonymous laparoscopic videos demonstrating the small bowel "walkthrough" in ileocolonic resection for primary and recurrent CD were distributed to the committee members together with the anonymous survey. The primary outcome was the rate of inter-observer variability on assessment of strictures, dilatations, complications and severity of mesenteric inflammation.

RESULTS

12 assessors completed the survey on 8 small bowel walkthrough videos. The evaluation of the small bowel thickening and of the mesenteric fat wrapping were the most reliable assessments with an overall agreement of 87.1% (k = 0.31; 95% CI - 0.22, 0.84) and 82.7% (k = 0.35; 95% CI - 0.04, 0.73), respectively. The presence of strictures and pre-stenotic dilatation demonstrated agreement of 75.2% (k = 0.06: 95% CI - 0.33, 0.45) and 71.2% (k = 0.33; 95% CI 0.15, 0.51), respectively. Evaluation of fistulae had an overall agreement of 75.3%, while there was a significant variation in the evaluation of mild, moderate and severe mesenteric disease with overall agreement ranging from 33.3 to 100%.

CONCLUSION

Laparoscopic assessment of the small bowel thickening and of the presence of mesenteric fat wrapping is reliable for the intraoperative evaluation of CD with high inter-rater agreement. There is significant heterogeneity in the assessment of the severity of the mesenteric disease involvement.

Strictureplasty versus bowel resection for the surgical management of fibrostenotic Crohn's disease: a systematic review and meta-analysis

BACKGROUND

Strictureplasty (SPX) conserves bowel length and minimizes the risk of developing short bowel syndrome in patients undergoing surgery for Crohn's disease (CD). However, SPX may be associated with a higher risk of recurrence compared with bowel resection (BR).

AIM

We sought to compare morbidity and recurrence following SPX and BR in patients with fibrostenotic CD.

METHODS

A systematic review was performed according to PRISMA and MOOSE guidelines. Observational studies that compared outcomes of CD patients undergoing either SPX or BR were identified. Log hazard ratios (InHR) for recurrence-free survival (RFS) and their standard errors were calculated from Kaplan-Meier plots or Cox regression models and pooled using the inverse variance method. Dichotomous variables were pooled as odds ratios (OR) using the Mantel-Haenszel method. Continuous variables were pooled as weighted mean differences.

RESULTS

Twelve studies of 1026 CD patients (SPX n = 444, 43.27%; BR with or without SPX n = 582, 56.72%) were eligible for inclusion. There was an increased likelihood of disease recurrence with SPX than with BR (OR 1.61; 95% CI, 1.03, 2.52; p = 0.04; I² = 0%). Patients who had a SPX alone had a significantly reduced RFS than those who underwent BR (HR 1.47; 95% CI, 1.08, 2.01; p = 0.02; I² = 0%). There was no difference in morbidity between the groups (OR 0.58; 95% CI, 0.26, 1.28; p = 0.18; I² = 0%).

CONCLUSION

SPX should only be performed in those patients with Crohn's strictures that are at high risk for short bowel syndrome and intestinal failure; otherwise, BR is the favored surgical technique for the management of fibrostenotic CD.

Temporary faecal diversion in ileocolic resection for Crohn's disease: is there an impact on long-term surgical recurrence?

AIM

Temporary faecal diversion after ileocolic resection (ICR) for Crohn's disease reduces postoperative anastomotic complications in high-risk patients. The aim of this study was to assess if this approach also reduces long-term surgical recurrence.

METHOD

This was a multicentre retrospective review of prospectively maintained databases. Patient demographics, medical and surgical details were collected by three specialist centres. All patients had undergone an ICR between 2000 and 2012. The primary end-point was surgical recurrence.

RESULTS

Three hundred and twelve patients (80%) underwent an ICR without covering ileostomy (one stage). Seventy-seven (20%) had undergone an ICR with end ileostomy/double-barrel ileostomy/enterocolostomy followed by closure (two stage). The median follow-up was 105 months [interquartile range (IQR) 76-136 months]. The median time to ileostomy closure was 9 months (IQR 5-12 months). There was no significant difference in surgical recurrence between the one- and two-stage groups (18% vs 16%, P = 0.94). We noted that smokers (20% vs 34%, P = 0.01) and patients with penetrating disease (28% vs 52%, P < 0.01) were more likely to be defunctioned. A reduced recurrence rate was observed in the small high-risk group of patients who were smokers with penetrating disease behaviour treated with a two-stage strategy (0/10 vs 4/7, P = 0.12).

CONCLUSION

Despite having higher baseline risk factors, the results in terms of rate of surgical recurrence over 9 years are similar for patients having a two-stage compared with a one-stage procedure.

Inflammatory bowel disease position statement of the Italian Society of Colorectal Surgery (SICCR): Crohn's disease

The Italian Society of Colorectal Surgery (SICCR) promoted the project reported here, which consists of a position statement of Italian colorectal surgeons to address the surgical aspects of Crohn's disease management. Members of the society were invited to express their opinions on several items proposed by the writing committee, based on evidence available in the literature. The results are presented, focusing on relevant points. The present paper is not an alternative to available guidelines; rather, it offers a snapshot of the attitudes of SICCR surgeons about the surgical treatment of Crohn's disease. The committee was able to identify some points of major disagreement and suggested strategies to improve quality of available data and acceptance of guidelines.

Meta-analysis of early bowel resection versus initial medical therapy in patient's with ileocolonic Crohn's disease

BACKGROUND

Early bowel resection (EBR) in ileocolonic Crohn's disease (CD) may be associated with more durable remission compared with initial medical therapy (IMT) even when biologic therapy is included.

AIM

To compare the efficacy of EBR versus IMT for ileocolonic CD METHODS: A systematic search was performed to identify studies that compared EBR (performed < 1 year from initial diagnosis) or IMT for the management of ileocolonic CD. Log hazard ratios (InHR) for relapse-free survival (RFS) and their standard errors were calculated from Kaplan-Meier plots and pooled using the inverse-variance method. Dichotomous variables were pooled as odds ratios (OR). Quality assessment of the included studies was performed using the Newcastle-Ottawa (NOS) and Jadad scales.

RESULTS

A total of 7 studies with 1863 CD patients (EBR n = 581, 31.2%; IMT n = 1282, 68.8%) were eligible for inclusion. There was a moderate-to-high risk of bias. The median NOS was 8 (range 7-9). There was a reduced likelihood of overall (OR, 0.53; 95% confidence interval (95% CI), 0.34, 0.83; p = 0.005) and surgical (OR, 0.47; 95% CI, 0.24, 0.91; p = 0.03) relapse with EBR. There was also a less requirement for maintenance biologic therapy (OR, 0.24; 95% CI, 0.14, 0.42; p < 0.0001). Patients who underwent EBR had a significantly improved RFS than those who underwent IMT (HR, 0.62; 95% CI, 0.52, 0.73; p < 0.001). There was no difference in morbidity (OR, 1.67; 95% CI, 0.44, 6.36; p = 0.45) between the groups.

CONCLUSION

EBR may be associated with less relapse and need for maintenance biologic therapy than IMT. 'Upfront' or early resection may represent a reasonable and cost-effective alternative to biologic therapy, especially in biologic-resistant subpopulations.

Mesenteric excision surgery or conservative limited resection in Crohn's disease: study protocol for an international, multicenter, randomized controlled trial

Background

The structures of the mesentery including adipose tissue, nerves, and lymphatics play an important role in the pathogenesis and disease progression of Crohn’s disease (CD). Conventional surgical resection for CD usually does not involve resecting the mesentery en bloc with the specimen. This contrasts with complete mesocolic excision (CME) in colorectal cancer, which involves radical resection of the mesentery. Preliminary evidence from smaller studies suggests that applying the principle of mesocolic excision to CD surgery may reduce the risk of postoperative recurrence. This randomized controlled trial is designed to test whether applying the principles of mesocolic excision to CD results in reduced postoperative recurrence. It also aims to evaluate intra- and postoperative morbidity between the two approaches.

Methods

This international, multicenter, randomized controlled trial will randomize patients (n = 116) scheduled to undergo primary ileocolic resection to either receive extensive mesenteric excision (EME) or conventional ileocolic resection with limited mesenteric excision (LME). Five sites will recruit patients in three countries. In the EME group, the mesentery is resected following CME, while avoiding the root region, i.e., 1 cm from the root of the ileocolic artery and vein. In the LME group, the mesentery is retained, i.e., “close shave” or < 3 cm from the border of bowel. The primary end point will be surgical recurrence after surgery. The secondary end points will be the postoperative endoscopic and clinical recurrence, and intra- and postoperative morbidity. Demographics, risk factors, laboratory investigations, endoscopy, postoperative prophylaxis and imaging examination will be assessed. Analysis of the primary outcome will be on an intention-to-treat basis.

Discussion

If mesocolic excision in CD reduces postoperative disease recurrence and does not increase morbidity, this trial has the potential to change practice and reduce recurrence of CD after surgical resection.

Trial registration

Clinical Trials.gov, ID: NCT03769922. Registered on February 27, 2019.

Mesenteric granulomas independently predict long-term risk of surgical recurrence in Crohn's disease

AIM

The risk factors that predict surgical recurrence in Crohn's disease (CD) remain controversial. Postoperative anti-tumour necrosis factor (anti-TNF) therapy might lower recurrence rates whilst the presence of mesenteric granulomas has been postulated to increase the risk. We hypothesized that mesenteric granulomas indicate disease severity and might predict the risk of surgical recurrence, irrespective of immunosuppressive therapy.

METHOD

We performed a retrospective review of all consecutive patients undergoing operations for CD between January 2000 and December 2014 at a single tertiary referral centre and assessed the perioperative factors and histological findings at the time of surgery. Surgical recurrence rates and the immunosuppressive regimen were assessed through retrospective chart review and telephone interviews.

RESULTS

A total of 274 patients were eligible for analysis. Median follow-up was 8.54 (5.48-14.42) years. A total of 63 patients (23.0%) underwent surgery for recurrent CD after a median of 4.75 (2.10-7.96) years. In final histology, 35 (12.8%) patients had mesenteric granulomas. TNF inhibitors were administered postoperatively in 104 (38.0%) and thiopurines in 137 (50.0%) patients. In univariate analysis, only the presence of mesenteric granulomas [hazard ratio (HR) 1.95; 95% CI 1.05-3.62; P = 0.035] significantly increased the risk for recurrent surgery while postoperative anti-TNF (HR 0.85; 95% CI 0.49-1.50; P = 0.581) or thiopurine therapy (HR 1.03; 95% CI 0.61-1.73; P = 0.916) did not. In multivariate analysis, only the presence of mesenteric granulomas significantly influenced the risk of surgical recurrence (HR 1.94, 95% CI 1.04-3.60; P = 0.037).

CONCLUSION

Intestinal and mesenteric granulomas should be differentiated in pathology reports, because mesenteric, but not intestinal, granulomas may be associated with an increased risk of surgical recurrence.

Does Smoking Cessation Reduce Surgical Recurrence After Primary Ileocolic Resection for Crohn's Disease?

BACKGROUND

Tobacco smoking is a known risk factor for recurrence of Crohn's disease after surgical resection.

OBJECTIVE

This study assessed the effect of smoking cessation on long-term surgical recurrence after primary ileocolic resection for Crohn's disease.

DESIGN

A retrospective review of a prospectively maintained database was conducted.

SETTINGS

Patient demographic data and medical and surgical details were combined from 2 specialist centers. After ethical approval, patients were contacted in case of missing data regarding smoking habit.

PATIENTS

All patients undergoing ileocolic resection between 2000 and 2012 for histologically confirmed Crohn's disease were included. Those with previous intestinal resection, strictureplasty for Crohn's disease, leak after ileocolic resection, or who were never reversed were excluded.

MAIN OUTCOME MEASURES

The primary end point was surgical recurrence measured by Kaplan-Meier survival analysis and secondary medical therapy at time of follow-up.

RESULTS

Over a 12-year period, 290 patients underwent ileocolic resection. Full smoking data were available for 242 (83%) of 290 patients. There were 169 nonsmokers (70%; group 1), 42 active smokers at the time of ileocolic resection who continued smoking up to last follow-up (17%; group 2), and 31 (13%) who quit smoking after ileocolic resection (group 3). The median time of smoking exposure after ileocolic resection for group 3 was 3 years (interquartile range, 0-6 y), and median follow-up time for the whole group was 112 months (9 mo; interquartile range, 84-148 mo). Kaplan-Meier survival analysis showed a significantly higher surgical recurrence rate for group 2 compared with group 3 (16/42 (38%) vs 3/31 (10%); p = 0.02; risk ratio = 3.9 (95% CI, 1-12)). In addition, significantly more patients in group 2 without surgical recurrence received immunomodulatory maintenance therapy compared with group 3 (12/26 (46%) vs 4/28 (14%); p = 0.01; risk ratio = 3.2 (95% CI, 1-9)).

LIMITATIONS

The study was limited by its retrospective design and small number of patients.

CONCLUSIONS

Smoking cessation after primary ileocolic resection for Crohn's disease may significantly reduce long-term risk of surgical recurrence and is associated with less use of maintenance therapy. See Video Abstract at http://links.lww.com/DCR/B86. ¿DEJAR DE FUMAR REDUCE LA RECURRENCIA QUIRÚRGICA DESPUÉS DE LA RESECCIÓN ILEOCÓLICA PRIMARIA PARA LA ENFERMEDAD DE CROHN?: Fumar tabaco es un factor de riesgo conocido para la recurrencia de la enfermedad de Crohn después de la resección quirúrgica.Evaluar el efecto de dejar de fumar en la recurrencia quirúrgica a largo plazo después de la resección ileocólica primaria para la enfermedad de Crohn.Revisión retrospectiva de una base de datos mantenida prospectivamente.Se combinaron datos demográficos del paciente, así como detalles médicos y quirúrgicos de dos centros especializados. Después de la aprobación ética, se contactó a los pacientes en caso de falta de datos sobre el hábito de fumar.Todos los pacientes sometidos a resección ileocólica entre 2000 y 2012 por enfermedad de Crohn confirmada histológicamente. Se excluyeron aquellos con resección intestinal previa, estenosis por enfermedad de Crohn, fuga después de resección ileocólica o que nunca se revirtieron.La principal variable fue la recurrencia quirúrgica medida por análisis de supervivencia de Kaplan-Meier, terapia médica secundaria en el momento del seguimiento.Durante un período de 12 años, 290 pacientes fueron sometidos a resección ileocólica. Se dispuso de datos completos sobre el tabaquismo para 242/290 (83%). Hubo 169 no fumadores (70%) (grupo 1), 42 (17%) fumadores activos en el momento de la resección ileocólica que continuaron fumando hasta el último seguimiento (grupo 2) y 31 (13%) que dejaron de fumar después de resección ileocólica (grupo 3). La mediana del tiempo de exposición al tabaquismo después de la resección ileocólica para el grupo 3 fue de 3 años (IQR 0-6) y la mediana del tiempo de seguimiento para todo el grupo fue de 112 meses (9 años) (IQR 84-148). El análisis de supervivencia de Kaplan-Meier mostró una tasa de recurrencia quirúrgica significativamente mayor para el grupo 2 en comparación con el grupo 3 (16/42 (38%) frente a 3/31 (10%), p = 0.02; razón de riesgo 3.9 (IC 95% 1-12)). Además, un número significativamente mayor de pacientes del grupo 2 sin recurrencia quirúrgica recibieron terapia de mantenimiento inmunomoduladora en comparación con el grupo 3 (12/26 (46%) frente a 4/28 (14%), p = 0.01; razón de riesgo 3.2 (IC 95% 1-9)).Diseño retrospectivo y pequeño número de pacientes.Dejar de fumar después de la resección ileocólica primaria para la enfermedad de Crohn puede reducir significativamente el riesgo a largo plazo de recurrencia quirúrgica y se asocia con un menor uso del tratamiento de mantenimiento. Consulte Video Resumen en http://links.lww.com/DCR/B86. (Traducción-Dr. Gonzalo Federico Hagerman).

Whole transcriptional analysis identifies markers of B, T and plasma cell signaling pathways in the mesenteric adipose tissue associated with Crohn's disease

Background

Crohn’s disease (CD) is a multifactorial disease characterized by chronic intestinal inflammation. The increased visceral adiposity near the affected intestinal area, of which mesenteric adipose tissue (MAT) is the main component, is a feature of CD. Both protective and pathological roles have been attributed to this disease-associated tissue in CD. To understand the contribution of MAT to CD pathophysiology, a molecular and cellular signature of disease-associated MAT in CD patients was provided.

Methods

We performed an observational study with whole transcriptional analysis by RNA sequencing (RNA-seq) of MAT and ileal mucosa from CD patients with active disease and controls. qPCR and immunohistology were performed for validation analysis.

Results

RNA-seq identified 17 significantly regulated genes (|FC| > 1.5; FDR < 0.05) in CD-MAT compared to non-IBD controls, with a marked upregulation of plasma cell genes (i.e., IGLL5, MZB1, CD79A, POU2AF1, FCRL5, JCHAIN, DERL3, SDC1, PIM2). A less strict statistical cutoff value (|FC| > 1.5, nominal p ≤ 0.05) yielded a larger list of 651 genes in CD-MAT compared to controls. CD ileum showed the significant regulation compared to control ileum of 849 genes (|FC| > 1.5; FDR < 0.05) or 2654 genes (|FC| > 1.5, nominal p ≤ 0.05). Ingenuity Pathway Analysis revealed the significant regulation of pathways related to T- and B cell functionality in the MAT of CD patients. Despite the differences between the MAT and ileal signatures of CD patients, we identified a subset of 204 genes significantly modulated in both tissues compared to controls. This common signature included genes related to the plasma cell signature. Genes such as S100A8, S100A9 (calprotectin) and IL1B, which are associated with acute inflammatory response, were exclusively regulated in the ileal mucosa of CD disease. In contrast, some genes encoding for lymphocyte receptors such as MS4A1, CD3D and CD79A were exclusively regulated in CD-MAT, exhibiting a different pattern of immune cell activation compared to the ileal mucosa in CD patients. qPCR and immunohistology confirmed the presence of large infiltrates of CD3⁺ CD20⁺ lymphocytes and CD138⁺ plasma cells in CD-MAT.

Conclusion

Our data strongly supports the role of CD-associated MAT as a site for T-, B- and plasma cell activation, and suggests that it could also act as a reservoir of memory immune responses.

Histopathology Scoring Systems of Stenosis Associated With Small Bowel Crohn's Disease: A Systematic Review

BACKGROUND & AIMS

Stenosis is a common complication of Crohn's disease (CD) that has no effective medical therapy. Development of antifibrotic agents will require testing in randomized controlled trials. Computed tomography enterography- and magnetic resonance enterography-based technologies might be used to measure outcomes in these trials. These approaches have been validated in studies of patients with symptomatic strictures who underwent imaging evaluations followed by resection with histopathologic grading of the intestinal tissue for inflammation and/or fibrosis (the reference standard). Imaging findings have correlated with findings from quantitative or semiquantitative histologic evaluation of the degree of fibromuscular stenosis and/or inflammation on the resection specimen. However, it is not clear whether histologic findings are an accurate reference standard. We performed a systematic review of all published histologic scoring systems used to assess stenosing CD.

METHODS

We performed a comprehensive search of Embase and MEDLINE of studies through March 13, 2019, that used a histologic scoring system to characterize small bowel CD and assessed inflammatory and fibrotic alterations within the same adult individual. All scores fitting the criteria were included in our analysis, independent of the presence of stricturing disease, as long as inflammation and fibrosis were evaluated separately but in the same scoring system.

RESULTS

We observed substantial heterogeneity among the scoring systems, which were not derived from modern principles for evaluative index development. None had undergone formal validity or reliability testing. None of the existing indices had been constructed according to accepted methods for the development of evaluative indices. Basic knowledge regarding their operating properties were lacking. Specific indices for evaluating the important pathologic component of myofibroblast hypertrophy or hyperplasia have not been proposed.

CONCLUSIONS

In a systematic review of publications, we found a lack of validated histopathologic scoring systems for assessment of fibromuscular stenosis. Data that describe the operating properties of existing cross-sectional imaging techniques for stenosing CD should be questioned. Development and validation of a histopathology index is an important research priority.

Systemic Molecular Mediators of Inflammation Differentiate Between Crohn's Disease and Ulcerative Colitis, Implicating Threshold Levels of IL-10 and Relative Ratios of Pro-inflammatory Cytokines in Therapy

BACKGROUND AND AIMS

Faecal diversion is associated with improvements in Crohn's disease but not ulcerative colitis, indicating that differing mechanisms mediate the diseases. This study aimed to investigate levels of systemic mediators of inflammation, including fibrocytes and cytokines, [1] in patients with Crohn's disease and ulcerative colitis preoperatively compared with healthy controls and [2] in patients with Crohn's disease and ulcerative colitis prior to and following faecal diversion.

METHODS

Blood samples were obtained from healthy individuals and patients with Crohn's disease or ulcerative colitis. Levels of circulating fibrocytes were quantified using flow cytometric analysis and their potential relationship to risk factors of inflammatory bowel disease were determined. Levels of circulating cytokines involved in inflammation and fibrocyte recruitment and differentiation were investigated.

RESULTS

Circulating fibrocytes were elevated in Crohn's disease and ulcerative colitis patients when compared with healthy controls. Smoking, or a history of smoking, was associated with increases in circulating fibrocytes in Crohn's disease, but not ulcerative colitis. Cytokines involved in fibrocyte recruitment were increased in Crohn's disease patients, whereas patients with ulcerative colitis displayed increased levels of pro-inflammatory cytokines. Faecal diversion in Crohn's disease patients resulted in decreased circulating fibrocytes, pro-inflammatory cytokines, and TGF-β1, and increased IL-10, whereas the inverse was observed in ulcerative colitis patients.

CONCLUSIONS

The clinical effect of faecal diversion in Crohn's disease and ulcerative colitis may be explained by differing circulating fibrocyte and cytokine responses. Such differences aid in understanding the disease mechanisms and suggest a new therapeutic strategy for inflammatory bowel disease.

Leptin induces TNFα-dependent inflammation in acquired generalized lipodystrophy and combined Crohn's disease

Leptin has been shown to modulate intestinal inflammation in mice. However, clinical evidence regarding its immune-stimulatory potential in human Crohn’s disease remains sparse. We here describe a patient with the unique combination of acquired generalized lipodystrophy and Crohn’s disease (AGLCD) featuring a lack of adipose tissue, leptin deficiency and intestinal inflammation. Using mass and flow cytometry, immunohistochemistry and functional metabolic analyses, the AGLCD patient was compared to healthy individuals and Crohn’s disease patients regarding immune cell composition, function and metabolism and the effects of recombinant N-methionylleptin (rLeptin) were evaluated. We provide evidence that rLeptin exerts diverse pro-inflammatory effects on immune cell differentiation and function, including the metabolic reprogramming of immune cells and the induction of TNFα, ultimately aggravating Crohn’s disease in the AGLCD patient, which can be reversed by anti-TNFα therapy. Our results indicate that leptin is required for human immune homeostasis and contributes to autoimmunity in a TNFα-dependent manner.

The adipokine leptin modulates intestinal inflammation in mice. Here the authors describe a patient with inflammatory bowel disease and lipodystrophy, providing evidence that leptin aggravates intestinal inflammation with proinflammatory effects on leukocytes that are reversible by TNFα blockade.

Elective Abdominal Surgery for Inflammatory Bowel Disease

Elective abdominal surgery for inflammatory bowel disease is common. Surgery for Crohn's disease is not curative, and treatment must be individualized to the disease process. Surgery for ulcerative colitis generally is curative but consideration of patient-specific factors is important for staging of the procedure and determining whether ileal pouch-anal anastomosis is appropriate.

A positive proximal resection margin is associated with anastomotic complications following primary ileocaecal resection for Crohn's disease

PURPOSES

Bowel resection in patients with Crohn's disease (CD) has a high reported rate of postoperative complications and surgical recurrence. A macroscopically normal resection margin is recommended in CD surgery as wider margins do not translate in reduced recurrence rates. The aim of this study was to evaluate the association between resection margin status and anastomotic complications following ileocaecal resection for primary CD.

METHODS

All patients treated with ileocaecal resection for primary CD from 2010 to 2018 were included in this retrospective observational study. Emergency operations and recurrent CD were excluded. Patients in whom an anastomosis was not fashioned at the time of the surgery were also excluded. Histopathology data collected included macroscopic description, presence of macroscopic and microscopic involvement of the proximal and distal resection margins. The primary outcome was the rate of positive resection margin in patients who developed anastomotic complications (anastomotic leaks and intra-abdominal collections), and the secondary outcomes were overall complications rate, length of hospital stay, reoperations and rehospitalisation within 30 days.

RESULTS

A total of 104 patients were included. The proximal resection margin was microscopically involved in 19 patients (18.2%). Ten patients (9.6%) developed intra-abdominal anastomotic related complications, with 5 patients out of 10 (50%) in the group of postoperative anastomotic complications having a positive microscopic proximal margin at histology, compared to 14 patients (14.9%) in the group that did not develop anastomotic complications (p < 0.0001).

CONCLUSIONS

Microscopic involvement of the proximal resection margin is more frequent in patients who develop postoperative anastomotic complications following elective ileocaecal resection for primary CD.

The surgeon and inflammatory bowel disease

Could be involved earlier

Adipocytes orchestrate the formation of tertiary lymphoid organs in the creeping fat of Crohn's disease affected mesentery

The formation of tertiary lymphoid organs (TLOs) is orchestrated by the stromal cells of tissues chronically submitted to inflammatory stimuli, in order to uphold specific adaptive immune responses. We have recently shown that the smooth muscle cells of the arterial wall orchestrate the formation of the TLOs associated with atherosclerosis in response to the local release of TNF-α. Observational studies have recently documented the presence of structures resembling TLOs the creeping fat that develops in the mesentery of patients with Crohn's disease (CD), an inflammatory condition combining a complex and as yet not elucidated infectious and autoimmune responses. We have performed a comprehensive analysis of the TLO structures in order to decipher the mechanism leading to their formation in the mesentery of CD patients, and assessed the effect of infectious and/or inflammatory inducers on the potential TLO-organizer functions of adipocytes. Quantitative analysis showed that both T and B memory cells, as well as plasma cells, are enriched in the CD-affected mesentery, as compared with tissue from control subjects. Immunohistochemistry revealed that these cells are concentrated within the creeping fat of CD patients, in the vicinity of transmural lesions; that T and B cells are compartmentalized in clearly distinct areas; that they are supplied by post-capillary high endothelial venules and drained by lymphatic vessels indicating that these nodules are fully mature TLOs. Organ culture showed that mesenteric tissue samples from CD patients contained greater amounts of adipocyte-derived chemokines and the use of the conditioned medium from these cultures in functional assays was able to actively recruit T and B lymphocytes. Finally, the production of chemokines involved in TLO formation by 3T3-L1 adipocytes was directly elicited by a combination of TNF-α and LPS in vitro. We therefore propose a mechanism in which mesenteric adipocyte, through their production of key chemokines in response to inflammatory/bacterial stimuli, may orchestrate the formation of functional TLOs developing in CD-affected mesentery.

Ex vivo model for a new bilateral antimesenteric V-modified side-to-side isoperistaltic anastomosis to prevent recurrence in ileocolic Crohn's disease

INTRODUCTION

The high rate of recurrence following ileocaecal resection for Crohn's disease may lead to repeat surgery in 20-30% of patients at five years after surgery. Recurrence usually occurs at the anastomosis and the neoterminal ileum and the association of a strictureplasty to widen the bowel lumen in the regions immediately proximal ('anastomotic inlet') and distal ('anastomotic outlet') to the anastomosis may delay or reduce the risk of surgical recurrence.

MATERIALS AND METHODS

A side to side isoperistaltic anastomosis, with an associated V-modified strictureplasty on the anti-mesenteric border at the level of the anastomosis inlet and outlet has been designed. We produced a wet lab ex vivo model of the anastomosis and, to evaluate the different calibre of the anastomotic segments, we compared it with ex vivo models of three anastomotic configurations currently used in surgery for Crohn's disease: i) side to side isoperistaltic anastomosis; ii) modified side-to-side isoperistaltic anastomosis with double Heineke-Mikulicz procedure (Sasaki anastomosis); iii) anti-mesenteric functional end-to-end handsewn anastomosis (Kono-S anastomosis).

RESULTS

Differences were recorded at the level of the anastomosis inlet and outlet, with a larger volume estimated in the Sasaki anastomosis and in the V-modified anastomosis. The V-modified anastomosis had a larger volume compared with the Sasaki anastomosis for a longer segment of small bowel.

CONCLUSIONS

We have developed an experimental animal model for a new anastomotic technique which could be applied in surgery for Crohn's disease following small-bowel or ileocolic resection.

Persistent Mesorectal Inflammatory Activity is Associated With Complications After Proctectomy in Crohn's Disease

BACKGROUND AND AIMS

Rectal resection in inflammatory bowel disease [IBD] is frequently complicated by disturbed perineal wound healing. Close rectal dissection, where the mesorectum remains in situ, is hypothesized to reduce complications by minimizing dead space, compared to total mesorectal excision. The aim of this study was to analyse post-operative outcomes of both techniques. In addition, immune activity in mesorectal tissue was assessed.

METHODS

Perineal complications and healing were retrospectively assessed in a series of 74 IBD patients undergoing proctectomy using close rectal dissection or total mesorectal excision. The mesorectums of 15 patients were analysed by fluorescence-activated cell sorting, immunofluorescence and in situ hybridization. Based on the clinical and in vitro findings, a novel surgical approach for Crohn's disease patients with disturbed perineal healing after proctectomy was developed.

RESULTS

In Crohn's disease, perineal complications were more frequent after close rectal dissection than after total mesorectal excision [59.5% vs 17.6%; p = 0.007] with lower healing rates [51.4% vs 88.2%; p = 0.014]. No differences were observed in ulcerative colitis. The mesorectal tissue in Crohn's disease contained enhanced numbers of tumour necrosis factor α-producing CD14+ macrophages, with less expression of the wound-healing marker CD206. Based on these findings, mesorectal excision with omentoplasty was performed in eight patients with perineal complications after close rectal dissection, resulting in complete perineal wound closure in six. Pro-inflammatory characteristics remained present in the mesorectum after close rectal dissection in these patients.

CONCLUSIONS

In Crohn's disease, close rectal dissection resulted in more perineal complications, associated with a pro-inflammatory immune status of the mesorectal tissue. Excision of this pro-inflammatory mesenteric tissue resulted in improved perineal healing rates.

No Association between staging operation and the 5-Year Risk of Reoperation in Patients with Crohn's Disease

The aim of this study was to investigate the impact of staging operation on the risk of reoperation in patients with CD who underwent primary bowel resection. This was a retrospective study of 980 patients with CD who were hospitalized in Jinling Hospital Affiliated to Nanjing Medical University between January 1, 2001, and October 1, 2016. The patients were grouped according to staging operation (n = 64) and one-stage operation (n = 148). Postoperative intestinal function recovery time, postoperative short-term complications, and reoperation rates were compared between the two groups. There was significant difference in disease behavior between the staging operation group and the one-stage operation group. There was no significant difference in postoperative tolerance of enteral nutrition among groups (P > 0.05). Obvious differences were found in the comparison of the first time of exhaustion, defecation after operation, postoperative length of stay and postoperative complications among groups (all P < 0.05). There was no difference in the 5-year cumulative reoperation-free rates between the two groups (P > 0.05). In conclusion, surgical intervention at proper time and appropriate operation during operation are essential for patients with CD. It is believed that staging operation with ostomy followed by intestinal anastomosis is feasible when there are more than two risk factors for postoperative intra-abdominal infectious complications.

The Mesentery, Systemic Inflammation, and Crohn's Disease

Initially thought to be a structure that only provided support to the abdominal contents, the mesentery has now gained special attention in the scientific community. The new approach of studying the mesentery as an individual organ has highlighted its importance in the development of local and systemic inflammatory diseases and its potential role in Crohn's disease. Its topographical relationship with the intestine in the setting of active inflammation and "creeping fat" is possibly one of the most important arguments for including the mesentery as an important factor in the pathogenesis of Crohn's disease. In this review, we discuss the importance of the mesentery from the anatomical and embryological standpoints. We also will summarize data on mesenteric inflammation in patients with Crohn's disease. The significance of the mesentery in systemic inflammatory syndromes will be discussed, and we provide an overview of primary inflammatory disorders of the mesentery. Finally, we discuss surgical approaches for patients requiring resection for Crohn's disease that incorporate mesenteric factors, pointing out recent data suggesting that these have the potential for improving outcomes and reducing disease recurrence. 10.1093/ibd/izy201_video1izy201.video15794169491001.

Novel Approaches to Ileocolic and Perianal Fistulising Crohn's Disease

Crohn's disease (CD) is a well-known idiopathic inflammatory bowel disease characterised by transmural inflammation which can ordinarily affect all the gastrointestinal tract. Its true aetiology is unknown, and a causal therapy is not available to date. The most peculiar aspect of CD lies in its absolute heterogeneity, as we might face various scenarios, locations of the disease, pathologic behaviours, and severity of the disease itself. For these reasons, the cornerstone for the treatment of CD lies in a complex multimodal management, requiring close collaborations among surgeons, gastroenterologists, radiologists, and staff nurses. Advances in surgical and medical therapy are changing the course of the disease. Nowadays, the introduction of both laparoscopy and novel surgical techniques, the improvement of recovery pathways, and the opening of new frontiers are allowing healthcare professionals to deal with complex and recurrent scenarios, trying to spare bowel and anal function, thus ensuring a better quality of life for the patient. Given the heterogeneity and complexity of this disease, it would be impractical to encompass all the aspects of surgical management of CD. This review will address areas that are considered to be hot topics, controversies, challenges, and novelties: thus, we will focus on complex ileocecal disease, surgical strategies, and fistulising perianal conditions.

The Association of Coloproctology of Great Britain and Ireland consensus guidelines in surgery for inflammatory bowel disease

AIM

There is a requirement of an expansive and up to date review of surgical management of inflammatory bowel disease (IBD) that can dovetail with the medical guidelines produced by the British Society of Gastroenterology.

METHODS

Surgeons who are members of the ACPGBI with a recognised interest in IBD were invited to contribute various sections of the guidelines. They were directed to produce a procedure based document using literature searches that were systematic, comprehensible, transparent and reproducible. Levels of evidence were graded. An editorial board was convened to ensure consistency of style, presentation and quality. Each author was asked to provide a set of recommendations which were evidence based and unambiguous. These recommendations were submitted to the whole guideline group and scored. They were then refined and submitted to a second vote. Only those that achieved >80% consensus at level 5 (strongly agree) or level 4 (agree) after 2 votes were included in the guidelines.

RESULTS

All aspects of surgical care for IBD have been included along with 157 recommendations for management.

CONCLUSION

These guidelines provide an up to date and evidence based summary of the current surgical knowledge in the management of IBD and will serve as a useful practical text for clinicians performing this type of surgery.