Post-operative recurrence in Crohn's disease. Critical analysis of potential risk factors. An update

The disease recurrence perception scale for patients with inflammatory bowel disease: Instrument development and cross-sectional validation study

Disease recurrence perception plays a key role in disease management and subsequent disease recurrence prevention. However, there are no specific tools for assessing disease recurrence perception in patients with inflammatory bowel disease (IBD) characterized by alternating remission and recurrence. To develop and validate an instrument for measuring disease recurrence perception of patients with IBD, the study was conducted in two steps: (1) instrument development and (2) psychometric tests. A total of 623 patients with IBD participated in the study. The common sense model of illness self-regulation (CSM) was used as a framework for instrument development. The administered version contained 48 items intended to be relevant to at least one of the six dimensions of the model. Based on preliminary analyzes, 12 items were deleted leaving 36 items for more detailed psychometric and factor analyzes. The Cronbach's alpha coefficient of the total 36-item instrument was 0.915. The content validity indexes at item and scale levels were satisfactory. The test-retest reliability of the total instrument was 0.870. Exploratory principal components analysis (n = 278) was used to identify six components congruent with intended CSM constructs that accounted for 62.6% of total item variance. Confirmatory factor analysis (n = 345) found acceptable fit for the six factor measurement model (χ2/df = 1.999, GFI = 0.846, NFI = 0.855, IFI = 0.922, TLI = 0.910, CFI = 0.921, RMSEA = 0.054). Overall, the DRPSIBD demonstrated satisfactory reliability and validity to warrant further development as a measure of disease recurrence perception of patients with IBD.

Interventional inflammatory bowel disease: current and future practice

PURPOSE OF REVIEW

Inflammatory bowel diseases (IBD) are associated with several well described neoplastic and structural complications. Increasing disease prevalence, healthcare barriers, and medication refractory phenotypes contribute to ongoing complications despite significant strides in medical management. Enhancements in endoscopic technology and techniques have allowed a minimally invasive approach for what has historically required surgery. In this article, we review the current and future landscape of endoscopic IBD intervention.

RECENT FINDINGS

Endoscopic resection is the first line for managing conventional and complex colitis-associated dysplasia. Evidence supporting endoscopic submucosal dissection is mounting, yet there is a paucity of studies evaluating modified endoscopic mucosal resection techniques or hybrid endoscopic submucosal dissection. We also have more clarity in how best to approach fibrostenotic disease, as we learn how to position endoscopic stricturotomy and stenting, relative to balloon dilation. Finally, applications in managing penetrating and postsurgical complications have been described, but still require further study.

SUMMARY

While important knowledge gaps still exist, the application of endoscopic therapies in IBD is more refined, especially within the management of colitis-associated dysplasia and strictures. The indications for endoscopy in perianal disease and other penetrating manifestations of Crohn's disease presents exciting opportunities for growth.

The ileal fungal microbiota is altered in Crohn's disease and is associated with the disease course

Introduction

Fungal microbiota's involvement in the pathogenesis of Crohn's disease (CD) is incompletely understood. The terminal ileum is a predilection site both for primary involvement and recurrences of CD. We, therefore, assessed the mucosa-associated mycobiota in the inflamed and non-inflamed ileum in patients with CD.

Methods

The mucosa-associated mycobiota was assessed by ITS2 sequencing in a total of 168 biopsies sampled 5 and 15 cm proximal of the ileocecal valve or ileocolic anastomosis in 44 CD patients and 40 healthy controls (HC). CD patients with terminal ileitis, with endoscopic inflammation at 5 cm and normal mucosa at 15 cm and no history of upper CD involvement, were analyzed separately. The need for additional CD treatment the year following biopsy collection was recorded.

Results

CD patients had reduced mycobiota evenness, increased Basidiomycota/Ascomycota ratio, and reduced abundance of Chytridiomycota compared to HC. The mycobiota of CD patients were characterized by an expansion of Malassezia and a depletion of Saccharomyces, along with increased abundances of Candida albicans and Malassezia restricta. Malassezia was associated with the need for treatment escalation during follow-up. Current anti-TNF treatment was associated with lower abundances of Basidiomycota. The alpha diversity of the inflamed and proximal non-inflamed mucosa within the same patients was similar. However, the inflamed mucosa had a more dysbiotic composition with increased abundances of Candida sake and reduced abundances of Exophiala equina and Debaryomyces hansenii.

Conclusions

The ileal mucosa-associated mycobiota in CD patients is altered compared to HC. The mycobiota in the inflamed and proximal non-inflamed ileum within the same patients harbor structural differences which may play a role in the CD pathogenesis. Increased abundance of Malassezia was associated with an unfavorable disease course.

State-of-the-art surgery for Crohn's disease: Part II-colonic Crohn's disease and associated neoplasms

Despite advances in medical therapy, surgery continues to play a vital role in the management of Crohn's disease and its complications. Continuing from Part I of this series (small intestine/ileal disease), we focus next on colonic Crohn's disease and associated neoplasms. We will first review the surgical management of medical-refractory Crohn's colitis and its complications and then examine cancer risk, surveillance, and surgical management of Crohn's-associated colorectal dysplasia and malignancy. We conclude with a discussion of restoration of gastrointestinal continuity following colonic surgery for Crohn's disease.

Deep Learning Analysis of Histologic Images from Intestinal Specimen Reveals Adipocyte Shrinkage and Mast Cell Infiltration to Predict Postoperative Crohn Disease

Most patients with Crohn disease (CD), a chronic inflammatory gastrointestinal disease, experience recurrence despite treatment, including surgical resection. However, methods for predicting recurrence remain unclear. This study aimed to predict postoperative recurrence of CD by computational analysis of histopathologic images and to extract histologic characteristics associated with recurrence. A total of 68 patients who underwent surgical resection of the intestine were included in this study and were categorized into two groups according to the presence or absence of postoperative disease recurrence within 2 years after surgery. Recurrence was defined using the CD Activity Index and the Rutgeerts score. Whole-slide images of surgical specimens were analyzed using deep learning model EfficientNet-b5, which achieved a highly accurate prediction of recurrence (area under the curve, 0.995). Moreover, subserosal tissue images with adipose cells enabled highly accurate prediction. Adipose cell morphology showed significant between-group differences in adipose cell size, cell-to-cell distance, and cell flattening values. These findings suggest that adipocyte shrinkage is an important histologic characteristic associated with recurrence. Moreover, there was a significant between-group difference in the degree of mast cell infiltration in the subserosa. These findings show the importance of mesenteric adipose tissue in patient prognosis and CD pathophysiology. These findings also suggest that deep learning-based artificial intelligence enables the extraction of meaningful histologic features.

Characterization of Crohn's disease patients in Egypt: Risk factors for postoperative recurrence (A cohort study)

BACKGROUND

The aim of study to identify the characterizations of Crohn's disease in Egyptian patients and to determine its predictors for postoperative recurrence.

METHODS

We conducted a retrospective observational cohort study on 15 patients diagnosed as Crohn's disease with surgical interventions. Different characteristics of studied patients were analyzed to determine the risk factors for postoperative recurrence such as age at diagnosis, gender, smoking, main presenting symptom, Montreal classification, perianal disease, laboratory findings and protocol of management including surgical characteristics like age at operation, surgical indication, preoperative medication, surgical approach, and operative findings.

RESULTS

Nine of the studied patients (60%) suffered from clinical postoperative recurrence with mean duration of 23.5 ± 40.6 months. In comparison the demographic, clinical, operative, and medical treatment data between patients with postoperative recurrence of Crohn's disease and those without recurrence, age at diagnosis (mean age 42.9 years) and age at operation (mean 44.7 years) were found statistically significant in postoperative recurrence group (p-value = 0.001). According to Montreal classification of Crohn's disease, patients >40 years were significantly found in postoperative recurrence group, while patients between 17 and 40 years were significantly found in postoperative non-recurrence group (p-value=0.007) and ileal location of Crohn's disease was found significantly in postoperative recurrent group (p-value=0.044). Postoperative biological therapy significantly decreased the incidence of postoperative recurrence in the current study (p-value= 0.041).

CONCLUSIONS

Age at diagnosis, age at operation, ileal location of Crohn's disease can significantly predict postoperative recurrence. Also, postoperative biological therapy can significantly decrease the incidence of postoperative recurrence.

Nr4A1 modulates inflammation-associated intestinal fibrosis and dampens fibrogenic signaling in myofibroblasts

Intestinal fibrosis is a common complication of the inflammatory bowel diseases (IBDs), contributing to tissue stiffening and luminal narrowing. Human nuclear receptor 4A 1 (NR4A1) was previously reported to regulate mesenchymal cell function and dampen fibrogenic signaling. NR4A1 gene variants are associated with IBD risk, and it has been shown to regulate intestinal inflammation. Here, we tested the hypothesis that NR4A1 acts as a negative regulator of intestinal fibrosis through regulating myofibroblast function. Using the SAMP1/YitFc mouse, we tested whether two pharmacological agents known to enhance NR4A1 signaling, cytosporone B (Csn-B) or 6-mercaptopurine (6-MP), could reduce fibrosis. We also used the dextran sulfate sodium (DSS) model of colitis and assessed the magnitude of colonic fibrosis in mouse nuclear receptor 4A 1 (Nr4a1^-/-) and their wild-type littermates (Nr4a1^+/+). Lastly, intestinal myofibroblasts isolated from Nr4a1^-/- and Nr4a1^+/+ mice or primary human intestinal myofibroblasts were stimulated with transforming growth factor-β1 (TGF-β1), in the presence or absence of Csn-B or 6-MP, and proliferation and ECM gene expression assessed. Csn-B or 6-MP treatment significantly reduced ileal thickness, collagen, and overall ECM content in SAMP1/YitFc mice. This was associated with a reduction in proliferative markers within the mesenchymal compartment. Nr4a1^-/- mice exposed to DSS exhibited increased colonic thickening and ECM content. Nr4a1^-/- myofibroblasts displayed enhanced TGF-β1-induced proliferation. Furthermore, Csn-B or 6-MP treatment was antiproliferative in Nr4a1^+/+ but not Nr4a1^-/- cells. Lastly, activating NR4A1 in human myofibroblasts reduced TGF-β1-induced collagen deposition and fibrosis-related gene expression. Our data suggest that NR4A1 can attenuate fibrotic processes in intestinal myofibroblasts and could provide a valuable clinical target to treat inflammation-associated intestinal fibrosis.NEW & NOTEWORTHY Fibrosis and increased muscle thickening contribute to stricture formation and intestinal obstruction, a complication that occurs in 30%-50% of patients with CD within 10 yr of disease onset. More than 50% of those who undergo surgery to remove the obstructed bowel will experience stricture recurrence. To date, there are no drug-based approaches approved to treat intestinal strictures. In the current submission, we identify NR4A1 as a novel target to treat inflammation-associated intestinal fibrosis.

What are the predictors for recurrence of Crohn's disease after surgery?

Surgical resection is an unavoidable part of the current treatment options for Crohn's disease (CD), and more than half of patients develop recurrence. The aim of this study was to investigate the predictors for recurrence in the long-term follow-up of CD patients after surgery.Medical records of consecutive CD patients who were operated on between January 2003 and January 2015 were retrospectively analyzed. Data including demographic and clinical characteristics of the patients were recorded. Recurrence was evaluated based on the Crohn's Disease Activity Index or endoscopic findings.The majority of 112 patients were males (n = 64, 57.1%), and 61 (54.4%) of them were active smokers. The median follow-up was 113 (range: 61-197) months. Disease recurrence occurred in 16 (14.3%) patients at a median of 13.5 months. The endoscopic recurrence rate was 8% (n = 9) at 1 year, 12.5% (n = 14) at 5 years, and 13.4% (n = 15) at 10 years. One (0.9%) patient underwent colonoscopic balloon dilatation at 1 year, and 7 (6.3%) patients needed re-resection at a median of 36 months. The age of the patient at the time of diagnosis (P = .033), penetrating disease behavior (P = .011), intra-abdominal abscess (P = 0.040) and, concomitant fistula and intra-abdominal abscess (P = .017) were associated with disease recurrence.Our study results suggest that the patients' age at the time of diagnosis, penetrating disease, intra-abdominal abscess, and concomitant fistula and abscess are the risk factors for CD recurrence after surgery.

Bacterial Mucosa-associated Microbiome in Inflamed and Proximal Noninflamed Ileum of Patients With Crohn's Disease

BACKGROUND

Microbiota is most likely essential in the pathogenesis of Crohn's disease (CD). Fecal diversion after ileocecal resection (ICR) protects against CD recurrence, whereas infusion of fecal content triggers inflammation. After ICR, the majority of patients experience endoscopic recurrence in the neoterminal ileum, and the ileal microbiome is of particular interest. We have assessed the mucosa-associated microbiome in the inflamed and noninflamed ileum in patients with CD.

METHODS

Mucosa-associated microbiome was assessed by 16S rRNA sequencing of biopsies sampled 5 and 15 cm orally of the ileocecal valve or ileocolic anastomosis.

RESULTS

Fifty-one CD patients and forty healthy controls (HCs) were included in the study. Twenty CD patients had terminal ileitis, with endoscopic inflammation at 5 cm, normal mucosa at 15 cm, and no history of upper CD involvement. Crohn's disease patients (n = 51) had lower alpha diversity and separated clearly from HC on beta diversity plots. Twenty-three bacterial taxa were differentially represented in CD patients vs HC; among these, Tyzzerella 4 was profoundly overrepresented in CD. The microbiome in the inflamed and proximal noninflamed ileal mucosa did not differ according to alpha diversity or beta diversity. Additionally, no bacterial taxa were differentially represented.

CONCLUSIONS

The microbiome is similar in the inflamed and proximal noninflamed ileal mucosa within the same patients. Our results support the concept of CD-specific microbiota alterations and demonstrate that neither ileal sublocation nor endoscopic inflammation influence the mucosa-associated microbiome.

The advanced lung cancer inflammation index predicts outcomes in patients with Crohn's disease after surgical resection

AIM

Precise biomarkers for predicting prognosis could help to identify high-risk Crohn's disease (CD) patients to facilitate better follow-up during the postoperative course. In this study, the primary aim is the identification of the most reliable nutrition marker that predicts surgical relapse in CD patients.

METHOD

We first evaluated the predictive value of various nutrition markers for postoperative surgical relapse in CD patients and identified the advanced lung cancer inflammation index (ALI) as a promising biomarker. Then, we assessed the clinical significance of preoperative ALI in CD patients using two cohorts.

RESULTS

Preoperative ALI showed the highest correlation with reoperation rate compared with other nutritional parameters in CD patients receiving surgical resection (sensitivity 53%, specificity 86%, area under the curve 0.71). Lower levels of preoperative ALI were significantly correlated with the presence of perianal disease. A lower level of preoperative ALI was an independent prognostic factor for reoperation rate after an intestinal resection (hazard ratio 3.37, 95% CI 1.38-10.12, P = 0.006), and the prognostic impact of preoperative ALI was successfully validated in an independent cohort using the same cut-off value.

CONCLUSION

Preoperative ALI might be useful for postoperative management of CD patients.

The Role of Active Inflammation and Surgical Therapy in Crohn's Disease Recurrence

An altered balance between effector and regulatory factors is supposed to sustain the tissue-damaging immune response in inflammatory bowel disease (IBD). Several studies demonstrate that severe active inflammation is a strong predictor for surgical complications and recurrence. Indeed, bowel resection in Crohn's disease (CD) patients has a high surgical recurrence rate. In this review, we examined the IBD inflammatory pathways, the current surgical treatments, and the almost inevitable recurrence. The question that might arise is if the cure of intestinal CD is to be found in the surgical approach. A selective search of two databases (PubMed and the Cochrane Library) has been carried out without considering a specific time horizon as inclusion criteria. The scope of this literature review was investigating on the role of inflammation in the management of CD. The following key words have been used to develop the query string: (i) inflammation; (ii) Crohn's disease; (iii) surgery; and (iv) postsurgical recurrence.

The Influence of Microscopic Inflammation at Resection Margins on Early Postoperative Endoscopic Recurrence After Ileocaecal Resection for Crohn's Disease

BACKGROUND AND AIMS

The pathogenesis and risk factors for early postoperative endoscopic recurrence of Crohn's disease [CD] remain unclear. Thus, this study aimed to identify whether histological inflammation at the resection margins after an ileocaecal resection influences endoscopic recurrence.

METHODS

We have prospectively followed up patients with CD who underwent ileocaecal resection at our hospital between January 2012 and January 2018. The specimens were histologically analysed for inflammation at both of the resection margins [ileal and colonic]. We evaluated whether histological results of the resection margins are correlated with endoscopic recurrence of CD based on colonoscopy 6 months after ileocaecal resection. Second, we assessed the influence of known risk factors and preoperative therapy on endoscopic recurrence of CD.

RESULTS

A total of 107 patients were included in our study. Six months after ileocaecal resection, 23 patients [21.5%] had an endoscopic recurrence of CD. The histological signs of CD at the resection margins were associated with a higher endoscopic recurrence [56.5% versus 4.8%, p < 0.001]. Disease duration from diagnosis to surgery [p = 0.006] and the length of the resected bowel [p = 0.019] were significantly longer in patients with endoscopic recurrence. Smoking was also proved to be a risk factor for endoscopic recurrence [p = 0.028].

CONCLUSIONS

Histological inflammation at the resection margins was significantly associated with a higher risk of early postoperative endoscopic recurrence after an ileocaecal resection for CD.

Surgical Recurrence at Anastomotic Site After Bowel Resection in Crohn's Disease: Comparison of Kono-S and End-to-end Anastomosis

BACKGROUND

Anastomotic surgical recurrence after bowel resection in Crohn's disease patients is problematic. This study was performed to evaluate the increased risk of anastomotic surgical recurrence.

METHODS

From 2006 to 2016, we performed anastomoses in 215 consecutive Crohn's disease patients. The cohort was divided into two groups: Kono-S anastomosis (n = 117) and end-to-end anastomosis (n = 98). Multivariate analysis of predictors of anastomotic surgical recurrence and Kaplan-Meier analysis for the 5-year anastomotic surgical recurrence rate were evaluated.

RESULTS

The two groups showed no statistically significant differences in patient backgrounds. During a median follow-up of 54 months, 28 patients required anastomotic surgical recurrence [4 (3.4%) in the Kono-S group and 24 (24.4%) in the end-to-end group]. Six leaks (5.1%) were detected in the Kono-S group and 17 leaks (17.3%) in the end-to-end group; all were successfully treated conservatively. End-to-end anastomosis, leakage, age < 45 years, and body mass index of ≥ 18 kg/m² at the first surgery had a higher risk of anastomotic surgical recurrence. Kono-S anastomosis significantly reduced the risk of anastomotic surgical recurrence after 1 year (odds ratio, 0.14). Anastomotic leakage influenced anastomotic surgical recurrence within 1 year (odds ratio, 4.84). The 5-year surgery-free survival rate at the anastomosis site with Kono-S anastomosis (95.0%) was significantly higher than that with end-to-end anastomosis (81.3%; P < 0.001).

CONCLUSIONS

Anastomotic leakage after bowel resection in Crohn's disease patients increased anastomotic surgical recurrence within 1 year, and Kono-S anastomosis is associated with a low risk of anastomotic surgical recurrence after > 1 year.

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

BACKGROUND AND AIMS

Inclusion of the mesentery during resection for colorectal cancer is associated with improved outcomes but has yet to be evaluated in Crohn's disease. This study aimed to determine the rate of surgical recurrence after inclusion of mesentery during ileocolic resection for Crohn's disease.

METHODS

Surgical recurrence rates were compared between two cohorts. Cohort A [n = 30] underwent conventional ileocolic resection where the mesentery was divided flush with the intestine. Cohort B [n = 34] underwent resection which included excision of the mesentery. The relationship between mesenteric disease severity and surgical recurrence was determined in a separate cohort [n = 94]. A mesenteric disease activity index was developed to quantify disease severity. This was correlated with the Crohn's disease activity index and the fibrocyte percentage in circulating white cells.

RESULTS

Cumulative reoperation rates were 40% and 2.9% in cohorts A and B [P = 0.003], respectively. Surgical technique was an independent determinant of outcome [P = 0.007]. Length of resected intestine was shorter in cohort B, whilst lymph node yield was higher [12.25 ± 13 versus 2.4 ± 2.9, P = 0.002]. Advanced mesenteric disease predicted increased surgical recurrence [Hazard Ratio 4.7, 95% Confidence Interval: 1.71-13.01, P = 0.003]. The mesenteric disease activity index correlated with the mucosal disease activity index [r = 0.76, p < 0.0001] and the Crohn's disease activity index [r = 0.70, p < 0.0001]. The mesenteric disease activity index was significantly worse in smokers and correlated with increases in circulating fibrocytes.

CONCLUSIONS

Inclusion of mesentery in ileocolic resection for Crohn's disease is associated with reduced recurrence requiring reoperation.

Adenocarcinoma Arising from Perianal Fistulizing Crohn's Disease

Perianal fistula is a very debilitating event and a cause of morbidity in patients with Crohn's disease (CD). Its malignant transformation is very rare with an incidence of around 0.004–0.7$. Presence of disease in the colon and rectum is the major risk factor for the development of a perianal fistula. In this report we show a case of adenocarcinoma arising from a perianal fistulizing CD. This type of tumor is highly aggressive, difficult to diagnose, and has a rather poor prognosis. The different neoplastic transformations and the different types of tumors that may appear in patients with CD, especially at the colorectal level or at the level of an eventual anastomosis, are to date well documented and described in the literature, while there is a lack of information and of treated cases concerning the occurrence of cancer at the level of a fistula. Due to the rarity of cases, we tried to identify the most frequent and important risk factors: sex, duration of disease, age at diagnosis, and the history of the fistula.

High Incidence of Recurrent Crohn's Disease Following Colectomy for Ulcerative Colitis Revealed with Long Follow-Up

BACKGROUND AND AIMS

Ulcerative colitis (UC) patients with progression of their disease despite optimized medical therapy may warrant "curative" proctocolectomy with end ileostomy or ileo-anal pouch (IPAA) anastomosis. The aim of our study was to assess the incidence of later recurrent ileitis that lead to altering the initial diagnosis to Crohn's disease (CD).

METHODS

A retrospective analysis was conducted on the inflammatory bowel disease database at Lenox Hill Hospital. The database consisted of patients that were diagnosed with UC or CD based on clinical assessment, endoscopic appearance, gross and histological examination, and imaging between 1960 and 2015. The post-colectomy follow-up period was at least 10 years. Recurrent disease was classified by evidence of transmural inflammation in the distal ileum, fistulizing disease, or stricturing disease.

RESULTS

From our IBD database, we identified 128 patients who underwent elective or urgent colectomy with the preoperative diagnosis of UC. Thirty-two (25%) had either an IPAA or end ileostomy with documented recurrence of inflammation in the small bowel mucosa consistent with CD. There was no significant difference between the type of surgical approach and the chance of recurrent disease (p = .20). The average time to clinically significant recurrence was 5 years.

CONCLUSION

The incidence of recurrent CD following colectomy for ulcerative colitis, when followed postoperatively for an average of 20 years, was 25%, considerably more than previously reported. Patients who come to colectomy for ulcerative colitis and are followed for at least 10 years show a high incidence of recurrent Crohn's disease in the ileostomy or ileo-anal pouch. Extended follow-up should be included in patients coming to colectomy for ulcerative colitis before they should be considered cured of their disease.

The current therapeutic options for Crohn's disease: from medical therapy to intestinal transplantation

Crohn's disease (CD) has an annual incidence per 100.000 person-year of 20.2 in North America and 12.7 in Europe, and the purpose of this review is to evaluate its medical management, from diagnosis to transplant. Pharmacologic manipulation with nutritional care aims to achieve and maintain remission, but more than half of patients will undergo an intestinal resection, very often repeated over time. They could experience short bowel syndrome (SBS) requiring total parenteral nutrition (TPN). Intestinal transplantation (ITx) represents an alternative in case of irreversible intestinal failure (IF) with life-threatening TPN complications. Patient survival after ITx is 79%, 53% and 43% at 1, 3 and 5 years respectively, with no differences among ITx for other disorders. Areas covered: The research discussed medical therapy with nutritional support, evaluating the role of endoscopy, surgery and transplant in CD. A systematic literature review was conducted using the PubMed search engine up to May 31^th, 2017 without restriction of the language. The decision on paper's eligibility was reached by consensus between the 3 screening authors. Expert commentary: CD treatment is mainly medical, leaving endoscopy and surgery for a complex course. ITx represents a therapeutic option if TPN complications with IF arise.

Risk factors for postoperative recurrence of Crohn's disease with emphasis on surgical predictors

Intestinal resection for Crohn’s disease is not curative and postoperative recurrence rates remain high. Early detection of indices associated with recurrence and risk stratification are fundamental for the postoperative management of patients. Early endoscopy at 6-12 months is the “gold standard” procedure, whereas other modalities such as fecal calprotectin and imaging techniques can contribute to the diagnosis of recurrence. The purpose of this review is to summarize current data regarding risk factors correlated with postoperative relapse. Smoking is a well-established, modifiable risk factor. There are sufficient data that correlate penetrating disease, perianal involvement, extensive resections, prior surgery, histological features (plexitis and granulomas), and improper management after resection with high rates for recurrence. The literature provides conflicting data for other possible predictors, such as age, sex, family history of inflammatory bowel disease, location of disease, strictureplasties, blood transfusions, and postoperative complications, necessitating further evidence. On the other hand, surgical factors such as anastomotic configuration, open or laparoscopic approach, and microscopic disease at specimen margins when macroscopic disease is resected, seem not to be related with an increased risk of recurrence. Further recognition of histological features as well as gene-related factors are promising fields for research.

[Second Korean Guidelines for the Management of Crohn's Disease]

Crohn's disease (CD) is a chronic, progressive, and disabling inflammatory bowel disease (IBD) with an uncertain etiopathogenesis. CD can involve any site of the gastrointestinal tract from the mouth to the anus, and is associated with serious complications, such as bowel strictures, perforations, and fistula formation. The incidence and prevalence rates of CD in Korea are still lower compared with those in Western countries, but they have been rapidly increasing during the recent decades. Although there are no definitive curative modalities for CD, various medical and surgical therapies have been applied for the treatment of this disease. Concerning CD management, there have been substantial discrepancies among clinicians according to their personal experience and preference. To suggest recommendable approaches to the diverse problems of CD and to minimize the variations in treatment among physicians, guidelines for the management of CD were first published in 2012 by the IBD Study Group of the Korean Association for the Study of the Intestinal Diseases. These are the revised guidelines based on updated evidence, accumulated since 2012. These guidelines were developed by using mainly adaptation methods, and encompass induction and maintenance treatment of CD, treatment based on disease location, treatment of CD complications, including stricture and fistula, surgical treatment, and prevention of postoperative recurrence. These are the second Korean guidelines for the management of CD and will be continuously revised as new evidence is collected.

Second Korean guidelines for the management of Crohn's disease

Crohn's disease (CD) is a chronic, progressive, and disabling inflammatory bowel disease (IBD) with an uncertain etiopathogenesis. CD can involve any site of the gastrointestinal tract from the mouth to the anus, and is associated with serious complications, such as bowel strictures, perforations, and fistula formation. The incidence and prevalence rates of CD in Korea are still lower compared with those in Western countries, but they have been rapidly increasing during the recent decades. Although there are no definitive curative modalities for CD, various medical and surgical therapies have been applied for the treatment of this disease. Concerning CD management, there have been substantial discrepancies among clinicians according to their personal experience and preference. To suggest recommendable approaches to the diverse problems of CD and to minimize the variations in treatment among physicians, guidelines for the management of CD were first published in 2012 by the IBD Study Group of the Korean Association for the Study of Intestinal Diseases. These are the revised guidelines based on updated evidence, accumulated since 2012. These guidelines were developed by using mainly adaptation methods, and encompass induction and maintenance treatment of CD, treatment based on disease location, treatment of CD complications, including stricture and fistula, surgical treatment, and prevention of postoperative recurrence. These are the second Korean guidelines for the management of CD and will be continuously revised as new evidence is collected.

Short Bowel Syndrome and Intestinal Failure in Crohn's Disease

Crohn's disease is a chronic and progressive inflammatory disorder of the gastrointestinal tract. Despite the availability of powerful immunosuppressants, many patients with Crohn's disease still require one or more intestinal resections throughout the course of their disease. Multiple resections and a progressive reduction in bowel length can lead to the development of short bowel syndrome, a form of intestinal failure that compromises fluid, electrolyte, and nutrient absorption. The pathophysiology of short bowel syndrome involves a reduction in intestinal surface area, alteration in the enteric hormonal feedback, dysmotility, and related comorbidities. Most patients will initially require parenteral nutrition as a primary or supplemental source of nutrition, although several patients may eventually wean off nutrition support depending on the residual gut anatomy and adherence to medical and nutritional interventions. Available surgical treatments focus on reducing motility, lengthening the native small bowel, or small bowel transplantation. Care of these complex patients with short bowel syndrome requires a multidisciplinary approach of physicians, dietitians, and nurses to provide optimal intestinal rehabilitation, nutritional support, and improvement in quality of life.

Systematic review with meta-analysis: the adverse effects of tobacco smoking on the natural history of Crohn's disease

BACKGROUND

Tobacco smoking is a well-established risk factor for the development of Crohn's disease, and this may lead to a more complicated disease course. However, recent evidence suggests that many patients with Crohn's disease are unaware of this fact.

AIM

To perform a systematic review and meta-analysis of the effects of smoking on disease course in Crohn's disease.

METHODS

A search of MEDLINE, EMBASE and EMBASE classic was carried out (up to July 2015) to identify observational studies reporting data on smoking and rates of surgery or flares of disease activity in patients with Crohn's disease. Dichotomous data were pooled to obtain odds ratios (ORs) for flares of disease activity or need for surgery, with 95% confidence intervals (CIs).

RESULTS

The search identified 33 eligible studies. Compared with nonsmokers, smokers had increased odds of flare of disease activity (OR, 1.56; 95% CI, 1.21-2.01), flare after surgery (OR, 1.97; 95% CI, 1.36-2.85), need for first surgery (OR, 1.68; 95% CI, 1.33-2.12) and need for second surgery (OR, 2.17; 95% CI, 1.63-2.89). The odds of these outcomes among ex-smokers diminished upon smoking cessation, with ORs comparable to those among nonsmokers and, in the case of flare or second surgery, significantly lower than smokers.

CONCLUSIONS

Smokers with Crohn's disease have a more complicated disease course than nonsmokers, and quitting smoking may ameliorate this. Patients should be reminded of the detrimental effects of smoking on the course of their disease, and smoking cessation advice should be provided to reduce disease burden and costs in these patients.

Colorectal Cancer in Patients With Inflammatory Bowel Disease: The Need for a Real Surveillance Program

The association between inflammatory bowel disease (IBD) and colorectal cancer (CRC) has been widely shown. This association is responsible for 10% to 15% of deaths in patients with IBD, even if according to some studies, the risk of developing CRC seems to be decreased. An adequate surveillance of patients identified as at-risk patients, might improve the management of IBD-CRC risk. In this article we review the literature data related to IBD-CRC, analyze potential risk factors such as severity of inflammation, duration, and extent of IBD, age at diagnosis, sex, family history of sporadic CRC, and coexistent primary sclerosing cholangitis, and update epidemiology on the basis of new studies. Confirmed risk factors for IBD-CRC are severity, extent, and duration of colitis, the presence of coexistent primary sclerosing cholangitis, and a family history of CRC. Current evidence-based guidelines recommend surveillance colonoscopy for patients with colitis 8 to 10 years after diagnosis, further surveillance is decided on the basis of patient risk factors. The classic white light endoscopy, with random biopsies, is now considered unsatisfactory. The evolution of technology has led to the development of new techniques that promise to increase the effectiveness of the monitoring programs. Chromoendoscopy has already proved highly effective and several guidelines suggest its use with a target biopsy. Confocal endomicroscopy and autofluorescence imaging are currently being tested and for this reason they have not yet been considered as useful in surveillance programs.