Magnetic resonance enterography for predicting the clinical course of Crohn's disease strictures

Colonic strictures in Crohn's disease: a non-surgical survival

BACKGROUND

Colonic stenosis in Crohn's disease (CD) is uncommon, and data on surgery-free survival are limited. This study aimed to determine surgery-free survival rates and identify associated factors.

PATIENTS AND METHODS

A retrospective study was conducted from 2003 to 2022, including patients with CD complicated by colonic stenosis. Patients with uncertain diagnoses or follow-up periods of less than six months were excluded.

RESULTS

Fifty-six patients were included (median age 44 years [range 14-65], male-to-female ratio = 0.93). Surgery-free survival rates were 58.9% at 6 months, 43.7% at 2 years, and 31.7% at 5 years, with an average surgery-free survival of 46.7 months. Univariate analysis showed that joint manifestations (p = 0.01), corticosteroids (p = 0.02), anti-TNF alpha (p = 0.02), salicylates (p = 0.02), and azathioprine (p = 0.01) increased surgery-free survival. Complications such as collections or internal fistulas (p = 0.03), parietal ulceration on imaging (p = 0.01), and acute intestinal obstruction (p = 0.01) were associated with reduced surgery-free survival. In multivariate analysis, biologic therapy was the only independent protective factor against surgery (p = 0.001, OR = 0.19).

CONCLUSION

The early introduction of biologic therapy is crucial for increasing surgery-free survival in patients with colonic stenosis in CD, given the limited effectiveness of conventional treatments.

Crohn's Disease Stricture Response to Treatment Assessed with Magnetic Resonance Imaging and Intestinal Ultrasound: STRIDENT Randomized Trial

BACKGROUND

Transmural healing is emerging as a key treatment target in Crohn's disease. This study aimed to determine the role of magnetic resonance imaging (MRI) and intestinal ultrasound (IUS) in the assessment of the radiologic response of Crohn's disease strictures to treatment.

METHODS

The STRIDENT (Stricture Definition and Treatment) study was a randomized controlled trial of (2:1) intensive high-dose adalimumab combined with a thiopurine vs standard dose monotherapy adalimumab in patients with stricturing Crohn's disease. Clinical response was defined as a reduction in the Obstructive Symptom Score at 12 months. Intestinal ultrasound was performed at baseline, 4, 8, and 12 months and MRI at baseline and 12 months. This study examines secondary outcomes of stricture resolution and changes in stricture morphology with treatment.

RESULTS

Of 77 patients, 52 were in the intensive treatment group and 25 in the standard therapy group. Clinical response was achieved in 56 of 77 patients (73%). Complete stricture resolution occurred in 17 patients on IUS (29%) and 16 patients on MRI (22%). Stricture improvement occurred in 23 of 59 patients on IUS (39%) and 24 of 72 patients on MRI (33%). Bowel wall thickness improved at 12 months on both IUS (P < .0001) and MRI (P < .001) and was significantly lower in clinical responders (IUS P = .003) and those with fecal calprotectin < 100 µg/g (IUS P < .001; MRI P = .001).

CONCLUSIONS

Radiologic severity of Crohn's disease strictures can improve with drug treatment, with complete stricture resolution observed in some. Intestinal ultrasound and MRI are effective modalities for monitoring the treatment response in patients with stricturing Crohn's disease (STRIDENT Drug Therapy Study: NCT03220841).

The Current Role of Imaging in the Diagnosis of Inflammatory Bowel Disease and Detection of Its Complications: A Systematic Review

Inflammatory bowel disease (IBD) encompasses complex gastrointestinal (GI) conditions, primarily Crohn's disease (CD) and ulcerative colitis (UC), requiring precise imaging for effective diagnosis and management of complications. This systematic review aimed to evaluate the current role of imaging modalities in diagnosing IBD and detecting related complications. The review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We performed a literature search using text words and controlled vocabulary applying Boolean operators "AND," "OR," with various combinations on databases such as PubMed, Embase, and Cochrane Library. The search targeted open-access articles involving humans, with full-text available, and published in the English Language from 2005 to 2024. The quality of the included studies was assessed using the Cochrane Risk-of-Bias (RoB) checklist. Our search process identified 127 records from Cochrane (39), Embase (29), and PubMed (59). After removing 98 irrelevant records, 29 underwent further screening. Five were excluded as they involved irrelevant problems or outcomes, leaving us with 24 reports with full text, all of which were accessible. Following the eligibility assessment, two more reports were excluded due to inaccessibility, and 22 studies were included in the final analysis. The risk of bias and methodological quality assessment revealed that out of 22 studies analyzed, five (23%) had a high risk of bias, while 13 (59%) were classified as moderate risk, and four (18%) showed low risk. This distribution highlights a predominance of moderate-risk studies in research on imaging in IBD, emphasizing the need for enhanced study designs in future investigations. Our findings revealed the varying effectiveness of imaging modalities in diagnosing complications of CD and UC. Magnetic resonance enterography (MRE) stands out as the preferred method for CD due to its high sensitivity and noninvasive nature. In contrast, colonoscopy remains the gold standard for UC, providing direct visualization of mucosal lesions. While techniques like ultrasound and capsule endoscopy offer valuable insights, they have limitations that may affect their utility in certain cases.

Imaging and clinical predictors of surgery in stricturing ileal Crohn's disease: a retrospective study from a large pediatric hospital

PURPOSE

(1) To determine the frequency of surgical management in children with Crohn's Disease (CD) and a new radiologic ileal stricture, and (2) to identify imaging and clinical features that predict the need for surgery.

METHODS

This retrospective study included pediatric patients (< 21 years old) with CD and a new ileal stricture diagnosed by MRE, CTE, or CT between July 2018 and June 2023. Three board-certified radiologists recorded stricture length, maximum mural thickness, minimum lumen diameter, maximum upstream diameter, and simplified magnetic resonance index of activity (sMaRIA) score. Anthropometrics, laboratory data, and surgical interventions performed after stricture diagnosis were also recorded. Multivariable logistic regression was used to identify imaging and clinical variables associated with the need for surgery.

RESULTS

44 pediatric CD patients (median age 16.5 years) presented with a new ileal stricture during the study period. 30 (68.2%) patients required surgery, with a median time of 87.5 days between stricture diagnosis and surgery. Median stricture measurements were length: 7.0 cm, maximum mural thickness: 7.3 mm, minimum lumen diameter: 0.2 cm, and maximum upstream diameter: 3.3 cm. Median sMaRIA score was 3.0, and 14 (31.8%) strictures had associated internal penetrating disease. Stricture ratio (ratio of maximum upstream lumen diameter to minimum lumen diameter) (OR = 1.15 [95% CI 1.02-1.30]; p = 0.02) and sMaRIA (OR = 2.12 [95% CI 0.87-5.17; p = 0.10) were associated with need for surgery.

CONCLUSION

Surgery remains common in stricturing pediatric CD, with increasing stricture ratio and sMaRIA score associated with need for surgical management.

Ultrasound Characteristics Can Predict Response to Biologics Therapy in Stricturing Crohn's Disease

INTRODUCTION

Stricture is a common complication in Crohn's disease (CD). Accurate identification of strictures that poorly respond to biologic therapy is essential for making optimal therapeutic decisions. The aim of this study was to determine the association between ultrasound characteristics of strictures and their therapeutic outcomes.

METHODS

Consecutive CD patients with symptomatic strictures scheduled for biologic therapy were retrospectively recruited at a tertiary hospital. Baseline intestinal ultrasound was conducted to assess stricture characteristics, including bowel wall thickness, length, stratification, vascularity, and creeping fat wrapping angle. Patients were followed up for a minimum of 1 year, during which long-term outcomes including surgery, steroid-free clinical remission, and mucosal healing were recorded. Statistical analyses were performed.

RESULTS

A total of 43 patients were enrolled. Strictures were located in the ileocecal region (39.5%), colon (37.2%), anastomosis (20.9%), and small intestine (2.3%). The median follow-up time was 17 months (interquartile range 7-25), with 27 patients (62.8%) undergoing surgery. On multivariant analysis, creeping fat wrapping angle > 180° (odds ratio: 6.2, 95% confidence interval [CI]: 1.1-41.1) and a high Limberg score (odds ratio: 2.3, 95% CI: 1.4-6.0) were independent predictors of surgery, with an area under the curve of 0.771 (95% CI: 0.602-0.940), accuracy of 83.7%, sensitivity of 96.3%, and specificity of 62.5%. On Cox survival analysis, creeping fat >180° was significantly associated with surgery (hazard ratio, 5.2; 95% CI: 1.2-21.8; P = 0.03). In addition, creeping fat was significantly associated with steroid-free clinical remission ( P = 0.015) and mucosal healing ( P = 0.06).

DISCUSSION

Intestinal ultrasound characteristics can predict outcomes in patients with stricturing CD who undertook biologic therapy.

Bowel Stiffness Assessed by Shear-Wave Ultrasound Elastography Predicts Disease Behavior Progression in Patients With Crohn's Disease

INTRODUCTION

There is a lack of reliable predictors of disease behavior progression in patients with Crohn's disease (CD). Real-time shear-wave elastography (SWE) is a novel method for evaluating tissue stiffness. However, its value for assessing CD has not yet been investigated. We aimed to explore the value of SWE and other ultrasound parameters at diagnosis in predicting CD behavior progression.

METHODS

We retrospectively collected data from patients with CD with the nonstenotic nonpenetrating disease (B1 phenotype based on the Montreal classification). All patients underwent intestinal ultrasound at baseline and were followed up. The end point was defined as disease behavior progression to stricturing (B2) or penetrating (B3) disease. Cox regression analysis was performed for the association between baseline characteristics and subsequent end points. In addition, a multivariate nomogram was established to predict the risk of disease behavior progression quantitatively.

RESULTS

A total of 130 patients with CD with B1 phenotype were enrolled. Twenty-seven patients (20.8%) developed B2 or B3 disease, with a median follow-up of 33 months. Multivariate analysis identified that SWE was the only independent predictor of disease behavior progression (hazard ratio 1.08, 95% confidence interval 1.03-1.12, P = 0.001). A reverse of the HR appeared at the cutoff 12.75 kPa. The nomogram incorporating SWE and other clinical characteristics showed a good prediction performance (area under the curve = 0.792).

DISCUSSION

Intestinal stiffness assessed using SWE is an independent predictor of disease behavior progression in patients with CD. Patients with CD with SWE >12.75 kPa at diagnosis are prone to progress toward stricturing or penetrating diseases.

Comprehensive review and update of stricturing Crohn's disease

Up to 50% of patients with Crohn's disease develop a stricture within 10 years of diagnosis. Crohn's strictures can compose of inflammation, fibrosis or smooth muscle expansion and usually a combination of these. There have been numerous new developments in imaging modalities in determining the composition of Crohn's strictures. Magnetic resonance imaging remains the best upfront imaging modality to characterize Crohn's strictures. Gastrointestinal ultrasound (GIUS) has an increasing role in clinical practice, particularly for monitoring stricture response as a treat-to-target tool. Novel imaging techniques to differentiate between fibrosis and inflammatory strictures have been developed including contrast-enhanced GIUS, strain or shear wave elastography with GIUS and multiple new magnetic resonance imaging (MRI) protocols, including diffusion weighted, delayed contrast enhancement and magnetization transfer MR protocols. However, these techniques require further validation and standardization. Regarding therapeutics, anti-tumor necrosis agents with a treat-to-target strategy have the highest quality evidence in treating strictures and can lead to stricture regression in some cases. Endoscopic balloon dilatation remains a mainstay in the treatment algorithm of treating predominantly fibrostenotic Crohn's strictures, particularly those which are symptomatic, < 5 cm in length and not causing prestenotic dilatation. Endoscopic balloon dilatation has greater effectiveness in anastomotic strictures. Surgery remains an important treatment option in Crohn's strictures, with segmental resection and stricturoplasty having their own advantages and disadvantages. Kono-S anastomosis may be superior to conventional anastomosis for endoscopic recurrence; however, further high-quality studies are required to confirm this. Using risk stratification models such as the BACARDI risk model is important to guide management decisions between a medical and surgical approach. Early post-operative medical prophylaxis with an advanced therapy is an important consideration to prevent disease recurrence. This review expands on the above topics, highlights research gaps and provides a suggested investigation and management pathway in stricturing Crohn's disease.

Infliximab response associates with radiologic findings in bio-naïve Crohn's disease

OBJECTIVES

Since a reliable model for predicting infliximab (IFX) benefits in bio-naïve Crohn's disease (CD) is still lacking, we constructed a magnetic resonance enterography (MRE)-based model to predict the risk of loss of response to IFX in bio-naïve patients with CD.

METHODS

This retrospective multicenter study enrolled 188 bio-naïve patients with CD who underwent MRE before IFX therapy. Therapeutic outcomes were determined based on clinical symptoms and endoscopic findings within 52 weeks. The areas of bowel wall segmentation were decided by two experienced radiologists in consensus. Texture features were extracted using the least absolute shrinkage and selection operator, and a radiomic model was built using multivariate logistic regression. The model performance was validated by receiver operating characteristic, calibration curve, and decision curve analysis.

RESULTS

The area under the curve of radiomic model was 0.88 (95% confidence interval: 0.82-0.95), and the model provided clinical net benefit in identifying the loss of response to IFX and exhibited remarkable robustness among centers, scanners, and disease characteristics. The high-risk patients defined by the radiomic model were more likely to develop IFX nonresponse than low-risk patients (all p < 0.05).

CONCLUSIONS

This novel pretreatment MRE-based model could act as an effective tool for the early estimation of loss of response to IFX in bio-naïve patients with CD.

KEY POINTS

• Magnetic resonance enterography model guides infliximab therapy in Crohn's disease. • The model presented significant discrimination and provided net clinical benefit. • Model divided patients into low- and high-risk groups for infliximab failure.

Intestinal MRI in Inflammatory Bowel Disease - Literature and Survey-Based Recommendations regarding Reporting by the German Radiological Society (DRG) and the German Competence Network for Inflammatory Bowel Diseases

BACKGROUND

MR-enterography/enteroclysis (MRE) is increasingly used for primary diagnosis, detection of complications, and monitoring of patients with inflammatory bowel disease (IBD). Standardization of reporting is relevant to ensure quality of the methodology and to improve communication between different faculties. The current manuscript describes the features that are required for optimized reporting of MRE in IBD.

METHODS

An expert consensus panel of radiologists and gastroenterologists conducted a systematic search of the literature. In a Delphi process, members of the German Radiological Society (DRG) and members of the Competence Network for Inflammatory Bowel Diseases voted on relevant criteria for the reporting of findings in MRE. Based on the voting results, statements were developed by the expert consensus panel.

RESULTS

Clinically relevant aspects of MRE findings have been defined to optimize reporting and to standardize terminology. Minimal requirements for standardized reporting are suggested. The statements focus on the description of disease activity as well as on complications of IBD. Attributes of intestinal inflammation are described and illustrated by exemplary images.

CONCLUSION

The current manuscript provides standardized parameters and gives practical recommendations on how to report and how to characterize MRE findings in patients with IBD.

KEY POINTS

· Systematic overview provides practice-oriented recommendations and names and evaluates the decisive criteria for reporting and interpretation of MRI in inflammatory bowel disease.. · Standardized terminology and reporting criteria for MRI in IBD improves interdisciplinary communication.. · Standardized collection and documentation of MRI findings in IBD helps to further establish the method and to improve care for IBD patients..

CITATION FORMAT

· Wessling J, Kucharzik T, Bettenworth D et al. Intestinal MRI in Inflammatory Bowel Disease - Literature and Survey-Based Recommendations regarding Reporting by the German Radiological Society (DRG) and the German Competence Network for Inflammatory Bowel Diseases. Fortschr Röntgenstr 2023; 195: 675 - 690.

Treatment escalation and de-escalation decisions in Crohn's disease: Delphi consensus recommendations from Japan, 2021

BACKGROUND

We aimed to develop criteria for treatment intensification in patients with (1) luminal Crohn's disease (CD), (2) CD with perianal disease and/or fistula, (3) CD with small bowel stenosis, (4) in the postoperative setting, and (5) for discontinuing or reducing the dose of treatment in patients with CD.

METHODS

PubMed and Embase were searched for studies published since 1998 which may be relevant to the five defined topics. Results were assessed for relevant studies, with preference given to data from randomized, controlled studies. For each question, a core panel of 12 gastroenterologists defined the treatment target and developed statements, based on the literature, current guidelines, and relevant additional studies. The evidence supporting each statement was graded using the Oxford Centre for Evidence-Based Medicine: Levels of Evidence (March 2009). A modified Delphi process was used to refine statements and gain agreement from 54 Japanese specialists at in-person and online meetings conducted between October 2020 and April 2021.

RESULTS

Seventeen statements were developed for treatment intensification in luminal CD (targeting endoscopic remission), six statements for treatment intensification in perianal/fistulizing CD (targeting healing of perianal lesions and complete closure of the fistula), six statements for treatment intensification in CD with small bowel stenosis (targeting resolution of obstructive symptoms), seven statements for treatment intensification after surgery (targeting endoscopic remission), and five statements for discontinuing or reducing the dose of treatment in patients with CD.

CONCLUSIONS

These statements provide guidance on how and when to intensify or de-intensify treatment for a broad spectrum of patients with CD.

Computed tomography enterography predicts surgical-free survival in symptomatic stricturing Crohn's disease

OBJECTIVES

The study aimed to predict surgical risks for patients with symptomatic stricturing Crohn's disease (CD) using computed tomography enterography (CTE) and to assess the association between CTE findings and pathological changes.

METHODS

Crohn's disease patients with symptomatic stricture(s) were included. Exclusion criteria were concomitant penetrating disease, intra-abdominal abscess, previous bowel resection, or asymptomatic. Patients from January 2016 to December 2019 were identified as the primary cohort and those from January 2020 to June 2020 were identified as the validation cohort. Two independent experienced radiologists evaluated CTE variables including mucosal enhancement, mural stratification, wall enhancement, comb sign, lymphadenopathy, thick non-enhancing wall, bowel wall thickness, luminal diameter, and upstream lumen. Receiver operating characteristic, logistic regression, and nomogram were performed to identify the independent predictors of surgical-free survival. Histopathological scores of surgical specimens were also evaluated.

RESULTS

198 patients (primary cohort, 123 with surgery and 75 under non-surgical intervention, and 41 patients (validation cohort) were analyzed. Bowel wall thickness < 5.9 mm, luminal stenosis > 3.35 mm, and upstream lumen < 27.5 mm were predictors of surgical-free survival for symptomatic stricturing CD patients. Logistic analysis showed the three CTE variables were the independent predictors of surgical-free survival (p < 0.001). A nomogram was developed with the concordance indexes of 0.905 and 0.892 in the primary and validation cohorts. Histopathological analysis showed bowel wall muscular hyperplasia/hypertrophy significantly correlated with luminal stenosis (r = - 0.655, p = 0.008) and combined CTE variable (r = - 0.683, p = 0.005).

CONCLUSIONS

CTE is highly predictive of disease course and surgical-free survival for patients with symptomatic stricturing CD, suggesting the important role of CTE in decision-making of treatment.

[Position paper on reporting of intestinal ultrasound findings in patients with inflammatory bowel disease]

BACKGROUND

Intestinal ultrasound is increasingly used for primary diagnosis, detection of complications and monitoring of patients with Crohn's disease and ulcerative colitis. Standardization of reporting is relevant to ensure quality of the methodology and to improve communication between different specialties. The current manuscript describes the features required for optimized reporting of intestinal ultrasound findings in inflammatory bowel disease (IBD).

METHODS

An expert consensus panel of gastroenterologists, radiologists, pathologists, paediatric gastroenterologists and surgeons conducted a systematic literature search. In a Delphi- process members of the Kompetenznetz Darmerkrankungen in collaboration with members of the German Society for Radiology (DRG) voted on relevant criteria for reporting of findings in intestinal ultrasound. Based on the voting results statements were agreed by expert consensus.

RESULTS

Clinically relevant aspects of intestinal ultrasound (IUS) findings have been defined to optimize reporting and to standardize terminology. Minimal requirements for standardized reporting are suggested. The statements focus on description of disease activity as well as on complications of IBD. Attributes of intestinal inflammation are described and illustrated by exemplary images.

CONCLUSION

The current manuscript provides practical recommendations on how to standardize documentation and reporting from intestinal ultrasound findings in patients with IBD.

ECCO-ESGAR Topical Review on Optimizing Reporting for Cross-Sectional Imaging in Inflammatory Bowel Disease

BACKGROUND AND AIMS

The diagnosis and follow up of patients with inflammatory bowel disease [IBD] requires cross-sectional imaging modalities, such as intestinal ultrasound [IUS], magnetic resonance imaging [MRI] and computed tomography [CT]. The quality and homogeneity of medical reporting are crucial to ensure effective communication between specialists and to improve patient care. The current topical review addresses optimized reporting requirements for cross-sectional imaging in IBD.

METHODS

An expert consensus panel consisting of gastroenterologists, radiologists and surgeons convened by the ECCO in collaboration with ESGAR performed a systematic literature review covering the reporting aspects of MRI, CT, IUS, endoanal ultrasonography and transperineal ultrasonography in IBD. Practice position statements were developed utilizing a Delphi methodology incorporating two consecutive rounds. Current practice positions were set when ≥80% of the participants agreed on a recommendation.

RESULTS

Twenty-five practice positions were developed, establishing standard terminology for optimal reporting in cross-sectional imaging. Assessment of inflammation, complications and imaging of perianal CD are outlined. The minimum requirements of a standardized report, including a list of essential reporting items, have been defined.

CONCLUSIONS

This topical review offers practice recommendations to optimize and homogenize reporting in cross-sectional imaging in IBD.

Transabdominal Ultrasound and Magnetic Resonance Enterography in Inflammatory Bowel Disease: Results of an Observational Retrospective Single-Center Study

Purpose Transabdominal ultrasound (US) and magnetic resonance enterography (MRE) are used to assess disease activity and extent in IBD, but their impact on therapeutic decisions is unclear. Therefore, our study has two goals: to compare the usefulness of US and MRE in assessing disease extent and activity in the small and large bowel, and to determine the relevance for clinical decisions in IBD.

Materials and Methods We included 54 IBD patients who had undergone both MRE and US within three months. We used the construct reference standard model to compare MRE and US for detecting inflammation and examined the impact on clinical decisions in IBD patients.

Results In 54 IBD patients (44 patients Crohn’s disease (CD), 5 ulcerative colitis (UC), 5 indeterminate colitis (IC)), 42 patients (77.8%) showed inflammation either in the small or large bowel. Small bowel disease was present in 34 patients (77.3%). Complications were found in 19 patients (35.2%). MRE and US both showed high sensitivity (90.5 and 88.1%) and moderate specificity (50% in MRE and US) for detecting inflammation. MRE revealed higher sensitivity than US for detecting conglomerate tumors without statistical significance (85.7 vs. 71.4%, p=1.0) and equal specificity (97.9 vs 97.7, p=1.0). Therapeutic decisions included steroids in 20 patients (47.6%) and surgery/percutaneous drainage in six patients (14.3%), these decisions were triggered by results of US or MRE in equal distribution.

Conclusion US and MRE have comparable sensitivity and specificity for detecting intestinal inflammation and complications in IBD patients. Therefore, both methods are sufficient for making clinical decisions.

Intensive drug therapy versus standard drug therapy for symptomatic intestinal Crohn's disease strictures (STRIDENT): an open-label, single-centre, randomised controlled trial

BACKGROUND

Strictures are the most common structural complication of Crohn's disease. Surgery and endoscopic balloon dilation are the main treatments; drug therapy has been considered contraindicated. Given that most strictures have an inflammatory component, we aimed to find out whether strictures are responsive to drug treatment and whether intensive drug therapy is more effective than standard drug therapy.

METHODS

This open-label, single-centre, randomised controlled trial was performed in one specialist inflammatory bowel disease centre in Australia. Patients aged 18 years or older with Crohn's disease were included. Eligible patients had a de novo or postoperative anastomotic intestinal stricture on MRI or ileocolonoscopy, symptoms consistent with chronic or subacute intestinal obstruction (postprandial abdominal pain in the presence of a confirmed stricture), and evidence of active intestinal inflammation. Patients were randomly assigned (2:1) to receive intensive high-dose adalimumab (160 mg adalimumab once per week for 4 weeks followed by 40 mg every 2 weeks, with escalation of dose at 4 months and 8 months if assessment of disease activity indicated active inflammation) plus thiopurine (initial dose of azathioprine 2·5 mg/kg or mercaptopurine 1·5 mg/kg, with dose adjustment based on thiopurine metabolite testing) or standard adalimumab monotherapy (160 mg at week 0, 80 mg at week 2, then 40 mg every 2 weeks) using stratified fixed block randomisation. Stratification factors were stricture dilation at study baseline colonoscopy and current biologic drug use. The primary endpoint was improvement (decrease) in the 14-day obstructive symptom score at 12 months by one or more points compared with baseline. This trial is registered with ClinicalTrials.gov, NCT03220841, and is completed.

FINDINGS

Between Sept 10, 2017, and Sept 6, 2019, 123 patients were screened and 77 randomly assigned to intensive adalimumab plus thiopurine treatment (n=52) or standard adalimumab treatment (n=25). At 12 months, improvement in obstructive symptom score was noted in 41 (79%) of 52 patients in the intensive treatment group and 16 (64%) of 25 in the standard treatment group (odds ratio [OR] 2·10 [95% CI 0·73-6·01]; p=0·17). Treatment failure occurred in five (10%) patients in the intensive treatment group versus seven (28%) in the standard treatment group (OR 0·27 [95% CI 0·08-0·97]; p=0·045); four patients in each group required stricture surgery (0·44 [0·10-1·92]; p=0·27). Crohn's Disease Activity Index was less than 150 in 36 (69%) patients in the intensive treatment group versus 15 (60%) in the standard treatment group (1·50 [0·56-4·05]; p=0·42). MRI at 12 months showed improvement using the stricture MaRIA score (≥25%) in 31 (61%) of 51 versus seven (28%) of 25 patients (3·99 [1·41-11·26]; p=0·0091). MRI complete stricture resolution was seen in ten (20%) versus four (16%) patients (1·28 [0·36 to 4·57]; p=0·70). Intestinal ultrasound at 12 months showed improvement (>25%) in bowel wall thickness in 22 (51%) of 43 versus seven (33%) of 21 patients (2·10 [0·71 to 6·21]; p=0·18). Faecal calprotectin normalised in 32 (62%) versus 11 (44%) patients (2·04 [0·77-5·36]; p=0·15). Normalisation of CRP was seen in 32 (62%) versus 11 (44%) patients (2·04 [0·77-5·36]; p=0·15). Eight (15%) patients in the intensive treatment group and four (16%) in the standard treatment group reported serious adverse events. No deaths occurred during the study.

INTERPRETATION

Crohn's disease strictures are responsive to drug treatment. Most patients had improved symptoms and stricture morphology. Treat-to-target therapy intensification resulted in less treatment failure, a reduction in stricture-associated inflammation, and greater improvement in stricture morphology, although these differences were not significantly different from standard therapy.

FUNDING

Australian National Health and Medical Research Council, Gastroenterological Society of Australia Ferring IBD Clinician Establishment Award, Australasian Gastro Intestinal Research Foundation, AbbVie, and the Spotlight Foundation.

Crohn's Disease Obstructions

Obstruction from stricturing Crohn's disease remains one of the most common reasons for intervention. Acute inflammation is often responsive to medications, but chronic fibrosis is unlikely to respond and will generally go on to require additional treatment. Newer methods, such as endoscopic balloon dilation, are gaining grounds in strictures that are amenable, but with high recurrence and strictures that may not be endoscopically accessible, surgery still plays a key role in the treatment of obstructing Crohn's disease.

Intestinal stricture in Crohn's disease: A 2020 update

Crohn's disease (CD) is a chronic and relapsing-remitting inflammatory disorder of the gastrointestinal tract. Approximately 70% of patients inevitably develop fibrosis-associated intestinal stricture after 10 years of CD diagnosis, which seriously affects their quality of life. Current therapies play limited role in preventing or reversing the process of fibrosis and no specific anti-fibrotic therapy is yet available. Nearly half of patients thus have no alternative but to receive surgery. The potential mechanisms of intestinal fibrosis remain poorly understood; extracellular matrix remodeling, aberrant immune response, intestinal microbiome imbalance and creeping fat might exert fundamental influences on the multiple physiological and pathophysiological processes. Recently, the emerging new diagnostic techniques have markedly promoted an accurate assessment of intestinal stricture by distinguishing fibrosis from inflammation, which is crucial for guiding treatment and predicting prognosis. In this review, we concisely summarized the key studies published in the year 2020 covering pathogenesis, diagnostic modalities, and therapeutic strategy of intestinal stricture. A comprehensive and timely review of the updated researches in intestinal stricture could provide insight to further elucidate its pathogenesis and identify novel drug targets with anti-fibrotic potentiality.

Which MRI Score and Technique Should Be Used for Assessing Crohn's Disease Activity?

Magnetic resonance (MR) enterography is assuming an increasingly important and central role in the management of patients with Crohn’s disease, as it is not only involved in diagnosis and staging of the disease but also allows for patients’ follow-up, evaluating the response to therapy, and predicting disease outcomes. Several MR scores have been developed but unfortunately there is no globally accepted score. The most widely used scores are the Magnetic Resonance Index of Activity (MaRIA) score, the London score, the Nancy score, and the Clermont score; however, there are multiple differences between these tools in terms of the assessed radiological items, fasting, administration of oral or intravenous contrast, and the use of diffusion-weighted images. Here we reviewed the main characteristics of each MR scoring system to clarify which is the most appropriate score for monitoring disease activity in both clinical practice and clinical trials.

Crohn's disease: prevalence, MR features, and clinical significance of enteric and colonic sinus tracts

Objectives

Enteric and colonic sinus tracts are inflammatory complications that precede intestinal fistulas in patients with Crohn’s disease (CD). The aim of this study was to retrospectively determine the prevalence, morphologic features, and outcome of sinus tracts using MR imaging.

Methods

A consecutive cohort of 642 patients with known CD, referred for MR enterography or MR enteroclysis (study period 01/2014–09/2019), was evaluated retrospectively for the presence of sinus tracts, their locations, presence and length of coexisting strictures, bowel wall thickness, CDMI score, upstream dilation, and bowel distension. Clinical outcome was assessed using medical records. For metric data, means and standard deviation, as well as one-way ANOVA and Pearson’s correlation coefficient, were calculated.

Results

In 36/642 patients with CD undergoing MRE, 49 sinus tracts (forty in small intestine, nine in left-sided colon) were detected with a prevalence of 6.9% in patients with MR-visible signs of CD (n = 519, overall prevalence of 5.6%). Mean segmental bowel wall thickness was 8.9 mm, and mean CDMI score was 9.3. All sinus tracts were located within a stenotic segment, showing mesenteric orientation within the small bowel and upstream dilation in 13 patients. Of 36 patients, 19 underwent immediate surgery and seven developed clinical progression within the segment containing the sinus tract.

Conclusions

Sinus tracts occur in 6.9% of patients with visible signs of CD. They are located within stenotic, severely thickened bowel segments with high MR inflammation scores. Their detection is clinically important, because they indicate a more aggressive phenotype and, if left untreated, may show severe progression.

Key Points

• Sinus tracts occur in 6.9% of patients with MR-visible signs of Crohn’s disease.

• Sinus tracts are a radiological indicator of early penetrating Crohn’s disease, with a high risk of progression, and require dedicated treatment.

• Sinus tracts can be recognized by characteristic findings and typically occur in stenotic, severely thickened bowel segments with high MR inflammation scores.