Natural History of Perianal Crohn's Disease: Long-term Follow-up of a Population-Based Cohort

Cumulative incidence and prevalence of perianal diseases in patients with inflammatory bowel disease and in the population: a nationwide Swedish study

BACKGROUND

Perianal diseases are more common in patients with Crohn's disease (CD) than in the general population, but data are scarce in other inflammatory bowel disease (IBD) subtypes.

METHOD

Using data from the Swedish National Patient Register (NPR) and SWIBREG, the national quality register for IBD, we estimated the cumulative incidence of perianal fistula/abscess and perianal diseases (fistula, abscess, stenosis, fissure or procedure code for perianal surgery) in relation to diagnosis, and the prevalence in 2023, in individuals with CD, ulcerative colitis (UC) and IBD-unclassified (IBD-U), and in a matched (age, sex, calendar year and region of residence) IBD-free cohort from the general population.

RESULTS

We identified 38,364 patients with incident IBD 2007-2017, and 98,229 patients with prevalent IBD as of 31 December 2022. The cumulative incidence of fistula/abscess was 6.7% at diagnosis, 8.3% at 1 year and 10.4% at 5 years in CD. The corresponding percentages in UC were 0.9%, 1.3% and 2.1%, and in IBD-U 2.4%, 3.1% and 4.5%, respectively. In 2023, 12.8%, 3.1% and 4.1% of patients with prevalent CD, UC and IBD-U had a history of fistula/abscess, compared to 0.8% in the general population. The corresponding numbers for perianal diseases were 19.7%, 7.4%, 8.6% and 2.2%.

CONCLUSIONS

The cumulative incidence and prevalence of perianal diseases in Swedish patients with CD was in parity with reports from other countries, and in patients with UC and IBD-U, it was 3-4 times higher than in the population.

Patients' Attitudes to Magnetic Resonance Imaging in Perianal Fistulizing Crohn's Disease: A Global Survey

Background

There is limited patient involvement in radiological research for perianal fistulizing Crohn's disease (pfCD), despite magnetic resonance imaging (MRI)'s critical role in diagnosis and management. Patient and public involvement is essential for aligning research with patient priorities. This study aimed to gather patient perspectives on the use of MRI in pfCD.

Methods

A mixed-methods approach was used, following Guidance for Reporting Involvement of Patients and the Public (GRIPP2) guidelines. An online survey, co-developed with a patient representative, included open and closed questions on MRI experiences, advantages, challenges, and the potential for Artificial Intelligence (AI)-generated reports. This was followed by a virtual session for further exploration of patient views. Thematic analysis was conducted on the data.

Results

Forty-seven patients with Crohn's disease (37 with pfCD) from 6 countries participated, with 28/37 (76%) completing the survey. Key themes included patient expectations for MRI, preferences for scan intervals, and report content. Most (93%) wanted MRI reports to compare with previous scans, highlighting fistula changes and new abscesses. A majority (57%) preferred MRI scans annually when well, and more frequently after surgery (64.3% preferred scans at 3 months). Emotional relief was associated with MRI improvements, though access to services and report clarity remained challenging. Interest in AI-generated reports was expressed if clearly explained and validated by professionals.

Conclusions

This is the first study exploring patient views on MRI use in pfCD, emphasizing the need for patient-centred MRI reporting and clearer communication. Future work should enhance patient access and validate AI-generated MRI reports.

Magnetic resonance imaging for suspected perianal Crohn's disease in children: a multi-reader agreement study

OBJECTIVES

We aimed to assess inter-radiologist agreement when interpreting pelvic MRI in children with newly diagnosed perianal Crohn's disease (CD).

MATERIALS AND METHODS

In this retrospective multi-reader study, we identified pediatric patients (< 18 years of age) who underwent a pelvic MRI examination for newly diagnosed perianal CD. Images were de-identified and uploaded to a cloud-based image platform for review by 13 fellowship-trained pediatric radiologists The reviewers assessed for the presence of a fistula and abscess, categorization of different imaging findings, and classification using the Parks and St James' University Hospital systems. Fleiss' kappa (κ) statistics and intra-class correlation coefficients (ICC) were used to measure inter-reader agreement, along with 95% confidence intervals (CI).

RESULTS

Forty-six patients were included in our study (median age = 13.0 years [IQR: 10.5 to 16.0 years]); thirty-five (76.1%) were boys. Most imaging features showed fair agreement (κ = 0.21 to 0.35). There was moderate agreement for categorical fistula length (κ = 0.42 [95% CI: 0.32 to 0.53]), involvement of the genitalia (κ = 0.45 [95% CI: 0.26 to 0.63]), and presence of an abscess/collection (κ = 0.52 [95% CI: 0.31 to 0.73]). Maximum abscess/collection length had good agreement (ICC = 0.81 [95% CI: 0.41, 1.00]). There was an almost equal split (yes vs. no: 50.7% vs. 49.3%) regarding whether postcontrast T1-weighted images added value compared to T2-weighted images alone across all radiologists and examinations.

CONCLUSION

Inter-radiologist agreement when interpreting pelvic MRI for perianal CD in children is fair for most imaging features, with fewer features demonstrating moderate or good agreement.

KEY POINTS

Question Pelvic magnetic resonance imaging (MRI) is used for diagnosing and monitoring children with perianal Crohn's disease (CD). Limited information is known about inter-radiologist agreement. Findings Agreement between pediatric radiologists when interpreting MRI for perianal CD in children is only fair for most imaging features (κ = 0.21 to 0.35). Clinical relevance Understanding MRI inter-radiologist agreement is crucial to improve the reliability of pelvic MRI in children with perianal Crohn's disease since it may affect patient management (e.g., surgery); further radiologist education and improved imaging feature definitions may help improve inter-radiologist agreement.

Differential Diagnosis Value of Neutrophil Gelatinase Associated Lipocalin as a Noninvasive Biomarker in Perianal Fistulizing Crohn's Disease

Background

Diagnosing perianal fistulizing Crohn's disease (pfCD) typically depends on costly and time-intensive endoscopic and radiographic procedures. Compelling evidence indicates that neutrophil gelatinase-associated lipocalin (NGAL) plays a role in the pathophysiology of Crohn's disease (CD) and may serve as a noninvasive biomarker for its diagnosis. This study aimed to evaluate NGAL's potential as a noninvasive diagnostic biomarker between pfCD and cryptoglandular (CG) perianal fistula, and its correlation with disease severity in pfCD.

Methods

Serum, fecal, and fistula tissue samples were collected from 96 patients with pfCD and 97 patients with CG perianal fistula as controls. Serum NGAL levels were quantified through ELISA and fistula tissue NGAL levels were quantified through immunohistochemical staining, while pfCD disease severity was evaluated using the Crohn's Disease Activity Index (CDAI) and Perianal Disease Activity Index (PDAI). Additional laboratory parameters, including NGAL, fecal calprotectin (FC), C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR), were analyzed, and their correlations were assessed. Receiver operating characteristic (ROC) analysis was conducted to evaluate NGAL's diagnostic potential for pfCD.

Results

Levels of serum NGAL, FC, CRP, and ESR in patients with pfCD were significantly elevated compared to the control group (p < 0.001); Spearman correlation analysis indicated a positive correlation between serum NGAL and FC, CRP, ESR, CDAI, and PDAI scores. The area under the ROC curve (AUC) for serum NGAL in diagnosing pfCD was 0.927 (95% CI: 0.890-0.964). The AUC for FC in diagnosing pfCD were 0.887 (95% CI: 0.839-0.935). Additionally, serum and fistula tissue NGAL levels were positively correlated with disease complexity in pfCD according to the Montreal classification.

Conclusion

These findings suggest that serum NGAL is associated with pfCD severity and may offer a promising noninvasive biomarker for diagnosing and assessing pfCD.

Allogenic Stem Cells in Anal Fistulas of Crohn's Disease: From Promising Premises to Real Life Experience

BACKGROUND

Allogenic adipocyte stem cells represent an unprecedented opportunity for regenerative therapy to treat Crohn anal fistulas. Apart from the results of one 8-year-old trial, scientific evidence remains scarce.

METHODS

Data from consecutive patients treated with darvadstrocel for Crohn anal fistulas were reviewed at 6 first tertiary reference centers. The judgment criteria combined asymptomatic status plus clinical occlusion of the fistula tract and MRI-confirmed healing of the tract (no inflammation and/or disappearance of the tract). Both clinical and MRI-confirmed healing of the tract defined a deep remission. Clinical remission was defined by an absence of complaint, occlusion of all external openings, and no fistula discharge.

RESULTS

A total of 116 patients were extracted (median follow-up after cell stem injection: 11 [6-14] months). No severe adverse events were reported after surgery except for subsequent anal surgery in 29 (25%) patients. Fifty-one (44%) patients had clinical remission defined by the absence of complaints, the occlusion of all external openings, and the presence of no fistula discharge. Deep remission was observed in 23 (29%) patients. Patients with clinical remission more often received combined therapy (immunosuppressant antitumor necrosis factors) than those with no improvement (31 of 51 [61%] vs 23 of 65 [35%]; P = .007). Regression analysis showed that high fistulas (odds ratio, 3.8 [1.1-12.5]; P = .03) and younger age (<38 years, odds ratio, 2.3 [1.0-58;4]; P = .02) were associated with a better outcome.

CONCLUSIONS

Allogeneic stem cell treatment of Crohn's anal fistulas results in complete remission in less than half of patients, with a significant reintervention rate.

How to Approach the Difficult Perineum in Crohn's Disease

Crohn's disease (CD) is a chronic, inflammatory bowel disease with a wide range of presentations, including perianal disease. Presentation is variable, ranging from skin tags to complex fistulas, strictures, and nonhealing wounds. Symptoms of perianal CD can be devastating and may impact quality of life. Optimal management requires coordinated medical and surgical therapy. When possible, conservative treatment of perianal disease should be attempted. However, surgical treatment is often required, and some patients may ultimately require total proctocolectomy with permanent diversion due to the severity of disease. Even with close attention and treatment, disease can be recurrent, and complications of treatment are sometimes worse than the initial presentation. Novel treatments, including use of mesenchymal stem cells and autologous fat grafting, hold some promise, but are not yet widely available. Thorough knowledge of treatment options, careful patient selection, coordination between medical and surgical providers, and setting realistic expectations are important in the successful treatment of difficult perineal CD.

Development and Validation of a Multimodal Machine Learning Model for Diagnosing and Assessing Risk of Crohn's Disease in Patients With Perianal Fistula

BACKGROUND

Diagnosis of Crohn's disease (CD) can pose challenges, particularly when perianal fistula is the initial presentation.

AIM

To develop and validate a predictive model, establishing a visual web tool for early diagnosis of CD in patients presenting with perianal fistula.

METHODS

This retrospective, multicentre validation study involved patients diagnosed with either perianal fistulising CD or cryptoglandular fistula who underwent initial perianal fistula surgery subsequent to rectal MRI at three Chinese centres from September 2016 to December 2020. A random forest classification model was trained on the derivation cohort (n = 550), randomly split into training and test sets at a 7:3 ratio. Validation utilised data from two external centres (n = 300). Model interpretation employed the Shapley Addictive explanation (SHAP) framework. The validated model was integrated into a web tool for calculating patient-specific risk.

RESULTS

In the derivation cohort, SHAP analysis highlighted rectal wall ulceration, rectal wall thickening, submucosal fistula, and T2 hyperintensity as risk factors, while age was identified as protective. A random forest classification model developed using these top 5 features achieved an AUROC of 0.9425 (95% CI: 0.8943-0.9906). In the validation cohort, the model performed well with AUROC values of 0.9187 (95% CI: 0.8620-0.9754) and 0.9341 (95% CI: 0.8876-0.9806), respectively. We developed a publicly accessible web-based application.

CONCLUSION

We have developed a multimodal machine learning model and a web tool that can predict and present CD risk in patients initially presenting with perianal fistula.

Monitoring-Based Model for Personalizing Fecal Incontinence in Patients With Crohn's Disease: A Multicenter Inception Cohort Study

BACKGROUND AND AIMS

Fecal incontinence (FI) is a common complaint that greatly affects the quality of life of patients with Crohn's disease (CD) and is associated with the clinical characteristics of CD. We aimed to identify risk factors related to FI and construct a risk prediction model for FI in patients with CD.

METHODS

This retrospective study included 600 Chinese patients with CD from 4 IBD centers between June 2016 and October 2021. The patients were assigned to the training (n = 480) and testing cohorts (n = 120). Two nomograms were developed based on the logistic regression and Cox regression models to predict the risk factors for FI in patients with CD. The discriminatory ability and accuracy of the nomograms were evaluated using the receiver operating characteristic (ROC) curves and the area under the ROC curves (AUCs). Additionally, the Kaplan-Meier survival curve was also used further to validate the clinical efficacy of the Cox regression model.

RESULTS

The overall prevalence of FI was 22.3% (n = 134 of 600). In the logistic regression model, age at diagnosis (odds ratio [OR], 1.032; P = .033), penetrating behavior of disease (OR, 3.529; P = .008) and Perianal Disease Activity Index score >4 (OR, 3.068; P < .001) were independent risk factors for FI. In the Cox regression model, age at diagnosis (hazard ratio [HR], 1.027; P = .018), Montreal P classification (HR, 2.608; P = .011), and Perianal Disease Activity Index score >4 (HR, 2.190; P = .001) were independent predictors of the prevalence of FI over time. Two nomograms were developed to facilitate risk score calculation, and they showed good discrimination ability according to AUCs.

CONCLUSIONS

In this study, we identified 4 risk factors related to the prevalence of FI and developed 2 models to effectively predict the risk scores of FI in CD patients, helping to delay the course of FI and improve the prognosis with timely intervention.

Development and validation of the MRI-based deep learning classifier for distinguishing perianal fistulizing Crohn's disease from cryptoglandular fistula: a multicenter cohort study

BACKGROUND

A singular reliable modality for early distinguishing perianal fistulizing Crohn's disease (PFCD) from cryptoglandular fistula (CGF) is currently lacking. We aimed to develop and validate an MRI-based deep learning classifier to effectively discriminate between them.

METHODS

The present study retrospectively enrolled 1054 patients with PFCD or CGF from three Chinese tertiary referral hospitals between January 1, 2015, and December 31, 2021. The patients were divided into four cohorts: training cohort (n = 800), validation cohort (n = 100), internal test cohort (n = 100) and external test cohort (n = 54). Two deep convolutional neural networks (DCNN), namely MobileNetV2 and ResNet50, were respectively trained using the transfer learning strategy on a dataset consisting of 44871 MR images. The performance of the DCNN models was compared to that of radiologists using various metrics, including receiver operating characteristic curve (ROC) analysis, accuracy, sensitivity, and specificity. Delong testing was employed for comparing the area under curves (AUCs). Univariate and multivariate analyses were conducted to explore potential factors associated with classifier performance.

FINDINGS

A total of 532 PFCD and 522 CGF patients were included. Both pre-trained DCNN classifiers achieved encouraging performances in the internal test cohort (MobileNetV2 AUC: 0.962, 95% CI 0.903-0.990; ResNet50 AUC: 0.963, 95% CI 0.905-0.990), as well as external test cohort (MobileNetV2 AUC: 0.885, 95% CI 0.769-0.956; ResNet50 AUC: 0.874, 95% CI 0.756-0.949). They had greater AUCs than the radiologists (all p ≤ 0.001), while had comparable AUCs to each other (p = 0.83 and p = 0.60 in the two test cohorts). None of the potential characteristics had a significant impact on the performance of pre-trained MobileNetV2 classifier in etiologic diagnosis. Previous fistula surgery influenced the performance of the pre-trained ResNet50 classifier in the internal test cohort (OR 0.157, 95% CI 0.025-0.997, p = 0.05).

INTERPRETATION

The developed DCNN classifiers exhibited superior robustness in distinguishing PFCD from CGF compared to artificial visual assessment, showing their potential for assisting in early detection of PFCD. Our findings highlight the promising generalized performance of MobileNetV2 over ResNet50, rendering it suitable for deployment on mobile terminals.

FUNDING

National Natural Science Foundation of China.

Review article: Measuring disease severity in inflammatory bowel disease - Beyond treat to target

BACKGROUND

Inflammatory bowel disease (IBD) follows a heterogenous disease course and predicting a patient's prognosis is challenging. There is a wide burden of illness in IBD and existing tools measure disease activity at a snapshot in time. Comprehensive assessment of IBD severity should incorporate disease activity, prognosis, and the impacts of disease on a patient. This review investigates the concept of disease severity in adults with IBD to highlight key components contributing to this.

METHODS

To perform this narrative review, a Medline search was conducted for full-text articles available at 1st March 2024 using search terms which encompassed disease activity assessment, disease severity, prognosis, natural history of Crohn's disease (CD) and ulcerative colitis (UC), and the burden of IBD.

RESULTS

Current methods of disease assessment in IBD have evolved from a focus on the burden of symptoms to one that includes inflammatory targets, genetic, serological, and proteomic profiles, and assessments of quality-of-life (QoL), disability, and psychosocial health. Longitudinal studies of IBD suggest that the burden of illness is driven by disease phenotype, clinical markers of complicated disease course (previous intestinal resection, corticosteroid use, perianal disease in CD, recent hospitalisations in UC), gut inflammation, and the impact of IBD on the patient.

CONCLUSIONS

Disease severity in IBD can be difficult to conceptualise due to the multitude of factors that contribute to IBD outcomes. Measurement of IBD severity may better encapsulate the full burden of illness rather than gut inflammation alone at a single timepoint and may be associated with longitudinal outcomes.

Perianal Crohn's disease: Still more questions than answers

In this editorial we comment on the article by Pacheco et al published in a recent issue of the World Journal of Gastroenterology. We focus specifically on the burden of illness associated with perianal fistulizing Crohn's disease (PFCD) and the diagnostic and therapeutic challenges in the management of this condition. Evolving evidence has shifted the diagnostic framework for PFCD from anatomical classification systems, to one that is more nuanced and patient-focused to drive ongoing decision making. This editorial aims to reflect on these aspects to help clinicians face the challenge of PFCD in day-to-day clinical practice.

Management of Perianal Fistulizing Crohn's Disease

Perianal fistulizing Crohn's disease (CD) represents a severe phenotype of CD that is associated with significant morbidity and reduction in quality of life. Perianal fistulizing CD is caused by a complex interplay of genetic predisposition, immune dysregulation, gut dysbiosis, and various unknown physiological and mechanical factors. A multidisciplinary approach is hence required for optimal management . A detailed anatomical description and classification of perianal fistula, including comprehensive clinical, endoscopic, and radiological diagnostic workup, is an important prerequisite to treatment. For simple perianal fistulas, use of antibiotics and immunomodulators, with or without fistulotomy, are appropriate measures. The medical management of complex perianal fistula, on the other hand, requires adequate control of infection before initiation of therapy with immunomodulators. In active complex perianal fistula, anti-tumor necrosis factors remain the most accepted therapy, with concomitant use of antibiotics or immunomodulators enhancing the efficacy. For patients refractory to anti-tumor necrosis factors, treatment with anti-integrins, anti-interleukins, and small molecules is being evaluated. Mesenchymal stem cells, hyperbaric oxygen therapy, and exclusive enteral nutrition have also been investigated as adjunct therapies. Despite the expansion of the medical armamentarium, a large proportion of the patients require surgical interventions. In this review, we provide an up-to-date overview of the pathophysiology, clinical presentation, diagnosis, and medical management of perianal fistulizing CD. A brief overview of the surgical management of perianal fistulizing CD is also provided.

Ten missteps in the management of inflammatory bowel disease in Asia: An expert report by the Asian Pacific Association of Gastroenterology Working Group on Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is rapidly emerging in the Asia Pacific region. However, there are many challenges in the diagnosis and management of this condition. The Asian Pacific Association of Gastroenterology (APAGE) Working Group on IBD conducted a round table meeting to identify 10 common mistakes in the management of IBD in Asia. To summarize, many physicians still over rely on a definitive histological diagnosis before starting treatment and do not fully establish disease extent such as perianal and proximal gastrointestinal involvement in Crohn's disease (CD) or extent of involvement in ulcerative colitis (UC). It is also essential to actively look for evidence of extra-intestinal manifestations, which may influence choice of therapy. In terms of conventional therapy, underuse of topical 5 aminosalicylates (5-ASAs) in UC and inappropriate dosing of corticosteroids are also important considerations. Acute severe UC remains a life-threatening condition and delay in starting rescue therapy after inadequate response to intravenous steroids is still common. Anti-tumor necrosis factors should be considered first line in all cases of complex perianal fistulizing CD. Most patients with IBD are on potent immunosuppressive therapy and should be screened for latent infections and offered vaccinations according to guidelines. Under-recognition and management of significant complications such as anemia, osteoporosis, malnutrition, and thromboembolism should also be addressed. Colonoscopy is still not properly performed for dysplasia/cancer surveillance and for evaluating post-op recurrence of CD. Another common misstep is inappropriate withdrawal of medications during pregnancy leading to increased complications for the mother and the newborn.

Relationship between histopathological findings, clinical severity and the need for surgery in patients with Crohn's disease

INTRODUCTION

Defining histological variables that make it possible to establish the activity of Crohn's disease (CD) and predict the patients who may present a higher risk of clinical complications and surgical interventions could lead to timely adjustments in medical therapy and elective surgeries that represent a lower risk of complications. The purpose of the study is to determine the relation between the histopathological findings using the Naini and Cortina (N&C) score, the clinical severity, and the indication for surgery in a group of patients with CD.

MATERIALS AND METHODS

Descriptive, retrospective, cross-sectional study of 44 patients diagnosed with CD, treated at the San Vicente Fundación University Hospital in Medellín, Colombia, between 2010 and 2022.

RESULTS

Of the 44 patients, 36 ileum samples and 34 colon samples were obtained. Of the patients with inflammatory behavior, 87.5% did not have surgical intervention (P=.022), a value that remained significant in the ileum subgroup (P=.0058). 91.3% of the patients with ileal involvement did not develop perianal disease (P=.01). Granulomas only occurred in two patients with a colon sample (5.8%). In the histological score of N&C both in the ileum and in the colon, no statistically significant differences were obtained in relation to the surgical outcome (P=.34 and P=.054, respectively).

CONCLUSION

The histological index of N&C was not a predictor in Crohn's disease (CD) related to the surgical outcome.

Efficacy and Safety of Filgotinib for the Treatment of Perianal Fistulising Crohn's Disease [DIVERGENCE 2]: A Phase 2, Randomised, Placebo-controlled Trial

BACKGROUND AND AIMS

There is an unmet need in the treatment of perianal fistulising Crohn's disease [PFCD]. This study evaluated the efficacy and safety of the Janus kinase 1 preferential inhibitor, filgotinib, for the treatment of PFCD.

METHODS

This phase 2, double-blind, multicentre trial enrolled adults with PFCD and prior treatment failure. Participants were randomised [2:2:1] to receive filgotinib 200 mg, filgotinib 100 mg, or placebo, once daily orally for up to 24 weeks. The primary endpoint was combined fistula response (reduction from baseline of at least one draining external opening determined by physical assessment, and no fluid collections >1 cm on pelvic magnetic resonance imaging [MRI]) at Week 24.

RESULTS

Between April 2017 and July 2020, 106 individuals were screened and 57 were randomised. Discontinuations were lowest in the filgotinib 200 mg group (3/17 [17.6%] versus 13/25 [52.0%] for filgotinib 100 mg and 9/15 [60.0%] for placebo). The proportion of participants who achieved a combined fistula response at Week 24 was 47.1% (8/17; 90% confidence interval [CI] 26.0, 68.9%) in the filgotinib 200 mg group, 29.2% [7/24; 90% CI 14.6, 47.9%] in the filgotinib 100 mg group, and 25.0% [3/12; 90% CI 7.2, 52.7%] in the placebo group. Serious adverse events occurred more frequently with filgotinib 200 mg (5/17 [29.4%]) than with placebo (1/15 [6.7%]). There were no treatment-related serious adverse events or deaths.

CONCLUSIONS

Filgotinib 200 mg was associated with numerical reductions in the number of draining perianal fistulas based on combined clinical and MRI findings compared with placebo, and was generally well tolerated [NCT03077412].

A phase I/II clinical trial of ex-vivo expanded human bone marrow derived allogeneic mesenchymal stromal cells in adult patients with perianal fistulizing Crohn's Disease

BACKGROUND

Perianal fistulas (PF) affect one-third patients with Crohn's disease (CD) with limited therapeutic options. There is dearth of literature on safety and efficacy of bone marrow-derived mesenchymal stromal cells (BMSCs) in this population.

METHODS

An open-label, phase I/II, single-arm study was conducted involving local administration of human allogeneic bone marrow-derived mesenchymal stromal cells in perianal fistula of patients with Crohn's disease refractory to standard therapies. Clinical severity and biomarkers were assessed at baseline and periodically until week 104 , and MRI at week 24 and 104. Primary and secondary objectives were to assess safety and efficacy respectively. Fistula remission was complete closure of fistula openings with < 2 cm perianal collection on MRI, and fistula response was decrease in drainage by ≥ 50%. Change in perianal disease activity index, quality-of-life and Van Assche index on MRI over time was assessed using mixed-effect linear regression model.

RESULTS

Ten patients (male:8, mean age:27.4 ± 12.0years) were recruited. Self-resolving procedure-related adverse events occurred in three patients, with no follow-up adverse events. In intention to treat analysis at week 24, two patients (20%) achieved fistula remission and seven (70%) had fistula response. At week 52, two (20%) patients were in remission and seven (70%) maintained response. At 104 weeks, two (20%) patients maintained response and one (10%) was in remission. Statistically significant decrease in perianal disease activity index (P = 0.008), Van Assche Index (P = 0.008) and improvement in quality-of-life (P = 0.001) were observed over time.

CONCLUSIONS

Allogeneic BMSCs are safe and effective for the treatment of perianal fistulizing CD with significant improvement in clinical severity and radiological healing.

TRIAL REGISTRATION

The study was prospectively registered on Clinical trials registry - India (CTRI), CTRI/2020/01/022743 on 14 January 2020, http://ctri.nic.in .

Perianal Fistula; from Etiology to Treatment - A Review

Anal fistula has been a challenging clinical issue for years due to its complex pathogenesis. The risk of frequent recurrence and incontinence complicates long-term treatment. Recent scientific literature has reviewed new techniques used for anal fistula treatment in recent years, assessing the advantages and disadvantages of each based on clinical outcomes. Although surgery is the main method used to treat anal fistula, there is no simple technique that can completely heal complex anal fistula. The surgical treatment should consider the healing outcome and the protection of anal function comprehensively. Several innovative techniques have emerged in recent years, such as combined techniques based on drainage seton and LIFT-plug, which appear to be relatively effective therapies. However, more multi-center prospective trials with long-term follow-up are needed to validate their effectiveness. In some situations, medical treatment may also be considered.

Perianal Mucinous Adenocarcinoma: A Case of Recurrent Anal Fistula

An anal fistula is a fairly common clinical condition, with a very low incidence of malignant transformation. Mucinous adenocarcinoma is a subtype of adenocarcinoma, and its occurrence within perianal fistula tracts is quite rare. This case report describes a 54-year-old male patient with recurrent anal fistula, initially suspected of Crohn's disease (CD), and ultimately diagnosed with perianal mucinous adenocarcinoma. After our joint internal medicine, surgery, and imaging reassessment, the diagnosis was confirmed. Anal fistula is usually considered a benign lesion, but it may also be associated with other diseases. Due to overlapping symptoms of related diseases, the investigation of malignant lesions is often overlooked. This case report emphasizes the importance of timely referral and multidisciplinary management for disease diagnosis and early treatment.

Perianal fistulizing Crohn's disease: Current perspectives on diagnosis, monitoring and management with a focus on emerging therapies

Crohn's disease (CD), a chronic inflammatory bowel disorder, manifests in various phenotypes, with fistulizing perianal CD (CD-PAF) being one of its most severe phenotypes. Characterized by fistula formation and abscesses, CD-PAF impacts 17% to 34% of all CD cases and with a significantly deleterious impact on patient's quality of life, while increasing the risk for anorectal cancers. The pathogenesis involves a complex interplay of genetic, immunological and environmental factors, with cytokines such as tumor necrosis factor-alpha (TNF-α) and transforming growth factor-beta (TGF-β) playing pivotal roles. Diagnostic protocols require a multi-disciplinary approach including colonoscopy, examination under anesthesia and magnetic resonance imaging. In terms of treatment, biologics alone often prove inadequate, making surgical interventions such as setons and fistula surgeries essential. Emerging therapies such as mesenchymal stem cells are under study. The South Asian context adds layers of complexity, including diagnostic ambiguities related to high tuberculosis prevalence, healthcare access limitations and cultural stigma toward perianal Crohn's disease and ostomy surgery. Effective management necessitates an integrated, multi-disciplinary approach, especially in resource-constrained settings. Despite advances, there remain significant gaps in understanding the disease's pathophysiology and a dearth of standardized outcome measures, underscoring the urgent need for comprehensive research.

The mode of delivery does not influence the occurrence of post-partum perianal disease flares in patients with inflammatory bowel disease

INTRODUCTION

Perianal disease occurs in up to 34% of inflammatory bowel disease (IBD) patients. An estimated 25% of women will become pregnant after the initial diagnosis, thus introducing the dilemma of whether mode of delivery affects perianal disease. The aim of our study was to analyze whether a cesarean section (C-section) or vaginal delivery influence perianal involvement. We hypothesized the delivery route would not alter post-partum perianal manifestations in the setting of previously healed perianal disease.

METHODS

All consecutive eligible IBD female patients between 1997 and 2022 who delivered were included. Prior perianal involvement, perianal flare after delivery and delivery method were noted.

RESULTS

We identified 190 patients with IBD who had a total of 322 deliveries; 169 (52%) were vaginal and 153 (48%) were by C-section. Nineteen women (10%) experienced 21/322 (6%) post-partum perianal flares. Independent predictors were previous abdominal surgery for IBD (OR, 2.7; 95% CI, 1-7.2; p = 0.042), ileocolonic involvement (OR, 3.3; 95% CI, 1.1-9.4; p = 0.030), previous perianal disease (OR, 22; 95% CI, 7-69; p < 0.001), active perianal disease (OR, 96; 95% CI, 21-446; p < 0.001) and biologic (OR, 4.4; 95% CI,1.4-13.6; p < 0.011) or antibiotic (OR, 19.6; 95% CI, 7-54; p < 0.001) treatment. Negative association was found for vaginal delivery (OR, 0.19; 95% CI, 0.06-0.61; p < 0.005). Number of post-partum flares was higher in the C-section group [17 (11%) vs. 4 (2%), p = 0.002].

CONCLUSIONS

Delivery by C-section section was not protective of ongoing perianal disease activity post-delivery, but should be recommended for women with active perianal involvement.

Typical MR features and interpretation of perianal fistulas in patients with Crohn's disease

Perianal fistulas in Crohn's disease (CD) are a poor prognostic phenotype requiring a combination of medical and surgical management. Perianal fistulas in CD are characterized by more complex and multi-branched fistulas, association with skin tags, and frequent presence of proctitis. A comprehensive approach with clinical examination, endoscopic and MR assessment is required, and in particular, MR interpretation provides detailed information on the type of fistula with its internal component and activity, secondary tracts and extension, internal, external openings, associated abscess, and presence of proctitis. Structured reporting of these items would be recommended for further discussion and management planning both at initial diagnosis and for disease monitoring during treatment follow-up. Management strategy would be individualized for each patient, and control of luminal disease activity could be an important determinant in the selection of treatment options. In this review, we provide an overview of the MRI evaluation of perianal fistulas in CD with a proposed structured MR report.

Clinical and magnetic resonance imaging spectrum of complex perianal fistulizing Crohn's disease: A cohort study from northern India

BACKGROUND

Fistulizing perianal Crohn's disease (CD) is a debilitating condition associated with significant morbidity and reduction in the quality of life. Magnetic resonance imaging (MRI) of the pelvis is the preferred imaging modality for the comprehensive assessment of the perianal fistula. There is a paucity of data from India on the MRI spectrum of complex perianal fistula in CD.

METHODS

A single-centre cross-sectional analysis of patients with fistulizing perianal CD, who underwent pelvic MRI between January 2020 and December 2021, was performed. The clinical (age, sex, disease duration, disease location and behavior, disease activity [Perianal Disease Activity Index, PDAI] and treatment received) and radiological (number and location of fistulae, extensions, number and location of internal and external openings, fistula activity, presence or absence of perianal abscess and associated proctitis) characteristics of complex perianal fistula (defined according to the American Gastroenterological Association classification) were recorded.

RESULTS

Of total 175 patients with CD who attended the gastroenterology clinic during the study period, 27 (15.42%) (mean age 42±15.5 years, 62.96% females and median disease duration four years) had complex perianal fistula and were included in the analysis. The mean PDAI was 5.48±2.53. The median Van Assche Index was 17 (interquartile range [IQR] 13-19). A majority (96.29%) of the fistulae were trans-sphincteric and four (14.81%) fistulae extended into the supralevator space. All fistulae were active on MRI. Concomitant perianal abscess and proctitis were seen in 59.26% (n=16) and 62.96% (n=17) of patients, respectively. Combination therapy with biologics and antibiotics/immune-suppressants were the most commonly prescribed medical therapy. Six (22.22%) patients underwent combined medical and surgical (non-cutting seton, fistulectomy, fecal diversion) treatment.

CONCLUSION

The cumulative risk of the development of fistulizing perianal CD in a northern Indian cohort was similar to the western populations. Complex perianal fistulae were predominantly trans-sphincteric and commoner in females. MRI evaluation is pivotal for the delineation of fistula anatomy, assessment of disease extent and activity and the evaluation of concomitant perianal abscess and other complications.

Natural History of Anal Ulcerations in Pediatric-Onset Crohn's Disease: Long-Term Follow-Up of a Population-Based Study

INTRODUCTION

Anal ulcerations are frequently observed in Crohn's disease (CD). However, their natural history remains poorly known, especially in pediatric-onset CD.

METHODS

All patients with a diagnosis of CD before the age of 17 years between 1988 and 2011 within the population-based registry EPIMAD were followed retrospectively until 2013. At diagnosis and during follow-up, the clinical and therapeutic features of perianal disease were recorded. An adjusted time-dependent Cox model was used to evaluate the risk of evolution of anal ulcerations toward suppurative lesions.

RESULTS

Among the 1,005 included patients (females, 450 [44.8%]; median age at diagnosis 14.4 years [interquartile range 12.0-16.1]), 257 (25.6%) had an anal ulceration at diagnosis. Cumulative incidence of anal ulceration at 5 and 10 years from diagnosis was 38.4% (95% confidence interval [CI] 35.2-41.4) and 44.0% (95% CI 40.5-47.2), respectively. In multivariable analysis, the presence of extraintestinal manifestations (hazard ratio [HR] 1.46, 95% CI 1.19-1.80, P = 0.0003) and upper digestive location (HR 1.51, 95% CI 1.23-1.86, P < 0.0001) at diagnosis were associated with the occurrence of anal ulceration. Conversely, ileal location (L1) was associated with a lower risk of anal ulceration (L2 vs L1 HR 1.51, 95% CI 1.11-2.06, P = 0.0087; L3 vs L1 HR 1.42, 95% CI 1.08-1.85, P = 0.0116). The risk of fistulizing perianal CD (pCD) was doubled in patients with a history of anal ulceration (HR 2.00, 95% CI 1.45-2.74, P < 0.0001). Among the 352 patients with at least 1 episode of anal ulceration without history of fistulizing pCD, 82 (23.3%) developed fistulizing pCD after a median follow-up of 5.7 years (interquartile range 2.8-10.6). In these patients with anal ulceration, the diagnostic period (pre vs biologic era), exposure to immunosuppressants, and/or anti-tumor necrosis factor did not influence the risk of secondary anoperineal suppuration.

DISCUSSION

Anal ulceration is frequent in pediatric-onset CD, with nearly half of patients presenting with at least 1 episode after 10 years of evolution. Fistulizing pCD is twice as frequent in patients with present or past anal ulceration.

Management of Perianal Crohn's Disease

Perianal Crohn's disease affects 25%-35% of patients with Crohn's disease and has proven to be one of the most difficult complications of the disease to treat. Patients with perianal Crohn's disease have lower health-related quality of life scores typically related to pain and fecal incontinence. In addition, patients with perianal Crohn's disease have higher rates of hospitalizations, surgeries, and overall healthcare costs. A multidisciplinary approach is necessary for the successful management of Crohn's disease with perianal fistula. Medical management is required to treat the underlying immune dysregulation to heal the luminal inflammation and the inflammation within the fistula tracts. Current options for medical therapy include biologics, dual therapy with thiopurines, therapeutic drug monitoring, and a close follow-up. Surgical management is critical to drain abscesses before immunosuppressive therapy and place setons when appropriate. Once the patient's inflammatory burden is well managed, definitive surgical therapies including fistulotomies, advancement flaps, and ligation of intersphincteric fistula tract procedures can be considered. Most recently, the use of stem cell therapy in the treatment of perianal fistula has given new hope to the cure of perianal fistula in Crohn's disease. This review will outline the most current data in the medical and surgical management of perianal Crohn's disease.

State-of-the-art surgery for Crohn's disease: part III-perianal Crohn's disease

PURPOSE

Diagnosis and treatment of perianal Crohn's disease is challenging and requires its own domain of therapy. Different types of perianal disease require a spectrum of treatment strategies. Treatment options range from conservative therapy, including immunosuppressives, biologics, or stem cell therapy, to surgical treatment with specific indications depending on the underlying lesion. This is part III of the series "state-of-the-art surgery for Crohn's disease," focusing on the management of perianal disease. We discuss the definition and diagnosis of perianal Crohn's disease, the treatment of perianal lesions, and specific surgical indications and techniques.

RESULTS AND CONCLUSION

Pitfalls and complications play a substantial role in the treatment of perianal Crohn's disease, and surgical therapy may fail. Realistic treatment goals and an individual patient-oriented treatment approach are crucial in the treatment of perianal Crohn's disease.

The Optimal Management of Fistulizing Crohn's Disease: Evidence beyond Randomized Clinical Trials

Fistulizing Crohn's disease (FCD) remains the most challenging aspect of treating patients with CD. FCD can occur in up to 30% of patients with CD and may lead to significant disability and impaired quality of life. The optimal treatment strategies for FCD require a multidisciplinary approach, including a combined medical and surgical approach. The therapeutic options for FCD are limited due to sparse evidence from randomized clinical trials (RCTs). The current recommendations are mainly based on post hoc analysis from RCTs, real-world clinical studies and expert opinion. There is variation in everyday clinical practice amongst gastroenterologists and surgeons. The evidence for anti-tumor necrosis factor therapy is the strongest in the treatment of FCD. However, long-term fistula healing can be achieved in only 30-50% of patients. In recent years, emerging data in the advent of therapeutic modalities, including the use of new biologic agents, therapeutic drug monitoring, novel surgical methods and mesenchymal stem cell therapy, have been shown to improve outcomes in achieving fistula healing. This review summarizes the existing literature on current and emerging therapies to provide guidance beyond RCTs in managing FCD.

Epidemiology and Natural History of Perianal Crohn's Disease: A Systematic Review and Meta-Analysis of Population-Based Cohorts

BACKGROUND AND AIMS

Perianal Crohn's disease (pCD) is a potentially severe phenotype of CD. We conducted a systematic review with meta-analysis to estimate cumulative incidence, risk factors, and outcomes of pCD in population-based cohort studies.

METHODS

Through a systematic literature review through March 1, 2021, we identified population-based inception cohort studies reporting cumulative incidence of perianal disease (primarily abscess and/or fistula) in patients with CD. We estimated the cumulative incidence of pCD at presentation and 1-, 5-, and 10-year follow-up, and risk factors for perianal disease and outcomes including risk of major (bowel resection, proctectomy, ostomy) and minor perianal (incision and drainage, seton placement, etc.) surgery.

RESULTS

In 12 population-based studies, prevalence of pCD was 18.7% (95% confidence interval [CI], 12.5%-27.0%) with 1-, 5-, and 10-year risk of perianal disease being 14.3% (95% CI, 7.9%-24.6%), 17.6% (95% CI, 11.3%-26.5%), and 18.9% (95% CI, 15.0%-23.4%), respectively. Approximately 11.5% of patients (95% CI, 6.7%-19.0%) had perianal disease at or before CD diagnosis. Colonic disease location and rectal involvement were associated with higher risk of pCD. Overall, 63.3% of patients (95% CI, 53.3-72.3) required minor perianal surgery and 6.4% of patients (95% CI, 1.8%-20.6%) required major abdominal surgery for pCD. Use of biologic therapy for pCD is common and has steadily increased throughout the years.

CONCLUSIONS

Approximately 1 in 5 patients with CD develops perianal disease within 10 years of CD diagnosis, including 11.5% who have perianal disease at presentation. Approximately two-thirds of patients require perianal surgery, with a smaller fraction requiring major abdominal surgery.

Approach to medical therapy in perianal Crohn's disease

Perianal Crohn's disease remains a challenging condition to treat and can have a substantial negative impact on quality of life. It often requires combined surgical and medical interventions. Anti-tumor necrosis factor (anti-TNF) therapy, including infliximab and adalimumab, remain preferred medical therapies for perianal Crohn's disease. Infliximab has been shown to be efficacious in improving fistula closure rates in randomized controlled trials. Clinicians can be faced with a number of questions relating to the optimal use of anti-TNF therapy in perianal Crohn's disease. Specific issues include evaluation for the presence of perianal sepsis, the treatment target of therapy, the ideal time to commence treatment, whether additional medical therapy should be used in conjunction with anti-TNF therapy, and the duration of treatment. This article will discuss key studies which can assist clinicians in addressing these matters when they are considering or have already commenced anti-TNF therapy for the treatment of perianal Crohn's disease. It will also discuss current evidence regarding the use of vedolizumab and ustekinumab in patients who are failing to achieve a response to anti-TNF therapy for perianal Crohn's disease. Lastly, new therapies such as local injection of mesenchymal stem cell therapy will be discussed.

Approach to the Management of Recently Diagnosed Inflammatory Bowel Disease Patients: A User's Guide for Adult and Pediatric Gastroenterologists

Inflammatory bowel diseases (IBDs), including Crohn's disease and ulcerative colitis, are chronic, progressive, immune-mediated diseases of adults and children that have no cure. IBD can cause significant morbidity and lead to complications such as strictures, fistulas, infections, and cancer. In children, IBD can also result in growth impairment and pubertal delays. IBD is highly heterogenous, with severity ranging from mild to severe and symptoms ranging from mild to debilitating. Delay in IBD diagnosis, especially in Crohn's disease, is common and associated with adverse outcomes. Early diagnosis and prompt institution of treatment are the cornerstones for improving outcomes and maximizing health. Early diagnosis requires a low threshold of suspicion and red flags to guide early specialist referral at the primary provider level. Although the armamentarium of IBD medications is growing, many patients will not respond to treatment, and the selection of first-line therapy is critical. Risk stratification of disease severity, based on clinical, demographic, and serologic markers, can help guide selection of first-line therapy. Clinical decision support tools, genomics, and other biomarkers of response to therapy and risk of adverse events are the future of personalized medicine. After starting appropriate therapy, it is important to confirm remission using objective end points (treat to target) with continued control of inflammation with adjustment of therapy using surrogate biomarkers (tight control). Lastly, IBD therapy extends far beyond medications, and other aspects of the overall health and wellbeing of the patient are critical. These include preventive health, nutrition, and psychobehavioral support addressing patients' concerns around complementary therapy and medication adherence, prevention of disability, and ensuring open communication.