A global consensus on the classification, diagnosis and multidisciplinary treatment of perianal fistulising Crohn's disease

A nanofiber-hydrogel composite improves tissue repair in a rat model of Crohn's disease perianal fistulas

Perianal fistulas (PAFs) represent a severe complication of Crohn's disease (CD). Despite the advent of biologic and small-molecule therapeutics for luminal disease, PAFs in CD (CD-PAF) are relatively resistant to treatment, with less than 50% responding to any therapy. We report an injectable, biodegradable, mechanically fragmented nanofiber-hydrogel composite (mfNHC) loaded with adipose-derived stem cells (ADSCs) for the treatment of fistulas in a rat model of CD-PAF. The ADSC-loaded mfNHC results in a higher degree of healing when compared to surgical treatment of fistulas, which is a standard treatment. The volume of fistulas treated with mfNHC is decreased sixfold compared to the surgical treatment control. Molecular studies reveal that utilization of mfNHC reduced local inflammation and improved tissue regeneration. This study demonstrates that ADSC-loaded mfNHC is a promising therapy for CD-PAF, and warrants further studies to advance mfNHC toward clinical translation.

SURGICAL INTERVENTION IN PATIENTS WITH IDIOPATHIC INFLAMMATORY BOWEL DISEASE AND PERIANAL DISEASE

OBJECTIVE

Aim: The aim of the study was to investigate the incidence of IBD in gastrointestinal surgery patients and record the disease's characteristics and treatment.

PATIENTS AND METHODS

Materials and Methods: A search was carried out in the archives of the gastroenterology clinics of the University General Hospital of Ioannina and the General Hospital of Ioannina "G. Hatzikosta" in Greece. All cases of operated patients from 1980 to 2018 were examined. The duration of the study was 4 months. Data were analyzed with the SPSS program, v.28.

RESULTS

Results: The total sample consisted of 1464 patients (n=1464). Most of them (915-62.5%) came from the University General Hospital of Ioannina, while the rest (549-37.5%) came from the GHI hospital "G. Hatzikosta". The mean age of the patients was 47 years (M=47.26, SD=17.34, Min=<1 month, Max=95 years). From the total sample, 58 patients (4%) suffered from IBD; most were men (42-72.41%). Their mean age was approximately 50 years (M=49.63, SD=16.48, Min=25 years, Max=77 years, range=52 years) and most belonged to the age groups of 31-40 years (11 patients- 19.6%) and 21-30 years and 61-70 years (10 patients-17.9%). The perianal disease was present in 43.1% (25 patients). The most frequent type of operation was fistula resection, ligation, curettage-biopsy (24.1%) and opening-drainage (22.4%-13 patients) and the most frequent type of anesthesia was general anesthesia (93.1%-54 patients).

CONCLUSION

Conclusions: This long-term study of the patients' data followed up over time showed that the possibility of surgery in patients with IBD is mitigated through systematic monitoring and multifaceted therapeutic treatment.The perianal disease which appeared more often in men shows that it can be diagnosed early and at an early stage and with the new minimally invasive techniques the patient with IBD can be treated with a better quality of life.

Characteristics of Patients with Crohn's Disease With or Without Perianal Fistulae in the CorEvitas Inflammatory Bowel Disease Registry

BACKGROUND

There are limited real-world data characterizing perianal fistulae in patients with Crohn's disease (CD).

AIM

To describe characteristics of patients with CD with and without perianal fistulae.

METHODS

In this cross-sectional study, characteristics, treatment history, and health outcomes of patients with CD enrolled in the CorEvitas IBD Registry were described according to perianal fistula status (current/previous or none).

RESULTS

Eight hundred and seventy-eight patients were included. Compared with patients with no perianal fistulae (n = 723), patients with current/previous perianal fistulae (n = 155) had longer disease duration since CD diagnosis (mean 16.5 vs 12.3 years; difference 4.3 years; 95% CI, 2.0, 6.6) and fewer had Harvey-Bradshaw Index scores indicative of remission (0-4, 56.8% vs 69.6%; difference - 12.9%; 95% CI, - 21.6, - 4.2). More patients with current/previous fistulae reported a history of IBD-related emergency room visits (67.7% vs 56.1%; difference 11.6%; 95% CI, 3.4, 19.8), hospitalizations (76.1% vs 58.4%; difference 17.7%; 95% CI, 10.1, 25.4), and surgeries (59.4% vs 27.7%; difference 31.7%; 95% CI, 23.3, 40.1), and a history of treatment with tumor necrosis factor inhibitors (81.3% vs 60.7%; difference 20.6%; 95% CI, 13.5, 27.7), immunosuppressants (51.6% vs 31.2%; difference 20.4%; 95% CI, 11.9, 29.0), and antibiotics (50.3% vs 23.7%; difference 26.6%; 95% CI, 18.2, 35.1) than patients without perianal fistulae.

CONCLUSIONS

Patients with CD with current/previous perianal fistulae have more symptomatic experiences of disease, higher medication use, hospitalization rates, and emergency room visits than patients without perianal fistulae. Interventions to prevent/reduce risk of developing fistulae may help improve outcomes in CD.

Dysfunctional Extracellular Matrix Remodeling Supports Perianal Fistulizing Crohn's Disease by a Mechanoregulated Activation of the Epithelial-to-Mesenchymal Transition

BACKGROUND AND AIMS

Perianal fistula represents one of the most disabling manifestations of Crohn's disease (CD) due to complete destruction of the affected mucosa, which is replaced by granulation tissue and associated with changes in tissue organization. To date, the molecular mechanisms underlying perianal fistula formation are not well defined. Here, we dissected the tissue changes in the fistula area and addressed whether a dysregulation of extracellular matrix (ECM) homeostasis can support fistula formation.

METHODS

Surgical specimens from perianal fistula tissue and the surrounding region of fistulizing CD were analyzed histologically and by RNA sequencing. Genes significantly modulated were validated by real-time polymerase chain reaction, Western blot, and immunofluorescence assays. The effect of the protein product of TNF-stimulated gene-6 (TSG-6) on cell morphology, phenotype, and ECM organization was investigated with endogenous lentivirus-induced overexpression of TSG-6 in Caco-2 cells and with exogenous addition of recombinant human TSG-6 protein to primary fibroblasts from region surrounding fistula. Proliferative and migratory assays were performed.

RESULTS

A markedly different organization of ECM was found across fistula and surrounding fistula regions with an increased expression of integrins and matrix metalloproteinases and hyaluronan (HA) staining in the fistula, associated with increased newly synthesized collagen fibers and mechanosensitive proteins. Among dysregulated genes associated with ECM, TNFAI6 (gene encoding for TSG-6) was as significantly upregulated in the fistula compared with area surrounding fistula, where it promoted the pathological formation of complexes between heavy chains from inter-alpha-inhibitor and HA responsible for the formation of a crosslinked ECM. There was a positive correlation between TNFAI6 expression and expression of mechanosensitive genes in fistula tissue. The overexpression of TSG-6 in Caco-2 cells promoted migration, epithelial-mesenchymal transition, transcription factor SNAI1, and HA synthase (HAs) levels, while in fibroblasts, isolated from the area surrounding the fistula, it promoted an activated phenotype. Moreover, the enrichment of an HA scaffold with recombinant human TSG-6 protein promoted collagen release and increase of SNAI1, ITGA4, ITGA42B, and PTK2B genes, the latter being involved in the transduction of responses to mechanical stimuli.

CONCLUSIONS

By mediating changes in the ECM organization, TSG-6 triggers the epithelial-mesenchymal transition transcription factor SNAI1 through the activation of mechanosensitive proteins. These data point to regulators of ECM as new potential targets for the treatment of CD perianal fistula.

The Intersection of Human and Veterinary Medicine-A Possible Direction towards the Improvement of Cell Therapy Protocols in the Treatment of Perianal Fistulas

The effective treatment of perianal fistulizing Crohn's disease is still a challenge. Local administration of mesenchymal stromal cells (MSCs) is becoming a part of accepted treatment options. However, as a fledgling technique, it still can be optimized. A new trend in translational research, which is in line with "One Health" approach, bases on exploiting parallels between naturally occurring diseases affecting humans and companion animals. Canine anal furunculosis (AF) has been indicated as condition analogous to human perianal Crohn's disease (pCD). This narrative review provides the first comprehensive comparative analysis of these two diseases based on the published data. The paper also outlines the molecular mechanisms of action of MSCs which are likely to have a role in modulating the perianal fistula niche in humans, and refers them to the current knowledge on the immunomodulatory properties of canine MSCs. Generally, the pathogenesis of both diseases shares main determinants such as the presence of genetic predispositions, dysregulation of immune response and the relation to intestine microbiota. However, we also identified many aspects which should be further specified, such as determining the frequency of true fistulas formation in AF patients, elucidating the role of TNF and Th17 pathway in the pathogenesis of AF, or clarifying the role of epithelial-to-mesenchymal transition phenomenon in the formation of canine fistulae. Nevertheless, the available data support the hypothesis that the results from testing cell therapies in dogs with anal furunculosis have a significant translational value in optimizing MSC transplants procedures in pCD patients.

Association of neutrophil extracellular traps with fistula healing in patients with complex perianal fistulising Crohn's disease

BACKGROUND AND AIMS

Perianal fistulising Crohn's disease (pfCD) is a disabling phenotype of Crohn's disease (CD) with suboptimal outcomes. We assessed neutrophil extracellular traps (NETs) in perianal fistulas and implicated their roles in pfCD healing.

METHODS

Patients with complex pfCD who developed preplaced seton drainage were recruited during the verified maintenance of remission in CD. Fistula tracts were sampled during definitive surgery plus seton removal. Patient demographics, CD classification, medication strategy, and healing of pfCD were recorded. RNA sequencing was applied for transcriptomic profile analysis. NETs components, including myeloperoxidase (MPO), neutrophil elastase (NE), and citrullinated histone H3 (CitH3), were identified using immunofluorescence. Serum infliximab (IFX), anti-IFX antibodies, and tissue levels of IFX, adalimumab (ADA), MPO and CitH3 were determined using enzyme-linked immunosorbent assays. Peptidyl arginine deiminase IV (PAD4), tumour necrosis factor (TNF)-α, and NE were detected using immunohistochemistry. Gene expression levels of PAD family members were assessed with qPCR.

RESULTS

Twenty-one patients were included, 15 of whom adopted IFX as maintenance treatment. RNA-seq revealed difference in neutrophil associated pathways between unhealed and healed fistulas. NETs components (MPO/NE/CitH3) were detectable in the fistulas and were parallel with the PAD4 levels. Eleven of 21 (52%) patients experienced complete healing of the pfCD 108 weeks post-operatively. Fistula NETs were significantly increased in patients with unhealed pfCD. Increased NETs were associated with abundant TNF-α production and the absence of IFX in fistulas.

CONCLUSIONS

NETs exist in pfCD fistulas, which are associated with unhealed post-operative fistulas in pfCD, suggesting their prognostic roles in pfCD.

Placebo response rates in randomized controlled trials for perianal Crohn's disease: A systematic review and meta-analysis

BACKGROUND AND AIMS

Perianal fistulizing disease is a common complication of Crohn's disease (CD), for which new therapies are urgently needed. To assist design of clinical trials for novel therapeutics, we conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to quantify placebo rates and identify factors influencing them in perianal CD.

METHODS

We searched MEDLINE, EMBASE and CENTRAL from inception to June 2021. Eligible studies were placebo-controlled trials of pharmacological interventions for perianal CD (pCD). Placebo fistula response and remission rates for induction and maintenance trials were extracted and pooled using a random-effects model. Mixed-effects meta-regression was used to evaluate the impact of patient and study-level characteristics on point estimates.

RESULTS

In 17 RCTs (13 induction, 5 maintenance) the pooled placebo fistula response and remission rate for induction trials was 25% (95% CI 17-36%) and 17% (95% CI 11-25%), respectively. For maintenance trials, the pooled placebo fistula response and remission rate was 23% (95% CI 17-32%) and 19% (95% CI 14-25%), respectively. Trials enrolling patients with less disease activity and a higher proportion with ileal predominant disease were associated with significantly higher placebo response rates. Trials originating in Europe (compared to North America), therapies requiring perianal injection and a longer timepoint to measure remission were associated with higher placebo remission rates.

CONCLUSIONS

Placebo response and remission rates in pCD trials are influenced by patient and disease-related factors, as well as the type of intervention being studied. These contemporary rates will inform trial design for novel therapeutics.

Imaging Evaluation of Inflammatory Bowel Disease Complications

Inflammatory bowel disease (IBD) is a chronic inflammatory condition that can progress to fibrostenotic and penetrating complications. Cross-sectional imaging is often needed for accurate diagnosis of IBD complication and for planning the appropriate management strategy. Computed tomography enterography, magnetic resonance enterography, and IBD ultrasound have become key tools for clinicians and interventional endoscopists. This article highlights and discusses various radiologic imaging techniques and their application to the diagnosis and management of IBD complications.

The relationship between perianal fistula activity and abdominal adipose tissue in Crohn’s disease: an observational study

Objective

The aim of this study was to analyze the relationship between abdominal adipose tissue and perianal fistula activity in patients with Crohn's disease (CD) using cross-sectional imaging.

Methods

Patients with perianal fistulizing CD who underwent pelvic magnetic resonance imaging (MRI) and abdominal computed tomography (CT) were retrospectively enrolled. We scored the fistulas in each patient's MRI images based on Van Assche's classification. The area and density of subcutaneous adipose tissue (SAT) and visceral adipose tissue (VAT) (at the third, fourth, and fifth lumbar (L3, L4, and L5) levels were measured by averaging five slices of measurements at each vertebral level in CT images, and areas were further standardized by the lumbar height2 (heightL1-5). The VAT/SAT ratio (VSR) and VAT/Total adipose tissue (VA/TA) index were calculated. Based on MRI scores, patients were divided into two groups with low and high activity, and their clinical, MRI features, and CT parameters were compared. We evaluated patients with follow-up MRI and compared the differences in clinical and radiological indicators among patients with different outcomes.

Results

Overall, 136 patients were included, 77 in the low-activity group and 59 in the high-activity group. Patients in the high activity group had lower subcutaneous adipose index (all levels, p < 0.05) and visceral adipose index (L3 level, p < 0.01), but higher SAT and VAT density (all levels, p < 0.01), VSR (L5 level, p = 0.07) and VA/TA index (L5 level, p < 0.05).

Conclusion

There were differences in adipose tissue composition among CD patients with different active perianal fistulas.

The Multidisciplinary Management of Perianal Fistulas in Crohn’s Disease: A Systematic Review

Perianal fistulas in Crohn's disease (CD) are often recurring and challenging to treat. This systematic review aimed to evaluate the medical, surgical, and combination treatment options and provide an overview of their efficacy. We performed this systematic review following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. Our group searched PubMed, Medline, PubMed Central, Google Scholar, and ScienceDirect for articles within the last ten years using different terms and criteria mentioned in detail in the search strategy and eligibility criteria sections. Initially, 739 records were retrieved, out of which we excluded 731 records for various reasons, such as irrelevant titles and abstracts and low scores on quality assessment tools. The evidence for combination (surgical and medical) therapy is superior to that for medical and surgical treatments individually. In contrast, the studies on medical and surgical treatments individually reported varied evidence and efficacy for their respective options.

Strategies to Distinguish Perianal Fistulas Related to Crohn's Disease From Cryptoglandular Disease: Systematic Review With Meta-Analysis

BACKGROUND

Management of perianal fistulas differs based on fistula type. We aimed to assess the ability of diagnostic strategies to differentiate between Crohn's disease (CD) and cryptoglandular disease (CGD) in patients with perianal fistulas.

METHODS

We performed a diagnostic accuracy systematic review and meta-analysis. A systematic search of electronic databases was performed from inception through February 2021 for studies assessing a diagnostic test's ability to distinguish fistula types. We calculated weighted summary estimates with 95% confidence intervals for sensitivity and specificity by bivariate analysis, using fixed effects models when data were available from 2 or more studies. The Quality Assessment of Diagnostic Accuracy Studies tool was used to assess study quality.

RESULTS

Twenty-one studies were identified and included clinical symptoms (2 studies; n=154), magnetic resonance imaging (MRI) characteristics (3 studies; n=296), ultrasound characteristics (7 studies; n=1003), video capsule endoscopy (2 studies; n=44), fecal calprotectin (1 study; n=56), and various biomarkers (8 studies; n=440). MRI and ultrasound characteristics had the most robust data. Rectal inflammation, multiple-branched fistula tracts, and abscesses on pelvic MRI and the Crohn's ultrasound fistula sign, fistula debris, and bifurcated fistulas on pelvic ultrasonography had high specificity (range, 80%-95% vs 89%-96%) but poor sensitivity (range, 17%-37% vs 31%-63%), respectively. Fourteen of 21 studies had risk of bias on at least 1 of the Quality Assessment of Diagnostic Accuracy Studies domains.

CONCLUSIONS

Limited high-quality evidence suggest that imaging characteristics may help discriminate CD from CGD in patients with perianal fistulas. Larger, prospective studies are needed to confirm these findings and to evaluate if combining multiple diagnostic tests can improve diagnostic sensitivity.

Examination Under Anesthesia May Not Be Universally Required Prior to Anti-TNF Therapy in Perianal Crohn's Disease: A Comparative Cohort Study

BACKGROUND

Multidisciplinary care involving exam under anesthesia (EUA) and tumor necrosis factor (TNF) inhibitors is recommended for perianal Crohn's disease. However, the impact of this combined approach is not well established.

METHODS

We performed a comparative cohort study between 2009 and 2019. Patients with perianal Crohn's disease treated with EUA before anti-TNF therapy (combined modality therapy) were compared with anti-TNF alone. The primary outcome was fistula closure assessed clinically. Secondary outcomes included subsequent local surgery and fecal diversion. Multivariable analysis adjusted for abscesses, concomitant immunomodulators, and time to anti-TNF initiation was performed.

RESULTS

Anti-TNF treatment was initiated 188 times in 155 distinct patients: 66 (35%) after EUA. Abscesses (50% vs 15%; P < .001) and concomitant immunomodulators (64% vs 50%; P = .07) were more common in the combined modality group, while age, smoking status, disease duration, and intestinal disease location were not significantly different. Combined modality therapy was not associated with higher rates of fistula closure at 3 (adjusted odds ratio [aOR], 0.7; 95% confidence interval [CI], 0.3-1.8), 6 (aOR, 0.8; 95% CI, 0.4-2.0) and 12 (aOR, 1.0; 95% CI, 0.4-2.2) months. After a median follow-up of 4.6 (interquartile range, 5.95; 2.23-8.18) years, combined therapy was associated with subsequent local surgical intervention (adjusted hazard ratio, 2.2; 95% CI, 1.3-3.6) but not with fecal diversion (adjusted hazard ratio, 1.3; 95% CI, 0.45-3.9). Results remained consistent when excluding patients with abscesses and prior biologic failure.

CONCLUSIONS

EUA before anti-TNF therapy was not associated with improved clinical outcomes compared with anti-TNF therapy alone, suggesting that EUA may not be universally required. Future prospective studies controlling for fistula severity are warranted.

Management of refractory inflammatory bowel disease

PURPOSE OF REVIEW

Nearly one-third of patients with inflammatory bowel disease (IBD) do not achieve remission despite our best therapies. When this happens, it is critical to understand the reason for treatment failure. Once nonresponse is confirmed, these patients should be referred to an IBD centre for multidisciplinary care. This review will discuss the remaining treatment options, including escalation of biologics to unlicensed doses, combination biologics, nonvalidated therapies and surgical options. It will additionally provide updates in the management of acute severe ulcerative colitis (ASUC).

RECENT FINDINGS

There is an increasing interest in combination biologics to treat refractory IBD, although data supporting its safety and effectiveness are limited. The use of hyperbaric oxygen, mesenchymal stem cell therapy and dietary interventions also show early promise in this area. Studies have additionally focused on personalized therapy to identify aggressive phenotypes and predict treatment response in these challenging patients. In ASUC, infliximab and cyclosporine remain mainstays of treatment, and tofacitinib shows promise as a salvage therapy.

SUMMARY

Refractory IBD is common, yet large knowledge gaps remain. Recent and ongoing studies have focused on medical, surgical and dietary approaches with mixed success. Larger prospective studies are desperately needed to address this complex issue.

The development of a minimum dataset for MRI reporting of anorectal fistula: a multi-disciplinary, expert consensus process

There are a range of sphincter-preserving procedures available to treat anorectal fistula, some of which can be precluded, or rendered more optimal by specific features of fistula anatomy. Magnetic resonance imaging (MRI) is the gold standard modality for assessing anorectal fistula. To maximise clinical utility, the MRI report should accurately describe these clinically relevant features. We aimed to develop a minimum dataset for reporting MRI of anorectal fistula, in order to improve the assessment and management of these patients. A longlist of 70 potential items for the minimum dataset was generated through systematic review of the literature. This longlist was presented to radiologists, surgeons and gastroenterologists in an online survey to understand the features that shape current clinical practice. The longlist and survey results were then presented to an expert consensus panel to generate the final minimum dataset through discussion and anonymous voting. The final minimum dataset details the general characteristics, features of the internal and external openings, path of the fistula through the sphincters and any associated extensions and collections that should be described in all MRI reports for anal fistula. Additional surgical and perianal Crohn's disease subsets were developed to indicate the features that aid decision-making for these patients, in addition to a minimum dataset for the clinical request. This study represents a multi-disciplinary approach to developing a minimum dataset for MRI reporting of anal fistula, highlighting the most important features to report that can assist in clinical decision-making. KEY POINTS: • This paper recommends the minimum features that should be included in all MRI reports for the assessment of anal fistula, including Parks classification, number of tracts, features of the internal and external opening, path of the tract through the sphincters, the presence and features of extensions and collections. • Additional features that aid decision-making for surgery or in the presence of Crohn's disease have been identified. • The items that should be included when requesting an MRI are specified.

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.

The Role of Magnetic Resonance Enterography in Crohn’s Disease: A Review of Recent Literature

Inflammatory bowel disease (IBD) is the term used to identify a form of chronic inflammation of the gastrointestinal tract that primarily contemplates two major entities: ulcerative colitis (UC) and Crohn’s disease (CD). The classic signs are abdominal pain and diarrhoea that correlate with the localization of gastro-enteric disease, although in this pathology extraintestinal symptoms may coexist. The diagnosis of CD relies on a synergistic combination of clinical, laboratory (stool and biochemical), cross-sectional imaging evaluation, as well as endoscopic and histologic assessments. The purpose of this paper is to prove the role of imaging in the diagnosis and follow-up of patients with CD with particular focus on recent innovations of magnetic resonance enterography (MRE) as a pivotal diagnostic tool, analysing the MRE study protocol and imaging features during the various phases of disease activity and its complications.

Development and Validation of a Pediatric MRI-Based Perianal Crohn Disease (PEMPAC) Index-A Report from the ImageKids Study

BACKGROUND

As part of the prospective multicenter ImageKids study, we aimed to develop and validate the pediatric MRI-based perianal Crohn disease (PEMPAC) index.

METHODS

Children with Crohn disease with any clinical perianal findings underwent pelvic magnetic resonance imaging at 21 sites globally. The site radiologist and 2 central radiologists provided a radiologist global assessment (RGA) on a 100 mm visual analog scale and scored the items selected by a Delphi group of 35 international radiologists and a review of the literature. Two weighted multivariable statistical models were constructed against the RGA.

RESULTS

Eighty children underwent 95 pelvic magnetic resonance imaging scans; 64 were used for derivation and 31 for validation. The following items were included: fistula number, location, length and T2 hyperintensity; abscesses; rectal wall involvement; and fistula branching. The last 2 items had negative beta scores and thus were excluded in a contending basic model. In the validation cohort, the full and the basic models had the same strong correlation with the RGA (r = 0.75; P < 0.01) and with the adult Van Assche index (VAI; r = 0.93 and 0.92; P < 0.001). The correlation of the VAI with the RGA was similar (r = 0.77; P < 0.01). The 2 models and the VAI had a similar ability to differentiate remission from active disease (area under the receiver operating characteristic curve, 0.91-0.94). The PEMPAC index had good responsiveness to change (area under the receiver operating characteristic curve, 0.89; 95% confidence interval, 0.69-1.00).

CONCLUSIONS

Using a blended judgmental and mathematical approach, we developed and validated an index for quantifying the severity of perianal disease in children with CD. The adult VAI may also be used with confidence in children.

Follow-up Study to Evaluate the Long-term Safety and Efficacy of Darvadstrocel (Mesenchymal Stem Cell Treatment) in Patients With Perianal Fistulizing Crohn's Disease: ADMIRE-CD Phase 3 Randomized Controlled Trial

BACKGROUND

Darvadstrocel is an expanded allogeneic adipose-derived mesenchymal stem cell therapy for the treatment of complex perianal fistulas in patients with Crohn's disease. Safety and efficacy outcomes from the clinical trial known as "Adipose derived mesenchymal stem cells for induction of remission in perianal fistulizing Crohn's disease," or ADMIRE-CD (NCT01541579), from up to 52 weeks posttreatment were previously reported. Here, the outcomes from an extended 104-week follow-up are reported.

OBJECTIVE

The goal of this study was to assess the long-term safety and efficacy of darvadstrocel at 2 years post-treatment in patients with Crohn's disease and complex perianal fistulas.

DESIGN

This was a phase 3 double-blind randomized controlled study (ADMIRE-CD) in patients with perianal fistulizing Crohn's disease.

SETTINGS

This study extension was conducted in multiple hospitals across 7 European countries and Israel.

PATIENTS

Forty patients entered the extended follow-up period: 25 patients in the darvadstrocel treatment group and 15 in the control group.

INTERVENTIONS

Darvadstrocel or saline solution (control group) was administered once, locally, after fistula tract curettage and internal opening closure (with previous seton placement). All patients were permitted to continue ongoing medical treatments for fistulas.

MAIN OUTCOME MEASURES

Treatment-emergent serious adverse events were recorded through week 104. Clinical remission, defined as closure of all treated external openings that were draining at baseline despite gentle finger compression, was assessed at week 104.

RESULTS

Of 40 patients, 37 completed the extended follow-up. Through week 104, 7 treatment-emergent serious adverse events were reported, of which 4 occurred between weeks 52 and 104. At week 104, clinical remission was reported in 14/25 (56%) patients in the darvadstrocel group and 6/15 (40%) patients in the control group.

LIMITATIONS

Limitations include the small number of patients who entered the extended follow-up period, and no imaging examinations were performed at the 104-week time point.

CONCLUSIONS

Darvadstrocel was well tolerated and clinical remission after treatment with darvadstrocel may be sustained for up to 104 weeks in patients with perianal fistulizing Crohn's disease. See Video Abstract at http://links.lww.com/DCR/B812.ClinicalTrials.gov No: NCT01541579.

ESTUDIO DE SEGUIMIENTO PARA EVALUAR LA SEGURIDAD Y EFICACIA A LARGO PLAZO DE DARVADSTROCEL TRATAMIENTO CON CLULAS MADRE MESENQUIMALES EN PACIENTES CON ENFERMEDAD DE CROHN PERIANAL FISTULIZANTE ENSAYO CONTROLADO ALEATORIZADO DE FASE ADMIRECD

ANTECEDENTES:Darvadstrocel es una terapia con células madre mesenquimales alogénicas expandidas derivadas de tejido adiposo para el tratamiento de fístulas perianales complejas en pacientes con enfermedad de Crohn. Los resultados del ensayo clínico conocido como "Células madre mesenquimales derivadas de tejido adiposo para la inducción de la remisión en la enfermedad de Crohn fistulizante perianal" o ADMIRE-CD (NCT01541579), en cuanto a la seguridad y eficacia hasta 52 semanas después del tratamiento, fueron previamente informados. Seguidamente, se presentan los resultados de un seguimiento extendido de 104 semanas.OBJETIVO:Evaluar la seguridad y eficacia a largo plazo de darvadstrocel a dos años del tratamiento en pacientes con enfermedad de Crohn y fístulas perianales complejas.DISEÑO:Este fue un estudio de fase 3, aleatorizado, a doble ciego, controlado (ADMIRE-CD) en pacientes con enfermedad de Crohn perianal fistulizante.DESARROLLO:Esta extensión del estudio se realizó en varios hospitales de siete países europeos e Israel.PACIENTES:Cuarenta pacientes participaron en la extensión de seguimiento: tratamiento con darvadstrocel (n = 25); grupo control (n = 15).INTERVENCIONES:Se administró Darvadstrocel o solución salina (grupo control) una vez, localmente, tras el legrado del trayecto fístuloso y cierre del orificio interno (con la colocación previa de setón). A todos los pacientes se les permitió continuar con los tratamientos médicos en curso para las fístulas.PRINCIPALES MEDIDAS DE RESULTADO:Los eventos de efectos adversos graves derivados del tratamiento se registraron hasta la semana 104. La remisión clínica, definida como el cierre de todas las aberturas externas tratadas que drenaban al inicio espontáneamente o por compresión suave de los dedos, fue evaluado en la semana 104.RESULTADOS:Del total de 40 pacientes, 37 completaron la extensión de seguimiento. Hasta la semana 104, se reportaron 7 eventos de efectos adversos graves resultantes del tratamiento, de los cuales 4 ocurrieron entre las semanas 52 y 104. En la semana 104, se reportó remisión clínica en 14/25 (56%) pacientes en el grupo de darvadstrocel y 6/15 (40%) pacientes en el grupo de control.LIMITACIONES:Solo una pequeña cantidad de pacientes participaron en el período de seguimiento extendido y no se realizaron exámenes por técnicas de imagen en la visita a 104 semanas.CONCLUSIONES:Darvadstrocel fue bien tolerado y la remisión clínica después del tratamiento con darvadstrocel puede mantenerse hasta 104 semanas en pacientes con enfermedad de Crohn perianal fistulizante. Consulte Video Resumen en http://links.lww.com/DCR/B812. (Traducción-Dr Osvaldo Gauto and Dr Julian Panés.)ClinicalTrials.gov No. NCT01541579.

Efficacy and Safety of 2 Vedolizumab Intravenous Regimens for Perianal Fistulizing Crohn's Disease: ENTERPRISE Study

BACKGROUND & AIMS

Fistulizing Crohn's disease (CD) is challenging to treat. We report results from ENTERPRISE, a randomized, double-blind, phase 4 trial evaluating 2 vedolizumab intravenous dosing regimens in patients with fistulizing CD.

METHODS

Patients with moderately to severely active CD and 1-3 active perianal fistulae (identified on magnetic resonance imaging [MRI]) received vedolizumab 300 mg intravenously at weeks 0, 2, 6, 14, and 22 (VDZ) or the same regimen plus an additional vedolizumab dose at week 10 (VDZ + wk10). Reduction from baseline in draining perianal fistulae and disease activity, MRI assessments, health-related quality of life (HRQoL), and safety were evaluated. Enrollment was stopped prematurely because of recruitment challenges; analyses are descriptive.

RESULTS

Of 32 patients with ≥1 active fistulae at baseline per MRI and postbaseline fistulae healing assessment, 28 (14 per dosing regimen) had ≥1 draining fistulae at baseline (assessed by gentle finger compression during clinical exam). Rapid and sustained fistula closure was observed; 53.6% (VDZ, 64.3%; VDZ + wk10, 42.9%) and 42.9% (VDZ, 50.0%; VDZ + wk10, 35.7%) of patients achieved ≥50% decrease in draining fistulae and 100% fistulae closure, respectively, at week 30. Mean (standard deviation) CD and Perianal Disease Activity Index scores decreased by 51.1 (78.3) and 4.1 (3.3), respectively, at week 30. HRQoL improved throughout the study. No new safety signals were observed.

CONCLUSIONS

Sustained improvements in fistulizing CD were seen with both vedolizumab regimens. An additional dose at week 10 does not appear to alter treatment outcomes. Safety profile was consistent with other vedolizumab studies.

CLINICALTRIALS

gov no: NCT02630966; EudraCT: 2015-000852-12.

Establishing a rabbit model of perianal fistulizing Crohn’s disease

BACKGROUND

Crohn's disease (CD) is a chronic nonspecific intestinal inflammatory disease. The aetiology and pathogenesis of CD are still unclear. Anal fistula is the main complication of CD and is a difficult problem to solve at present. The main limitation of developing new therapies is bound up with the short of preclinical security and effectiveness data. Therefore, an ideal animal model is needed to establish persistent anal fistula and an inflamed rectal mucosa.

AIM

To improve the induction method of colitis and establish a reliable and reproducible perianal fistulizing Crohn’s disease animal model to evaluate new treatment strategies.

METHODS

Twenty male New Zealand rabbits underwent rectal enema with different doses of 2,4,6-trinitrobenzene sulfonic acid to induce proctitis. Group A was treated with an improved equal interval small dose increasing method. The dosage of group B was constant. Seven days later, the rabbits underwent surgical creation of a transsphincteric fistula. Then, three rabbits were randomly selected from each group every 7 d to remove the seton from the fistula. The rabbits were examined by endoscopy every 7 days, and biopsy forceps were used to obtain tissue samples from the obvious colon lesions for histological analysis. The disease activity index (DAI), colonoscopy and histological scores were recorded. Perianal endoscopic ultrasonography (EUS) was used to evaluate the healing of fistulas.

RESULTS

Except for the DAI score, the colonoscopy and histological scores in group A were significantly higher than those in group B (P < 0.05). In the ideal model rabbit group, on the 7^th day after the removal of the seton, all animals had persistent lumens on EUS imaging, showing continuous full-thickness high signals. Histological inspection of the fistula showed acute and chronic inflammation, fibrosis, epithelialization and peripheral proctitis of the adjoining rectum.

CONCLUSION

The improved method of CD colitis induction successfully established a rabbit perianal fistula CD preclinical model, which was confirmed by endoscopy and pathology.

Time to Revisit Disease Classification in Inflammatory Bowel Disease: Is the Current Classification of Inflammatory Bowel Disease Good Enough for Optimal Clinical Management?

Inflammatory bowel disease (IBD), historically subdivided into Crohn's disease and ulcerative colitis, is a very heterogeneous condition. While the tendency in medicine is to try to reduce complexity, IBD is a disease that cannot justify a one-size-fits-all principle. Our current clinical classification tools are suboptimal and need further refinement to capture, at least in part, the variety of phenotypes encountered in daily clinical practice. Although these revised classification tools alone will not be sufficient and should be complemented by more detailed molecular subclassifications, optimized clinical phenotypes can contribute to improved trial designs, future translational research approaches, and better treatment outcomes. In the current review, we discuss key clinical features important in IBD disease heterogeneity, tackle limitations of the current classification systems, propose some potential improvements, and raise priorities for future research in this domain.

Relationship between clinical remission of perianal fistulas in Crohn’s disease and serum adalimumab concentrations: A multi-center cross-sectional study

BACKGROUND

Crohn’s disease (CD) is complicated by perianal fistulas in approximately 20% of patients. Achieving permanent fistula closure remains a challenge for physicians. An association between serum anti-tumor necrosis factor-α concentrations and clinical outcomes in patients with CD has been demonstrated; however, little information is available on serum adalimumab (ADA) concentrations and remission of perianal fistulas in such patients.

AIM

To study the relationship between serum ADA concentrations and clinical remission of CD-associated perianal fistulas.

METHODS

This cross-sectional study of patients with CD-associated perianal fistulas treated with ADA was performed at four French hospitals between December 2013 and March 2018. At the time of each serum ADA concentration measurement, we collected information about the patients and their fistulas. The primary study endpoint was clinical remission of fistulas defined as the absence of drainage (in accordance with Present’s criteria), with a PDAI ≤ 4, absence of a seton and assessment of the overall evaluation as favorable by the proctologist at the relevant center. We also assessed fistula healing [defined as being in clinical and radiological (magnetic resonance imaging, MRI) remission] and adverse events.

RESULTS

The study cohort comprised 34 patients who underwent 56 evaluations (patients had between one and four evaluations). Fifteen patients had clinical remissions (44%), four of whom had healed fistulas on MRI. Serum ADA concentrations were significantly higher at evaluations in which clinical remission was identified than at evaluations in which it was not [14 (10-16) vs 10 (2-15) μg/mL, P = 0.01]. Serum ADA concentrations were comparable at the times of evaluation of patients with and without healed fistulas [11 (7-14) vs 10 (4-16) μg/mL, P = 0.69]. The adverse event rate did not differ between different serum ADA concentrations.

CONCLUSION

We found a significant association between high serum ADA concentrations and clinical remission of CD-associated perianal fistulas.

Choosing the right biologic for complications of inflammatory bowel disease

INTRODUCTION

Inflammatory bowel disease (IBD) is a chronic, inflammatory condition that involves the intestinal tract, and can also present with extra-intestinal manifestations (EIM). Choosing the right treatment for IBD is often nuanced and decisions can become even more complicated when a patient presents with or develops a complication of the disease.

AREAS COVERED

We aimed to provide an overview of the most common complications of IBD, specifically intestinal and EIM, and summarize the data regarding biologic therapy for treatment of these conditions. A comprehensive literature review was performed using PubMed and Medline databases to identify studies published in the English language relevant to the broad scope of this review.

EXPERT OPINION

There are still significant gaps in our understanding of the pathophysiology of IBD and its treatment, especially in regards to complications of the disease. As novel therapies continue to emerge for treatment of IBD, we feel concurrent examination of their impact on intestinal complications and EIM of IBD is important and should be a priority of future research.

Perianal Crohn's Disease Is Associated With Poor Disease Outcome: A Nationwide Study From the epiIIRN Cohort

BACKGROUND & AIMS

Limited population-based data have explored perianal involvement in Crohn's disease (CD) and compared the disease course between severe and non-severe perianal CD (PCD). We aimed to explore the disease course of these phenotypes in a population-based study of CD.

METHODS

Cases were identified from the epi-IIRN cohort and included 2 Israeli health maintenance organizations covering 78% of the population. We validated specific algorithms to identify fistulizing PCD and to differentiate severe from non-severe disease by medication utilization, International Classification of Disease, 9th Revision codes, and perianal procedures.

RESULTS

A total of 12,904 CD patients were included in an inception cohort from 2005 (2186 pediatric-onset, 17%) providing 86,119 person-years of follow-up. Fistulizing PCD was diagnosed in 1530 patients (12%) (574 with severe PCD, 4%). The prevalence of PCD was 7.9%, 9.4%, 10.3%, and 11.6% at 1, 3, 5, and 10 years from CD diagnosis, respectively. At 5 years, PCD patients were more likely to be hospitalized (36% in non-PCD vs 64% in PCD; P < .001), undergo inflammatory bowel disease-related surgeries (9% vs 38%, respectively; P < .001), and develop anorectal cancer (1.2/10,000 person-years for non-PCD vs 4.2/10,000 for PCD; P = .01). Severe PCD was associated with poorer outcomes compared with non-severe PCD, as shown for hospitalizations (61% in non-severe PCD vs 73% in severe; P = .004) and surgeries (35% vs 43%; P = .001).

CONCLUSIONS

Despite higher utilization of immunomodulators and biologics, PCD is associated with poor disease outcomes, especially in severe PCD.

Hyperbaric oxygen therapy for the treatment of perianal fistulas in 20 patients with Crohn's disease: Results of the HOT-TOPIC trial after 1-year follow-up

Background

Previously published short‐term results (week 16) of this trial showed a significant improvement in clinical, radiologic and biochemical outcomes in Crohn's disease patients with therapy‐refractory perianal fistulas after treatment with hyperbaric oxygen therapy.

Objective

To assess the long‐term (week 60) efficacy, safety and feasibility of hyperbaric oxygen therapy in perianal fistula in Crohn's disease.

Methods

Crohn's disease patients with high perianal fistula(s) failing conventional treatment >6 months were included. Exclusion criteria were presence of a stoma, rectovaginal fistula(s) and recent changes in treatment regimens. Patients received 40 hyperbaric oxygen sessions and outcomes were assessed at week 16 and week 60.

Results

Twenty patients were included (median age 34 years). At week 16, median scores of the perianal disease activity index and modified Van Assche index (co‐primary outcomes) decreased from 7.5 (95% CI 6–9) to 4 (95% CI 3–6, p < 0.001) and 9.2 (95% CI 7.3–11.2) to 7.3 (95% CI 6.9–9.7, p = 0.004), respectively. At week 60, the respective scores remained significantly lower than baseline: 4 (95% CI 3–7, p < 0.001) and 7.7 (95% CI 5.2–10.2, p = 0.003). Perianal disease activity index score of 4 or less (representing inactive perianal disease) was observed in 13 patients at week 16 and 12 patients at week 60. Using fistula drainage assessment, 12 and 13 patients showed a clinical response at week 16 and 60, respectively, and clinical remission was achieved in four patients for both time points. At week 16, a statistically significant biochemical improvement (C‐reactive protein and faecal calprotectin levels) was found, but this effect was no longer significant at week 60.

Conclusions

The clinical and radiologic improvement of perianal fistula in Crohn's disease, that was found at week 16 after treatment with hyperbaric oxygen therapy, is maintained at 1‐year follow‐up.

Surgical closure, mainly with glue injection and anti-tumour necrosis factor α, in fistulizing perianal Crohn's disease: A multicentre randomized controlled trial

AIM

In patients with fistulizing perianal Crohn's disease (CD), the need for a secondary surgical step is not defined. The aim was to assess the efficacy of surgical closure compared to a single seton removal in patients with drained fistulizing perianal CD treated with adalimumab.

METHODS

This was a multicentre, randomized controlled trial, comparing seton removal + surgical closure (closure group) to seton removal alone (control group) with a stratification according to the American Gastroenterological Association classification. The primary end-point was fistula closure at month 12 defined by the association of the following criteria: no seton, absence of a visible external opening, absence of discharge from the tract after finger compression, absence of an internal opening, absence of perianal pain/abscess and absence of fistula-related abnormalities.

RESULTS

Among the 64 included patients (262 expected) (48 complex fistula, 75%), 33 were randomized to the closure group and 31 to the control group. In the closure group, 26 patients (78.8%) had glue. At month 12, overall fistula closure was achieved in 35 of the evaluable 58 patients (60%): 18/32 (56%) in the surgery group and 17/26 (65%) in the control group (P = 0.479). In the closure group, fistula closure was observed in 13/25 (52%) and 5/7 (71%) patients with complex and simple fistula respectively (P = 0.426), compared with 12/18 (67%) and 5/8 (63%), respectively in the control group (P = 1.000).

CONCLUSIONS

Seton removal alone seems to be no more effective than a secondary surgical step (in particular glue injection) in patients having fistulizing perianal CD controlled by an initial drainage combined with adalimumab. The results should be interpreted with caution.

Impact on Quality of Life of Seton Placing in Perianal Crohn's Disease

Introduction

Often, in perineal Crohn's disease (CD), a seton is placed to guarantee a constant drainage and prevent septic complication while biologic therapy is ongoing. This study aimed to assess the long-term quality of life after surgery for perineal CD in relation to seton placing.

Patients and Methods

Data of 65 consecutive patients with CD and non-CD operated on from 2014 to 2019 for perianal fistula or abscess were retrieved. Forty-three had CD and 14 of them had a seton placed during surgery and they kept it on while they had anti-TNF-alpha therapy. Patients were interviewed with the Cleveland Global Quality of Life (CGQL) and SF-12 quality of life questionnaires. Disease activity was defined as Harvey-Bradshaw Index (HBI) and Perianal Disease Activity Index (PDAI). Comparisons between groups were carried out with the nonparametric tests, and multiple regression models were used to assess predictors of quality of life.

Results

The total CGQL score and SF-12 mental component score (MCS) were significantly higher (and thus better) in the seton group than in patients treated without seton. On the contrary, SF-12 physical component score (PCS) was not different between the two groups. HBI was significantly better in patients in the seton group. At multivariate analysis, seton placement and HBI were confirmed to be independent predictors of long-term SF-12 MCS whereas only HBI confirmed to be a predictor of total CGQL score.

Conclusions

Seton placing during anti-TNF-alpha therapy is independently associated with a better MCS. Unexpectedly, this device, instead of to cause psychological distress, seems to assure patients during their biologic therapy providing psychological benefit beyond the mere medical effect.

The Essential Role of a Multidisciplinary Approach in Inflammatory Bowel Diseases: Combined Medical-Surgical Treatment in Complex Perianal Fistulas in CD

Perianal fistulizing Crohn's disease (PFCD) represents a challenging and complex disease phenotype. Patients typically suffer a more severe disease course than those without perianal complications and are often managing debilitating symptoms. Etiology is understood to be multifactorial, with genetic predisposition, microbiological insult, aberrant immunity, and mechanical factors all implicated. As a result, multimodal treatment strategies must be employed to achieve disease control and fistula closure. This requires the complimentary involvement of medical and surgical disciplines in order to ensure thorough assessment and treatment tailored to the individual scenario and patient goals. The aim of this article is to describe an overview of the various treatment strategies available for PFCD, focusing on how a synergistic approach is required to ensure maximal chances of success.

Managing complex perianal disease after anti-TNF failure: Where to go next?

Crohn's disease is a chronic inflammatory bowel disease that affects various intestinal segments and can involve the perianal region. Although anti-tumor necrosis factor (TNF) agents have revolutionized the management of Crohn's disease and improved the prognosis for patients with perianal Crohn's disease (pCD), their long-term effectiveness is limited: over 60% of patients relapse after one year of maintenance therapy. In recent years, significant advances have been made in the treatment of complex perianal fistulas after anti-TNF failure. Concomitant treatment with antibiotics and immunosuppressants improves the effectiveness of anti-TNF agents. Therapeutic drug monitoring and dose adjustment of anti-TNF therapy (targeting a higher trough level) might also improve treatment response. Novel therapeutic strategies might provide new opportunities for pCD management; for example, ustekinumab might be effective after anti-TNF treatment failure, although more studies are needed. As suggested in recent international guidelines, mesenchymal stem cell injection might be an effective, safe treatment for complex pCD.

Combined therapy with early initiation of infliximab following drainage of perianal fistulising Crohn's disease: a retrospective cohort study

BACKGROUND

Recent studies have confirmed that combined surgery and anti-TNF therapy could improve outcomes in patients with perianal fistulising Crohn's disease (PFCD). However, the optimal timing for infliximab infusion after surgical intervention is uncertain. We aimed to determine the long-term efficacy of early initiation of infliximab following surgery among PFCD patients.

METHODS

We performed a retrospective cohort study of PFCD patients who received combined infliximab and surgical treatment between 2010 and 2018 at a tertiary referral hospital. Patients were grouped according to the time interval between surgery and infliximab infusion, with < 6 weeks into early infliximab induction group and > 6 weeks into delayed infliximab induction group. The primary outcome was to compare surgical re-intervention between early and delayed infliximab induction groups. The secondary outcomes were fistula healing and predictors associated with these outcomes of early infliximab induction approach.

RESULTS

One hundred and seventeen patients were included (73 in early infliximab induction, 44 in delayed infliximab induction). The median interval between surgery and infliximab initiation was 9.0 (IQR 5.5-17.0) days in early infliximab induction group and 188.0 (IQR 102.25-455.75) days in delayed infliximab induction group. After followed-up for a median of 36 months, 61.6% of patients in early infliximab induction group and 65.9% in delayed infliximab induction group attained fistula healing (p = 0.643). The cumulative re-intervention rate was 23%, 32%, 34% in early infliximab induction group and 16%, 25%, 25% in delayed infliximab induction group, at 1, 2, and 3 years respectively (p = 0.235). Presence of abscess at baseline (HR = 5.283; 95% CI, 1.61-17.335; p = 0.006) and infliximab maintenance therapy > 3 infusions (HR = 3.691; 95% CI, 1.233-11.051; p = 0.02) were associated with re-intervention in early infliximab induction group. Presence of abscess at baseline also negatively influenced fistula healing (HR = 3.429, 95% CI, 1.216-9.668; p = 0.02).

CONCLUSION

Although no clear benefit was shown compared with delayed infliximab induction group, early initiation of infliximab after surgery could achieve promising results for PFCD patients. Before infliximab infusion, durable drainage is required for patients with concomitant abscess or prolonged infliximab maintenance therapy.

Advanced Regenerative Medicine Strategies for Treatment of Perianal Fistula in Crohn's Disease

Regenerative medicine is an emerging therapeutic method that aims to reconstruct tissues and organs. This advanced therapeutic approach has demonstrated great potential in addressing the limitations of medical and surgical procedures for treating perineal fistula in patients with Crohn's disease. Recent developments in stem cell technology have led to a massive good manufacturing practices (GMPs) production of various stem cells, including mesenchymal and embryonic cells, along with induction of pluripotent stem cells to repair damaged tissues in the fistula. The recent advances in separation and purification of exosomes, as biologic nanovesicles carrying anti-inflammatory and regenerative agents, have made them powerful tools to treat this inflammatory disease. Further, tremendous advances in nanotechnology, biomaterials, and scaffold fabrication methods enable tissue engineering methods to synthesize tissue-like structures to assist surgical techniques. This review focuses on advanced regenerative-based methods including stem cell therapy, exosome therapy, and tissue engineering used in the treatment of perianal fistula. Relevant in vitro and in vivo studies and the latest innovations in implementation of regenerative medicine for this disease are also separately reviewed. Additionally, current challenges regarding implementation of g stem cells, exosomes, and tissue engineering methods for bridging the gaps between laboratory findings and clinic application will be discussed.

Altered gut bacterial and metabolic signatures and their interaction in inflammatory bowel disease

Dysregulation of the gut microbiome has been implicated in the progression of many diseases. This study explored the role of microbial and metabolic signatures, and their interaction between the Human inflammatory bowel disease (IBD) and healthy controls (HCs) based on the combination of machine learning and traditional statistical analysis, using data collected from the Human Microbiome Project (HMP) and the Integrative Human Microbiome Project (iHMP). It was showed that the microbial and metabolic signatures of IBD patients were significantly different from those of HCs. Compared to HCs, IBD subjects were characterized by 25 enriched species and 6 depleted species. Furthermore, a total of 17 discriminative pathways were identified between the IBD and HC groups. Those differential pathways were mainly involved in amino acid, nucleotide biosynthesis, and carbohydrate degradation. Notably, co-occurrence network analysis revealed that non-predominant bacteria Ruminococcus_obeum and predominant bacteria Faecalibacterium_prausnitzii formed the same broad and strong co-occurring relationships with pathways. Moreover, the essay identified a combinatorial marker panel that could distinguish IBD from HCs. Receiver Operating Characteristic (ROC) and Decision Curve Analysis (DCA) confirmed the high accuracy (AUC = 0.966) and effectiveness of the model. Meanwhile, an independent cohort used for external validation also showed the identical high efficacy (AUC = 0.835). These findings showed that the gut microbes may be relevant to the pathogenesis and pathophysiology, and offer universal utility as a non-invasive diagnostic test in IBD.

Perianal magnetic resonance imaging findings and their potential impact on outcome in children with perianal fistulizing Crohn disease

BACKGROUND

Children with perianal fistulizing Crohn disease require intensive medical management but also have a higher risk for subsequent surgical interventions.

OBJECTIVE

We performed a retrospective study to identify patient factors and perianal anatomical features by pelvic MR that are associated with surgical interventions in these children.

MATERIALS AND METHODS

We included children with Crohn disease and perianal fistula who underwent pelvic MR with available, archived images and collected demographic, clinical and laboratory data. Radiologists reviewed pelvic MR exams and identified Park classification and additional anatomical features of perianal fistulas, including fistula branching, horseshoe ramifications, abscess, inflammatory mass, supralevator extension, anal sphincter damage, proctitis and posterior anal space involvement. We performed univariate and subsequent multivariate analysis to determine features associated with subsequent surgical intervention.

RESULTS

Ninety-nine children with Crohn disease underwent pelvic MR. In this cohort, 69 children had no surgical interventions prior to baseline MRI, with subsequent median clinical follow-up of 5.5 years. Univariate analysis demonstrated that branching (P=0.009), supralevator extension (P=0.015) and anal sphincter damage (P=0.031) were significantly associated with subsequent surgical intervention. Age at baseline MRI was also associated with intervention (hazard ratio [HR] every 5 years: 2.13; 95% confidence interval [CI]: 1.18-3.83; P=0.012). A multivariable model identified only fistula branching (HR: 2.31; 95% CI: 1.28-4.15; P=0.005) and age (HR: 5.18; CI: 1.57-17.14; P=0.007) as independent predictors of subsequent surgery. No demographic, clinical or laboratory parameter predicted subsequent surgical intervention.

CONCLUSION

Age and anatomical MR features indicating fistula complexity (branching, supralevator extension) and sphincter damage confer a higher risk of subsequent surgical intervention in children with perianal Crohn disease.

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.

Fibrosis and MAGNIFI-CD Activity Index at Magnetic Resonance Imaging to Predict Treatment Outcome in Perianal Fistulizing Crohn's Disease Patients

BACKGROUND AND AIMS

Characteristic magnetic resonance imaging [MRI] features associated with long-term perianal fistula closure are still being discussed. This study evaluated the predictive value of degree of fibrosis and disease activity (MAGNIFI-CD index) at MRI for long-term clinical closure of Crohn's perianal fistulas.

METHODS

Crohn's disease [CD] patients treated with surgical closure following anti-tumour necrosis factor [anti-TNF] induction or anti-TNF alone for high perianal fistulas as part of a patient preference randomized controlled trial [PISA-II] between 2013 and 2020 with a post-treatment MRI and long-term clinical follow-up data were retrospectively included. Two radiologists scored the degree of fibrosis and MAGNIFI-CD index at pre- and post-treatment MRI. The accuracy of post-treatment MRI findings in predicting long-term clinical closure [12 months after the MRI] was evaluated using receiver operating characteristics [ROC] analysis.

RESULTS

Fifty patients were included: 31 female, median age 33 years (interquartile range [IQR] 26-45). Fourteen patients showed a 100% fibrotic fistula at post-treatment MRI, all of which had long-term clinical closure. Median MAGNIFI-CD index at post-treatment MRI was 0 [IQR 0-5] in 25 patients with long-term clinical closure and 16 [IQR 10-20] in 25 patients without. ROC analysis showed an area under the curve of 0.90 (95% confidence interval [CI] 0.82-0.99) for degree of fibrosis and 0.95 [95% CI 0.89-1.00] for the MAGNIFI-CD index, with a Youden cut-off point of 6 [91% specificity, 87% sensitivity].

CONCLUSIONS

Degree of fibrosis and MAGNIFI-CD index at post-treatment MRI are accurate in predicting long-term clinical closure and seem valuable in follow-up of perianal CD. A completely fibrotic tract at MRI is a robust indicator for long-term fistula closure.

EUDRACT

2013-002932-25 and 2018-002064-15.

Development and initial psychometric validation of a patient-reported outcome measure for Crohn's perianal fistula: the Crohn's Anal Fistula Quality of Life (CAF-QoL) scale

INTRODUCTION

Crohn's perianal fistulas are challenging for patients and clinicians. Many do not respond to available treatments and despite recommendations by a global consensus, there are currently no specific patient-derived quality of life tools to measure response to treatment. We present a new validated patient-reported outcome measure (PROM) for this complicated disease phenotype.

METHODS

A draft questionnaire was generated using unstructured qualitative patient interviews on the experience of living with Crohn's perianal fistula, a nationwide multidisciplinary consensus exercise, a systematic review of outcomes assessing medical/surgical/combined treatment and a patient and public involvement day. Psychometric properties were assessed including construct validity (by comparison with the Hospital Anxiety and Depression Scale (HADS) and the UK Inflammatory Bowel Disease Questionnaire (UK-IBDQ)), and reliability and responsiveness was assessed by test-retest analysis.

RESULTS

Data from 211 patients contributed to development of a final 28-item questionnaire. The Crohn's Anal Fistula Quality of Life (CAF-QoL) demonstrated good internal consistency (Cronbach's alpha 0.88), excellent stability (intraclass correlation 0.98) and good responsiveness and construct validity, with positive correlation with the UK-IBDQ and HADS.

CONCLUSION

The CAF-QoL scale is ready for use as a PROM in research and clinical practice. It complements objective clinical evaluation of fistula by capturing impact on the patient.

Managing Complex Perianal Fistulizing Disease

Perianal disease is a particularly morbid phenotype of Crohn's disease, affecting up to one third of patients, with a significantly diminished quality of life. Conventional medical therapy and surgical interventions have limited efficacy. Medical treatment options achieve long-term durable remission in only a third of patients. Therefore, most patients undergo an operation, leaving them with a chronic seton or at risk of incontinence with multiple interventions. Mesenchymal stem cell therapy is an emerging therapy without risk of incontinence and improved efficacy as compared with conventional therapy. Laser therapy is another new intervention. Unfortunately, up to 40% of patients still require a stoma related to perianal fistulizing disease.

Perianal and Luminal Relapse Following Perianal Surgical Intervention in Crohn's Disease

Background and Aims

Fistula relapse occurs in 20–30% of patients with perianal Crohn’s disease (PCD) despite optimal medico-surgical management. We aimed in this study to assess the rate of perianal and luminal relapse after surgically induced remission and to determine factors associated with fistula relapse.

Methods

Consecutive perianal CD patients who achieved clinical remission after surgery for fistulising PCD from January 2013 to January 2019 were included. The cumulative probabilities of relapse-free survival were estimated using the Kaplan–Meier method.

Results

A total of 130 patients were included. Sixty-six of 130 patients received infliximab (IFX) therapy after perianal surgery. After a median follow-up of 62 months (interquartile range [IQR]: 28–117 months), perianal relapse occurred in 30 of 64 (46.9%) nonbiological medication-treated cases and in 14 of 66 (21.1%) cases in the IFX therapy group. The cumulative probabilities of perianal relapse-free survival in patients with nonbiological treatment were 77.1% at 1 year, 54.6% at 3 years, and 30% at 5 years. The rates of survival without perianal fistula relapse in the IFX-treated group were 91.6%, 69.2%, and 59.3% at 1, 3 and 5 years, respectively. In patients treated with IFX after perianal surgery, discontinuation of IFX therapy (odds ratio [OR]=2.43, p=0.036), a penetrating CD phenotype (OR=4.324, p=0.019), and a complex perianal fistula (OR=3.392, p=0.026) were independently associated with perianal relapse in multivariate analysis.

Conclusion

Infliximab therapy reduced the risk of perianal relapse after surgical remission in PCD patients compared with nonbiological treatment. However, approximately 40% of patients using infliximab experienced perianal relapse at 5 years, and patients who discontinued use of IFX or experienced a penetrating phenotype or a complex perianal fistula were associated with increased relapse rate.

Comparative perianal fistula closure rates following autologous adipose tissue-derived stem cell transplantation or treatment with anti-tumor necrosis factor agents after seton placement in patients with Crohn's disease: a retrospective observational study

BACKGROUND

Perianal fistula is one of the most common complications in Crohn's disease, and various medical and surgical treatments are being tried. The aim of this study was to compare the perianal fistula closure rates following treatment with anti-tumor necrosis factor (TNF) agents or autologous adipose tissue-derived stem cell (auto-ASC) transplantation with Crohn's disease (CD).

METHODS

CD patients who underwent seton placement for perianal fistula from January 2015 to December 2019 at a tertiary referral center were retrospectively reviewed. Patients were divided into two groups, one that received sequential treatments with anti-TNF agents (anti-TNF group) and the other that underwent auto-ASC transplantation (stem cell group). Clinical variables and fistula closure rates were compared in the two groups.

RESULTS

Of the 69 patients analyzed, 39 were treated with anti-TNF agents and 30 underwent auto-ASC transplantation. Compared with the stem cell group, patients in the anti-TNF group were older (p=0.028), were more frequently male (p=0.019), had fistulas with more penetrating behavior (p=0.002), had undergone surgery more frequently (p=0.010), and had a shorter interval from seton placement to intended treatment (p<0.001). During a median follow-up of 46 months (range, 30-52.5 months), fistula closure rates were significantly faster (83.3% vs. 23.1%, p<0.001), and the mean interval from seton placement to fistula closure significantly shorter (14 vs. 37 months, p<0.001) in the stem cell than in the anti-TNF group. Three patients experienced fistula recurrence, all in the stem cell group.

CONCLUSIONS

Medical treatment using anti-TNF agents and auto-ASC transplantation are feasible treatment options after seton placement for Crohn's perianal fistula. However, the closure rate was significantly faster and the time to closure significantly shorter in patients who underwent auto-ASC transplantation than medical treatment.

TRIAL REGISTRATION

This study was retrospectively registered and approved by the Institutional Review Board of Asan Medical Center, number 2020-1059 .

Ability of Pelvic Magnetic Resonance Imaging to Predict Clinical Course of Perianal Fistula in Paediatric Crohn's Disease Patients

BACKGROUND AND AIMS

Evidence is limited regarding clinical course and magnetic resonance imaging [MRI] features of perianal fistula [PAF] in Korean children with Crohn's disease [CD]. We investigated MRI features of PAF and associations with long-term outcomes.

METHODS

We retrospectively analysed 243 patients with pelvic MRI for diagnosis of CD. Incidence of clinically evident PAF at diagnosis was determined, as were the proportions of patients with clinical failure [failure to achieve fistula healing within 1 year] and recurrence [new/recurrent PAF after fistula healing within 1 year]. Associations between outcomes and MRI features, specified in modified Van Assche index and MAGNIFI-CD, were evaluated. Associations between later development of clinically evident PAF and subclinical PAF detected on MRI at diagnosis were evaluated.

RESULTS

Among 243 included patients, 108 [44.4%] and 76 [31.3%] had clinically evident and subclinical PAF at diagnosis, respectively; 66.4% of the patients with clinically evident PAF achieved fistula healing within 1 year, and 32.7% of those patients developed recurrence. Fistula length and dominant features of the tracts were associated with clinical failure, and fistula length was associated with recurrence. Clinically evident PAF developed in 17.0% of the patients without clinically evident PAF at diagnosis. We did not find statistically significant association between subclinical PAF and later development of clinically evident PAF [adjusted hazard ratio, 2.438; p = 0.15].

CONCLUSIONS

A considerable proportion of Korean paediatric CD patients had clinically evident and subclinical PAF. Fistula length and dominant feature of the tract on MRI are useful predictors of outcomes.

Multidisciplinary management of perianal Crohn's disease

PURPOSE OF REVIEW

Multiple new medications with novel mechanisms of action are now available to treat Crohn's disease (CD). However, they have varying effectiveness in the management of perianal CD. Identifying the most appropriate therapy and optimizing it is essential to maximize effectiveness of therapy. Additionally, the management of perianal CD requires imaging of the perianal area to identify the fistula anatomy and local complications such as abscesses that require surgical drainage. Initial surgical assessment is key to drain abscesses and allow fistula healing with medical therapy.

RECENT FINDINGS

Although anti-tumor necrosis factor (TNFs) remain the most effective medications to treat perianal CD, real-world data suggests that ustekinumab may be a 2nd-line option in patients nonresponsive to an anti-TNF or having contraindications. Mesenchymal stem cells are an emerging therapeutic approach that is currently in Phase 3 trials in the United States and poised to play a major role in the treatment algorithm.

SUMMARY

The management of perianal CD requires a multidisciplinary approach with a combination of initial imaging and surgical assessment to adequately control local sepsis, optimization of biological therapy with adjunct antibiotics or immunomodulators, and close clinical follow-up with imaging to evaluate response to therapy and guide further surgical management options.

Role of a multidisciplinary team (MDT) in the diagnosis, treatment, and outcomes of inflammatory bowel disease: a single Chinese center's experience

The incidence of inflammatory bowel disease (IBD) with a poor prognosis is increasing, and a single field is not capable of fully diagnosing and comprehensively treating IBD. The purpose of the current study was to explore the role of a multidisciplinary team (MDT) in the diagnosis and treatment of IBD. Subjects were 55 patients with IBD who underwent surgery at this hospital before the establishment of a MDT (before June 2016) and 276 patients who were discussed by a MDT; 72 of the latter patients underwent surgery. The preoperative rate of diagnosis, preoperative basic nutritional status, frequency of emergency surgery, and surgical complications in the two groups were compared to determine whether the MDT significantly affected the diagnosis and treatment of IBD and to explore trends in the types of patients with IBD and treatment decision-making since the establishment of MDT. Results revealed that the MDT significantly improved preoperative diagnostic accuracy for patients with IBD who underwent surgery (p < 0.005), and the frequency of elective surgery decreased significantly (p < 0.005). There were significant differences in the rate of clinical recurrence (p < 0.005) and the rate of additional surgery (p < 0.01) between the two groups, with higher rates in the control group. In terms of preoperative nutritional status, the proportion of decreased serum albumin and hemoglobin in the experimental group was significantly lower than that in the control group (p < 0.05). MDT plays a positive role in accurate preoperative diagnosis, improvement of preoperative preparations, and a reduction in postoperative adverse events for patients with IBD undergoing surgery.

MRI of Perianal Crohn Disease: Technique and Interpretation

ABSTRACT

Magnetic resonance imaging (MRI) has emerged as the imaging method of choice for evaluation of perianal fistulizing disease. As treatment of Crohn disease and associated perianal fistulas has evolved to include a combination of systemic treatments and surgical interventions, perianal MRI provides critical information to guide treatment selection and timing. Radiologists need to be familiar with the normal regional anatomy to accurately describe perianal fistulas and any associated complications which can then be used to classify fistulas based on several available classification systems. Following treatment, MRI can provide information that suggests treatment success or failure. We propose a perianal fistula reporting template that includes the necessary information to convey fistula complexity, guide treatment, and evaluate treatment response. This review article will also discuss the postoperative appearance of many treatments currently used for management of perianal fistulizing disease and some associated complications.

Effectiveness of Infliximab on Deep Radiological Remission in Chinese Patients with Perianal Fistulizing Crohn's Disease

BACKGROUND AND AIMS

Information concerning deep radiological healing of perianal fistulas in Chinese patients with CD is limited. The present study aimed to establish the effectiveness of infliximab on CD-related perianal fistulas using magnetic resonance imaging (MRI) and identify predictors of deep radiological remission of fistulas.

METHODS

We retrospectively reviewed patients with CD with draining perianal fistulas treated with infliximab and included only those who underwent clinical assessment and MRI before and after infliximab therapy.

RESULTS

Among 178 patients who underwent repeated MRI and clinical assessment, 65.2% had complex fistulas. Post-infliximab therapy, 55.1% of patients with perianal fistulizing CD showed clinical remission and 26.4% presented a clinical response; 38.2% had deep radiological remission, and 34.3% had a partial response based on the Ng score; the Van Assche scores decreased obviously compared with baseline. Prolonged infliximab infusion (18 times) presented higher radiological remission rates in patients with CD with complex fistulas. Concomitant treatment with azathioprine increased the fistula healing rate compared with infliximab alone (50% vs. 36.9%, P < 0.001). Younger age at diagnosis of CD, proctitis and requiring perianal surgery were identified as predictors of poor deep radiological remission of fistulas. Eight of ten patients who stopped infliximab and switched to an alternative agent retained a status of fistula healing in the first year of follow-up.

CONCLUSIONS

Infliximab induced deep radiological remission of perianal fistulas in Chinese patients with CD. Routine MRI should be used to monitor fistula healing. Patients with younger age at diagnosis of CD, proctitis, and/or requiring perianal surgery should receive combined therapy and careful monitoring.