Fistulas In Crohn's Disease Research Articles

Evaluation of the Effectiveness and Safety of Mesenchymal Stem Cell Treatment in Fistulising Crohn's Disease: An International Real-Life Retrospective Multicentre Cohort Study.

Perianal fistulas of Crohn's disease (CD) create a significant burden on patients' lives. However, the efficacy and safety of adipose-derived mesenchymal stem cell treatment are contradicting, and real-world evidence is lacking. To examine the usability of darvadstrocel therapy in managing perianal CD. We enrolled patients with CD and perianal fistulas in this retrospective multicenter study. The primary outcome was perianal clinical remission (defined as all treated fistulas closed) at weeks 26 and 52. Secondary outcomes were clinical response rates (≥ 1 fistulas closed), perianal activity (PDAI), patient satisfaction, and adverse events. Data were recorded at baseline and weeks 12, 26 and 52. Prediction of primary outcomes was performed by logistic regression. Overall, among 223 patients (male/female ratio: 0.48), perianal clinical remission was achieved in 78.2% and 62.3% until weeks 26 and 52. Baseline PDAI score (OR 0.75), number of fistulas (OR 0.28) and the number of weeks after preparation for surgery (OR 0.98) were associated with treatment failure. The clinical response rates were 84.8% and 79.8% at weeks 26 and 52. Improvement of subjective perianal symptoms was achieved in 77.8% and 78.4% of patients, respectively. Adverse events occurred in 13.5% of patients; perianal abscesses and proctalgia were the most frequently reported. Effectiveness data were higher than in clinical trials. The safety profile was reassuring, and patients' satisfaction was high. Appropriate patient selection, fistula preparation and expertise may help to achieve treatment success.

Granulomas without foreign body giant cells in perianal fistula tissue suggest Crohn's disease.

Histopathological characteristics of granulomas in perianal fistula of patients with Crohn's disease (CD) remain unexplored. We aimed to assess the histopathological features of granulomas in perianal fistula in CD. A retrospective analysis was conducted by reviewing the medical and pathological records of 4430 cases who underwent perianal fistulectomy at our hospital between June 2015 and June 2023. The patients were divided into the CD group, tuberculosis (TB), and non-CD group, respectively, based on their final diangosis. The detection rate of granulomas and differential histopathological features were investigated. Among the 4430 patients, granulomas were identified in 41 cases, including 25 had CD, 2 had pulmonary TB, and 14 only exhibiting perianal lesions with no other comorbidities. Additionally, there were altogether 93 CD cases, resulting in a detection rate of granuloma of 26.9%, which was considerably higher than that in the non-CD group (26.9% vs 0.3%, p < 0.001). The majority (85.7%) of the perianal fistula tissues in the non-CD group contained foreign body giant cells, while this was observed in only 1 (4.0%) out of the 25 cases with CD. We proposed that granulomas in the perianal fistula in the non-CD group were mostly foreign body granulomas. Moreover, granulomas in the non-CD group were larger than that of the CD group (1135 μm vs 519 μm, p < 0.001). Most CD cases have less granulomas (≤3) and no foreign body giant cells. Ribbon-like granulomas can be seen only in CD cases.

Activated HLA-DR+CD38+ Effector Th1/17 Cells Distinguish Crohn's Disease-associated Perianal Fistulas from Cryptoglandular Fistulas.

Perianal fistulas are a debilitating complication of Crohn's disease (CD). Due to unknown reasons, CD-associated fistulas are in general more difficult to treat than cryptoglandular fistulas (non-CD-associated). Understanding the immune cell landscape is a first step towards the development of more effective therapies for CD-associated fistulas. In this work, we characterized the composition and spatial localization of disease-associated immune cells in both types of perianal fistulas by high-dimensional analyses. We applied single-cell mass cytometry (scMC), spectral flow cytometry (SFC), and imaging mass cytometry (IMC) to profile the immune compartment in CD-associated perianal fistulas and cryptoglandular fistulas. An exploratory cohort (CD fistula, n = 10; non-CD fistula, n = 5) was analyzed by scMC to unravel disease-associated immune cell types. SFC was performed on a second fistula cohort (CD, n = 10; non-CD, n = 11) to comprehensively phenotype disease-associated T helper (Th) cells. IMC was used on a third cohort (CD, n = 5) to investigate the spatial distribution/interaction of relevant immune cell subsets. Our analyses revealed that activated HLA-DR+CD38+ effector CD4+ T cells with a Th1/17 phenotype were significantly enriched in CD-associated compared with cryptoglandular fistulas. These cells, displaying features of proliferation, regulation, and differentiation, were also present in blood, and colocalized with other CD4+ T cells, CCR6+ B cells, and macrophages in the fistula tracts. Overall, proliferating activated HLA-DR+CD38+ effector Th1/17 cells distinguish CD-associated from cryptoglandular perianal fistulas and are a promising biomarker in blood to discriminate between these 2 fistula types. Targeting HLA-DR and CD38-expressing CD4+ T cells may offer a potential new therapeutic strategy for CD-related fistulas.

A new treatment option for complex perianal fistulas in Crohn's disease patients; development of darvadstrocel (allogeneic expanded adipose-derived mesenchymal stem cells) in Japan

Crohn's disease (CD) is a chronic and relapsing inflammatory bowel disease affecting the entire gastrointestinal tract. The prevalence of CD among Japanese people is increasing. One of the most frequent complications of CD is perianal fistulas. People living with CD may experience complex perianal fistulas, which can cause intense pain, bleeding, swelling, infection, and anal discharge. Despite medical and surgical advancements, complex perianal fistulas in CD remain challenging for clinicians to treat. CD patients living with perianal fistulas reported a negative impact on many aspects of their quality of life. Darvadstrocel is a cell therapy product containing a suspension of allogeneic expanded adipose-derived mesenchymal stem cells. It has been approved in Europe and Japan for the treatment of complex perianal fistulas that have shown an inadequate response to at least one conventional or biologic therapy in adult patients with non-active/mildly active luminal CD. By exhibiting immunomodulatory and local anti-inflammatory effects at the site of inflammation, it offers a new treatment option for complex perianal fistulas in CD patients. In this manuscript, the characteristic of darvadstrocel, the summary of results from the pivotal phase 3 studies in Europe and Japan, and the development strategy in Japan were introduced.

Injection of Freshly Collected Adipose Tissue for the Treatment Complex Cryptoglandular Anal Fistula: Case Report

AbstractIntroduction Perianal fistula is a common colorectal disease which is caused mainly by cryptoglandular disease. Although most cases are treated successfully by surgery, management of complex perianal fistulas (CPAF) remains a challenge with limited results in recurrence and sometimes associated with fecal incontinence. The CPAF treatment with autologous adipose-derived mesenchymal stem cells (ASCs) had become a research hotspot. The technique started to be used in the treatment of Crohn's disease (CD) fistulas, where the studies showed safe and goods result from the procedure. Cultured ASCs have been used but this approach requires the preceding collection of adipose tissue, time for isolation of ASCs and subsequent in vitro expansion, need for laboratory facilities, and expertise in cell culturing. These factors have been getting over by using the commercially available alternative, allogenic ASCs. Treatment with allogeneic ASCs has shown good results in patients with CD fistulas, however with the disadvantage of being expensive. Objective To show that the injection with freshly collected adipose tissue is an alternative to treatment with autologous or allogenic ASCs with several advantages. Methods: In this case report, we show our first experience in the treatment of CPAF with the application of collected adipose tissue in a tertiary referral hospital from Belo Horizonte, Brazil. Results The patient had a good postoperative recuperation with a complete fistula healing after 8 months without adverse effects. Conclusion Injection with freshly collected adipose tissue is a promising and apparently safe sphincter-sparing technique in the treatment of CPAF.

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

Fistulizing perianal Crohn's disease (CD) is a debilitating condition associated with significant morbidity and reduction in thequality of life. Magnetic resonance imaging (MRI) of the pelvis is the preferred imaging modality for thecomprehensive assessment of the perianal fistula. There is apaucity of data from India on the MRI spectrum of complex perianal fistula in CD. 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. 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. The cumulative risk of thedevelopment 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 forthe delineation of fistula anatomy, assessment of disease extent and activity and theevaluation of concomitant perianal abscess and other complications.

Risk of anorectal cancer in patients with Crohn's disease and perianal fistula: a nationwide Danish cohort study.

Patients with Crohn's disease (CD) often suffer from perianal fistulizing disease. Their risk of anorectal cancer remains uncertain. We aimed to examine the long-term risk of anorectal cancer in a population-based cohort of CD patients with anorectal fistula. Our study population covered all individuals (n = 7 987 520) aged 15+ years living in Denmark from 1978 to 2018. We identified all patients with CD and anorectal fistula in the Danish National Patient Register (NPR) and 50 matched noninflammatory bowel disease (IBD) individuals from the general population. Using Cox regression analyses, we examined the risk of anorectal cancer in CD fistula patients versus non-IBD individuals. All patients with CD were identified using codes from the International Classification of Diseases and their data extracted from the NPR. The main outcome measure was cases of anorectal cancer. A total of 2786 CD patients with anorectal fistula and 139 300 non-IBD individuals were followed for 1 553 917 person-years. During follow-up, anorectal cancer was observed in 19 CD patients (0.68%) and 340 non-IBD individuals (0.24%), corresponding to a 2.9-fold increased hazard ratio (HR) of anorectal cancer in CD fistula patients (95% CI 1.80-4.53), with a particularly high risk of anal cancer (HR 15.13, 95% CI 6.88-33.31) and a mean time from CD fistula diagnosis to anorectal cancer of 6.7 (SD 6.5) years. The risk was slightly higher in women than men and had no apparent relation to treatment with tumour necrosis factor-α inhibitors. Sensitivity analyses using CD nonfistula patients for comparison revealed similar results. Individual data on smoking and infection with human papilloma virus were not available. Patients with CD and anorectal fistula have a three-fold increased risk of anorectal cancer compared with the general population. The number needed to surveil to detect one case of anorectal cancer in this patient population was 2160 patients per year in patients with long-standing fistula (>6 years).

Approaches in the treatment of perianal fistula in Crohn disease

AbstractPerianal fistula is a common complication of Crohn disease, and it is a great burden on the life and psychology of patients, but its treatment is still a difficult problem to face. In recent years, progress in the treatment of Crohn disease has progressed rapidly due to the advent of biological agents, but there has been a lack of research on perianal fistula in Crohn disease, and the direction of research has been scattered; therefore, the author reviews the traditional treatment of perianal fistula in Crohn disease in the context of the available literature and discusses emerging and potential therapeutic approaches.

P107 Decreased epithelial keratinization contributes to defective wound healing in Crohn's disease fistula

Abstract Background Up to 30% of Crohn's Disease (CD) patients suffer from perianal fistula creating a high disease burden. Treating CD fistula is challenging compared to cryptoglandular fistula, which have a significantly better wound healing response. Previous studies suggested epithelial to mesenchymal transition as an inducer of fistula formation, as markers were observed in fistula tracts. However, most studies compared CD fistula to normal mucosa, thus disregarding whether any observed difference was in fact a sign of healing (as CD fistula will have more active healing than uninjured mucosa) or a sign of pathology (as healing is not occurring effectively). Therefore, in this study we evaluated CD fistula, as well as both healthy mucosa (no active healing) and cryptoglandular fistula (effective healing) in order to determine the role of differences found. Methods Biopsies from the internal opening (n=20) of perianal fistula of CD patients were collected and compared to two publicly available datasets obtained from un-inflamed rectum (RISK cohort and GSE83245). In addition, curettage material of CD (n=54) and cryptoglandular fistula (n=15) was obtained. Expression profiling was performed using RNASeq. Results Comparing the mucosa at the internal opening of CD fistula to publicly available datasets of healthy rectum, 770 genes were differentially expressed. Pathway analysis revealed upregulation of proliferative and inflammatory processes, consistent with expected immune and wound healing responses. Interestingly, strongest upregulation was seen for processes of cornification and keratinization, including expression of IVL (involucrin) and FLGR2 (fillagrin2), involved in keratinocyte differentiation. To evaluate whether this was contributing to active wound healing or rather to persistent disease, we analyzed the actual tract in CD and cryptoglandular fistula. Strikingly, cornification and keratinization processes were more pronounced in cryptoglandular fistula, suggesting a role in effective healing rather than the persistent pathology seen in CD. Similar data was observed for TGFb, previously detected in CD fistula and thus considered a pathological contributor. While we confirm increased TGFb activity in CD fistula compared to normal mucosa, activity in cryptoglandular fistula tracts was higher than in CD fistula tracts. Again, this would suggest TGFb signaling as part of the wound healing response rather than part of the pathogenic mechanism. Conclusion Perianal fistulas show upregulation of keratinization and cornification pathways compared to healthy mucosa. Comparing CD and cryptoglandular fistula, we saw more cornification in the better healing cryptoglandular fistula, suggesting involvement in effective healing rather than pathology.

Efficacy and safety of mesenchymal stem cells in the treatment of perianal fistulas in Crohn's disease: a meta-analysis of randomized controlled trials.

Local mesenchymal stem cell (MSC) therapy for perianal fistulas in Crohn's disease (CD) has yielded promising results, but it still remains controversial. In this study, we aimed to conduct a meta-analysis of randomized controlled trials (RCTs) to evaluate the efficacy and safety of MSC therapy for perianal CD (pCD). RCTs reporting MSC therapy for perianal fistulas in CD were searched and included. The effectiveness and safety data were analyzed using RevMan 5.3. A total of 7 RCTs were included in this meta-analysis. The analysis showed that patients receiving MSC therapy presented a higher healing rate (HR) of pCD than those in the control group (odds ratio (OR)=1.42; 95% confidence interval (CI) 1.18, 1.71; P=0.0002). Compared with placebo (saline solution), MSC therapy improved the HR of pCD (OR=1.85; 95% CI 1.32, 2.60; P=0.0004). MSC therapy showed significant long-term efficacy (OR=1.36; P=0.009; 95% CI 1.08, 1.71). When MRI was used to evaluate fistula healing, a pooled analysis showed that the MSC group achieved a higher HR than the control group (OR=1.95; 95% CI 1.33, 2.87; P=0.0007). Allogeneic MSC therapy was superior to the control treatment in improving HR (OR = 1.97; 95% CI 1.40, 2.75; P<0.001). Furthermore, no significant differences were observed between MSC therapy and placebo in terms of adverse events (AEs) (OR = 1.16; 95% CI 0.76, 1.76; P = 0.48). None of the AEs were judged to be related to MSC treatment. This meta-analysis of RCTs provided evidence that local MSC injection is safe and efficacious for perianal fistulas in CD. In addition, this treatment has favorable long-term efficacy and safety profiles.

Increasing experience with the LIFT procedure in Crohn's disease patients with complex anal fistula.

Surgical management of anal fistulas in Crohn's disease (CD) is associated with high failure rates, and treatment options are limited due to ongoing proctitis, multiple tracts, and concern for incontinence and non-healing wounds. The aim of this study was to investigate the healing rate of ligation of the inters-sphincteric fistula tract (LIFT) for anal fistulas in Crohn's disease and identify prognostic factors for healing. This prospective analysis compared long-term healing rates of CD patients undergoing LIFT for anal fistulas. Consecutive patients with CD who underwent LIFT procedure at our institution, in the period from March 2012 to September 2019 were included. The main outcome was anal fistula healing rate. The study cohort of 46 patients (mean age of 34.2 ± 13.0years, 18 (40%) males). After a mean follow-up time of 33 ± 28months, fistula healing was seen in 30 (65%) patients. A total of 8 patients were noted to have inter-sphincteric recurrence and 8 patients had trans-sphincteric recurrence. Smoking at the time of surgery was significantly associated with LIFT failure (HR 3.18, 95% CI 1.18-8.61, p = 0.02). Other factors, such as age, sex, race, disease duration and location, type of fistula history of proctitis, preoperatively use of biologics or a seton, and previous repair attempts, did not appear to influence LIFT healing. Although not statistically significant, there was a trend toward increase in failure among patients with active proctitis at the time of surgery (HR 1.97, 95% CI 0.71-5.42, p = 0.19). Our increasing experience with LIFT for anal fistula in CD demonstrates a higher rate of healing (65%) than previously reported (48%). Smoking appears to negatively influence healing of LIFT in CD.

Symptoms, diagnostic and therapy of perianal disease in patients with inflammatory bowel diseases

Symptoms, diagnostic and therapy of perianal disease in patients with inflammatory bowel diseases Abstract. Inflammatory bowel diseases (IBD) frequently affect the perianal region. Due to the great functional importance of the anorectum, this frequently results in a significant burden of disease for the patient. For assessment of perianal IBD symptoms, the clinical history is of great importance. Often, anorectal symptoms are not reported spontaneously by patients, and a respectful direct conversation remains crucial. More than 30 % of patients with Crohn's disease (CD) will develop perianal fistulas. Perianal fistulas can be further characterized by endoscopic ultrasound, MRI, and investigation under anesthesia. These investigations provide complementary information. Fistula therapy is based on symptoms; the short-term goal is improvement of pain and secretion; the long-term goal of treatment remains fistula closure. However, preservation of the anal sphincter is of utmost importance and incontinence needs to be avoided. Antibiotics and/ or seton drainage are the mainstay for acute fistula treatment. The anti-tumor necrosis factor antibody infliximab can improve fistula symptoms, as demonstrated in a randomized controlled study. Surgical fistula closure is only possible in a clinically stable situation without rectal inflammation or other symptoms of active CD. Several surgical strategies exist including 1) fistulotomy, 2) disconnection of the fistula, 3) filling of the fistula tract and 4) fistula ablation. The optimal strategy needs to be decided on an individual basis. Intraoperative application of mesenchymal donor stem cells into the fistula tract and surrounding tissue is possibly the most effective fistula therapy. Due to the significant logistic effort, this therapy is only available in a few selected centers. Currently, stem cell therapy for CD fistulas is limited to patients with no more than two external fistula openings. The therapy of fissures and hemorrhoids in IBD patients is similar to patients without intestinal inflammation; however, due to a high rate of complications, surgery should be avoided whenever possible in CD patients. Incontinence is a frequent problem in IBD patients leading to highly relevant restrictions in daily life. Therapy is directed against intestinal inflammation but also comprises measures for normalization of stool consistency and intestinal motility. However, there are no IBD-specific concepts for the treatment of incontinence. Functional intestinal diseases are frequent in IBD patients and can contribute to urge and incontinence. Some IBD patients might benefit from anorectal physiotherapy. IBD patients have an increased risk for colorectal carcinoma, fistula carcinoma and possibly also anal carcinoma. Therefore, malignancy needs to be excluded at reasonable intervals.

Epidemiology and diagnosis of inflammatory bowel diseases

Background: Over the past three decades, inflammatory bowel diseases (IBD) have been rapidly increasing in the African, South American, and Asian countries, including Korea. However, in Korea, the public awareness of IBD remains low, and diagnostic delay is not uncommon due to the physicians' lack of clinical experience. It is essential to understand the trends and regional differences in the epidemiology of IBD for proper diagnosis and treatment.Current Concepts: Although lower than those of the West, the prevalence and incidence of IBD in Korea rank among the highest in Asia and are steadily increasing. In the past 10 years, the prevalence of IBD has almost doubled, while its incidence has decreased gradually. As compared to Western IBD patients, Korean patients have higher proportion of proctitis in ulcerative colitis, male predominance, more ileocolonic involvement, and higher incidence of perianal fistula in Crohn disease. There is no single gold standard for the diagnosis of IBD. Thus, diagnosis can be made by clinical evaluation, including a detailed history taking, physical examination, and a combination of endoscopic, radiologic, laboratory, and histologic findings.Discussion and Conclusion: Population-based studies have revealed the current trends and characteristics of the epidemiology of IBD in Korea. Continued education and development of diagnostic tools will help clinicians to diagnose IBD accurately and differentiate it from other diseases such as intestinal tuberculosis.

Statement of the polish expert group on the current practice and prospects for the treatment of complex perianal fistulas in Crohn&apos;s disease. Update 2021.

Perianal fistulas in Crohn's disease (CD) are a major problem. In majority of patient, inflammation involves the rectum. Perianal fistulas in CD pose a diagnostic and therapeutic challenge due to severe symptoms and worse prognosis compared to cryptogenic fistulas. The accurate diagnosis is crucial for an effective treatment of CD-related perianal fistulas, and the following should be determined: anatomy of the fistula, possible strictures and inflammation of the alimentary tract, including the rectum and the anal canal. Treatment of fistulas might be challenging and requires cooperation between the colorectal surgeon and the gastroenterologist. The combination of surgical and pharmacological therapy is more effective than surgical or pharmacological therapy alone. In conservative treatment, aminosalicylates or steroids have little significance. In everyday practice, antibacterial chemotherapeutics, antibiotics and thiopurines are applied. The most effective are TNF-neutralizing antibodies, i.e. infliximab (IFX), adalimumab (ADA) and certolizumab (CER). Surgical management can be urgent including drainage. Elective procedures include dissection of the fistula (simple fistula) or more complex interventions such as mucosal flap or ligation of the intersphincteric portion of the fistula. Surgical interventions can be enhanced using the video-assisted anal fistula treatment (VAAFT) or negative-pressure therapy. In extreme cases, creation of a stoma may be necessary. Also, tissue glues or so-called plugs may be applied in managing perianal fistulas. The use of stem cells seems promising, i.e. application of multipotent non-hematopoietic stem cells around the fistula in order to induce immunomodulation and wound healing.

Long-term outcomes after seton placement for perianal fistulas with and without Crohn's disease.

Perianal sepsis in Crohn's disease (CD) fistulas is managed with antibiotics and surgical drainage; a noncutting seton is used for an identified transsphincteric fistula tract. The optimal management following seton placement for initial control of perianal sepsis remains to be determined. Our main aim was to assess the success rates of curative surgery, seton removal or long-term indwelling seton in patients with and without CD. This was a retrospective cohort of consecutive patients with a perianal fistula treated with a noncutting seton between 2010 and 2019, including 83 CD patients and 94 patients without CD. Initial control of symptomatic perianal infection with a seton and subsequent healing and reintervention rates were compared between the three postseton management strategies. A total of 177 patients, 61% male and 83.1% with complex fistulas, were followed for a median of 23months (interquartile range 11-40months). Immunomodulatory treatment was used in 90.4% of CD patients after seton placement. Good initial control of perianal infection was achieved with a seton in CD and non-CD patients, at 92.9% and 96.7%, respectively (p=0.11). Overall fistula healing or control for CD and non-CD patients was, respectively, 64% and 86% (p=0.1) after curative surgery, 49% and 71% after seton removal (p=0.21) and 58% and 50% with long-term seton placement (p=0.72). Overall reintervention for recurrence was 83% in CD versus 53.1% in non-CD patients during the follow-up period (p=0.002). Definitive surgery was possible in only a minority of CD patients. Long-term seton management was an effective option in patients with CD with acceptable improvement and recurrence rates.

Evaluation of animal models of Crohn's disease with anal fistula (Review).

Anal fistula is a common and serious complication of Crohn's disease (CD). A sufficiently suitable animal model that may be used to simulate this disease is yet to be established. The aim of the present review was to summarize the different characteristics and experimental methods of commonly used animal models of CD with anal fistula. Electronic databases were searched for studies reporting on the use of this type of animal model. A total of 234 related articles were retrieved, of which six articles met the inclusion criteria; these were used as references for the present review article. The characteristics of the animal models, the advantages and disadvantages of the modeling methods and the similarities with patients with CD and anal fistula were summarized and analyzed. The evidence suggests that a sufficiently suitable animal preclinical model requires to be established.

Efficacy of Permacol injection for perianal fistulas in a tertiary referral population: poor outcome in patients with complex fistulas

AimInjection of Permacol collagen paste can be used as a sphincter‐sparing treatment for perianal fistulas. In a tertiary referral population we aimed to evaluate the efficacy of Permacol injection and the clinical and fistula‐related factors associated with recurrence.MethodThis was a retrospective analysis of consecutive patients with perianal fistulas treated with Permacol injection at a specialist centre between June 2015 and April 2019. Endoanal ultrasonography was systematically reanalysed, blinded to treatment outcome. Rectovaginal, anovaginal and Crohn's disease fistulas were excluded. Healed fistulas were defined as absent anal symptoms and a closed external opening on physical examination at a minimum follow‐up of 6 months. Regression analyses were performed to identify factors associated with unhealed fistulas.ResultsA total of 90 patients (51 men; median age 45 years) were analysed. Seventy‐two (80.0%) patients had complex perianal fistulas (greater than one‐third sphincter involvement or multiple tracts). After a single Permacol injection, fistulas were healed in 20 (22.2%) patients at 3 months follow‐up and in 18 (20.0%) patients at a median follow‐up of 30 months (interquartile range 17–37). Eight (11.1%) patients with unhealed fistulas had significant improvement in their symptoms. Complex fistulas were significantly associated with unhealed status [OR 3.53 (95% CI 1.12–11.09); p = 0.031]. Twenty patients underwent subsequent Permacol injections, which were successful in six (30.0%) patients after one (n = 3) or two (n = 3) additional injections.ConclusionThis largest study to date in patients with mainly complex perianal fistulas, demonstrated that the efficacy of a single Permacol injection was only 20%. Complex fistulas were associated with a poor outcome.

Impact of preoperative enteral nutritional support on postoperative outcome in patients with Crohn's disease complicated by malnutrition: Results of a subgroup analysis of the nationwide cohort registry from the GETAID Chirurgie group.

Postoperative morbidity is high in patients operated on for Crohn's disease (CD) complicated by malnutrition. This study aimed to evaluate the impact of preoperative enteral nutritional support (PENS) on postoperative outcome in patients with CD complicated by malnutrition included in a prospective nationwide cohort. Malnutrition was defined as body mass index <18kg/m2 and/or albuminaemia <30g/L and/or weight loss >10%. Failure of PENS was defined as the requirement for additional preoperative parenteral nutrition to PENS. Univariate analysis of the risk factors for PENS failure was performed. Propensity score matching (PSM) was used to compare the outcomes between 'upfront surgery' and 'PENS' groups. The primary endpoint was the rate of intra-abdominal septic morbidity and/or temporary defunctioning stoma. Among 592 patients included, 149 were selected. In the intention-to-treat population including 20 (13.4%) patients with PENS failure after PSM, 78 'upfront surgery' and 71 'PENS'-matched patients were compared, with no significant difference in the primary endpoint. Perforating CD and preoperative intra-abdominal fistula were associated with PENS failure [37.5 vs 16.1% (P=0.047) and 41.2% vs 16.2% (P=0.020), respectively]. After exclusion of these 20 patients, PSM was used to compare 45 'upfront surgery' and 51 'PENS'-matched patients, with a significantly decreased rate of intra-abdominal septic complications and/or temporary defunctioning stoma in the PENS group (19.6 vs 42.2%, P=0.016). Preoperative enteral nutritional support is associated with a trend but no conclusive evidence of a reduction in intra-abdominal septic complications and/or requirement for defunctioning stoma. Patients with perforating CD complicated with malnutrition are at risk of PENS failure.

Contribution of CD3+CD8- and CD3+CD8+ T Cells to TNF-α Overexpression in Crohn Disease-Associated Perianal Fistulas and Induction of Epithelial-Mesenchymal Transition in HT-29 Cells.

Fistulas represent a frequent and severe complication in patients with Crohn disease (CD). Tumor necrosis factor-alpha (TNF-α), transforming growth factor-beta, and interleukin (IL)-13 are known to trigger epithelial-mesenchymal transition (EMT), promoting fistula formation. Here, we investigated the role of T-lymphocytes (T cells) in fistula pathogenesis. CD3+CD8-, CD3+CD8+, or CD45+CD3- cells from healthy volunteers, patients with CD, and patients with CD with perianal fistula were co-cultured with HT-29 cells. The EMT, cytokine production, and mRNA expression were analyzed. Perianal CD fistula specimens were immunohistochemically stained for cytokines and their receptors. The effect of cytokines on EMT induction was investigated using an EMT spheroid model. Patients with CD with fistula revealed more CD3+CD8- and less CD3+CD8+ T cells in blood than healthy control patients and patients with CD without fistula. In perianal fistula specimens, CD4+ cells-and to a lesser extent CD8+ cells-were highly present around fistula tracts. When co-cultured with HT-29 cells, both cell subsets promoted EMT-related gene expression and TNF-α production in a time-dependent manner. The CD3+CD8- T cells from patients with CD with fistula also produced higher amounts of IL-13 than cells from healthy control patients or patients with CD without a fistula. We found that IL-22 and IL-22Rα1 were highly expressed in perianal CD fistula specimens and that IL-22 cotreatment potentiated TNF-α-induced EMT in HT-29 spheroids. Our data indicate that both CD3+CD8- and CD3+CD8+ T cells play an important role in the pathogenesis of perianal CD fistulas by the secretion of TNF-α. Our data support clinical evidence indicating that anti-TNF-α therapy is effective in fistula treatment and identify IL-13 and IL-22 as possible novel therapeutic targets for fistula therapy.

Outcomes of Definitive Draining Seton Placement for Complex Anal Fistula in Crohn's Disease.

Definitive draining seton (DDS) alone is an accepted treatment for complex refractory anal fistulas in Crohn's disease (CD). We evaluated the long-term success of DDS in CD patients. DDS was defined as draining seton placed definitively for at least 12months. Primary end point was clinical response (CR) defined as a lack of induration, pain, swelling, abscess recurrence, or unintended dislodgement. The study cohort of 23 patients had a median age of 29 (range; 9-61) years and included 14 males (61%). Reasons for DDS included anal stenosis (n = 9; 39%), active proctitis (n = 9; 39%), and/or anal canal ulceration (n = 9; 39%). Median number of setons was 2 (range; 1-6) and 65% had multiple fistula tracts. Almost all patients (n = 22; 96%) were on a biologic postoperatively. At 12-month follow-up, only 39% (n = 9) had a CR. The remaining 14 patients failed due to new abscess formation (n = 6; 26%), new fistula formation (n = 6; 26%), and seton dislodgement (n = 2; 9%). Six (26%) patients required fecal diversion. No patients required proctectomy. DDS for complex CD fistula results in a mediocre CR with many patients developing recurrent abscess/fistula or requiring diversion despite biologic therapy.