Pathophysiology of fistula formation in Crohn's disease

Outcomes of abdominal wall closure with fascial bridging using a polyglactin 910 (Vicryl) Mesh following non-trauma laparotomy: a multi-center study

INTRODUCTION

Complete primary fascial closure following midline laparotomy is occasionally unachievable, necessitating abdominal wall closure via fascial bridging with polyglactin 910 (Vicryl) mesh. Despite its frequent use, literature on the outcomes of Vicryl mesh for fascial bridging remains sparse and controversial, with some studies indicating potential associations with enterocutaneous fistulas and bowel obstruction. This study evaluates the outcomes of fascial bridging utilizing Vicryl mesh for non-trauma laparotomies.

METHODS

We conducted a retrospective analysis of adult patients who underwent abdominal wall closure using Vicryl mesh at Cleveland Clinic centers from January 2018 to April 2023. Data were extracted from the Epic System, focusing on outcomes including fistula formation, the need for interventions for small bowel obstruction, and overall wound and postoperative morbidity, with a minimum follow-up of six months.

RESULTS

Among the 124,536 patients who underwent non-trauma laparotomies, 202 (0.17%) met the inclusion criteria, with a median follow-up of 47 months (SD ± 18.9 months). Postoperative outcomes following abdominal wall closure with Vicryl mesh included a 48.5% rate of surgical site infections, a 27.2% incidence of skin dehiscence, a 9.9% occurrence of soft tissue necrosis, and 2% experienced bowel evisceration secondary to mesh detachment. Enterocutaneous fistulas developed in 8.4% of patients, with no interventions for small bowel obstruction required within the first six months postoperatively. These complication rates are comparable to other abdominal closure techniques in similarly complex cases.

CONCLUSIONS

Fascial bridging with Vicryl mesh is a safe method for abdominal wall closure, with enterocutaneous fistula and small bowel obstruction rates comparable to those seen with other techniques. Nevertheless, primary closure of the linea alba should be prioritized, with mesh implantation minimized whenever feasible.

Emerging Technologies in Inflammatory Bowel Disease: A Minireview on Future Treatment Modalities

Inflammatory bowel disease (IBD) can present as either Crohn's disease or ulcerative colitis. Both phenotypes are inflammatory conditions of the gastrointestinal tract. Despite scientific advances, the overall incidence and morbidity of IBD continues to increase worldwide. Fortunately, we continue to develop novel therapies, in hopes of providing safer, more effective treatment options. Such therapies include cell therapy, exosome therapy, hyperbaric oxygen therapy, and central nerve stimulation. The aim of this review is to briefly highlight each of these novel therapeutic interventions as they relate to the treatment of IBD.

Clinical relevance of calprotectin in patients with perianal fistulas in Crohn's disease and cryptoglandular fistulas

BACKGROUND AND AIMS

Previous literature suggests that faecal calprotectin (FC) discriminates Crohn's disease perianal fistulas from cryptoglandular fistulas, irrespective of luminal disease. This study aims to prospectively validate this and analyse if increased local fistula calprotectin levels are associated with fistula characteristics.

METHODS

In this prospective study, all consecutive patients with an active perianal fistula undergoing examination under anaesthesia were included. Faecal and fistula tract scraping calprotectin levels were determined. The primary objective was to analyse whether FC levels could be used to differentiate between Crohn's disease and cryptoglandular perianal fistulas. Secondary outcome parameters were the levels of local calprotectin in fistula scrapings and their correlation with fistula characteristics.

RESULTS

Sixty-three patients were included in this study (perianal Crohn's disease; 45, cryptoglandular; 18). Faecal calprotectin levels were significantly higher in Crohn's disease patients compared with cryptoglandular fistula (354.3 [58.8-1076.3] vs. 47.3 [14.6-233.6] μg/g, p = 0.003). Faecal calprotectin could accurately discriminate Crohn's disease patients with active luminal disease from patients without luminal disease (median [interquartile range]) (1167.0 [557.0-2806.3] vs. 93.0 [47.5-571.6] μg/g, p = 0.001). Faecal calprotectin was not related to calprotectin levels in fistula scrapings. No fistula characteristic was found to be correlated to scraping calprotectin, but a correlation was found with the TOpCLASS classification system, which stratifies fistulas according to disease severity and outcome: class 2a (amenable for repair), class 2b (symptom control) and class 2c (gradually debilitating disease): 140[31.0-149.0]) μg/g versus 706[198.5-1936] μg/g versus 4000[1337-5894] μg/g, p < 0.001). Scraping calprotectin was also related to pronounced hyperintensity of the fistula tract on MRI in Crohn's disease patients: (69.0[30.0-821.0] vs. 1284.0[204.3-4185.5]; p = 0.01)) and cryptoglandular patients: (30.0[13.5-80.5] vs. 3012.0 [923.8-5021.0]; p = 0.002).

CONCLUSION

Crohn's disease and cryptoglandular perianal fistulas differ in FC levels. Local fistula calprotectin production did not explain this difference, implying FC reflects the luminal condition. A correlation exists between scraping calprotectin levels and Crohn's disease fistula severity, which could be clinically relevant for prognostic cohorts and tailored treatment.

Crohn's-like Ileal Pouch Illness and Ileal Pouch Salvage Strategies

De novo Crohn's disease (CD) of the pouch or Crohn's-like Ileal Pouch Illness (CLIPI) is an increasingly common occurrence in an ever-growing ileal pouch population. Although currently undetermined if a subset of classic CD or a completely new entity, it primarily affects the prepouch afferent limb, pouch, and rectal cuff. Symptoms can mimic other more common disorders, such as pouchitis, and requires a thorough workup, including pouchoscopy with biopsy and often cross-sectional imaging, for the diagnosis to be made. There is an increased risk of long-term pouch failure in this population. Treatment is typically dependent upon the disease phenotype with surgical management considered in a step-up fashion. Medical management is primarily performed with "biologics," such as antitumor necrosis factor agents, although data are limited due to the lack of randomized controlled trials. Surgical management for CLIPI can include endoscopic, anorectal, and abdominal approaches to assist as "pouch-salvage strategies." The performance of advanced pouch-salvage techniques in the CLIPI population requires careful patient selection and should preferably be performed at high-volume pouch centers.

The improvement of a refractory enterocutaneous fistula with colchicine in a patient with Crohn's disease who had an MEFV gene mutation

Enterocutaneous fistulas (ECFs) occurring in the setting of Crohn's disease (CD) are difficult to cure with medical treatment alone and affects a patient's quality of life. A 39-year-old man was diagnosed with an ileocolitis-type CD in 2007. His inflammation was insufficiently controlled despite the administration of an anti-tumor necrosis factor-alpha antibody. Therefore, he underwent subtotal colectomy, terminal ileal resection, and ileostomy for multiple colon and anal stenoses in Dec 2015. The patient subsequently received ustekinumab; however, purulent discharge was observed from a postoperative scar around the umbilicus in July 2019. In July 2021, enteroscopy and magnetic resonance imaging (MRI) showed an ECF extending from the small intestine to the umbilicus. Upon referral to our hospital, laboratory data showed elevated C-reactive protein (CRP) and serum amyloid A (SAA). After receiving colchicine, his purulent discharge disappeared, and his CRP and SAA levels rapidly decreased. Enteroscopy and MRI performed 1 year and 5 months after the administration of colchicine revealed ECF closure. Genetic analysis revealed that the patient harbored an MEFV exon 1 (E84K) mutation.

Management of Anal Fistula with Crohn's Disease

Crohn's disease (CD) causes gastrointestinal symptoms (i.e., diarrhea and abdominal pain), systemic symptoms (i.e., fatigue, anemia, weight loss, and fever), and perianal fistulas that produce anal pain. Because of the frequent occurrence of diarrhea and ulcers in the rectum, CD is often exacerbated by perianal abscesses and/or fistulas. Perianal fistulizing CD (PFCD) has an unknown etiology and recurring symptoms such as pain and discharge, which seriously affects the patient's quality of life (QOL). In the past, radical surgery was performed for PFCD, but due to the risk of anal sphincter impairment, conservative therapy using antibiotics and immunosuppressive medications is currently the first treatment option. PFCD management has greatly improved with the use of biologics such as the antitumor necrosis factor alpha (TNF-α) antibodies infliximab and adalimumab. In this review, the results of the administration of anti-TNF-α (certolizumab pegol), anti-interleukin-12/23 (ustekinumab), and anti-α4β7 integrin antibodies (vedolizumab) were evaluated. Our investigation showed that these medications may be effective for maintenance therapy to prevent the recurrence of anal fistulas. In addition to biologics, molecular target drugs and even regenerative medicine using mesenchymal stem cells have been introduced to further expand the treatment options for consideration by medical personnel. We herein discuss the management of PFCD by focusing on studies conducted in the United States and Europe where researchers used recommended guidelines and consensus statements to evaluate the efficacy of each medication and published their findings in peer-reviewed journals.

Localized Administration of Mesenchymal Stem Cell-Derived Exosomes for the Treatment of Refractory Perianal Fistula in Patients With Crohn's Disease: A Phase II Clinical Trial

BACKGROUND

Crohn's disease perianal fistulas are often resistant to standard anti-tumor necrosis factor-α therapies. Mesenchymal stem cell-derived exosomes are extracellular vesicles with highly potent anti-inflammatory effects, and the previous phase of this study demonstrated their safety in the treatment of refractory perianal fistulas.

OBJECTIVE

To evaluate the efficacy of mesenchymal stem cell-derived exosomes for the treatment of refractory perianal fistulas.

DESIGN

Nonrandomized, nonblinded single-center phase II clinical trial.

SETTINGS

Tertiary university hospital.

PATIENTS

Twenty-three patients were enrolled, 20 of whom completed the study. Refractory perianal fistula was defined as resistance to at least 1 course of treatment with anti-tumor necrosis factor-α therapy.

INTERVENTIONS

After clinical assessment and MRI, the patients received general anesthesia, and 5 mL of exosome solution was injected directly into the fistula tracts. The injections were repeated 3 times at 2-month intervals, and patients were followed monthly for 6 months after the last injection. Tissue samples from the tracts were obtained before each injection and subjected to immunohistopathological assessment. MRI data were obtained before and 6 months after the last injection.

MAIN OUTCOME MEASURES

The primary outcome of this study was fistula tract closure on clinical examination and MRI. The secondary outcome was an improvement in the discharge from the tracts.

RESULTS

Fistula tracts were fully closed in 12 patients (60%). Four patients showed clinical improvement, with some tracts remaining open, and 4 patients were completely resistant to treatment. A total of 43 fistula tracts were treated during the trial, 30 of which (69.7%) showed complete closure. Histopathological analysis revealed substantial reductions in local inflammation and signs of enhanced tissue regeneration. Immunohistochemical analysis of CD68, CD20, and CD31 reaffirmed these results.

CONCLUSIONS

Mesenchymal stem cell-derived exosomes are safe and effective for treating refractory perianal fistulas in patients with Crohn's disease. See Video Abstract .

ADMINISTRACIN LOCALIZADA DE EXOSOMAS DERIVADOS DE CLULAS MADRE MESENQUIMALES PARA EL TRATAMIENTO DE LA FSTULA PERIANAL REFRACTARIA EN PACIENTES CON ENFERMEDAD DE CROHN ENSAYO CLNICO DE FASE II

ANTECEDENTES:Las fístulas perianales de la enfermedad de Crohn a menudo son resistentes a las terapias anti-TNF-α estándares. Los exosomas derivados de células madre mesenquimales (MSC) son vesículas extracelulares que tienen efectos antiinflamatorios muy potentes, y la fase anterior de este estudio demostró su seguridad en el tratamiento de fístulas perianales refractarias.OBJETIVO:Evaluar la eficacia de los exosomas derivados de MSC para el tratamiento de fístulas perianales refractarias.DISEÑO:Ensayo clínico de fase II, no aleatorizado y no ciego, unicéntrico.LUGARES:Hospital universitario terciario.PACIENTES:Se inscribieron veintitrés pacientes, 20 de los cuales completaron el estudio. La fístula perianal refractaria se definió como la resistencia a al menos un ciclo de tratamiento con terapia anti-TNF-α.INTERVENCIONES:Después de la evaluación clínica y la resonancia magnética, los pacientes fueron sometidos a anestesia general y se inyectaron 5 ml de solución de exosoma directamente en los trayectos de la fístula. Las inyecciones se repitieron tres veces a intervalos de 2 meses y los pacientes fueron seguidos mensualmente durante 6 meses después de la última inyección. Se obtuvieron muestras de tejido de los tractos antes de cada inyección y se sometieron a evaluación inmunohistopatológica. Los datos de imágenes de resonancia magnética se obtuvieron antes y seis meses después de la última inyección.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario de este estudio fue el cierre del trayecto de la fístula en el examen clínico y la imagen de resonancia magnética. El resultado secundario fue una mejora en la descarga de los tractos.RESULTADOS:Los trayectos de la fístula se cerraron completamente en 12 (60%) de los pacientes. Cuatro pacientes mostraron mejoría clínica, algunos tractos permanecieron abiertos y cuatro pacientes fueron completamente resistentes al tratamiento. Durante el ensayo se trataron un total de 43 trayectos fistulosos, 30 (69,7%) de los cuales mostraron un cierre completo. El análisis histopatológico reveló reducciones sustanciales en la inflamación local y signos de una mayor regeneración tisular. El análisis inmunohistoquímico del grupo de diferenciación 68, 20 y 31 reafirmó estos resultados.CONCLUSIONES:Los exosomas derivados de MSC son seguros y eficaces para el tratamiento de fístulas perianales refractarias en pacientes con enfermedad de Crohn. (Traducción-Dr. Aurian Garcia Gonzalez ).

Optimizing Treatment Outcomes in Crohn's Disease: A Comprehensive Systematic Review and Meta-Analysis of Regenerative Therapies with Emphasis on Platelet-Rich Plasma

BACKGROUND/OBJECTIVES

Crohn's disease (CD) is a chronic inflammatory disorder that significantly affects patients' quality of life; conventional treatments often provide limited relief.

METHODS

This systematic review and meta-analysis explored the potential of regenerative therapies, particularly platelet-rich plasma (PRP), as an adjunctive treatment for CD. The study protocol was registered with PROSPERO (CRD42024576683), and a comprehensive search was conducted across major databases, such as PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials. The search included terms related to CD and PRP. Studies assessing the efficacy of PRP in CD treatment were selected. Statistical analysis was conducted using the PICO framework with R software (version 4.3.2) and meta-package.

RESULTS

Of the 29 studies identified, 10 met the inclusion criteria, comprising pilot studies and controlled trials. Nine studies focused on Crohn's disease perianal fistulas (CDPF), and one focused on colonic CD. Among 138 patients with CDPF, 82.44% showed some fistula healing after PRP treatment, with 48.05% achieving complete resolution. In a sub-analysis, combining PRP with a stromal vascular fraction (SVF) resulted in a 58.62% complete healing rate, whereas combining PRP with adipose-derived stem cells (ASCs) showed even higher efficacy at 85.89%. PRP treatment alone resulted in a lower complete healing rate of 38.51%. PRP was well tolerated, with minor side effects such as localized pain.

CONCLUSIONS

These findings suggest that PRP, especially when combined with stem cells, offers a promising new approach for treating CD. However, larger trials are needed to confirm its long-term benefits and refine its clinical applications.

Associations of intestinal diseases with anal diseases: a Mendelian randomization study

Although observational clinical studies have established an association between Intestinal Diseases (IDS) and Anal Diseases (ADS), the causal relationship is still not fully understood due to the limitations of observational studies. Genome-wide association study (GWAS) statistical data for IDS and ADS were obtained from publicly available databases. To assess the causal effects of IDS on ADS, we conducted Mendelian randomization analysis. The inverse variance weighted method indicated that Inflammatory bowel disease (IBD) had a significant causal relationship with three kinds of ADS: Anorectal abscess (ARB), Haemorrhoidal disease (HEM), and Fissure and fistula of anal and rectal regions (FISSANAL). Crohn's disease (CD) and Ulcerative colitis (UC) also showed significant causal effects with three ADS: ARB, HEM, and FISSANAL. Furthermore, a potential link between CD and BNA(Benign neoplasm of anus and anal canal), Irritable bowel syndrome (IBS) and HEM, Colorectal cancer (CRC) and BNA, and Celiac disease and MNA (Malignant neoplasm of anus and anal canal) was observed. This comprehensive MR analysis highlight the significant and increased risk of common Anal Diseases (ARB, FISSANAL, and HEM) in patients with IBD, CD, and UC. Additionally, potential positive causal associations emerged between IBS and HEM, CRC and BNA, as well as between celiac disease and MNA.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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).

CONCLUSION

Most CD cases have less granulomas (≤3) and no foreign body giant cells. Ribbon-like granulomas can be seen only in CD cases.

Mechanisms of action behind the protective effects of proactive esophageal cooling during radiofrequency catheter ablation in the left atrium

Proactive esophageal cooling for the purpose of reducing the likelihood of ablation-related esophageal injury resulting from radiofrequency (RF) cardiac ablation procedures is increasingly being used and has been Food and Drug Administration cleared as a protective strategy during left atrial RF ablation for the treatment of atrial fibrillation. In this review, we examine the evidence supporting the use of proactive esophageal cooling and the potential mechanisms of action that reduce the likelihood of atrioesophageal fistula (AEF) formation. Although the pathophysiology behind AEF formation after thermal injury from RF ablation is not well studied, a robust literature on fistula formation in other conditions (eg, Crohn disease, cancer, and trauma) exists and the relationship to AEF formation is investigated in this review. Likewise, we examine the abundant data in the surgical literature on burn and thermal injury progression as well as the acute and chronic mitigating effects of cooling. We discuss the relationship of these data and maladaptive healing mechanisms to the well-recognized postablation pathophysiological effects after RF ablation. Finally, we review additional important considerations such as patient selection, clinical workflow, and implementation strategies for proactive esophageal cooling.

Efficacy of cx601 (darvadstrocel) for the treatment of perianal fistulizing Crohn's disease-A prospective nationwide multicenter cohort study

BACKGROUND

The use of mesenchymal stem cells is considered a novel and promising therapeutic option for patients with perianal fistulizing Crohn's disease; however, data on its clinical application remain scarce. This multicenter nationwide study aimed to assess the clinical efficacy of mesenchymal stem cells in closing complex anal fistulas.

METHODS

In this study 14 Crohn's disease patients (3 males, 11 females) with complex anal fistulas treated in 3 tertiary hospitals in Austria were included between October 2018 and April 2021. Injection of 120 million allogeneic expanded adipose-derived mesenchymal stem cells (Cx601-darvadstrocel) was performed in each patient. Closure of the external fistula opening without secretion by external manual compression was defined as treatment success.

RESULTS

The median age of the patient population at the time of surgery was 32 years (range 26-53 years) with a median body mass index of 21.7 kg/m2 (range 16.7-26.6 kg/m2). Of the patients 12 (86%) received monoclonal antibodies (infliximab, adalimumab, ustekinumab, vedolizumab) at the time of surgery. The median number of complex fistulas was 1.4 (range 1-2), The median operative time was 20 min (range 6-50 min) with no perioperative complications. After a median follow-up of 92 weeks, we found successful fistula closure in 57.1% (n = 8) of treated patients. The perianal disease activity index did not improve significantly from initially 7 to a median of 6 after 52 weeks (p = 0.495).

CONCLUSION

Darvadstrocel is a safe, minimally invasive surgical technique without significant perioperative complications. Clinical success can be expected in about half of the treated patients.

Protocol of the LATFIA trial (Laser Assisted Treatment of Fistula in Ano): a multicentre, prospective, randomized controlled trial comparing fistula-tract laser closure (FiLaC™) with rectal advancement flap for high trans-sphincteric fistulas

AIM

Anal fistula is one of the most common anal diseases, affecting between 1 and 3 per 10 000 people per year. Symptoms have a potentially severe effect on a patient's quality of life. Surgery is the mainstay of treatment, aiming to cure the fistula and preserve anal sphincter function. Rectal advancement flap (RAF) is currently the gold standard treatment but has recurrence rates varying between 20% and 50% and might lead to disturbance of continence. The aim of the trial described in this work is to discover if the minimally invasive fistula tract laser closure (FiLaC™) technique could achieve higher healing rates and a better functional outcome than RAF.

METHOD

We will perform a randomized prospective multicentre noninferiority study of the treatment of high trans-sphincteric perianal fistulas, comparing FiLaC™ with RAF in terms of fistula healing, recurrence rate, functional outcome and quality of life. Primary and secondary fistula healing will be evaluated at 26 and 52 weeks' follow-up. Quality of life will be evaluated using the SF-36 questionnaire, the Faecal Incontinence Quality of Life Scale questionnaire and the Vaizey score at 3, 6, 12 and 26 weeks postoperatively.

CONCLUSION

High trans-sphincteric fistulas have a potentially severe effect on a patient's quality of life. Classical treatment with RAF is a time-consuming invasive procedure. The LATFIA trial aims to compare FiLaC™ with the gold standard treatment with RAF. In case of noninferiority, FiLaC™ treatment could be standardized as a first line treatment for high trans-sphincteric fistulas. Better conservation of the patient's anal sphincter function could possibly be obtained. Likewise, we will report on the postoperative quality of life when applying these two techniques.

Prevalence, incidence, and treatment patterns of fistulizing Crohn disease: A US population-based cohort study

BACKGROUND

Population-based studies for patients with fistulizing Crohn disease (CD), a severe complication of CD, are limited.

OBJECTIVE

To report estimates of the prevalence and incidence rates of fistulizing CD in the United States and examine associated treatment patterns among incident cases.

METHODS

This retrospective, observational cohort study used a US administrative claims database from January 1, 2016, to December 31, 2019, with at least 365 days' continuous insurance enrollment. The prevalent patient population comprised patients with incident or existing cases of fistulizing CD. Crude, age, and sex-adjusted prevalence and incidence rates of fistulizing CD were estimated. Baseline characteristics, comorbidities, and CD-related medications and medical procedures were examined for patients with fistulizing CD.

RESULTS

The overall crude prevalence (prevalent cases: n = 5,082) and incidence rates (incident cases: n = 2,399) between 2017 and 2019 were 25.2 (95% CI = 24.5-25.9) per 100,000 persons and 6.9 (95% CI = 6.6-7.1) per 100,000 person-years, respectively. Age- and sex-adjusted prevalence and incidence rates were 24.9 (95% CI = 24.2-25.6) per 100,000 persons and 7.0 (95% CI = 6.7-7.3) per 100,000 person-years, respectively. Approximately half of all patients with incident fistulizing CD were prescribed biologic therapies within 1 year of an incident fistula diagnosis, with anti-tumor necrosis factor therapies the most widely prescribed biologic class; antibiotic and corticosteroid use was also common. Among the incident cases, approximately one-third of patients required surgery during the follow-up period, most of which occurred within 3 months of the index date.

CONCLUSIONS

This study reports age- and sex-adjusted prevalence and incidence rates for fistulizing CD of 24.9 per 100,000 persons and 7.0 per 100,000 person-years, respectively. As a concerning complication of CD, first-year treatment of fistulas in the United States commonly includes anti-tumor necrosis factor therapy, and there is a considerable surgical burden.

An in vitro model to study immune activation, epithelial disruption and stromal remodelling in inflammatory bowel disease and fistulising Crohn's disease

At present, preclinical models of inflammatory bowel disease (IBD) are insufficient, limiting translation between research and new therapeutics. This is especially true for fistulising Crohn's disease (CD), as the severe lack of relevant models hinders research progression. To address this, we present in vitro human IBD mucosal models that recapitulate multiple pathological hallmarks of IBD simultaneously in one model system - immune cell infiltration, stromal remodelling and epithelial disruption. Stimulation of models induces epithelial aberrations common in IBD tissue including altered morphology, microvilli abnormalities, claudin gene expression changes and increased permeability. Inflammatory biomarkers are also significantly increased including cytokines and chemokines integral to IBD pathogenesis. Evidence of extracellular matrix remodelling, including upregulated matrix-metalloproteinases and altered basement membrane components, suggests the models simulate pathological stromal remodelling events that closely resemble fistulising CD. Importantly, MMP-9 is the most abundant MMP and mimics the unique localisation observed in IBD tissue. The inflamed models were subsequently used to elucidate the involvement of TNF-α and IFN- γ in intestinal stromal remodelling, in which TNF-α but not IFN- γ induced MMP upregulation, specifically of MMP-3 and MMP-9. Collectively, our results demonstrate the potential of the IBD models for use in preclinical research in IBD, particularly for fistulising CD.

Surgical correction of multiple renoduodenal fistulas due to chronic pyelonephritis: a case report and literature review

Renoduodenal fistulas are a rare and uncommon phenomenon that account for ˂1% of those found between the urinary and intestinal tracts. Precipitation of this pathologic tract can be caused by chronic inflammation, necrosis, or ischemia. This case illustrates a 72-year-old man presenting with flank pain discovered to have multiple renoduodenal fistulas and our approach that led to the resolution of his symptoms. We review the pathophysiology, management, and effects of these fistulous tracts on renal function. Patients with staghorn calculi should undergo immediate evaluation for removal of the stone. In cases complicated by fistula formation, need for radical nephrectomy should be investigated and surgical repair should be pursued.

multi-GPA-Tree: Statistical approach for pleiotropy informed and functional annotation tree guided prioritization of GWAS results

Genome-wide association studies (GWAS) have successfully identified over two hundred thousand genotype-trait associations. Yet some challenges remain. First, complex traits are often associated with many single nucleotide polymorphisms (SNPs), most with small or moderate effect sizes, making them difficult to detect. Second, many complex traits share a common genetic basis due to 'pleiotropy' and and though few methods consider it, leveraging pleiotropy can improve statistical power to detect genotype-trait associations with weaker effect sizes. Third, currently available statistical methods are limited in explaining the functional mechanisms through which genetic variants are associated with specific or multiple traits. We propose multi-GPA-Tree to address these challenges. The multi-GPA-Tree approach can identify risk SNPs associated with single as well as multiple traits while also identifying the combinations of functional annotations that can explain the mechanisms through which risk-associated SNPs are linked with the traits. First, we implemented simulation studies to evaluate the proposed multi-GPA-Tree method and compared its performance with existing statistical approaches. The results indicate that multi-GPA-Tree outperforms existing statistical approaches in detecting risk-associated SNPs for multiple traits. Second, we applied multi-GPA-Tree to a systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA), and to a Crohn's disease (CD) and ulcertive colitis (UC) GWAS, and functional annotation data including GenoSkyline and GenoSkylinePlus. Our results demonstrate that multi-GPA-Tree can be a powerful tool that improves association mapping while facilitating understanding of the underlying genetic architecture of complex traits and potential mechanisms linking risk-associated SNPs with complex traits.

Genetic coding variant in complement factor B (CFB) is associated with increased risk for perianal Crohn's disease and leads to impaired CFB cleavage and phagocytosis

OBJECTIVE

Perianal Crohn's disease (pCD) occurs in up to 40% of patients with CD and is associated with poor quality of life, limited treatment responses and poorly understood aetiology. We performed a genetic association study comparing CD subjects with and without perianal disease and subsequently performed functional follow-up studies for a pCD associated SNP in Complement Factor B (CFB).

DESIGN

Immunochip-based meta-analysis on 4056 pCD and 11 088 patients with CD from three independent cohorts was performed. Serological and clinical variables were analysed by regression analyses. Risk allele of rs4151651 was introduced into human CFB plasmid by site-directed mutagenesis. Binding of recombinant G252 or S252 CFB to C3b and its cleavage was determined in cell-free assays. Macrophage phagocytosis in presence of recombinant CFB or serum from CFB risk, or protective CD or healthy subjects was assessed by flow cytometry.

RESULTS

Perianal complications were associated with colonic involvement, OmpC and ASCA serology, and serology quartile sum score. We identified a genetic association for pCD (rs4151651), a non-synonymous SNP (G252S) in CFB, in all three cohorts. Recombinant S252 CFB had reduced binding to C3b, its cleavage was impaired, and complement-driven phagocytosis and cytokine secretion were reduced compared with G252 CFB. Serine 252 generates a de novo glycosylation site in CFB. Serum from homozygous risk patients displayed significantly decreased macrophage phagocytosis compared with non-risk serum.

CONCLUSION

pCD-associated rs4151651 in CFB is a loss-of-function mutation that impairs its cleavage, activation of alternative complement pathway, and pathogen phagocytosis thus implicating the alternative complement pathway and CFB in pCD aetiology.

Reactivation of embryonic genetic programs in tissue regeneration and disease

Embryonic genetic programs are reactivated in response to various types of tissue damage, providing cell plasticity for tissue regeneration or disease progression. In acute conditions, these programs remedy the damage and then halt to allow a return to homeostasis. In chronic situations, including inflammatory diseases, fibrosis and cancer, prolonged activation of embryonic programs leads to disease progression and tissue deterioration. Induction of progenitor identity and cell plasticity, for example, epithelial-mesenchymal plasticity, are critical outcomes of reactivated embryonic programs. In this Review, we describe molecular players governing reactivated embryonic genetic programs, their role during disease progression, their similarities and differences and lineage reversion in pathology and discuss associated therapeutics and drug-resistance mechanisms across many organs. We also discuss the diversity of reactivated programs in different disease contexts. A comprehensive overview of commonalities between development and disease will provide better understanding of the biology and therapeutic strategies.

Crohn's Disease: Basic Characteristics of the Disease, Diagnostic Methods, the Role of Biomarkers, and Analysis of Metalloproteinases: A Review

Crohn's disease is a chronic inflammatory bowel disease that affects the ileum and/or large intestine. At the same time, it can also affect any other part of the human body, i.e., from the mouth to the anus. In Crohn's disease, the physiology and functioning of the epithelial barrier are inhibited due to the correlation of various factors, such as the environment, genetic susceptibility or intestinal microbiota. The symptoms are very troublesome and cause a significant reduction in quality of life, sometimes occurring with paralyzing permanent damage to the digestive tract, requiring enteral or parenteral nutrition throughout life. In order to make a proper and accurate diagnosis, an appropriately selected diagnostic path in a given clinical entity is necessary. Standard diagnostic methods are: laboratory examination, histopathological examination, endoscopic examination, X-ray, computed tomography, ultrasound examination and magnetic resonance imaging. Medical biology and the analysis of metalloproteinases have also proved helpful in diagnosing changes occurring as a result of Crohn's disease. Here we provide a thorough review of the latest reports on Crohn's disease and its genetic conditions, symptoms, morphology, diagnosis (including the analysis of Crohn's disease biomarkers, i.e., metalloproteinases) and treatment.

[Stem Cell Therapy for Complex Anal Fistula in Crohn`s Disease: Current Evidence and Future Perspectives]

Despite progress in multidisciplinary diagnostic and therapeutic strategies, complex anal fistulas associated with Crohn's disease remain a challenge for both medical and surgical management. Conventional surgical techniques such as flap procedures or LIFT are still associated with considerable persistence and recurrence rates. Based on this background, results of stem cell therapy for Crohn's anal fistula have shown promising results and are a sphincter-preserving technique. In particular, adipose-derived, allogeneic stem cell therapy (Darvadstrocel) has shown encouraging healing rates within the randomised controlled ADMIRE-CD trial, which were reproducible in "real world" data of limited clinical studies. The current evidence has led to the integration of allogeneic stem cell therapy into international guidelines. To date, the definitive status of allogeneic stem cells in the multidisciplinary treatment algorithm for complex anal fistulas associated with Crohn's disease cannot be evaluated.

Antimicrobial PVA Hydrogels with Tunable Mechanical Properties and Antimicrobial Release Profiles

Hydrogels are broadly employed in wound healing applications due to their high water content and tissue-mimicking mechanical properties. Healing is hindered by infection in many types of wound, including Crohn's fistulas, tunneling wounds that form between different portions of the digestive system in Crohn's disease patients. Owing to the rise of drug-resistant infections, alternate approaches are required to treat wound infections beyond traditional antibiotics. To address this clinical need, we designed a water-responsive shape memory polymer (SMP) hydrogel, with natural antimicrobials in the form of phenolic acids (PAs), for potential use in wound filling and healing. The shape memory properties could allow for implantation in a low-profile shape, followed by expansion and would filling, while the PAs provide localized delivery of antimicrobials. Here, we developed a urethane-crosslinked poly(vinyl alcohol) hydrogel with cinnamic (CA), p-coumaric (PCA), and caffeic (Ca-A) acid chemically or physically incorporated at varied concentrations. We examined the effects of incorporated PAs on antimicrobial, mechanical, and shape memory properties, and on cell viability. Materials with physically incorporated PAs showed improved antibacterial properties with lower biofilm formation on hydrogel surfaces. Both modulus and elongation at break could be increased simultaneously in hydrogels after both forms of PA incorporation. Cellular response in terms of initial viability and growth over time varied based on PA structure and concentration. Shape memory properties were not negatively affected by PA incorporation. These PA-containing hydrogels with antimicrobial properties could provide a new option for wound filling, infection control, and healing. Furthermore, PA content and structure provide novel tools for tuning material properties independently of network chemistry, which could be harnessed in a range of materials systems and biomedical applications.

Causal Link between Inflammatory Bowel Disease and Fistula: Evidence from Mendelian Randomization Study

BACKGROUND

Previous observational studies have found that fistulas are common in Crohn's disease (CD) and less common in ulcerative colitis (UC). However, some patients have a fistula before diagnosis. Based on retrospective analysis, it was not possible to determine whether there was a bi-directional causal relationship between inflammatory bowel disease (IBD) and fistulas.

METHODS

Data were extracted from the open GWAS database; 25,042 cases and 34,915 controls were included for IBD, and 6926 cases and 30,228 controls were included for fistula. Two-sample Mendelian randomization and multivariable Mendelian randomization were used in combination to determine the causal relationship between IBD and fistula.

RESULTS

Forward MR showed that IBD increased the risk of colonic or urogenital fistula (FISTULA) (OR: 1.09, 95% CI: 1.05 to 1.13, p = 1.22 × 10^-6), mainly associated with fissure and fistula of the anal and rectal regions (FISSANAL) (OR:1.10, 95% CI:1.06 to 1.14, p = 6.12 × 10^-8), but not with fistulas involving the female genital tract (FEMGENFISTUL) (OR:0.97, 95% CI: 0.85 to 1.11, p = 0.669). Furthermore, both UC and CD increased the risk of FISTULA. However, after adjusting by MVMR, only CD increased the risk of FISTULA (OR: 1.06, 95% CI: 1.02 to 1.11, p = 0.004), and UC did not increase the risk of FISTULA (OR: 1.01, 95% CI: 0.95 to 1.06, p = 0.838). Reverse MR showed that fistulas did not increase the risk of IBD.

CONCLUSION

Our study confirms it is CD, rather than UC, that casually leads to an increased risk of fistula, but fistulas do not increase the risk of IBD.

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

OBJECTIVES

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).

METHODS

RCTs reporting MSC therapy for perianal fistulas in CD were searched and included. The effectiveness and safety data were analyzed using RevMan 5.3.

RESULTS

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.

CONCLUSIONS

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.

Adipose-Derived Mesenchymal Stromal Cells in Basic Research and Clinical Applications

Adipose-derived mesenchymal stromal cells (AD-MSCs) have been extensively studied in recent years. Their attractiveness is due to the ease of obtaining clinical material (fat tissue, lipoaspirate) and the relatively large number of AD-MSCs present in adipose tissue. In addition, AD-MSCs possess a high regenerative potential and immunomodulatory activities. Therefore, AD-MSCs have great potential in stem cell-based therapies in wound healing as well as in orthopedic, cardiovascular, or autoimmune diseases. There are many ongoing clinical trials on AD-MSC and in many cases their effectiveness has been proven. In this article, we present current knowledge about AD-MSCs based on our experience and other authors. We also demonstrate the application of AD-MSCs in selected pre-clinical models and clinical studies. Adipose-derived stromal cells can also be the pillar of the next generation of stem cells that will be chemically or genetically modified. Despite much research on these cells, there are still important and interesting areas to explore.

Crohn's Disease-Associated and Cryptoglandular Fistulas: Differences and Similarities

Perianal fistulas are defined as pathological connections between the anorectal canal and the perianal skin. Most perianal fistulas are cryptoglandular fistulas, which are thought to originate from infected anal glands. The remainder of the fistulas mainly arises as complications of Crohn's disease (CD), trauma, or as a result of malignancies. Fistulas in CD are considered as a consequence of a chronic and transmural inflammatory process in the distal bowel and can, in some cases, even precede the diagnosis of CD. Although both cryptoglandular and CD-associated fistulas might look similar macroscopically, they differ considerably in their complexity, treatment options, and healing rate. Therefore, it is of crucial importance to differentiate between these two types of fistulas. In this review, the differences between CD-associated and cryptoglandular perianal fistulas in epidemiology, pathogenesis, and clinical management are discussed. Finally, a flow chart is provided for physicians to guide them when dealing with patients displaying their first episode of perianal fistulas.

Transmural remission improves clinical outcomes up to 5 years in Crohn's disease

INTRODUCTION

Evidence supporting transmural remission (TR) as a long-term treatment target in Crohn's disease (CD) is still unavailable. Less stringent but more reachable targets such as isolated endoscopic (IER) or radiologic remission (IRR) may also be acceptable options in the long-term.

METHODS

Multicenter retrospective study including 404 CD patients evaluated by magnetic resonance enterography and colonoscopy. Five-year rates of hospitalization, surgery, use of steroids, and treatment escalation were compared between patients with TR, IER, IRR, and no remission (NR).

RESULTS

20.8% of CD patients presented TR, 23.3% IER, 13.6% IRR and 42.3% NR. TR was associated with lower risk of hospitalization (odds-ratio [OR] 0.244 [0.111-0.538], p < 0.001), surgery (OR 0.132 [0.030-0.585], p = 0.008), steroid use (OR 0.283 [0.159-0.505], p < 0.001), and treatment escalation (OR 0.088 [0.044-0.176], p < 0.001) compared to no NR. IRR resulted in lower risk of hospitalization (OR 0.333 [0.143-0.777], p = 0.011) and treatment escalation (OR 0.260 [0.125-0.540], p < 0.001), while IER reduced the risk of steroid use (OR 0.442 [0.262-0.745], p = 0.002) and treatment escalation (OR 0.490 [0.259-0.925], p = 0.028) compared to NR.

CONCLUSIONS

TR improved clinical outcomes over 5 years of follow-up in CD patients. Distinct but significant benefits were seen with IER and IRR. This suggests that both endoscopic and radiologic remission should be part of the treatment targets of 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.

Active esophageal cooling during radiofrequency ablation of the left atrium: data review and update

INTRODUCTION

Radiofrequency (RF) ablation of the left atrium of the heart is increasingly used to treat atrial fibrillation (AF). Unfortunately, inadvertent thermal injury to the esophagus can occur during this procedure, potentially creating an atrioesophageal fistula (AEF) which is 80% fatal. The ensoETM (Attune Medical, Chicago, IL), is an esophageal cooling device that has been shown to reduce thermal injury to the esophagus during RF ablation.

AREAS COVERED

This review summarizes growing evidence related to active esophageal cooling during RF ablation for the treatment of AF. The review presents data demonstrating improved outcomes related to patient safety and procedural efficiency and suggests directions for future research.

EXPERT OPINION

The use of active esophageal cooling during RF ablation reduces esophageal injury, reduces or eliminates fluoroscopy requirements, reduces procedure duration and post-operative pain, and increases long-term freedom from arrhythmia. These effects in turn increase patient same-day discharge rates, decrease operator cognitive load, and reduce cost. These findings are likely to further accelerate the adoption of active esophageal cooling.

Diagnostic and therapeutic potential of RNASET2 in Crohn's disease: Disease-risk polymorphism modulates allelic-imbalance in expression and circulating protein levels and recombinant-RNASET2 attenuates pro-inflammatory cytokine secretion

Ribonuclease T2 gene (RNASET2) variants are associated in genome wide association studies (GWAS) with risk for several autoimmune diseases, including Crohn's disease (CD). In T cells, a functional and biological relationship exists between TNFSF15-mediated enhancement of IFN-γ production, mucosal inflammation and RNASET2. Disease risk variants are associated with decreased mRNA expression and clinical characteristics of severe CD; however, functional classifications of variants and underlying molecular mechanisms contributing to pathogenesis remain largely unknown. In this study we demonstrate that allelic imbalance of RNASET2 disease risk variant rs2149092 is associated with transcriptional and post-transcriptional mechanisms regulating transcription factor binding, promoter-transactivation and allele-specific expression. RNASET2 mRNA expression decreases in response to multiple modes of T cell activation and recovers following elimination of activator. In CD patients with severe disease necessitating surgical intervention, preoperative circulating RNASET2 protein levels were decreased compared to non-IBD subjects and rebounded post-operatively following removal of the inflamed region, with levels associated with allelic carriage. Furthermore, overexpression or treatment with recombinant RNASET2 significantly reduced IFN-γ secretion. These findings reveal that RNASET2 cis- and trans-acting variation contributed regulatory complexity and determined expression and provide a basis for linking genetic variation with CD pathobiology. These data may ultimately identify RNASET2 as an effective therapeutic target in a subset of CD patients with severe disease.

Pathogenesis of Fistulating Crohn's Disease: A Review

Sustained, transmural inflammation of the bowel wall may result in the development of a fistula in Crohn's disease (CD). Fistula formation is a recognized complication and cause of morbidity, occurring in 40% of patients with CD. Despite advanced treatment, one-third of patients experience recurrent fistulae. Development of targeting treatment for fistulae will be dependent on a more in depth understanding of its pathogenesis. Presently, pathogenesis of CD-associated fistulae remains poorly defined, in part due to the lack of accepted in vitro tissue models recapitulating the pathogenic cellular lesions linked to fistulae and limited in vivo models. This review provides a synthesis of the existing knowledge of the histopathological, immune, cellular, genetic, and microbial contributions to the pathogenesis of CD-associated fistulae including the widely accredited contribution of epithelial-to-mesenchymal transition, upregulation of matrix metalloproteinases, and overexpression of invasive molecules, resulting in tissue remodeling and subsequent fistula formation. We conclude by exploring how we might utilize advancing technologies to verify and broaden our current understanding while exploring novel causal pathways to provide further inroads to future therapeutic targets.

Won't You be My Neighbor: How Epithelial Cells Connect Together to Build Global Tissue Polarity

Epithelial tissues form continuous barriers to protect against external environments. Within these tissues, epithelial cells build environment-facing apical membranes, junction complexes that anchor neighbors together, and basolateral surfaces that face other cells. Critically, to form a continuous apical barrier, neighboring epithelial cells must align their apico-basolateral axes to create global polarity along the entire tissue. Here, we will review mechanisms of global tissue-level polarity establishment, with a focus on how neighboring epithelial cells of different origins align their apical surfaces. Epithelial cells with different developmental origins and/or that polarize at different times and places must align their respective apico-basolateral axes. Connecting different epithelial tissues into continuous sheets or tubes, termed epithelial fusion, has been most extensively studied in cases where neighboring cells initially dock at an apical-to-apical interface. However, epithelial cells can also meet basal-to-basal, posing several challenges for apical continuity. Pre-existing basement membrane between the tissues must be remodeled and/or removed, the cells involved in docking are specialized, and new cell-cell adhesions are formed. Each of these challenges can involve changes to apico-basolateral polarity of epithelial cells. This minireview highlights several in vivo examples of basal docking and how apico-basolateral polarity changes during epithelial fusion. Understanding the specific molecular mechanisms of basal docking is an area ripe for further exploration that will shed light on complex morphogenetic events that sculpt developing organisms and on the cellular mechanisms that can go awry during diseases involving the formation of cysts, fistulas, atresias, and metastases.

Peripartum Exposure to Biologic Therapy Does Not Impact Postpartum Wound Healing in Women With IBD

BACKGROUND

Inflammatory bowel disease (IBD) commonly affects women during childbearing years and often requires antepartum therapy. Data regarding effects of biologic exposure on delivery outcomes are limited. We explored whether peripartum biologic exposure impacts wound healing following cesarean section (C-section) and vaginal delivery (VD) in IBD patients.

METHODS

Pregnancy and IBD data from the IBD Preconception and Pregnancy Planning (I-PrePP) Clinic database were collected and analyzed. Primary outcome was frequency of postpartum wound infection in women receiving peripartum biologics, defined as exposure in the third trimester and up to 2 weeks postdelivery relative to nonexposed patients. Secondary outcomes included effect of peripartum biologic timing and IBD phenotype on wound healing. Descriptive statistics summarized data using frequency for categorical variables and median for continuous variables. Univariate analyses tested associations when appropriate.

RESULTS

Of 100 deliveries (interquartile range, 30-35; median, 33 years old), 58 were C-sections and 42 VDs. Peripartum biologic exposure occurred in 72% (42 of 58) and 57% (24 of 42), respectively. Median time from last dose to delivery was 6 (interquartile range, 4-8) weeks; 21 (32%) received biologics within 72 hours following delivery. Seven infections occurred following C-section among 5 unique CD patients. Peripartum biologic exposure was not associated with infection (4 of 66 [6%] exposed vs 3 of 34 [8.8%] nonexposed; P = .68), nor was disease activity (P = 1.0). Crohn's disease (P = 0.02), internal penetrating phenotype (P < .001), prior IBD surgery (P = .03), and prior postpartum infection (P = .04) were associated with infection.

CONCLUSIONS

Peripartum biologic exposure does not impair postpartum wound healing; however, patients with more complicated disease phenotypes require close monitoring.

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.

Surgical Management of Small Bowel Crohn's Disease

Crohn's disease in the small bowel could present itself as an inflammatory stricture, a fibrotic stricture as penetrating disease or a combination of both. It is pertinent to differentiate the disease process as well as its extent to effectively manage the disease. Currently, a combination of medical and surgical therapies forms part of the treatment plan while the debate of which therapy is better continues. In managing the strictures, identification of the disease process through imaging plays a pivotal role as inflammatory strictures respond to anti-tumor necrosis factor (TNF) and biological agents, while fibrotic strictures require endoscopic or surgical intervention. Recent evidence suggests a larger role for surgical excision, particularly in ileocolic disease, while achieving a balance between disease clearance and bowel preservation. Several adaptations to the surgical technique, such as wide mesenteric excision, side to side or Kono-S anastomosis, and long-term metronidazole therapy, are being undertaken even though their absolute benefit is yet to be determined. Penetrating disease requires a broader multidisciplinary approach with a particular focus on nutrition, skincare, and intestinal failure management. The current guidance directs toward early surgical intervention for penetrating disease when feasible. Accurate preoperative imaging, medical management of active diseases, and surgical decision-making based on experience and evidence play a key role in success.

MMP9 expression in intestinal fistula from patients with fistulizing CD and from human xenograft mouse model

Fistula treatment represents a major unmet medical need in the therapy of Crohn's disease (CD). Current medical therapies, such as anti-TNF antibody treatments, are often insufficient and do not achieve permanent fistula closure. Previously published data point toward a critical role for metalloproteinase-9 (MMP-9)/gelatinase B in fistula pathogenesis. The aim of this project was to investigate in detail MMP-9 expression in different fistula types and to confirm that MMP-9 is a potential target for fistula therapy in CD patients.Immunohistochemistry for total and active MMP-9, Cytokeratin 8 (CK-8) and co-staining of active MMP-9/CK-8 was performed in specimen derived from perianal fistulas, entero-enteric fistulas and fistulas from patients not responding to anti-TNF therapy. In addition, fistulas from the xenograft mouse model (anti-TNF treated or untreated) were analyzed.Total and active MMP-9 protein was detectable in cells lining the tracts of perianal and entero-enteric fistulas. Of note, total and active MMP-9 was also expressed in fistulas of CD patients non-responding to anti-TNF treatment. Interestingly, we detected considerable co-staining of active MMP-9 and CK-8 in particular in cells lining the fistula tract and in transitional cells around the fistulas. Furthermore, total and active MMP-9 are detectable in both anti-TNF treated and untreated xenograft fistulas.Taken together, our data suggest that MMP-9 is involved in fistula pathogenesis in CD patients, in fistulas of different origins and particularly in patients non-responding to anti-TNF therapy. Our xenograft fistula model is suitable for in vivo studies investigating a possible therapeutic role for MMP-9 targeting as fistula therapy.

Vedolizumab for perianal fistulizing Crohn's disease: systematic review and meta-analysis

BACKGROUND/AIMS

Perianal fistulas are a debilitating manifestation of Crohn's disease (CD). Despite the advent of anti-tumor necrosis factor (anti-TNF) therapy, the medical management of fistulizing CD continues to be challenged by unmet needs. We conducted a systematic review and meta-analysis of the effectiveness of vedolizumab for the management of perianal fistulizing CD.

METHODS

A search of PubMed, EMBASE and the Cochrane Library was performed from inception to June 2020 for studies reporting rates of perianal fistula healing in CD patients treated with vedolizumab. The primary outcome of interest was complete healing of perianal fistulas and the secondary outcome was partial healing. The pooled fistula healing rates with 95% confidence intervals (CI) were calculated utilizing a random effects model.

RESULTS

A total of 74 studies were initially identified, 4 of which met the inclusion criteria. A total of 198 patients with active perianal fistulas were included, 87% of whom had failed previous anti-TNF therapy. The pooled complete healing rate was 27.6% (95% CI, 18.9%-37.3%) with moderate heterogeneity (I2=49.4%) and the pooled partial healing rate was 34.9% (95% CI, 23.2%-47.7%) with high heterogeneity (I2=67.1%).

CONCLUSIONS

In a meta-analysis of 4 studies that included 198 patients with perianal fistulizing CD, the majority of whom had failed previous anti-TNF therapy, vedolizumab treatment led to healing of perianal fistulas in nearly one-third of the patients. The lack of high-quality data and significant study heterogeneity underscores the need for future prospective studies of fistula healing in patients receiving anti-integrin therapy.

Mesenchymal Stromal Cell Therapy Improves Refractory Perianal Fistula in Crohn's Disease: Case Series Clinical Interventional Study

OBJECTIVE

Perianal fistulas in Crohn's disease (CD) are the main challenges in inflammatory bowel diseases (IBDs). Some of the fistulas are refractory to any therapeutic strategy. The aim of this study was to evaluate the therapeutic effects of mesenchymal stromal cells (MSCs) as a novel promising modality for the treatment of fistulizing CD.

MATERIALS AND METHODS

This case series clinical interventional study was conducted from 2014 to 2017 at Shariati Hospital, an IBD referral center in Tehran, Iran. Refractory adult patients with CD who had draining perianal fistulas were enrolled in this study. All patients were examined by a colorectal surgeon and the fistula imaging studies were performed by pelvic magnetic resonance imaging (MRI). After autologous bone marrow (BM) aspiration and MSCs isolation, the cells were cultured and passaged under current good manufacturing practice (cGMP) conditions. Four intra-fistula injections of cells, each containing 40×106 MSCs suspended in fibrin glue, were administered by an expert surgeon every 4 weeks. Procedure safety, feasibility and closure of the perianal fistulas at week 24 were assessed. Clinical examination and MRI findings were considered as the primary end points.

RESULTS

In total, 5 patients (2 males and 3 females) were enrolled in this study. No adverse events were observed during the six-month follow-up in these patients. Both the Crohn's Disease Activity Index (CDAI) and Perianal Disease Activity Index (PDAI) scores decreased in all patients after cell injections and one patient achieved complete remission with closure of fistulas, discontinuation of fistula discharge, and closure of the external opening.

CONCLUSION

Local injection of MSCs combined with fibrin glue is potentially a safe and effective therapeutic approach for complex perianal fistulas in patients with CD.

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.

Regenerative medicine for digestive fistulae therapy: Benefits, challenges and promises of stem/stromal cells and emergent perspectives via their extracellular vesicles

Despite current management strategies, digestive fistulae remain extremely debilitating complications associated with significant morbidity and mortality, generating a need to develop innovative therapies in these indications. A number of clinical trials and experimental studies have thus investigated the potential of stem/stromal cells (SCs) or SC-derived extracellular vesicles (EVs) administration for post-surgical and Crohn's-associated fistulae. This review summarizes the physiopathology and current standards-of-care for digestive fistulae, along with relevant evidence from animal and clinical studies regarding SC or EV treatment for post-surgical digestive fistulae. Additionally, existing preclinical models of fistulizing Crohn's disease and results of SC therapy trials in this indication will be presented. The optimal formulation and administration protocol of SC therapy products for gastrointestinal fistula treatment and the challenges for a widespread use of darvadstrocel (Alofisel) in clinical practice will be discussed. Finally, the potential advantages of EV therapy and the obstacles towards their clinical translation will be introduced.

Polyherbal formulation Anoac‑H suppresses the expression of RANTES and VEGF for the management of bleeding hemorrhoids and fistula

Hemorrhoids and fistula are considered the most common anorectal conditions in the general population. These conditions affect the quality of a patient's life by causing pain and bleeding during defecation or even in the resting state. Lower grades of hemorrhoids may be controlled by traditional measures. However, surgery is an effective treatment option in recurrent-lower and higher-grade hemorrhoids. Surgical procedures are associated with various complications, including pain and delayed wound healing. Recurrence of hemorrhoids is also a major concern in the post-operative period. An anal fistula is the connection between the anus and the skin and causes severe pain, swelling, as well as blood and pus discharge. Fistula has serious social and economic consequences. Hence, it is important to understand the pathophysiology and molecular pathology of hemorrhoids and fistula, to identify the molecular targets and to develop pharmacological-interventions. In a previous study by our group, the polyherbal formulation Anoac-H was developed for the treatment of different stages of hemorrhoids and fistula, and it was demonstrated that Anoac-H is an effective formulation for treating hemorrhoids. However, the molecular mode of action of Anoac-H on hemorrhoids and fistula had remained elusive. In the present study, it was determined that this formulation reduces the migration of mesenchymal (fibroblasts) and immune (RAW 264.7) cells without affecting their viability. It was also observed that Anoac-H suppresses the expression of regulated upon activation, normal T cell expressed and presumably secreted (RANTES) and VEGF in fibroblasts and macrophages. Inflammation and elevated expression of RANTES and VEGF were observed in hemorrhoids and fistula. However, inflammation, as well as the expression of RANTES and VEGF, were significantly reduced in treated human hemorrhoid and fistula tissues as compared to untreated ones, confirming the in vitro results.

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.

Prospective randomised controlled trial of adults with perianal fistulising Crohn's disease and optimised therapeutic infliximab levels: PROACTIVE trial study protocol

INTRODUCTION

Perianal fistulising Crohn's disease (pfCD) can be somewhat treatment refractory. Higher infliximab trough levels (TLIs) may improve fistula healing rates; however, it remains unclear whether escalating infliximab therapy to meet higher TLI targets using proactive, or routine, therapeutic drug monitoring (TDM) improves outcomes. This randomised controlled trial aimed to assess whether infliximab therapy targeting higher TLIs guided by proactive TDM improves outcomes compared with standard therapy.

METHODS AND ANALYSIS

Patients with active pfCD will be randomised 1:1 to either the proactive TDM arm or standard dosing arm and followed up for 54 weeks. Patients in the proactive TDM arm will have infliximab dosing optimised to target higher TLIs. The targets will be TLI ≥ 25 µg/mL at week 2, ≥ 20 µg/mL at week 6 and ≥ 10 µg/mL during maintenance therapy. The primary objective will be fistula healing at week 32. Secondary objectives will include fistula healing, fistula closure, radiological fistula healing, patient-reported outcomes and economic costs up to 54 weeks. Patients in the standard dosing arm will receive conventional infliximab dosing not guided by TLIs (5 mg/kg at weeks 0, 2 and 6, and 5 mg/kg 8 weekly thereafter). Patients aged 18-80 years with pfCD with single or multiple externally draining complex perianal fistulas who are relatively naïve to infliximab treatment will be included. Patients with diverting ileostomies or colostomies and pregnant or breast feeding will be excluded. Fifty-eight patients per arm will be required to detect a 25% difference in the primary outcome measure, with 138 patients needed to account for an estimated 6.1% primary non-response rate and 10% dropout rate.

ETHICS AND DISSEMINATION

Results will be presented in peer-reviewed journals and international conferences. Ethics approval has been granted by the South Western Sydney Local Health District Human Research Ethics Committee in Australia.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12621000023853); Pre-results.

Stem cell injection for complex anal fistula in Crohn’s disease: A single-center experience

BACKGROUND

Despite tremendous progress in medical therapy and optimization of surgical strategies, considerable failure rates after surgery for complex anal fistula in Crohn’s disease have been reported. Therefore, stem cell therapy for the treatment of complex perianal fistula can be an innovative option with potential long-term healing.

AIM

To evaluate the results of local administration of allogenic, adipose-derived mesenchymal stem cells (darvadstrocel) for complex anal Crohn’s fistula.

METHODS

All patients with complex anal fistulas associated with Crohn’s disease who were amenable for definite fistula closure within a defined observation period were potential candidates for stem cell injection (darvadstrocel) if at least one conventional or surgical attempt to close the fistula had failed. Darvadstrocel was only indicated in patients without active Crohn’s disease and without presence of anorectal abscess. Local injection of darvadstrocel was performed as a standardized procedure under general anesthesia including single-shot antibiotic prophylaxis, removal of seton drainage, fistula curettage, closure of the internal openings and local stem cell injection. Data collection focusing on healing rates, occurrence of abscess and follow-up was performed on a regular basis of quality control and patient care. Data were retrospectively analyzed.

RESULTS

Between July 2018 and January 2021, 12 patients (6 females, 6 males) with a mean age of 42.5 (range: 26-61) years underwent stem cell therapy. All patients had a minimum of one complex fistula, including patients with two complex fistulas in 58.3% (7/12). Two of the 12 patients had horse-shoe fistula and 3 had one complex fistula. According to Parks classification, the majority of fistulas were transsphincteric (76%) or suprasphincteric (14%). All patients underwent removal of seton, fistula curettage, transanal closure of internal opening by suture (11/12) or mucosal flap (1/12) and stem cell injection. At a mean follow-up of 14.3 (range: 3-30) mo, a healing rate was documented in 66.7% (8/12); mean duration to achieve healing was 12 (range: 6-30) wk. Within follow-up, 4 patients required reoperation due to perianal abscess (33.3%). Focusing on patients with a minimum follow-up of 12 mo (6/12) or 24 mo (4/12), long-term healing rates were 66.7% (4/6) and 50.0% (2/4), respectively.

CONCLUSION

Data of this single-center experience are promising but limited due to the small number of patients and the retrospective analysis.

Current concepts in the pathogenesis of cryptoglandular perianal fistula

Cryptoglandular perianal fistula is a common benign anorectal disorder that is managed mainly with surgery. A fistula is typically defined as a pathological communication between two epithelialized surfaces. More specifically, perianal fistula manifests as an abnormal tract between the anorectal canal and the perianal skin. Perianal fistulas are often characterized by significantly decreased patient quality of life. The cryptoglandular theory of perianal fistulas suggests their development from the proctodeal glands, which originate from the intersphincteric plane and perforate the internal sphincter with their ducts. Involvement of proctodeal glands in the inflammatory process could play a primary role in the formation of cryptoglandular perianal fistula. The objective of this narrative review was to investigate the current knowledge of the pathogenesis of cryptoglandular perianal fistula with the specific aims of characterizing the potential role of proinflammatory factors responsible for the development of chronic inflammation. Further studies are crucial to improve the therapeutic management of cryptoglandular perianal fistulas.

Nutrition Management of the High-Output Fistulae

Enterocutaneous fistulae (ECFs) are commonly encountered complications in medical and surgical practice. High-output fistulae are associated with significant morbidity and mortality, poor quality of life, and a substantial healthcare burden. An interdisciplinary team approach is crucial to prevent and mitigate the adverse clinical consequences of high-output ECFs including sepsis, metabolic derangements, and malnutrition. Patients with ECFs are at a significantly higher risk of developing malnutrition and close monitoring by nutrition support professionals and/or a nutrition support team is an essential component of their medical management. High-output ECFs often require the initiation of nutrition support through either enteral or parenteral routes. Historically, parenteral nutrition (PN) has been the primary method of nutrition support in these patients. However, oral and enteral nutrition (EN) should remain viable options if an evaluation of the location of the ECF, amount of remaining functional bowel, and volume of ECF output identifies favorable conditions. Additionally, in contrast to PN, oral nutrition and EN are the preferred method of feeding because of the maintenance of the structural and functional integrity of the gastrointestinal tract. The inclusion of pharmacological interventions can greatly assist with the reduction and stabilization of ECF output and thereby permit sustained enteral feeding. Initiation of supplemental or full PN will be required if oral nutrition and EN lead to metabolic derangements, fail to meet energy requirements, or do not maintain or improve the patient's nutrition status. The main focus of this review is to discuss the nutrition management of patients with high-output ECFs.

Autologous Platelet-Rich Plasma in the Treatment of Perianal Fistula in Crohn's Disease

AIM

To assess clinical healing in patients with perianal Crohn's disease with local intrafistular injection of autologous platelet-rich plasma.

METHOD

The pilot study was conducted at a single centre between January 2013 and December 2015. Autologous platelet-rich plasma was prepared in platelet-rich and platelet-poor fractions for local intrafistular injection in patients with proven, established perianal Crohn's disease. Patients were permitted biological therapies, and the Perianal Crohn's Disease Activity Index was recorded. Patients were followed for 48 weeks for clinical signs of healing (complete, partial or non-healing), monitoring fistula drainage, closure and epithelialization.

RESULTS

The study included 29 patients (19 males; mean age 38 ± 12.8 years) with four exclusions in the operating room because surgery was not indicated and four lost to follow-up. Five adverse events were recorded, with two requiring the drainage of abscess collections. Of the 21 patients assessable at 24 weeks, there was complete healing, partial healing and non-healing in 7 (33.3%), 8 (38.1%) and 6 (28.6%) patients, respectively. By 48 weeks, there was complete healing, partial healing and non-healing in 6 (40%), 6 (40%) and 3 (20%) patients, respectively, with a reduction in the number of visible external fistula openings at both time points (P = 0.021). By the end of the study, there was a higher trend of healing if biological therapies were continued (85.7% with biologics vs. 75% without, P = 0.527), but there were no statistically significant differences and no differences in the Perianal Crohn's Disease Activity Index.

CONCLUSION

Autologous platelet-rich plasma is safe in patients with perianal Crohn's disease, with an acceptable healing rate over a medium-term follow-up, particularly if biological therapies are used concomitantly.