Systematic review: the combined surgical and medical treatment of fistulising perianal Crohn's disease

First Mexican Consensus on Crohn's disease

INTRODUCTION

Crohn's disease (CD) is a subtype of chronic and incurable inflammatory bowel disease. It can affect the entire gastrointestinal tract and its etiology is unknown.

OBJECTIVE

The aim of this consensus was to establish the most relevant aspects related to definitions, diagnosis, follow-up, medical treatment, and surgical treatment of Crohn's disease in Mexico.

MATERIAL AND METHODS

Mexican specialists in the areas of gastroenterology and inflammatory bowel disease were summoned. The consensus was divided into five modules, with 69 statements. Applying the Delphi panel method, the pre-meeting questions were sent to the participants, to be edited and weighted. At the face-to-face meeting, all the selected articles were shown, underlining their level of clinical evidence; all the statements were discussed, and a final vote was carried out, determining the percentage of agreement for each statement.

RESULTS

The first Mexican consensus on Crohn's disease was produced, in which recommendations for definitions, classifications, diagnostic aspects, follow-up, medical treatment, and surgical treatment were established.

CONCLUSIONS

Updated recommendations are provided that focus on definitions, classifications, diagnostic criteria, follow-up, and guidelines for conventional medical treatment, biologic therapy, and small molecule treatment, as well as surgical management.

Pharmacological Therapies for the Management of Fistulizing Crohn's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Fistulas are a debilitating complication of Crohn's disease [CD]. We conducted a systematic review to assess the efficacy of medical therapies for fistulizing CD.

METHODS

MEDLINE, Embase, and CENTRAL were searched on May 26, 2022, for randomized controlled trials [RCTs] of pharmacological therapy in adults with fistulizing CD. The primary outcome was induction and maintenance of fistula response. Pooled risk ratios [RRs] and 95% confidence intervals [CIs] were calculated. GRADE was used to assess the certainty of evidence.

RESULTS

Thirty-eight RCTs were included. Nineteen trials [50%] exclusively involved perianal fistula. The remaining studies included some participants with non-perianal fistula. Pooled RRs for anti-tumour necrosis factor [TNF] agents were not statistically significant for induction [RR 1.36, 95% CI 0.97-1.91] or maintenance of fistula response [RR 1.48, 95% CI 0.97-2.27]. However, in a sensitivity analysis of studies with fistula response as the primary outcome, anti-TNFs were superior to placebo for induction [RR 1.94, 95% CI 1.10-3.41] and maintenance [RR 1.88, 95% CI 1.23-2.88] of fistula response. Oral small molecules [RR 2.56, 95% CI 1.18-5.53] and mesenchymal stem cell [MSC] therapy [RR 1.26, 95% CI 1.01-1.57] were effective for induction of fistula response. Ustekinumab was associated with maintenance of fistula response [RR 1.80, 95% CI 1.04-3.11]. Vedolizumab was not superior to placebo. The certainty of evidence ranged from very low to moderate.

CONCLUSION

Very low- to moderate-certainty evidence suggests that anti-TNF therapy, oral small molecules, ustekinumab, and MSCs are effective for perianal fistulizing CD. Dedicated fistula studies evaluating biologics and small molecules are needed.

Long-term outcome of stem cell transplantation with and without anti-tumor necrotic factor therapy in perianal fistula with Crohn's disease

BACKGROUND

Stem cell transplantation is a promising therapeutic option for curing perianal fistula in Crohn's disease (CD). Anti-tumor necrotic factor (TNF) therapy combined with drainage procedure is effective as well. However, previous studies are limited to proving whether the combination treatment of biologics and stem cell transplantation improves the effect of fistula closure.

AIM

This study aimed to evaluate the long-term outcomes of stem cell transplantation and compare Crohn's perianal fistula (CPF) closure rates after stem cell transplantation with and without anti-TNF therapy, and to identify the factors affecting CPF closure and recurrence.

METHODS

The patients with CD who underwent stem cell transplantation for treating perianal fistula in our institution between Jun 2014 and December 2022 were enrolled. Clinical data were compared according to anti-TNF therapy and CPF closure.

RESULTS

A total of 65 patients were included. The median age of females was 26 years (range: 21-31) and that of males was 29 (44.6%). The mean follow-up duration was 65.88 ± 32.65 months, and complete closure was observed in 50 (76.9%) patients. The closure rates were similar after stem cell transplantation with and without anti-TNF therapy (66.7% vs 81.6% at 3 year, P = 0.098). The patients with fistula closure had short fistulous tract and infrequent proctitis and anorectal stricture (P = 0.027, 0.002, and 0.008, respectively). Clinical factors such as complexity, number of fistulas, presence of concurrent abscess, and medication were not significant for closure. The cumulative 1-, 2-, and 3-year closure rates were 66.2%, 73.8%, and 75.4%, respectively.

CONCLUSION

Anti-TNF therapy does not increase CPF closure rates in patients with stem cell transplantation. However, both refractory and non-refractory CPF have similar closure rates after additional anti-TNF therapy. Fistulous tract length, proctitis, and anal stricture are risk factors for non-closure in patients with CPF after stem cell transplantation.

Surface-enhanced Raman spectroscopy analysis reveals biochemical difference in urine of patients with perianal fistula

BACKGROUND & AIMS

Perianal fistulising Crohn's disease (PFCD) is different from the characteristics and outcomes of traditional non-inflammatory bowel disease (IBD) anal fistulas. The presence of perianal disease was a poor prognostic indicator for Crohn's disease (CD) patients and PFCD patients were more likely to bear an increased risk of recurrence. However, the effective and accurate diagnosis methods to early distinguish PFCD from simple perianal fistula were still scarce. The purpose of this study is to develop a non-invasive detecting approach to predict CD in patients with perianal fistulas.

METHODS

Data on patients with anal fistulizing disease were collected from July 2020 to September 2020 in two IBD centers. Urine samples from PFCD and simple perianal fistula patients were investigated by surface-enhanced Raman spectroscopy (SERS). Principal component analysis (PCA)-support vector machine (SVM) was utilized to establish classification models to distinguish PFCD from simple perianal fistula.

RESULTS

After a case-matched 1:1 selection by age and gender, 110 patients were included in the study. By analyzing the average SERS spectra of PFCD and simple perianal fistula patients, it revealed that there were significant differences in intensities at 11 Raman peaks. The established PCA-SVM model distinguished PFCD from simple perianal fistula with a sensitivity of 71.43%, specificity 80.00% and accuracy 75.71% in the leave-one-patient-out cross-validation. The accuracy of the model in validation cohort was 77.5%.

CONCLUSIONS

Investigation of urine samples by SERS helps clinicians to predict Crohn's disease from perianal fistulas, which make patients achieve benefit from a more individualized treatment strategy.

Mesenchymal stem cell therapy for Crohn's perianal fistula-a real-world experience

AIM

Remission rates of medically and surgically treated complex perianal fistulas in Crohn's disease are low. Recently, trials have demonstrated the potential for long-term remission with local injection of allogeneic adipose-derived mesenchymal stem cells (darvadstrocel). Our aim was to analyse outcomes from our real-world experience with this new treatment.

METHODS

All patients with Crohn's disease suffering complex perianal fistulas who consecutively underwent administration of darvadstrocel at two centres were followed up and evaluated. Patients were assessed for clinical remission, response, failure, and any complications during follow-up. The results of all patients with a minimum of 3 months' follow-up are presented.

RESULTS

Thirty-three patients with Crohn's disease and complex perianal fistulas were included. Of these, 20 (61%) experienced clinical remission that was maintained for a mean follow-up of 14 (3-32) months. A total of 24 of 33 (73%) experienced at least 3 months of clinical remission, with four later having recurrence (3-12 months). Among the remaining nine patients who did not experience clinical remission, two (6%) had partial remission (such as one of two fistulas closing), two (6%) showed signs of response but not remission, and five (15%) showed no signs of healing. The mean time to maintained clinical remission was 6 weeks (range 2 weeks to 6 months), and there were no severe adverse events.

CONCLUSION

In this real-world experience, treatment of Crohn's disease complex perianal fistulas with darvadstrocel had a 61% success rate for maintained clinical remission.

Where Are We and Where to Next?-The Future of Perianal Crohn's Disease Management

Perianal fistulizing Crohn's Disease (pCD) affects about 25% of patients with Crohn's Disease (CD). It remains a difficult entity to manage with a therapeutic ceiling of treatment success despite improving medical and surgical management. The refractory nature of the disease calls for an imminent need to better understand its immunopathogenesis and classification to better streamline our treatment options. In this article, we overview the current state of pCD management and discuss where the future of its management may lie.

Management of Perianal Fistulizing Crohn's Disease

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

Rates and Predictors of Long-term Clinical Outcomes in Patients With Perianal Crohn's Disease on Biologic Therapy

BACKGROUND AND GOALS

Perianal Crohn's disease (pCD) represents an aggressive phenotype with limited studies on long-term outcomes. We evaluated 5-year outcomes of these patients on biologic therapies.

METHODS

We performed a retrospective analysis of patients with pCD at a tertiary medical center. We used Kaplan-Meier curves to estimate rates and multivariate logistic regression to identify predictors of long-term outcomes.

RESULTS

We included 311 patients with pCD of which 168 patients were started on biologics [138 anti-tumor necrosis factor (TNF) α, 14 vedolizumab, 16 ustekinumab] at the time of diagnosis. Anti-TNF use at the time of diagnosis was associated with decreased rates of perianal abscess recurrence [hazard ratio (HR)=0.48, 95% confidence interval (CI): 0.32-0.74], whereas ustekinumab use was associated with increased rates of perianal fistula closure (HR=3.58, 95% CI: 1.04-12.35) and decreased rates of perianal abscess recurrence (HR=0.20, 95% CI: 0.07-0.56) at follow-up. Among patients who failed their first anti-TNF, switching to another anti-TNF was associated with decreased rates of colectomy (HR=0.20, 95% CI: 0.04-0.90) and permanent diversion (HR=0.16, 95% CI: 0.03-0.94) compared with ustekinumab, whereas vedolizumab use was associated with decreased perianal fistula closure (HR=0.22, 95% CI: 0.05-0.96) compared with ustekinumab. Predictors of colectomy included colonic disease (odds ratio=2.71, 95% CI: 1.36-5.38) and anal stenosis (odds ratio=4.44, 95% CI: 1.59-12.43).

CONCLUSION

Type of biologic use at the time of pCD diagnosis or after first anti-TNF failure may be associated with long-term outcomes in patients with pCD.

Short-term anti-TNF therapy with surgical closure versus anti-TNF therapy alone for Crohn's perianal fistulas (PISA-II): long-term outcomes of an international, multicentre patient preference, randomised controlled trial

Background

The PISA-II trial showed that short-term anti-tumour necrosis factor (anti-TNF) therapy followed by surgical closure induces radiological healing of perianal fistulas in patients with Crohn's disease more frequently than anti-TNF therapy alone after 18 months. This study aimed to compare long-term outcomes of both treatment arms.

Methods

Follow-up data were collected from patients who participated in the PISA-II trial, an international patient preference randomised controlled trial. This multicentre trial was performed in nine hospitals in the Netherlands and one hospital in Italy. Patients with Crohn's disease above the age of 18 years with an active high perianal fistula and a single internal opening were asked to participate. Patients were allocated to anti-TNF therapy (intravenous infliximab, or subcutaneous adalimumab, at the discretion of the gastroenterologist) for one year, or surgical closure combined with 4-months anti-TNF therapy. Patients without a treatment preference were randomised (1:1) using random block randomisation (block sizes of six without stratification), and patients with a treatment preference were treated according to their preferred treatment arm. For the current follow-up study, data were collected until May 2022. Primary outcome was radiological healing on magnetic resonance imaging (MRI), including all participants with a MRI made less than 6 months ago at the time of data collection. Analysis was based on observed data.

Findings

Between September 14, 2013, and December 7, 2019, 94 patients were enrolled in the trial. Long-term follow-up data were available in 91 patients (36/38 (95%) anti-TNF + surgical closure, 55/56 (98%) anti-TNF). A total of 14/36 (39%) patients in the surgical closure arm were randomly assigned, which was not significantly different in the anti-TNF treatment arm (16/55 (29%) randomly assigned). Median follow-up was 5.7 years (interquartile range (IQR) 5-7). Radiological healing occurred significantly more often after anti-TNF + surgical closure (15/36 = 42% versus 10/55 = 18%; P = 0.014). Clinical closure was comparable (26/36 = 72% versus 34/55 = 62%; P = 0.18) in both groups. However, clinical closure in the surgical group was achieved with less re-interventions 4/26 (= 15%) versus 18/34 (= 53%), including (redo-)surgical closure procedures. Recurrences occurred in 0/25 (0%) patients with radiological healing versus 27/76 (36%) patients with clinical closure, sometime during follow-up. Anti-TNF trough levels were higher in patients with long-term clinical closure in both groups (P = 0.031 and P = 0.014). In 6/11 (55%) patients in the anti-TNF group with available trough levels, recurrences were diagnosed within three months of a drop under 3.5ug/ml. 36 patients stopped anti-TNF, after which 0/14 (0%) patients with radiological healing developed a recurrence and 9/22 (41%) with clinical closure. Self-rated (in)continence was comparable between groups, and 79% (60/76) of patients indicated comparable/improved continence after treatment. Decision-regret analysis showed that all (30/30) anti-TNF + surgical closure patients agreed or strongly agreed that surgery was the right decision versus 78% (36/46) in the anti-TNF arm. All surgical closure patients would go for the same treatment again, whereas this was 89% (41/46) in the anti-TNF arm.

Interpretation

This study confirmed that surgical closure should be considered in amenable patients with perianal fistulas and Crohn's disease as long-term outcomes were favourable, and that radiological healing should be the aim of treatment as recurrences only occurred in patients without radiological healing. In patients with complete MRI closure, anti-TNF could be safely stopped.

Funding

None.

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

PURPOSE

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

RESULTS AND CONCLUSION

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

A Novel Patient-like Swine Model of Perianal Crohn's Disease

BACKGROUND

Perianal Crohn's disease is associated with poor outcomes and high medical costs. It is notoriously difficult to treat despite therapeutic advancements for luminal disease. A large animal model that mimics human perianal disease is needed to test innovative therapies.

OBJECTIVE

This study aimed to create a swine model that replicates the inflammatory component and therapeutic challenges found in patients with perianal Crohn's disease.

DESIGN

This was an animal preclinical study.

SETTINGS

The experiments were performed at the animal laboratory at the Johns Hopkins University.

PATIENTS

Four sus scrufus female pigs were included in the study.

INTERVENTIONS

Four female pigs underwent creation of 3 surgical perianal fistulas each, 1 rectovaginal and 2 perianal. Size 24 French setons were placed to maintain patency of the fistula tracts for 4 weeks. After removal of the setons, trinitrobenzene sulfonic acid was administered into the fistula tract to create and maintain local inflammation mimicking perianal Crohn's disease.

MAIN OUTCOMES MEASURES

An MRI was obtained to assess the fistulas and the pigs were euthanized to review histopathology.

RESULTS

Three inflammatory chronic fistula tracts were successfully created in each pig as confirmed by MRI and examination under anesthesia. This is the first report of maintaining patent fistulas in swine 2 weeks after removal of setons. For the first time, we reported that 2 pigs developed branching fistulas and small abscesses reminiscent of human perianal Crohn's disease. The corresponding histopathologic examination found significant chronic active inflammation on standard hematoxylin and eosin staining.

LIMITATIONS

The fistulas were surgically induced and did not occur naturally.

CONCLUSIONS

A chronic perianal fistula model in pigs that strongly resembles human perianal Crohn's disease was successfully created. This model can be used to test novel therapeutics and techniques to pave the path for human trials. See Video Abstract at http://links.lww.com/DCR/B969 .

UN NUEVO MODELO PORCINO SIMILAR A UN PACIENTE DE LA ENFERMEDAD DE CROHN PERIANAL ANTECEDENTES

La enfermedad de Crohn perianal se asocia con malos resultados y altos costos médicos. Es notoriamente difícil de tratar a pesar de los avances terapéuticos para la enfermedad luminal. Se precisa de un modelo animal grande que imite la enfermedad perianal humana para probar terapias innovadoras.OBJETIVO:Nuestro objetivo de este estudio fue crear un modelo porcino que replique el componente inflamatorio y los desafíos terapéuticos que se encuentran en los pacientes con enfermedad de Crohn perianal.DISEÑO:Este fue un estudio preclínico en animales.AJUSTES:Los experimentos se realizaron en el laboratorio de animales de la Universidad Johns Hopkins.PACIENTES:Se incluyeron en el estudio cuatro cerdas sus scrofa.INTERVENCIONES:Cuatro cerdas fueron sometidas a la creación de 3 fístulas perianales quirúrgicas cada una: 1 recto vaginal y 2 perianales. Se colocaron sedales de 24 French para mantener la permeabilidad de los trayectos fistulosos durante 4 semanas. Tras el retiro de los sedales, se administró ácido trinitrobenceno sulfónico en el trayecto de la fístula para crear y mantener la inflamación local simulando la enfermedad de Crohn perianal.PRINCIPALES MEDIDAS DE RESULTADOS:Se obtuvo una resonancia magnética para evaluar las fístulas y los cerdos fueron sacrificados para revisar la histopatología.RESULTADOS:Se crearon de manera exitosa tres trayectos fistulosos inflamatorios crónicos en cada cerdo, confirmados por imágenes de resonancia magnética y examen bajo anestesia. Este es el primer informe de preservación de fístulas permeables en cerdos 2 semanas tras el retiro de los setones. Por primera vez, informamos que dos cerdos desarrollaron fístulas ramificadas y pequeños abscesos que recuerdan a la enfermedad de Crohn perianal humana. El examen histopatológico correspondiente encontró una significativa inflamación crónica activa en la tinción estándar de hematoxilina y eosina.LIMITACIONES:Las fístulas se indujeron quirúrgicamente y no se produjeron de forma natural.CONCLUSIONES:Se logro recrear con éxito un modelo de fístula perianal crónica en cerdos que se asemeja mucho a la enfermedad de Crohn perianal humana. Este modelo se puede utilizar para probar nuevas terapias y técnicas para allanar el camino para los ensayos en humanos. Consulte Video Resumen en http://links.lww.com/DCR/B969 . (Traducción-Dr Osvaldo Gauto).

Comparative Efficacy of Biologic Therapies for Inducing Response and Remission in Fistulizing Crohn's Disease: Systematic Review and Network Meta-Analysis of Randomized Controlled Trials

BACKGROUND

The medical treatment of fistulizing Crohn's disease (CD) remains a challenge to clinicians. Over the last 20 years, biologic therapies have been the mainstay of medical treatment of fistulizing CD. The purpose of this study is to compare the efficacy of biologic therapies in inducing response and remission in fistulizing CD.

METHODS

We performed a systematic review of the EMBASE, MEDLINE, and Cochrane Central databases from inception to December 2021. Inclusion criteria were any randomized controlled trials (RCTs) that evaluated the efficacy of biologic therapies against an active comparator or placebo for induction of response or remission in adults with fistulizing CD. The proportion of patients with fistula response or remission, as defined by each clinical trial, was our primary study outcome. A Bayesian random-effects network meta-analysis was used to measure treatment effects and results were reported as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

In our analysis, 10 studies were included, and all were RCTs. Infliximab was superior to adalimumab in inducing response (OR, 0.24; 95% CI, 0.06-0.99) but not in inducing remission (OR, 0.31; 95% CI, 0.04-2.27). Tumor necrosis factor antagonists were superior to placebo in the induction of response (OR, 0.51; 95% CI, 0.35-0.750) and remission (OR, 0.36; 95% CI, 0.22-0.58). Infliximab was superior to placebo in inducing response (OR, 0.36; 95% CI, 0.17-0.75) and remission (OR, 0.17; 95% CI, 0.03-0.87). Ustekinumab was superior to placebo in inducing response (OR, 0.48; 95% CI, 0.26-0.860) but not in inducing remission (OR, 0.50; 95% CI, 0.13-1.93). When comparing biologic therapies against each other, there was no statistical difference in inducing remission. Vedolizumab was not superior to placebo in inducing remission (OR, 0.32; 95% CI, 0.04-2.29). Certolizumab was not superior to placebo in inducing response (OR, 0.78; 95% CI, 0.40-1.55) or remission (OR, 0.78; 95% CI, 0.40-1.55).

CONCLUSIONS

Tumor necrosis factor antagonists are effective in inducing response and remission in fistulizing CD. Infliximab was superior to adalimumab for inducing response but not for inducing remission. Ustekinumab is effective in the induction of response but not in the induction of remission. When compared against each other, biologic therapies showed no significant difference in the induction of remission. Based on the available data, infliximab is the preferred first-line treatment. As for other biologics, the limited published data do not allow us to make firm recommendations. This study supports current practice and emphasizes the need for dedicated RCTs to evaluate the efficacy of biologic therapies in fistulizing CD.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Development of a core descriptor set for Crohn's anal fistula

AIM

Crohn's anal fistula (CAF) is a complex condition, with no agreement on which patient characteristics should be routinely reported in studies. The aim of this study was to develop a core descriptor set of key patient characteristics for reporting in all CAF research.

METHOD

Candidate descriptors were generated from published literature and stakeholder suggestions. Colorectal surgeons, gastroenterologists and specialist nurses in inflammatory bowel disease took part in three rounds of an international modified Delphi process using nine-point Likert scales to rank the importance of descriptors. Feedback was provided between rounds to allow refinement of the next ratings. Patterns in descriptor voting were assessed using principal component analysis (PCA). Resulting PCA groups were used to organize items in rounds two and three. Consensus descriptors were submitted to a patient panel for feedback. Items meeting predetermined thresholds were included in the final set and ratified at the consensus meeting.

RESULTS

One hundred and thirty three respondents from 22 countries completed round one, of whom 67.0% completed round three. Ninety seven descriptors were rated across three rounds in 11 PCA-based groups. Forty descriptors were shortlisted. The consensus meeting ratified a core descriptor set of 37 descriptors within six domains: fistula anatomy, current disease activity and phenotype, risk factors, medical interventions for CAF, surgical interventions for CAF, and patient symptoms and impact on quality of life.

CONCLUSION

The core descriptor set proposed for all future CAF research reflects characteristics important to gastroenterologists and surgeons. This might aid transparent reporting in future studies.

Predictors of Perianal Fistula Healing in Children With Newly Diagnosed Crohn Disease

OBJECTIVES

Perianal fistulas are among the most severe complications of Crohn disease, but limited data regarding their outcomes are available in children. Our objective was to determine predictors of perianal fistula healing among pediatric patients newly diagnosed with Crohn disease.

METHODS

This single-center retrospective study followed patients with perianal fistulas at Crohn disease diagnosis until fistula healing. Time to healing was analyzed using Cox proportional hazard regression models considering relevant covariates including patient demographics, disease characteristics, medical therapies [no anti-tumor necrosis factor (TNF)α therapy, anti-TNFα therapy ±therapeutic drug monitoring], and perianal surgical procedures including fistulotomy, fistulectomy, removal of perianal lesions, seton placement, and incision and drainage.

RESULTS

Of 485 patients identified, 107 (22%) had a perianal fistula at Crohn disease diagnosis. Multivariate analysis identified that perianal fistulotomy, fistulectomy, and lesion removal [hazard ratio (HR) 0.46; P = 0.028], non-White race (HR 0.30, P < 0.01), and male sex (HR 0.42; P = 0.02) were associated with delayed fistula healing. Faster fistula healing was associated with treatment with anti-TNFα with therapeutic drug monitoring (HR 1.78, P = 0.009). There were no other differences in healing by treatment.

CONCLUSIONS

Fistulotomy, fistulectomy, and perianal lesion removal as well as non-White race were associated with delayed fistula healing. Anti-TNFα therapy was associated with faster fistula healing when combined with therapeutic drug monitoring, compared to all other medical treatment groups, including anti-TNFα therapy without therapeutic drug monitoring.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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

BACKGROUND & AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICALTRIALS

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

Therapeutic Drug Monitoring in Perianal Fistulizing Crohn’s Disease

Perianal fistulas are a common complication of Crohn’s disease (CD) that has, historically, been challenging to manage. Despite the strong available evidence that anti-tumor necrosis factor (anti-TNF) agents are useful in the treatment of perianal fistulizing Crohn’s disease (PFCD), a significant number of these patients do not respond to therapy. The use of therapeutic drug monitoring (TDM) in patients with CD receiving biologic agents has evolved and is currently positioned as an important tool to optimize and guide biologic treatment. Considering the treatment of PFCD can represent a challenge; identifying novel tools to improve the efficacy of current treatments is an important unmet need. Given its emerging role in other phenotypes of Crohn’s disease, the use of TDM could also offer an opportunity to enhance the effectiveness of available therapies and improve outcomes in the subset of patients with PFCD receiving biologics. Overall, there is mounting evidence that higher anti-TNF drug levels are associated with better rates of “fistula healing”. However, studies have been limited by their use of subjective outcomes and observational designs. Ultimately, further interventional, randomized controlled trials looking into the relationship between drug exposure and fistula outcomes are needed.

Three-year outcome of local injection of autologous stromal vascular fraction cells and microfat in refractory perianal fistulas of Crohn's disease

Perianal fistulas in Crohn's disease are frequent and disabling, with a major impact on patients' quality of life. Cell-based therapy using mesenchymal stem cells represents new hope for these patients, but long-term efficacy remains challenging. In a pilot study, including patients with refractory complex perianal fistulas, autologous adipose-derived stromal vascular fraction (ADSVF) combined with microfat achieved combined remission in 60% of cases, with a good safety profile at 1 year. The purpose of this study is to assess whether these results were maintained at longer term. The safety and efficacy data of the ten patients were evaluated retrospectively 3 years after injection on the basis of clinical and radiological data. MRI were analysed according to the MAGNIFI-CD score. No adverse event was attributed to the experimental stem-cell treatment. Combined remission was achieved in 7 patients (70%) and associated with a significant improvement in the MAGNIFI-CD MRI score. In conclusion, the safety and efficacy of ADSVF and microfat injection in Crohn's disease fistulas were maintained at 3 years, demonstrating that this innovative strategy is effective in producing a long-lasting healing effect. The ongoing multicentre randomized placebo-controlled trial (NCT04010526) will be helpful to define the place for this approach in the current therapeutic arsenal.

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

BACKGROUND AND AIMS

The natural history of perianal Crohn's disease (PCD) remains poorly described and is mainly based on retrospective studies from referral centers. The aim of this study was to assess the incidence, outcomes and predictors of the onset of PCD.

METHODS

All incident cases of patients diagnosed with possible CD were prospectively registered from 1994 to 1997 in Brittany, a limited area in France. At diagnosis, the clinical features of perianal disease were recorded. All patient charts were reviewed from the diagnosis to the last clinic visit in 2015.

RESULTS

Among the 272 out of 331 incident CD patients followed up, 51 (18.7%) patients had PCD at diagnosis. After a mean follow-up of 12.8 years, 93 (34%) patients developed PCD. The cumulative probabilities of perianal CD occurrence were 22%, 29%, and 32% after 1 year, 5 years, and 10 years, respectively. The cumulative probabilities of anal ulceration were 14%, and 19% after 1 year and 10 years, respectively. Extraintestinal manifestations were associated with the occurrence of anal ulceration. The cumulative probabilities of fistulizing PCD were 11%, 16%, and 19% after 1 year, 5 years, and 10 years, respectively. Extraintestinal manifestations, rectal involvement and anal ulceration were predictors of fistulizing PCD. The cumulative probability of developing anal stricture was 4% after 10 years.

CONCLUSIONS

PCD is frequently observed during CD, in approximately one-third of patients. These data underline the need for targeted therapeutic research on primary perianal lesions (proctitis, anal ulceration) to avoid the onset of fistulizing perianal disease.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

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

Surgery for inflammatory bowel disease in the era of biologics

Therapy for inflammatory bowel diseases (IBD) has changed dramatically in recent years with the wide use of biologics. Despite these advances in medical therapy, surgery still plays an indispensable role in the management of IBD. And with more and more patients receiving biologics, surgeons also need to adapt to the impact of biologics on the disease. The purpose of this article is to review the role of surgery in the treatment of IBD in the era of biologics and the impact of these medications on perioperative outcomes.

Minor Sphincter Sparing Surgery for Successful Closure of Perianal Fistulas in Patients with Crohn's Disease

The purpose of this study is to demonstrate that repetitive minor surgical procedures allow for a high rate of permanent closure of perianal fistulas in patients with Crohn’s disease (CD). Patients with perianal fistulizing CD (PFCD) who underwent perianal surgery at the University Hospital of Muenster between 2003 and 2018 were assessed for fistula characteristics and surgical procedures. We included 45 patients (m:f = 28:17) with a mean age of 27 years at first fistula appearance. Of these, 49% suffered from a complex fistula. An average of 4.2 (1–14) procedures were performed, abscess incisions and fistula seton drainages included. Draining setons were left in place for 5 (1–54) months, until fistula closure. Final surgical techniques were fistulotomy (31.1%), seton removal with sustained biological therapy (26.7%), Anal Fistula Plug (AFP) (17.8%), Over-The Scope-Clip proctology (OTSC) (11.1%), and mucosa advancement flap (4.4%). In 8.9% of cases, the seton was kept as permanent therapy. The time from first to last surgery was 18 (0–182) months and the median follow-up time after the last surgery was 90 (15–200) months. The recurrence rate was 15.5% after 45 (17–111) months. Recurrent fistulas healed after another 1.86 (1–2) surgical re-interventions. The final success rate was 80%. Despite biological treatment, PFCD management remains challenging. However, by repeating minor surgical interventions over a prolonged period of time, high permanent healing rates can be achieved.

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

Background

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

Methods

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

Results

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

Conclusions

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

Trial registration

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

Approach to medical therapy in perianal Crohn's disease

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

Predictors of reoperation for perianal fistula in Crohn's disease

OBJECTIVE

Treating perianal fistula in cases of Crohn's disease (CD) remains challenging and the postoperative recurrence rate of perianal fistula is 22%-28%. This study aimed to identify the predictive risk factors for reoperation in Korean CD patients with perianal fistula.

METHODS

Medical records of the patients with clinically and pathologically confirmed CD who underwent surgical treatment for perianal fistulas at four referral centers in Korea between March 2010 and February 2020 were retrospectively reviewed. The rate of reoperation due to perianal fistula recurrence, which was defined as any subsequent surgery for perianal fistula or abscess, and the potential risk factors for reoperation were analyzed.

RESULTS

Fifty-one patients at a mean age of 22 years were included in the study. During a median follow-up period of 26 months (range 2-89 mo), 21 (41.2%) patients underwent reoperation because of recurrent perianal fistula or abscess. The median interval from the first surgery to reoperation was 13 months. A multivariate Cox regression analysis revealed that drug escalation (from 5-aminosalicylic acid [5-ASA] to thiopurine or from 5-ASA or thiopurine to anti-tumor necrosis factor agents) after the first surgery was associated with a reduced likelihood of reoperation (hazard ratio 0.316, 95% confidence interval 0.117-0.858, P = 0.024).

CONCLUSIONS

The postoperative recurrence rate was relatively high (41.2%) after the first surgery for perianal fistula in Korean patients with CD. Drug escalation therapy after the first surgery may help reduce the need for reoperation for perianal fistula.

Higher Postinduction Infliximab Concentrations Are Associated With Improved Clinical Outcomes in Fistulizing Crohn's Disease: An ACCENT-II Post Hoc Analysis

INTRODUCTION

There are only limited data regarding the role of therapeutic drug monitoring in fistulizing Crohn's disease (CD). We investigated the association between both induction and maintenance serum infliximab concentrations and favorable therapeutic outcomes in patients with fistulizing CD.

METHODS

This was a post hoc analysis of the ACCENT-II trial evaluating patients with fistulizing CD receiving induction (n = 282) and maintenance infliximab therapy (n = 139). Investigated therapeutic outcomes at both week 14 and week 54 included fistula response, complete fistula response, C-reactive protein (CRP) normalization (≤5 mg/L) in patients with an elevated baseline CRP, and a more stringent outcome of composite remission, defined as combined complete fistula response and CRP normalization. Associations between serum infliximab concentrations and outcomes were assessed by multivariable logistic regression models.

RESULTS

Higher week 14 infliximab concentrations were independently associated with week 14 fistula response (odds ratio [OR]: 1.16; 95% confidence interval [CI]: 1.02-1.32; P = 0.019), and composite remission (OR: 2.32; 95% CI: 1.55-3.49; P < 0.001). Higher week 14 infliximab concentrations were also independently associated with week 54 composite remission (OR: 2.05; 95% CI: 1.10-3.82; P = 0.023). Based on receiver operating characteristic curve analysis, week 14 infliximab concentrations thresholds with combined maximal sensitivity and specificity of ≥20.2 μg/mL at week 2, ≥15 μg/mL at week 6, and ≥7.2 μg/mL at week 14 were associated with week 14 composite remission.

DISCUSSION

Higher post-induction infliximab concentrations are associated with early and long-term favorable therapeutic outcomes in patients with fistulizing CD.

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

BACKGROUND AND AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effectiveness of infliximab treatment of complex idiopathic anal fistulas

OBJECTIVES

To investigate the effects of infliximab treatment in patients with complex idiopathic anal fistulas refractory to standard surgical treatment.

MATERIALS AND METHODS

We retrospectively evaluated the effects ofinfliximab treatmentin patients with complex idiopathic anal fistulas refractory to standard surgical intervention. The primary outcome was achievement of substantial clinical improvement defined as sustained, reduced inflammatory activity at perioperativeevaluation, i.e., only minimal-to-moderate secretion and induration and a reduction of fistula size of a magnitude that would make it possible to perform a lay-open or sphincter-sparring closure procedure. Secondary outcomes weresymptom improvement, adverse treatment events and fistula healing after the surgical procedure in those achieving the primary outcome.

RESULTS

Twenty-two patients were included (18 high transsphincteric, 3complex low transsphincteric, 1 suprasphincteric fistula). Fistulas had been present for a median of 24 [interquartile range, IQR: 12-33] months. In total, 16 patients (73%) achieved the primary outcome of substantial clinical improvement. Median time from infliximab initiation to patients achieved the primary outcome was 11 [IQR: 8-22] months. Sixteen of the patients responding to infliximab received subsequent lay-open or sphincter-sparring closure procedure surgery. Of these, ten (63%) achieved fistula healing. No serious infectious complications to infliximab treatment were seen. One patient developed a new abscess. One patient developed psoriasis (pustolosispalmoplantaris).

CONCLUSIONS

Infliximab treatment may be considered a supplement to repeated curettage and setondrainage in the management of selected, complex idiopathic anal fistulas. Such combined treatment may make otherwise refractory fistulas amenable to definitive closure attempts.

Treatment Strategy for Perianal Fistulas in Crohn Disease Patients: The Surgeon's Point of View

Perianal fistula is a frequent complication and one of the subclassifications of Crohn disease (CD). It is the most commonly observed symptomatic condition by colorectal surgeons. Accurately classifying a perianal fistula is the initial step in its management in CD patients. Surgical management is selected based on the type of perianal fistula and the presence of rectal inflammation; it includes fistulotomy, fistulectomy, seton procedure, fistula plug insertion, video-assisted ablation of the fistulous tract, stem cell therapy, and proctectomy with stoma creation. Perianal fistulas are also managed medically, such as antibiotics, immunomodulators, and biologics including anti-tumor necrosis factor-alpha agents. The current standard treatment of choice for perianal fistula in CD patients is the multidisciplinary approach combining surgical and medical management; however, the rate of long-term remission is low and is reported to be 50% at most. Therefore, the optimum management strategy for perianal fistulas associated with CD remains controversial. Currently, the goal of management for CD-related perianal fistulas are controlling symptoms and maintaining long-term anal function without proctectomy, while monitoring progression to anorectal carcinoma. This review evaluates perianal fistula in CD patients and determines the optimal surgical management strategy based on recent evidence.

Perianal fistulodesis – A pilot study of a novel minimally invasive surgical and medical approach for closure of perianal fistulae

BACKGROUND

Perianal fistulae strongly impact on quality of life of affected patients.

AIM

To challenge and novel minimally invasive treatment options are needed.

METHODS

Patients with Crohn’s disease (CD) in remission and patients without inflammatory bowel disease (non-IBD patients) were treated with fistulodesis, a method including curettage of fistula tract, flushing with acetylcysteine and doxycycline, Z-suture of the inner fistula opening, fibrin glue instillation, and Z-suture of the outer fistula opening followed by post-operative antibiotic prophylaxis with ciprofloxacin and metronidazole for two weeks. Patients with a maximum of 2 fistula openings and no clinical or endosonographic signs of a complicated fistula were included. The primary end point was fistula healing, defined as macroscopic and clinical fistula closure and lack of patient reported fistula symptoms at 24 wk.

RESULTS

Fistulodesis was performed in 17 non-IBD and 3 CD patients, with a total of 22 fistulae. After 24 wk, all fistulae were healed in 4 non-IBD and 2 CD patients (overall 30%) and fistula remained closed until the end of follow-up at 10-25 mo. In a secondary per-fistula analysis, 7 out of 22 fistulae (32%) were closed. Perianal disease activity index (PDAI) improved in patients with fistula healing. Low PDAI was associated with favorable outcome (P = 0.0013). No serious adverse events were observed.

CONCLUSION

Fistulodesis is feasible and safe for perianal fistula closure. Overall success rates is at 30% comparable to other similar techniques. A trend for better outcomes in patients with low PDAI needs to be confirmed.

Management of perianal fistula in inflammatory bowel disease: identification of prognostic factors associated with surgery

PURPOSE

As one of the clinical manifestations of inflammatory bowel disease (IBD), perianal fistula disease (PFD) can potentially impact the patient quality of life. The management of PFD employs a multidisciplinary approach which includes antibiotics, biological therapies, immunomodulators, and surgery. We analyzed the outcome and prognostic factors of anal fistula surgery in IBD patients.

METHODS

We conducted a retrospective study of IBD patients undergoing elective surgery for anal fistula between January 2015 and December 2018 at our University Department of Surgery. We collated demographic factors, disease activity, imaging (MRI and endoanal ultrasound), surgical interventions, and medical treatment assessing the rate of fistula closure and fecal incontinence, 2 months and 1 year after surgery.

RESULTS

Thirty-five IBD patients with anal fistula underwent surgery (28 Crohn's disease, four ulcerative colitis, and three indeterminate colitis). Twenty-seven patients presented with complex fistulas and eight with simple fistulas with 10 patients undergoing single-stage surgery. In 25 patients, a two-stage surgical approach was planned and performed (draining seton plus medical treatment and then second-stage surgery with curative intent). At 1 year of follow-up, the fistula healing rate was 50% for single-stage surgery and 60% for two-stage surgery (P = 0.09). Overall, 19.2% of patients developed postoperative fecal incontinence. A time interval greater than 12 months between surgeries is a favorable prognostic factor for fistula healing with the two-stage approach (P = 0.002).

CONCLUSIONS

In our retrospective study, two-stage surgery in IBD patients presenting with complex perianal fistulous disease results in a better medium-term outcome with a longer time interval between surgeries.

Long-term outcomes of perianal fistulizing Crohn's disease in the biologic era

Background and Aim

While the advent of biologic therapy has led to improved outcomes in perianal fistulizing Crohn's disease (pfCD), loss of response is common. Previous studies suggest that patients who achieve radiological healing (with healing of underlying tracts on magnetic resonance imaging [MRI]) have a longer duration of response. The aim of this study was to characterize MRI outcomes of pfCD at a specialist inflammatory bowel disease (IBD) unit and compare the long-term clinical outcomes between patients achieving MRI and clinical healing.

Methods

A retrospective analysis of perianal fistulizing Crohn's patients treated at one specialist IBD unit was performed. Records were reviewed for patient demographics, disease history, clinical assessments, investigation results, and disease flares. Clinical remission was defined as closure of all baseline fistula openings. Radiological healing was defined as the absence of any T2-hyperintense sinuses, tracts, or collections. The primary end-point was rate of MRI healing. The secondary outcome was defined as flare-free period (time between clinical or radiological healing and patients' first signs/symptoms requiring therapy escalation).

Results

A total of 93 patients were included, with a median follow-up of 4.8 years (interquartile range, 2.4-6 years). Of 44 patients, 22 (50%) achieved clinical remission, while 15 of 93 (16%) achieved radiological healing. Of 22 patients, 10 (45%) with clinical remission had a subsequent disease flare (median time of 7 months) compared with 3 of 15 (20%) patients with MRI healing (median time of 3.6 years). Radiological healing was associated with a significantly longer flare-free period (P = 0.01).

Conclusion

Radiological healing occurs less commonly but represents a deeper form of healing, associated with improved long-term clinical outcomes.

Efficacy and Safety of Mesenchymal Stem Cells in Treatment of Complex Perianal Fistulas: A Meta-Analysis

Complex perianal fistula is a highly debilitating and difficult to treat condition. Local mesenchymal stem cell (MSC) therapy for perianal fistula has shown considerable promise but still remains controversial. Therefore, we performed the meta-analysis to evaluate the efficacy and safety of local MSC therapy for complex perianal fistula. PubMed and Embase databases were searched for published randomized clinical trials (RCTs) that reported local MSC therapy for complex perianal fistulas. The effectiveness and safety data analysis was conducted using RevMan5.3. Subgroup analyses were performed based on the characteristics of the studies. Seven RCTs with 730 participants were included. Local MSC treatment showed significantly higher healing rate (HR) of perianal fistulas compared to control (odds ratio (OR) = 2.03; 95% confidence interval (CI) 1.50, 2.74; P < 0.00001). MSCs combined with fibrin glue therapy can improve the HR compared with fibrin glue alone (OR = 3.27; 95% CI 1.15, 9.28; P = 0.03). Subgroup analyses showed that local therapy can improve the HR in patients with perianal fistulas associated with Crohn's disease (CD) (OR = 2.05; 95% CI 1.41, 3.00; P = 0.0002) and cryptoglandular origin (no-Crohn) (OR = 2.98; 95% CI 0.86, 10.29; P = 0.08). The pooled OR for studies that combined reepithelialization of the external opening with pelvic magnetic resonance imaging (MRI) to evaluate the healing of fistulas was 1.77 (95% CI 1.28, 2.45; P = 0.0006). The pooled OR for studies where fistula healing was defined as complete reepithelialization of external openings was 5.92 (95% CI 1.34, 26.15; P = 0.02). Both autologous MSCs (OR = 3.19; 95% CI 1.05, 9.65; P = 0.04) and allogeneic MSCs (OR = 1.97; 95% CI 1.34, 2.91; P = 0.0006) can obtain higher HR for perianal fistula compared with control. The adipose-derived MSC group can obtain higher HR than the control group (OR = 2.29; 95% CI 1.38, 3.79; P = 0.001). There were no significant differences in adverse events (AEs) (OR = 1.06; 95% CI 0.71, 1.59; P = 0.77). None of the adverse events was judged to be related to MSCs. Our study supported that local MSC therapy alone or combined with fibrin glue is safe and efficacious for complex perianal fistula. In the future, more RCTs are needed to confirm this conclusion.

The informational and decisional preferences of patients undergoing surgery for Crohn's anal fistula: a qualitative study

AIM

One in three patients with Crohn's disease will develop a perianal fistula, but only a few achieve long-term healing. Treatment is both medical and surgical. Since there is no 'best' surgical procedure, patient preference is important in selecting the appropriate treatment for this condition. The aim of this study was to investigate the informational and decisional preferences of patients when surgical treatment is being considered.

METHOD

Patients who had undergone surgery for Crohn's anal fistula underwent face-to-face semi-structured interviews. These explored the experience of treatments for fistula, of receiving information and of participation in decision-making. Transcripts were analysed by two investigators through inductive thematic analysis. Saturation was assessed for at 12 interviews and then after each subsequent interview.

RESULTS

Seventeen patients completed interviews, and saturation was achieved. Five themes were identified, of which two (desired information and decision-making) were relevant to this study. Other themes included experience of Crohn's disease, experience of receiving information and procedure-specific comments. Participants wanted to have information on any risks, high-level outcomes (e.g. success), impact on day-to-day life and aftercare. Participants felt they did not always receive the information they needed to select the best treatment option. Participants felt uninvolved in treatment decisions and would have liked to trade off operations to reach their treatment goal.

CONCLUSION

Information provided to patients about surgical treatment of Crohn's perianal fistula does not meet their needs. Clinicians should address aftercare, impact on quality of life and the risks and benefits of the any proposed procedure.

Management of patients with complex perianal fistulas in Crohn's disease: Optimal patient flow in the Italian clinical reality

Perianal fistulizing Crohn's disease (PFCD) is a common, disabling and aggressive phenotype that negatively impacts on the quality of life of affected patients. Its successful treatment is still a struggle for both physicians and patients. Significant advances in the management of this condition have occurred in the last two decades holding promise for a better future. This culminated into the concept of a collaborative multidisciplinary approach using the latest medical therapies combined with modern surgical and endoscopic techniques. Despite this, PFCD management and treatment have not been standardized yet. Thus the gastroenterologist and surgeon have to be familiar with several approaches and/or techniques. The positioning of each therapeutic option will certainly evolve with new data, but for the time being it should be driven by patient's characteristics, physician's preference and/or experience, costs and availability in local practice. Additionally, patient's perception of benefits and risks of treatment may differ from those of physicians and recognition of this difference is a starting point for difficult clinical decision-making. In this paper, a multidisciplinary group of Italian IBD experts explore and discuss current medical and surgical therapeutic options, highlighting areas of unmet needs in PFCD, with particular focus on the optimal patient flow within the Italian clinical reality.

Optimized timing of using infliximab in perianal fistulizing Crohn's disease

Infliximab (IFX), as a drug of first-line therapy, can alter the natural progression of Crohn’s disease (CD), promote mucosal healing and reduce complications, hospitalizations, and the incidence of surgery. Perianal fistulas are responsible for the refractoriness of CD and represent a more aggressive disease. IFX has been demonstrated as the most effective drug for the treatment of perianal fistulizing CD. Unfortunately, a significant proportion of patients only partially respond to IFX, and optimization of the therapeutic strategy may increase clinical remission. There is a significant association between serum drug concentrations and the rates of fistula healing. Higher IFX levels during induction are associated with a complete fistula response in these patients. Given the apparent relapse of perianal fistulizing CD, maintenance therapy with IFX over a longer period seems to be more beneficial. It appears that patients without deep remission are at an increased risk of relapse after stopping anti-tumor necrosis factor agents. Thus, only patients in prolonged clinical remission should be considered for withdrawal of IFX treatment when biomarker and endoscopic remission is demonstrated, especially when the hyperintense signals of fistulas on T2-weighed images have disappeared on magnetic resonance imaging. Fundamentally, the optimal timing of IFX use is highly individualized and should be determined by a multidisciplinary team.

Inflammatory bowel disease position statement of the Italian Society of Colorectal Surgery (SICCR): Crohn's disease

The Italian Society of Colorectal Surgery (SICCR) promoted the project reported here, which consists of a position statement of Italian colorectal surgeons to address the surgical aspects of Crohn's disease management. Members of the society were invited to express their opinions on several items proposed by the writing committee, based on evidence available in the literature. The results are presented, focusing on relevant points. The present paper is not an alternative to available guidelines; rather, it offers a snapshot of the attitudes of SICCR surgeons about the surgical treatment of Crohn's disease. The committee was able to identify some points of major disagreement and suggested strategies to improve quality of available data and acceptance of guidelines.

ECCO Guidelines on Therapeutics in Crohn's Disease: Surgical Treatment

This article is the second in a series of two publications relating to the European Crohn's and Colitis Organisation [ECCO] evidence-based consensus on the management of Crohn's disease. The first article covers medical management; the present article addresses surgical management, including preoperative aspects and drug management before surgery. It also provides technical advice for a variety of common clinical situations. Both articles together represent the evidence-based recommendations of the ECCO for Crohn's disease and an update of previous guidelines.

Predictors of long-term outcomes of radiologically defined perianal fistulizing Crohn's disease treated with antitumor necrosis factor-alpha agents based on Parks' classification

BACKGROUND AND AIMS

Perianal fistulizing Crohn's disease (PFCD) leads to significant disability. Data assessing healing of complex PFCD based on pelvic MRI using Parks' classification remains sparse. We aimed to assess the frequency of closure of fistula tract on MRI in patients treated with antitumor necrosis factor alpha antagonists and identify predictors of poor response.

MATERIALS AND METHODS

We retrospectively identified patients registered in the Saudi Inflammatory Bowel Disease Information System registry, who were diagnosed as PFCD based on MRI and treated with infliximab or adalimumab. Fistulae were classified based on Parks' classification and response to treatment was determined as full, partial, or no response, after at least 12 months of treatment.

RESULTS

Out of 960 patients, 61 had complex PFCD that required treatment with an anti-TNF agent. The median age was 27 years (range: 14-69 years) and the median duration of disease was 6.2 ± 5.8 years. A full response to treatment was achieved in 27 (44.4%), whereas 10 patients (16.3%) had partial response and 24 (39.3%) had no response. On univariable analysis, a statistically significant association was observed between poor fistula response and low BMI, rectal involvement, fistulae classification, and the presence of an abscess. According to multivariable regression, only low BMI predicted poor fistulae outcome (odds ratio = 1.37, 95% confidence interval: 0.69-0.98).

CONCLUSION

Less than half of this cohort of patients with PFCD achieved complete radiological fistula healing with anti-TNF therapy. Low BMI appears to be the only predictor of poor outcome.

Efficacy of Tumour Necrosis Factor-alpha therapy in paediatric Crohn's disease patients with perianal lesions: a systematic review

Introduction: Anti-Tumor Necrosis Factor-alpha (TNF-α) therapy, primarily infliximab and adalimumab, are now increasingly used to induce and maintain disease remission in the pediatric perianal Crohn's disease (CD) population, however, their optimal use has not yet been defined in the pediatric setting.Areas covered: In accordance with a published protocol (PROSPERO no. CRD42019118838), we systematically and critically evaluated all published evidence on the efficacy and safety of anti-TNF-α in children with perianal CD, in the PubMed, MEDLINE, Embase, Cochrane and clinicalTrials.gov databases until October, 18^th, 2018. We included in our systematic review 29 articles yielding a total of 565 perianal CD patients aged between 9 months to 18 years.Expert opinion: According to low-quality evidence from small, uncontrolled and heterogeneous descriptive studies, and very few randomized controlled trial, nearly three-fifths children with perianal CD achieved remission with anti-TNF-α treatment and in approximately 40% remission was maintained after 12 months, with practically low discontinuation rate due to serious adverse events. More than half of the patients achieved complete fistula closure. There is still a need for more robust evidence adequately assessing the efficacy and safety of anti-TNF-α therapy in pediatric perianal CD, as well as in comparison with other therapies.

Radiological outcomes in perianal fistulizing Crohn's disease: A systematic review and meta-analysis

Perianal fistulas are a common and debilitating manifestation of Crohn's disease. Since the advent of biological agents, patient outcomes appear to have improved. While rates of clinical response and remission are well characterized in literature, magnetic resonance imaging (MRI) outcomes remain less so. This is despite previous studies demonstrating the persistence of fistula tracts on MRI, in spite of clinical healing, suggesting radiological markers of improvement may be more accurate. The aims of this study were to systematically review the literature for all studies reporting on MRI outcomes following biological therapy and to compare rates of radiological healing to clinical remission. A search was performed according to the Preferred Reporting Items For Systematic Reviews and Meta‐Analysis (PRISMA) guidelines. Nine articles were included, with a total sample size of 259 patients. Of these 259 patients, 47% achieved clinical remission following induction therapy and 42% following a median of 52 weeks' maintenance therapy. Out of the 259 patients, 7% achieved radiological healing in the short term and 25% in the long term. The odds ratio of MRI versus clinical healing was 0.10 (95% confidence interval [CI], 0.02–0.39) and 0.43 (95% CI, 0.26–0.71), respectively, at those corresponding time points. MRI healing of perianal fistulizing Crohn's, while arguably a more accurate assessment of treatment response, is significantly less common than clinical remission. Heterogeneity exists in the definition of radiological and clinical response, leading to variation in reported rates. Further studies, directly comparing the long‐term outcomes of patients achieving clinical remission and MRI healing are required, to better inform the role of MRI follow up in clinical practice.

Medical and surgical management of pediatric perianal crohn's disease: A systematic review

BACKGROUND

The timely management of pediatric Crohn's disease (CD), and specifically perianal CD, is important owing to the possible adverse effects on growth, development, and quality of life. Perianal involvement is increasingly common, with up to 62% of pediatric CD patients affected. Presently, literature addressing the management of perianal CD has focused primarily on adults, with findings that cannot always be extrapolated to the pediatric population. We aimed to review the rates of healing, recurrence, and need for surgical intervention in perianal CD to provide evidence-based recommendations for the ideal management in children.

METHOD

We conducted a systematic review of CENTRAL, PubMed, Medline, and EMBASE databases (January 1997-December 2017) in accordance with PRISMA. Two independent reviewers performed data extraction.

RESULT

Ten studies met the inclusion criteria with a combined total of 538 patients. Median study population size was 17 (range 7-276), with a median age at intervention of 13.9 years (range 1-18). Seton placement allowed complete healing in 28.6% of children. Similar results (28.5%) were seen in children undergoing fecal diversion. One study demonstrated complete resolution of fistulizing disease in 70% of children treated with infliximab (IFX). One quarter of patients treated with IFX required further surgical intervention for disease control. Recurrence occurred most frequently in children undergoing Seton placement alone (5/14, 35.7%), compared with IFX (46/197, 23.4%) and combination therapy (12/276, 4.3%).

CONCLUSION

In the pediatric population, a combination of medical and surgical treatment is required to control perianal CD, with fewer side effects.

LEVEL OF EVIDENCE

Level II.