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

Predictive modeling to evaluate long-term treatment effectiveness of darvadstrocel in patients with complex perianal fistulas in Crohn's disease

BACKGROUND

Current therapies for complex Crohn's perianal fistulas (CPF) have a limited ability to achieve long-term healing. Darvadstrocel (DVS) is an expanded allogeneic adipose-derived mesenchymal stem cell therapy that has demonstrated efficacy in treating complex CPF in clinical trials. There are, however, limited long-term comparative data with standard of care (SoC). The aim of this study was to combine clinical trial data and real-world evidence using statistical methodologies to predict long-term effectiveness of DVS versus SoC in patients with CPF.

METHODS

Data were pooled from a clinical trial (ADMIRE-CD) and two retrospective chart review studies (INSPECT and PREFACE). Predictive statistical models extrapolated clinical outcomes beyond observed follow-up using parametric curves, which were implemented into a semi-Markov model to obtain the number of patients in remission. The setting was multinational and multicenter. ADMIRE-CD was conducted in 49 hospitals in 7 European countries and Israel. INSPECT used data from the ADMIRE study. PREFACE involved patients from Belgium, France, Germany, Italy, and Spain. The participants were patients with complex CPF treated with DVS or SoC. Times to remission and relapse (clinical, and clinical plus patient-centric remission) were analyzed. Additionally, the proportion of patients in clinical and patient-centric remission was examined.

RESULTS

In total, 513 patients were included in the analysis (ADMIRE-CD [N = 200] and PREFACE [N = 313]). Patients in ADMIRE-CD and PREFACE were similar in age (median [interquartile range, IQR], 36 [20.0] versus 36 [22.0] years, respectively) and gender (males, 54% and 52%, respectively). The median (IQR) duration of Crohn's disease was 9.4 [11.3] years for patients in ADMIRE-CD and 6.5 [12.9] years for patients in PREFACE. The estimated time to remission was shorter for patients treated with DVS versus SoC. The estimated time to relapse was longer for patients treated with DVS versus SoC. A higher estimated proportion of patients treated with DVS versus SoC had clinical and patient-centric remission at 24 months (48% and 35%, respectively) and 48 months (49% and 32%, respectively).

CONCLUSION

This novel approach enabled pooled data from a clinical trial and real-world settings to predict long-term effectiveness of DVS versus SoC in patients with complex CPF.

Management of Perianal Fistulas Associated with Crohn Disease: A Nurse's Perspective

Crohn disease perianal fistulas are associated with considerable morbidity and impaired quality of life. Nurses who specialize in inflammatory bowel disease (IBD) play a vital role in the management of Crohn disease perianal fistulas from diagnosis to long-term care; however, there is little evidence available to inform Crohn associated perianal fistula management strategies for nurses. This narrative review aims to provide IBD nurses with an up-to-date overview of Crohn perianal fistulas. It discusses the vital role IBD nurses play within the multidisciplinary team; the physical, social, and psychological impacts of Crohn perianal fistulas on patients; available treatment options; and how IBD nurses can support patients in their perianal fistula journey to enable optimum outcomes for patients. It also reviews diagnostic techniques and IBD nurses' involvement in Crohn perianal fistula diagnosis. While this article is aimed at IBD nurses, it is relevant to all nurses irrespective of their role (unit, clinic, community, and stoma) who interact with patients with Crohn perianal fistulas because awareness of the signs and symptoms of this condition will enable timely referrals and diagnosis.

Real-World Long-Term Persistence and Surgical Procedure-Free Period Among Bio-naïve Patients with Crohn's Disease and Fistula Initiated on Ustekinumab

INTRODUCTION

Fistula is a common complication of Crohn's disease (CD). Treatment with biologics has been associated with fistula healing. Long-term persistence is an important factor for a chronic inflammatory process such as fistula. This study described 24-month persistence and time-to-surgery endpoints among bio-naïve patients with CD and intestinal fistula who were initiated on ustekinumab.

METHODS

Adults with CD and any enteric or perianal fistula initiated on ustekinumab (index date) between September 23, 2016, and March 2, 2022, were selected from the IQVIA PharMetrics® Plus database and followed up to 24 months. Persistence on ustekinumab (no gaps in days of supply of > 120 days) and composite endpoints of being persistent while on monotherapy and persistent while corticosteroid free were also assessed. The date of surgery was defined as the date of first claim for any CD-related surgeries. Persistence and time-to-surgery endpoints were assessed from the index date until the earliest of discontinuation (event), immunomodulator or other biologic use (event), corticosteroid use (event), date of surgery (event), 24-month follow-up or data end (censoring) using Kaplan-Meier analyses.

RESULTS

The sample included 445 patients (mean age: 42.8 years; 56.6% female). The most common type of fistula was anal fistula (36.0%). At 24 months after ustekinumab initiation, 64.2% of patients remained persistent (95% confidence interval [CI] 55.8-71.4). Furthermore, 53.3% of patients were persistent while on monotherapy (95% CI 45.1-60.7), and 45.6% of patients were persistent while being corticosteroid free (95% CI 36.9-53.8). At 24 months, 22.8% (95% CI 17.0-30.3) of patients underwent any CD-related surgery.

CONCLUSION

This study quantified long-term persistence on ustekinumab among bio-naïve patients with CD and fistula. Over half of patients initiated on ustekinumab were persistent and persistent while on monotherapy 24 months after initiation. Time-to-surgery estimate was comparable to existing evidence. These findings support ustekinumab as a treatment option for long-term management of CD with fistula.

Impact of Seton Use on Clinical, Patient-Reported, and Healthcare Resource Utilization Outcomes in Complex Crohn's Perianal Fistulas: A Systematic Literature Review

BACKGROUND

Optimal treatment strategies for seton use in patients with Crohn's perianal fistulas (CPF) remain elusive. This systematic literature review aimed to summarize clinical, patient-reported, and healthcare resource utilization (HCRU) outcomes associated with seton use for symptomatic relief and treatment of complex CPF.

METHODS

Electronic databases (MEDLINE, Embase, EBM Reviews, EconLit) were searched. Titles, abstracts, and relevant full texts were screened by 2 reviewers for inclusion using prespecified PICOS-T criteria. Articles published in English between January 1, 1980 and September 6, 2021 were included; animal/in vitro studies and case reports with <5 patients were excluded. Outcomes of interest included rates of complete response/remission and fistula recurrence in patients receiving seton with/without infliximab or biologics. Data were summarized using descriptive statistics.

RESULTS

Overall, 56 studies were included (full texts: n = 43; congress abstracts: n = 13). CPF and clinical outcome definitions were heterogeneous. Rates (range) of complete response/remission varied widely (seton: 13%-75%; seton + infliximab: 23%-100%; seton + biologics: 23%-59%) as did rates for fistula recurrence (seton: 4%-68%; seton + infliximab: 0%-50%; seton + biologics: 0%-17%). Rates of fistula-related reintervention, new fistula or abscess formation, and abscess recurrence were also varied; more consistency was observed regarding the use of patient-reported outcomes. Few studies reported outcomes from pediatric/adolescent patients or HCRU.

CONCLUSIONS

Optimal use of seton in patients with CPF remains unclear. International standardization of definitions for CPF and related clinical outcomes are required to permit data comparability and identify the most effective treatment strategies involving seton use in CPF.

The potential for medical therapies to address fistulizing Crohn's disease: a state-of-the-art review

INTRODUCTION

Crohn's disease (CD) is a chronic, relapsing immune mediated disease, which is one of the two major types of inflammatory bowel disease (IBD). Fistulizing CD poses a significant clinical challenge for physicians. Effective management of CD requires a multidisciplinary approach, involving a gastroenterologist and a GI surgeon while tailoring treatment to each patient's unique risk factors, clinical representations, and preferences.

AREAS COVERED

This comprehensive review explores the intricacies of fistulizing CD including its manifestations, types, impact on quality of life, management strategies, and novel therapies under investigation.

EXPERT OPINION

Antibiotics are often used as first-line therapy to treat symptoms. Biologics that selectively target TNF-α, such infliximab (IFX), have shown high efficacy in randomized controlled trials. However, more than 50% of patients lose response to IFX, prompting them to explore alternative strategies. Current options include adalimumab and certolizumab pegol combination therapies, as well as small-molecule drugs targeting Janus kinases such as Upadacitinib. Furthermore, a promising treatment for complex fistulas is mesenchymal stem cells such as Darvadstrocel (Alofisel), an allogeneic stem cell-based therapy. However, surgical interventions are necessary for complex cases or intra-abdominal complications. Setons and LIFT procedures are the most common surgical options.

Long-term outcomes of intestinal penetrating Crohn's disease following successful nonoperative management

There is a paucity of data on the surgical or medical treatment for abscess/fistula complicating Crohn's disease after successful nonsurgical management. We conducted a cohort study to investigate the long-term outcomes and the risk factors for the requirement of subsequent surgical intervention in Crohn's disease patients with complicating fistulas/abscess following successful nonsurgical management. Data were collected on penetrating Crohn's disease experiencing successful nonsurgical treatment between December 2012 and December 2021. Long-term outcomes and risk factors of surgery were assessed by univariate and multivariate analysis, and subgroup analysis was performed based on penetrating phenotype including abscess, fistula, and phlegmon. A total of 523 penetrating Crohn's disease patients; there were 390, 125, and 60 patients complicated with fistulas, abscess, and phlegmon, respectively. Long-term outcomes showed that BMI < 18.5 (kg/m 2 ), the recurrent abscess, and stricture were independent risk factors of surgery. Biologics and resolution of abscess were independent protective factors of surgery. Furthermore, in 399 patients undergoing early surgery, stricture and BMI < 18.5 (kg/m 2 ) were independent risk factors, and biologics and abscess resolution were protective of the early surgery. Subgroup analysis based on fistula, abscess, and phlegmon phenotype also demonstrated that concomitant stricture was an independent risk factor and the use of biologics was protective of surgical resection. Our data indicate that biologics can delay the requirement of surgery and may be given to patients with penetrating complicating Crohn's disease who have been successfully treated nonoperatively, but surgical resection should be considered in the setting of malnutrition and stenosis formation.

Antibiotics for inflammatory bowel disease: Current status

There is abundant literature reporting about the use of antibiotics in inflammatory bowel disease (IBD), but their role in the management of IBD is not entirely clear. Diverse infectious organisms have been implicated in the pathogenesis of Crohn's disease. Also, infections are believed to be a trigger for flares of ulcerative colitis. The benefit of the routine use of antibiotics in IBD is equivocal. However, there are certain situations, where antibiotics have a clear role and evidence of benefit: perianal fistula, intra-abdominal abscesses in Crohn's disease, acute pouchitis and infection-related flares. However, there is a lack of supportive evidence for the routine use of antibiotics in all disease-related flares. Evidence indicates a lack of benefit of intravenous antibiotics in acute severe ulcerative colitis and only limited benefit in active ulcerative colitis. Limited evidence suggests the role of a combination of oral antibiotics in pediatric ulcerative colitis. Certain targeted antibiotic regimens have been used in IBD. In ulcerative colitis, limited evidence suggests the benefit of the use of an antibiotic cocktail directed against Fusobacterium varium. Therapy directed against Escherichia coli does not seem to have a benefit in inflammatory Crohn's disease. In Crohn's disease, antimycobacterial therapy may result in symptomatic improvement but no durable benefit. Antitubercular therapy (ATT), on the contrary, may result in fibrotic transformation, suggesting a need to avoid misdiagnosis and limit the duration of ATT in Crohn's disease. This review assesses the published literature with respect to antibiotic use and provides guidance to clinicians in appropriate antibiotic use in various situations in the setting of IBD.

Understanding the role of the primary care physician in the management of patients with Crohn's perianal fistulas

OBJECTIVES

To understand the role of primary care physicians (PCPs) in the recognition, diagnosis, and management of Crohn's perianal fistulas (CPF) and their referral patterns and treatment expectations.

METHODS

This survey-based study was conducted between September 2020 and October 2020. US-based PCPs managing at least one patient with Crohn's disease per week were included. Participants were presented with two case vignettes relevant to primary care practice; Case Vignette 1 comprised three parts and focused on initial CPF presentation and progression to partial response; Case Vignette 2 focused on recurrent CPF. Survey questions elicited the physician's clinical approach to each case. Data were presented as descriptive statistics.

RESULTS

Overall, 151 PCPs (median 23 years in practice) who saw about three patients per month with new/existing CPF responded. For Case Vignette 1, upon identification of a fistulous tract, 89% of respondents would refer the patient, mostly to a colorectal surgeon or gastroenterologist. Most PCPs (69%) would begin the patient on medication; 46% would conduct a diagnostic/imaging study. Treatment expectations after referral varied: 55% of respondents believed surgeons would place a seton or use one prior to surgery; 23% expected medical management only; 23% were unsure. Case Vignette 2 revealed that 98% of PCPs preferred to be involved in patient care after referral; however, only 49% were. Of these, 76% considered reinforcing patient treatment adherence as their primary role. While 80% of PCPs were at least moderately satisfied with communication and care coordination with multidisciplinary teams, 52% considered lack of access to specialists as at least a moderate barrier to multidisciplinary team management.

CONCLUSION

PCPs want more involvement in multidisciplinary management of patients with CPF. Continuing education providing PCPs with up-to-date information on diagnostic modalities, treatment options, early diagnosis, the role of PCPs within a multidisciplinary team, and effective initial CPF care is required.

Evaluation of the Cutting Seton Technique in Treating High Anal Fistula

Objectives Fistula-in-ano is a common condition that negatively affects the quality of life of its sufferers. A high anal fistula poses a significant challenge for surgeons due to its proximity to the anorectal ring and the potential risk of incontinence rather than recurrence. Many modalities have been used in a justified search for a satisfactory cure for the condition, but the seton remains a mainstay of surgical treatment. Therefore, the rationale of this study is to assess the outcome of treating a high anal fistula using the cutting seton technique in a hospital in Al Madinah, Saudi Arabia. The evaluation is intended through a retrospective analysis of patients' outcomes, comparing its effectiveness to similar articles. Methods This is a retrospective study that includes 50 patients with high anal fistulas who were treated with a cutting seton at the National Guard Hospital over a four-year period (2019-2022). Information obtained from medical records included clinical and demographic data. The data collected during the study was compiled and statistically analyzed using the SPSS Statistics version 26.0 (IBM Corp. Released 2019. IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY: IBM Corp.). A p-value of <0.05 was considered statistically significant. Results A total of 50 patients with high anal fistula treated with a cutting seton were included: 82% were males and 18% were females, with 66% below 45 years of age. Approximately 92% had inter-sphincteric fistulas, and only 28% had a recurrent fistula. Almost all patients (98%) had an MRI done before surgery. Around 70% of patients were completely cured, 26% had minor complications, 8% of the operated patients experienced mild incontinence, and only one recurrence (2%). Conclusion The cutting seton is still a valid modality in treating patients with a high anal fistula, as it is considerably safe, effective, and yields good outcomes. Standard preoperative assessment and thorough surgical techniques are cornerstones for achieving a satisfactory outcome.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

A complex presentation and successful management of fistulizing perianal Crohn's disease extending to the mid-back

Fistulizing perianal disease is a debilitating complication present in nearly half of all patients diagnosed with Crohn's disease. The majority of anal fistulas arising in these patients are complex. Treatment can be challenging with therapy often requiring both medical and surgical interventions with differing levels of symptomatic relief. Fecal diversion is an option after medical and surgical modalities have been exhausted but demonstrates limited efficacy. Complex perianal fistulizing Crohn's disease is inherently morbid and can be difficult to manage. We present a case of a young male with Crohn's, severe malnutrition and multiple perianal abscess with extensive fistula tracts up to his back; a planned fecal diversion was instituted to control sepsis and allow for wound healing and optimize medical therapy.

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

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