Tumor Necrosis Factor Inhibitors May Have Limited Efficacy for Complex Perianal Fistulas Without Luminal Crohn's Disease.

BACKGROUND: Complex perianal fistulas occurring in the absence of luminal inflammation (isolated perianal disease, IPD) may represent a specific phenotype of Crohn's disease (CD). AIM: We assessed the effectiveness of tumor necrosis factor (TNF)-antagonists in patients with IPD compared to those with perianal CD (PCD) with luminal inflammation. METHODS: Patients were identified through our institutional radiology database and were classified as PCD or IPD based on the presence or absence of luminal inflammation by ileocolonoscopy and abdominal enterography. Consecutive adults (> 17 years) with recurrent IPD who were treated with TNF antagonists were matched by age and gender to patients with complex PCD (1:2 ratio). Fistula remission was defined as an absence of fistula drainage. Surgery-free survival was assessed by Cox proportional hazard models. RESULTS: Twenty-two patients with IPD treated with a TNF antagonist were compared with 44 matched patients with PCD. A similar proportion of patients with IPD and PCD were treated with concomitant immunomodulators (55% vs. 66%) and underwent examinations under anesthesia prior to therapy (36% vs. 46%). Fistula remission at 3, 6, and 12 months was lower for the IPD cohort: 9.5% versus 34%; 19% versus 39%; and 19% versus 43%. Surgical intervention after initiating anti-TNF therapy was more common for patients with IPD (HR 3.99: 95% CI, 1.62-9.83; p = 0.0026). CONCLUSIONS: Fewer patients with IPD achieved fistula remission, and more required surgical intervention after anti-TNF therapy, suggesting that TNF antagonists may not be as effective in these patients.

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

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

Video Capsule Endoscopy can Identify Occult Luminal Crohn's Disease in Patients with Isolated Perianal Fistulas.

BACKGROUND: Accurate tools to distinguish Crohn's disease [CD] from cryptoglandular disease in patients with perianal fistulas without detectable luminal inflammation on ileocolonoscopy and abdominal enterography (isolated perianal fistulas [IPF]) are lacking. We assessed the ability of video capsule endoscopy [VCE] to detect luminal inflammation in patients with IPF. METHODS: We studied consecutive adults [>17 years] with IPF who were evaluated by VCE after a negative ileocolonoscopy and abdominal enterography between 2013 and 2022. We defined luminal CD by VCE as diffuse erythema, three or more aphthous ulcers, or a Lewis score greater than 135. We compared rates of intestinal inflammation in this cohort with age- and sex-matched controls without perianal fistulas, who underwent VCE for other indications. We excluded persons with pre-existing inflammatory bowel disease [IBD] and exposure to non-steroidal anti-inflammatory drugs or immunosuppressive treatments. RESULTS: A total of 45 patients with IPF underwent VCE without complications. Twelve patients [26%] met our definition of luminal CD. Luminal CD was more common in patients with IPF than in controls [26% vs 3%; p <0.01]. Among patients with IPF, male sex (OR [odds ratio], 9.2; 95% confidence interval [CI] [1.1-79.4]), smoking (OR, 4.5; 95% CI [0.9-21.2]), abscess (OR, 6.3; 95% CI [1.5-26.8]), rectal enhancement on magnetic resonance imaging [MRI] (OR, 9.0; 95% CI [0.8-99.3]), and positive antimicrobial serology (OR, 7.1; 95% CI, [0.7-70.0]) were more common in those with a positive VCE study. CONCLUSIONS: VCE detected small intestinal inflammation suggestive of luminal CD in approximately one-quarter of patients with IPF. Larger studies are required to validate these findings.

Systematic review with meta-analysis: Safety and efficacy of local injections of mesenchymal stem cells in perianal fistulas.

Perianal fistulas in Crohn's disease (CD) represent a highly debilitating and difficult-to-treat condition. Given emerging supportive evidence, we conducted a systematic review and meta-analysis of all trials/observational studies to establish the safety and efficacy of local injections of mesenchymal stem cells (MSCs). The PRISMA-P statement was applied for planning and reporting, and MEDLINE, EMBASE, Web of Science, Cochrane, CINAHL, ClinicalTrials.gov database, and ECCO 2017 proceedings were searched for published observational studies and one-arm and randomized clinical trials (RCTs). Safety was assessed in terms of acute local/systemic events, long-term events, and relatedness with MSC treatment. Efficacy was evaluated in terms of external and/or radiological closure of fistula tracks. After a review of 211 citations, 23 studies, including 696 participants, were evaluated. Four were RCTs with a total of 483 patients. Overall, fistula closure occurred in 80% of MSC-treated patients. In RCTs, this rate was 64% in the MSC arm and 37% in the control arm (relative risk (RR) = 1.54). Radiological response occurred in 83% of MSC-treated patients. Treatment-related adverse events occurred in 1% of MSC-treated patients, with severe treatment-related adverse events reaching 0% over a median follow-up of 6 months. In RCTs, treatment-related adverse events occurred in 13% in the MSC arm and 24% in the control arm (RR = 0.65). The relapse rate was 0. These results suggest that a local MSC injection is safe and efficacious. Further clinical trials with standardized end-points are required to ensure the timely implementation of this new therapy in the management of perianal CD.

Efficacy of an anal fistula plug for fistulas-in-Ano in children.

BACKGROUND: In children, perianal abscesses have a good prognosis and often heal with age. However, some perianal abscesses are refractory to treatment and remain as fistulas-in-Ano. Treatment with a Surgisis Anal Fistula Plug® has been reported as a new method of treatment for fistulas. In adults, the plug has been reported to cause little pain and have a high cure rate, but there have been no reported cases of its use in children. PURPOSE: This study was designed to analyze the efficacy of the plug for closure of refractory fistulas in children. METHODS: Since the plug has not been approved as a medical device in Japan, application for its use was submitted to the ethics committee of our university, and approval was granted, marking the first use of the plug in Japan. We classified refractory fistulas as those treated for 6months or longer and remaining unhealed, even after 1year of age, despite continued conservative treatment. The plug was used in 11 refractory fistulas in 8 children. RESULTS: Eight of 11 fistulas (72.7%) were successfully treated. Three fistulas recurred, and fistulectomies were performed. No sequelae were observed after AFP treatment. CONCLUSION: The plug was effective even for closure of refractory fistulas without sequelae in children. LEVELS OF EVIDENCE: Treatment Study, Level IV.