Crohn's fistula: current concepts in management

Insufficiency of ileocolic anastomosis in Crohn’s disease patients – prevention and treatment

Resection of the terminal ileum and ileocecal valve remains the most commonly performed procedure in patients with Crohn's disease. However, despite radical treatment, there is a risk of disease recurrence at the site of the intestinal anastomosis in some cases. Therefore, long-term postoperative management is crucial and requires systematic clinical assessment, endoscopic surveillance, and pharmacological support when indicated. A key challenge is identifying the risk factors associated with the recurrence of anastomotic failure and defining the principles of follow-up care to prevent secondary intestinal insufficiency. This paper focuses on both surgical and non-surgical factors that may play a role in preventing complications in patients undergoing ileocecal resection, providing a comprehensive approach to postoperative management.

Diagnostic Process and Applied Criteria for Crohn's Disease in Patients Presenting with Perianal Lesions in Japan: A Retrospective Observational Multicenter Cohort Study

Introduction

In Japan, the confirmed diagnosis of Crohn's disease (CD) is based on a single, historically established set of clinical criteria. However, for patients who present with a perianal lesion (PL), the diagnostic pattern actually applied is unclear.

Methods

We conducted a retrospective observational multicenter study among patients who presented with a PL without synchronous abdominal symptoms and were subsequently diagnosed with confirmed or probable CD according to the Japanese diagnostic criteria from May 1996 to April 2024. In total, 100 patients with confirmed CD and 10 with probable CD were identified and enrolled.

Results

Among the 100 patients with confirmed CD, 72% met the criterion for the category "confirmed 1: main finding A (longitudinal ulcer) or B (cobblestone appearance)." In the same cohort, 35% met the criterion for the category "confirmed 2: main finding C (non-caseating epithelioid cell granuloma [NCEG]) with secondary finding a (extensive irregular-to-round ulcers or aphthae in the gastrointestinal tract) or b (characteristic anorectal lesions)," including 24% without the main finding A or B. Finally, 4% met the criterion for the category "confirmed 3: all secondary findings a, b, and c (characteristic gastric and duodenal lesions)." All 10 patients with probable CD were diagnosed based on secondary finding b only or secondary findings a and b.

Conclusion

In cases of suspected CD due to initial PLs, histological investigation of NCEG and precise total gastrointestinal inspection should be conducted to confirm the diagnosis.

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.

Antimicrobial PVA Hydrogels with Tunable Mechanical Properties and Antimicrobial Release Profiles

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

Shape memory polymer hydrogels with cell-responsive degradation mechanisms for Crohn's fistula closure

Crohn's disease, a form of inflammatory bowel disease, commonly results in fistulas, tunneling wounds between portions of the urinary, reproductive, and/or digestive systems. These tunneling wounds cause pain, infection, and abscess formation. Of Crohn's patients with fistula formation, 83% undergo surgical intervention to either drain or bypass the fistula openings, and ~23% of these patients ultimately require bowel resections. Current treatment options, such as setons, fibrin glues, and bioprosthetic plugs, are prone to infection, dislodging, and/or require a secondary removal surgery. Thus, there is a need for fistula filling material that can be easily and stably implanted and then degraded during fistula healing to eliminate the need for removal. Here, the development of a shape memory polymer hydrogel foam containing polyvinyl alcohol (PVA) and cornstarch (CS) with a disulfide polyurethane crosslinker is presented. These materials undergo controlled degradation by amylase, which is present in the digestive tract, and by reducing thiol species such as glutathione/dithiothreitol. Increasing CS content and using lower molecular weight PVA can be used to increase the degradation rate of the materials while maintaining shape memory properties that could be utilized for easy implantation. This material platform is based on low-cost and easily accessible components and provides a biomaterial scaffold with cell-responsive degradation mechanisms for future potential use in Crohn's fistula treatment.

Reduced Systemic Corticosteroid Use among Pediatric Patients With Inflammatory Bowel Disease in a Large Learning Health System

OBJECTIVES

Corticosteroids have long been used to treat inflammatory bowel disease. However, cumulative corticosteroid exposure is associated with adverse effects, particularly in growing children. Professional guidelines recommend steroid-sparing strategies. It remains unknown whether corticosteroid use has decreased in children with inflammatory bowel disease.

METHODS

We performed retrospective cohort study using data from 2007 to 2018 from the international multi-center ImproveCareNow Network, a pediatric inflammatory bowel disease quality improvement collaborative. Pediatric patients diagnosed with inflammatory bowel disease were included. Patients with missing diagnosis or corticosteroid use data were excluded. We performed serial cross-sectional analyses of period prevalence and used multivariate regression models.

RESULTS

27,321 patients were included (65% Crohn disease, 28% ulcerative colitis, 7% indeterminate colitis). Corticosteroids were used in 10,206 (37%). Corticosteroid use decreased from 28% (2007) to 12% (2018). Black patients received corticosteroids more commonly than white patients. This disparity improved as corticosteroid use decreased in both groups. Most corticosteroid use occurred <120 days after diagnosis. Corticosteroid or 5-aminosalicylate use <120 days after diagnosis predicted later corticosteroid use. Anti-tumor necrosis factor-alpha medication use <120 days after diagnosis was associated with a reduction in corticosteroid use. As corticosteroid use decreased, steroid-sparing therapy use increased and height and weight z scores improved, particularly among children with Crohn disease. Despite improvement across the network, variation in corticosteroid usage remains.

CONCLUSIONS

Corticosteroid use among pediatric patients with inflammatory bowel disease in the ImproveCareNow Network has decreased over time. Racial disparities in corticosteroid use were found, but gradually improved.

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 .

Clinical, microbiological, immunological and imaging characteristics of tunnels and fistulas in hidradenitis suppurativa and Crohn's disease

Hidradenitis suppurativa (HS) tunnels and Crohn's disease (CD) fistulas are a challenge to treat. Although pathogenic similarities have been described between HS and CD, recent studies indicate that clinical, microbiological, immunological and imaging characteristics differ between these diseases. This review highlights the differences between HS tunnels and CD fistulas. Next-generation sequencing studies demonstrate a microbiome in HS tunnels dominated by Porphyromonas spp., Prevotella spp. whereas no specific bacteria have been associated with cutaneous CD. Immunologically, TNF has been found upregulated in HS tunnels along with various interleukins (IL-8, IL-16, IL-1α and IL-1β). In CD fistulas, Th1, Th17, IL-17, IFN-ɤ, TNF and IL-23 are increased. US imaging is an important tool in HS. US of HS tunnels depict hypoechoic band-like structure across skin layers in the dermis and/or hypodermis connected to the base of a widened hair follicle. In CD, MR imaging of simple perianal fistulas illustrates a linear, non-branching inflammatory tract relating to an internal opening in the anus or low rectum and an external opening to the skin surface. An increased awareness of the immediate potential differences between HS tunnels and CD fistulas may optimize treatment regimens of these intractable skin manifestations.

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 Mesenchymal Stromal Cells for Fistula Treatment of Crohn's Disease: A Systematic Review and Meta-Analysis

BACKGROUND AND AIM

The introduction of mesenchymal stromal cells (MSCs) has changed the management of Crohn's fistula, while it remains controversial. The aim of this study was to provide an overview of efficacy and optimum state of MSCs treatment on Crohn's fistula.

METHODS

Studies reporting MSCs treatment on Crohn's fistula were searched and included. A fixed-effects model was used to assess the efficacy of MSCs, and outcomes of healing and recurrence were used to evaluate the best states of MSCs intervention.

RESULTS

Fourteen articles were enrolled (n = 477). Pooled analysis showed MSCs had a significant efficacy compared to other treatments [risk difference: 0.21 (0.09, 0.32), P = 0.000]. Notably, after MSCs treatment, the group of Crohn's disease activity index (CDAI) baseline >150 group had a higher healing rate (HR) and a clinical response (a change in CDAI of >50 points) (79.17 ± 8.78 vs. 47.54 ± 15.90, P = 0.011) compared to CDAI baseline of <150. The duration time of CD and fistulas had a negative correlation with HR accompanied by MSC therapy (r = -0.900, -0.925). Then, a moderate dose MSCs (2-4 × 10⁷ cells/ml) had a higher HR (80.07%) and lower recurrence rate (RR 13.98%) compared to other dosages. Moreover, adipose-derived MSCs therapy had an advantage over bone marrow-derived MSCs in terms of low RR (7.4 ± 4.28 vs. 13.39 ± 0.89).

CONCLUSIONS

The evidence supported the effect of MSCs at a more appropriate time of Crohn's fistula. And CDAI baseline (the points >150) has been a candidate for evaluating effectiveness of MSCs application on Crohn's fistula.

A Systematic Review Assessing Medical Treatment for Rectovaginal and Enterovesical Fistulae in Crohn's Disease

BACKGROUND

Rectovaginal and enterovesical fistulae are difficult to treat in patients with Crohn's disease. Currently, there is no consensus regarding their appropriate management.

AIM OF THE STUDY

The aim of the study was to review the literature on the medical management of rectovaginal and enterovesical fistulae in Crohn's disease and to assess their response to treatment.

METHOD

A literature search of MEDLINE, EMBASE, Science Citation Index Expanded, and Cochrane was performed.

RESULTS

Twenty-three studies were identified, reporting on 137 rectovaginal and 44 enterovesical fistulae. The overall response rates of rectovaginal fistulae to medical therapy were: 38.3% complete response (fistula closure), 22.3% partial response, and 39.4% no response. For enterovesical fistulae the response rates to medical therapy were: 65.9% complete response, 20.5% partial response, and 13.6% no response. Specifically, response to anti-tumor necrosis factor therapy of 78 rectovaginal fistulae was: 41.0% complete response, 21.8% partial response, and 37.2% no response. Response of 14 enterovesical fistulae to anti-tumor necrosis factor therapy was: 57.1% complete response, 35.7% partial response, and 7.1% no response. The response to a combination of medical and surgical therapy in 43 rectovaginal fistulae was: 44.2% complete response, 20.9% partial response, and 34.9% no response.

CONCLUSIONS

Medical therapy, alone or in combination with surgery, appears to benefit some patients with rectovaginal or enterovesical fistula. However, given the small size and low quality of the published studies, it is still difficult to draw conclusions regarding treatment. Larger, better quality studies are required to assess response to medical treatment and evaluate indications for surgery.

Mucosally transplanted mesenchymal stem cells stimulate intestinal healing by promoting angiogenesis

Mesenchymal stem cell (MSC) therapy is an emerging field of regenerative medicine; however, it is often unclear how these cells mediate repair. Here, we investigated the use of MSCs in the treatment of intestinal disease and modeled abnormal repair by creating focal wounds in the colonic mucosa of prostaglandin-deficient mice. These wounds developed into ulcers that infiltrated the outer intestinal wall. We determined that penetrating ulcer formation in this model resulted from increased hypoxia and smooth muscle wall necrosis. Prostaglandin I₂ (PGI₂) stimulated VEGF-dependent angiogenesis to prevent penetrating ulcers. Treatment of mucosally injured WT mice with a VEGFR inhibitor resulted in the development of penetrating ulcers, further demonstrating that VEGF is critical for mucosal repair. We next used this model to address the role of transplanted colonic MSCs (cMSCs) in intestinal repair. Compared with intravenously injected cMSCs, mucosally injected cMSCs more effectively prevented the development of penetrating ulcers, as they were more efficiently recruited to colonic wounds. Importantly, mucosally injected cMSCs stimulated angiogenesis in a VEGF-dependent manner. Together, our results reveal that penetrating ulcer formation results from a reduction of local angiogenesis and targeted injection of MSCs can optimize transplantation therapy. Moreover, local MSC injection has potential for treating diseases with features of abnormal angiogenesis and repair.

Long-term results of adipose-derived stem cell therapy for the treatment of Crohn's fistula

A previous phase II clinical trial of adipose-derived stem cell (ASC) therapy for fistulae associated with Crohn's disease, a devastating condition with a high recurrence rate, demonstrated safety and therapeutic potential with a 1-year sustained response. In the present study, 41 of the 43 phase II trial patients were followed for an additional year, regardless of response in the initial year. At 24 months, complete healing was observed in 21 of 26 patients (80.8%) in modified per protocol analysis and 27 of 36 patients (75.0%) in modified intention-to-treat analysis. No adverse events related to ASC administration were observed. Furthermore, complete closure after initial treatment was well-sustained. These results strongly suggest that autologous ASCs may be a novel treatment option for Crohn's fistulae.

Anorectal fistula is an early manifestation of Crohn's disease that occurs before bowel lesions advance: a study of 11 cases

The diagnostic significance of single-balloon enteroscopy (SBE) in patients presenting with Crohn's disease (CD)-like anorectal fistula is unknown. We experienced 11 cases undergoing SBE due to CD-like fistulas between December 2007 and April 2013. The mean interval from fistula onset to SBE was 19.2 months with a range of 1.3-44.7. Prior to SBE, all patients underwent anorectal examination under anesthesia (EUA), and 9 patients underwent total colonoscopy with terminal ileal cannulation (TCS-I). One of 7 patients undergoing upper gastrointestinal endoscopy had CD-like gastritis. EUA revealed CD fissures in 7 patients, 1 of whom had no intestinal lesion. Primary TCS-I identified early lesions, such as aphthes and small ulcers, in 4 patients. Among the other 5 patients without any intestinal lesions with TCS-I, SBE indicated early lesions in 3 patients. One of 2 patients who initially underwent SBE without TCS-I showed multiple aphthes. Of the 11 patients, only 4 patients fulfilled the definitive Japanese diagnostic criteria for CD and 7 remained 'suspected CD' cases. Intrinsic anorectal fistulas as a presenting symptom of CD may be an early predictor of bowel lesions. SBE has the potential to reveal incipient disease because an early ileal lesion is not rare for patients with anorectal fistulas.

Pentadecapeptide BPC 157 and the esophagocutaneous fistula healing therapy

Esophagocutaneous fistulas are a failure of the NO-system, due to NO-synthase blockage by the NOS-blocker L-NAME consequently counteracted by l-arginine and gastric pentadecapeptide BPC 157 (l-arginine Collapse

Key Words Collapse

MESH Headings

• Animals
• Arginine/pharmacology
• Cutaneous Fistula/drug therapy
• Cutaneous Fistula/physiopathology
• Drug Interactions
• Esophageal Diseases/drug therapy
• Esophageal Diseases/physiopathology
• Male
• NG-Nitroarginine Methyl Ester/pharmacology
• Peptide Fragments/pharmacology
• Peptide Fragments/therapeutic use
• Proteins/pharmacology
• Proteins/therapeutic use
• Rats
• Rats, Wistar
• Wound Healing/drug effects

Collapse

Grants Collapse

Affiliation(s)

Vedran Cesarec Department of Pharmacology, University of Zagreb, Zagreb, Croatia
Tomislav Becejac
Marija Misic
Zeljko Djakovic
Danijela Olujic
Domagoj Drmic
Luka Brcic
Dinko Stancic Rokotov
Sven Seiwerth
Predrag Sikiric

Collapse

Collaborators Collapse

Long-term efficacy of infliximab maintenance therapy for perianal Crohn’s disease

AIM: To assess the long-term efficacy of seton drainage with infliximab maintenance therapy in treatment of stricture for perianal Crohn’s disease (CD).

METHODS: Sixty-two patients with perianal CD who required surgical treatment with or without infliximab between September 2000 and April 2010 were identified from our clinic’s database. The activities of the perianal lesions were evaluated using the modified perianal CD activity index (mPDAI) score. The primary endpoint was a clinical response at 12-15 wk after surgery as a short-term efficacy. Secondary endpoints were recurrence as reflected in the mPDAI score, defined as increased points in every major element. The clinical responses were classified as completely healed (mPDAI = 0), partially improved (mPDAI score decreased more than 4 points), and failure or recurrence (mPDAI score increased or decreased less than 3 points).

RESULTS: There were 43 males and 19 females, of whom 26 were consecutively treated with infliximab after surgery as maintenance therapy. Complete healing was not seen. Failure was seen in 10/36 (27.8%) patients without infliximab and 4/26 (15.4%) patients with infliximab (P = 0.25). Partial improvement was seen in 26/36 (72.2%) patients without infliximab and 22/26 (88.5%) patients with infliximab (P = 0.25). Short-term improvement was achieved in 48/62 (77.4%) patients. Although the mPDAI score improved significantly with surgery regardless of infliximab, it decreased more from baseline in patients with infliximab (50.0%) than in those without infliximab (28.6%), (P = 0.003). In the long-term, recurrence rates were low regardless of infliximab in patients without anorectal stricture. In patients with anorectal stricture, cumulative recurrence incidences increased gradually and exceeded 40% at 5 years regardless of infliximab. No efficacy of infliximab treatment was found (P = 0.97). Although the cumulative rate of ostomy creation was also low in patients without stricture and high in patients with stricture, no protective efficacy was found with infliximab treatment (P = 0.6 without stricture, P = 0.22 with stricture).

CONCLUSION: Infliximab treatment was demonstrated to have short-term efficacy for perianal lesions. Long-term benefit with infliximab was not proven, at least in patients with anorectal stricture.

Ultrasound and inflammatory bowel disease

Transabdominal bowel sonography is a fast, efficient, and cheap way of examining the intestines. It is also virtually hazard-free and well accepted by patients. During the last 20 years, it has been established as a procedure for detecting bowel disease early in the diagnostic workup. Although rather unspecific, the method is sensitive for detection of bowel disease and can be applied to find the extent and location of inflammatory bowel disease. In patients with known ulcerative colitis and Crohn disease, it can also be used for follow-up because it is easily repeatable and radiation-free. Because it can be applied to find both intraluminal and peri-intestinal pathological features, it is a particularly valuable tool for the detection of complications of Crohn disease as stenosis, fistulas, and abscesses. Neither B-mode nor Doppler techniques have been proven obviously useful in categorizing disease activity, but new techniques using intravenous contrast might come closer to solving this question. Finally, recent longitudinal studies using transabdominal bowel sonography show that it can also give important prognostic information and be used for monitoring the effect of therapy.

Placebo therapy in Crohn's disease

The knowledge of the outcome among patients receiving placebo is important for evaluating the response to therapy, for evaluating the natural history of a disease and for calculating the sample size for future clinical trials. In Crohn's disease placebo has been used in therapeutic trials in every relevant setting: active disease, prevention of relapse after induced medical remission and after surgery and fistulising disease. The analysis of the placebo response shows that in every setting there is a high heterogeneity demonstrating mainly that the selection of patients is not often homogeneous and that the outcome criteria used in the trials is not highly reliable. Better selection of patients and more precise definition of outcome measures are warranted to reduce the heterogeneity among placebo response in clinical trials.

Simultaneous occurrence of hyperthyroidism and fistulizing Crohn's disease complicated with intra-abdominal fistulas and abscess: a case report and review of the literature

Introduction

Fistula formation in patients with Crohn’s disease is a common complication during the course of the disease. Perianal and enteroenteric are the most common forms of fistulas, whereas the involvement of the upper gastrointestinal tract with gastrocolic and duodenocolic fistulas represents an extremely unusual condition. Moreover, hyperthyroidism in association with Crohn’s disease has been rarely described.

Case presentation

We present here a rare case of a 25-year-old male with simultaneous onset of hyperthyroidism and fistulizing Crohn’s disease. Crohn’s disease was complicated with intra-abdominal fistulas involving the upper gastrointestinal tract (duodenocolic, gastrocolic) and an intra-peritoneal abscess formation in the lesser sac. We describe the clinical presentation and therapeutic management of the patient including both medical treatment and surgical intervention. Despite intense medical treatment with total parenteral nutrition, antibiotics, aminosalicylates and corticosteroids the clinical course of the disease was suboptimal. Finally, the patient underwent laparotomy and right hemi-colectomy with ileo-transverse anastomosis performed, with simultaneous drainage of the abdominal abscess and primary closure of the upper gastrointestinal tract openings (gastric, duodenal and jejunal) at one stage operation. Although the surgical approach definitively cured the perforating complications of the disease (fistulas and abscess), the luminal disease in the colon remnant was still active and steroid-refractory. The subsequent successful treatment with infliximab, azathioprine and mesalazine resulted in the induction and maintenance of the disease remission. Thyrotoxicosis was successfully treated with methimazole and the hyperthyroidism has definitely subsided.

Conclusion

The management of intra-abdominal fistulas in Crohn’s disease is a complex issue, requiring a multi-disciplinary approach and ‘tailoring’ of the treatment to the individual patient’s needs. Probably, a sensible approach involves early surgical intervention with prior optimization of the patient’s general condition when feasible. Common autoimmune mechanisms are probably involved in thyroid dysfunction associated with Crohn’s disease. Moreover, diagnosis and treatment of coexisting thyroid disorder in patients with Crohn’s disease has a favorable impact in disease prognosis.

Long-term success rate after surgical treatment of anorectal and rectovaginal fistulas in Crohn's disease

BACKGROUND

Due to the considerable variety in the clinical presentation of anorectal and rectovaginal fistulas in Crohn's disease, data on treatment results for each type of fistula are limited. The aim of this study was to summarize the results after surgical treatment of such fistulas in a large consecutive series of patients.

PATIENTS AND METHODS

All patients with anorectal or rectovaginal fistula due to Crohn's disease requiring surgery in our institution between 1991 and 2001 were extracted from a prospective database. A standardized telephone interview was conducted and patients were followed in our outpatient clinic, the department of internal medicine, or at their gastroenterologist. Type of fistula and interventions were classified and analyzed. Recurrence-free time intervals were estimated for each type of fistula and for the different surgical procedures. The influence of the surgical procedure, the number of operations performed, and the correlation to other localizations of the disease were analyzed in regard to the recurrence rate.

RESULTS

From 777 patients with Crohn's disease undergoing surgery between 1991 and 2001, 147 had anorectal or rectovaginal fistula (292 operations). Ninety-eight percent of them also had Crohn's disease in the colon or rectum compared to only 21% of patients without a fistula (p value <0.001). Over long-term follow-up, 29 patients (20%) required proctectomy. Submucosal fistulas needed major surgery in only 14% of cases compared to 56% of cases with rectovaginal fistulas. After 5 years, complex fistulas showed a strong trend towards a higher recurrence rate after surgery than simple submucosal fistulas (45.6% vs. 18.8%, p = 0.079). Whereas recurrences occurred over the whole observation period in the group of patients with complex fistulas, there was no further recurrence in patients with submucosal fistulas 13 months after surgery. In rectovaginal fistulas, additional levatorplasty showed no advantage over standard endorectal advancement flap.

CONCLUSIONS

Long-term follow-up demonstrates that recurrence rates after repair of complex fistulas for Crohn's disease are high and continuously increase over time. Submucosal fistulas have the best outcome; after 13 months without recurrence, definite cure can be expected.

Clinical course of Crohn's disease first diagnosed at surgery for acute abdomen

BACKGROUND

The severity of clinical activity of Crohn's disease is high during the first year after diagnosis and decreases thereafter. Approximately 50% of patients require steroids and immunosuppressants and 75% need surgery during their lifetime. The clinical course of patients with Crohn's disease first diagnosed at surgery has never been investigated.

AIM

To assess the clinical course of Crohn's disease first diagnosed at surgery for acute abdomen and to evaluate the need for medical and surgical treatment in this subset of patients.

PATIENTS AND METHODS

Hospital clinical records of 490 consecutive Crohn's disease patients were reviewed. Patients were classified according to the Vienna criteria. Sex, extraintestinal manifestations, family history of inflammatory bowel diseases, appendectomy, smoking habit and medical/surgical treatments performed during the follow-up period were assessed.

STATISTICAL ANALYSIS

Kaplan-Meier survival method and Cox proportional hazards regression model.

RESULTS

Of the 490 Crohn's disease patients, 115 had diagnosis of Crohn's disease at surgery for acute abdomen (Group A) and 375 by conventional clinical, radiological, endoscopic and histologic criteria (Group B). Patients in Group A showed a low risk of further surgery (Log Rank test p<0.001) and a longer time interval between diagnosis and first operation compared to Group B (10.8 years vs. 5.8 years, p<0.01, respectively). Furthermore, patients in Group A used less steroids and immunosuppressants (OR 0.3, p<0.0001; OR 0.6, p<0.004, respectively).

CONCLUSIONS

Crohn's disease patients first diagnosed at surgery for acute abdomen showed a low risk for reintervention and less use of steroids and immunosuppressants during follow-up than those not operated upon at diagnosis. Early surgery may represent a valid approach in the initial management of patients with Crohn's disease, at least in the subset of patients with ileal and complicated disease.

The effect of medical treatment on patients with fistulizing Crohn's disease: a retrospective study

BACKGROUND

Fistulas are a major complication of Crohn's disease (CD), but the treatment strategy for fistulizing Crohn's disease is controversial. The aim of this study is to analyze the efficacy of medical therapy for fistulizing Crohn's disease.

METHODS

Therapeutic regimens and clinical outcome of medical therapy were evaluated in 10 patients with fistulizing Crohn's disease (6 with external fistulas, 4 with internal fistulas). Complete response was defined as fistula closure with complete arrest of drainage in cases of external fistula, and disappearance of the fistula demonstrated by imaging studies in cases of internal fistula. Clinical remission was defined as a Crohn's disease activity index of less than 150 points.

RESULTS

Complete responses were observed in all 6 patients with external fistulas (4 patients treated with a combination of antibiotics and immunomodulators, and 2 also treated with infliximab). In contrast, fistula closure was observed in only 1 of 4 patients with internal fistulas. Clinical remission of CD was achieved in all patients with external fistulas, whereas there was no significant difference in the CD activity index before and after medical therapy in patients with internal fistulas.

CONCLUSIONS

External fistulas were more responsive to medical therapy than internal fistulas in patients with CD. Combined treatment with antibiotics and immunomodulators might be a suitable initial therapy for CD patients with external fistulas, and infliximab can be used as an additional therapy in cases refractory to this combination therapy. However, randomized controlled studies will be required to investigate what kinds of therapies are optimal for CD patients with fistulas.

Imaging of perianal Crohn's disease

Perianal fistulas and abscesses are common complications of Crohn's disease, affecting up to 50% of patients during their disease course. Accurate diagnosis and classification of perianal disease is crucial before and during treatment to plan an adequate approach for each patient and to avoid irreversible functional consequences. Although examination under anaesthesia has been considered the gold standard for diagnosis and classification of Crohn's disease perianal fistulas, taken alone it does not have perfect accuracy, stressing the need for concomitant or alternative, non-invasive, methods of evaluation. In this context, imaging modalities assessed for diagnosis, classification and monitoring of Crohn's disease perianal fistulas include pelvic magnetic resonance imaging, anorectal endoscopic ultrasonography, transcutaneous perianal ultrasound, fistulography and computed tomography. In particular, magnetic resonance imaging and endoscopic ultrasonography findings have shown the best accuracy, and the ability to influence therapeutic management of these patients. For transcutaneous perianal ultrasound too, good preliminary data have been reported. This paper reviews the available data on imaging methods for the management of perianal Crohn's disease.

The immune response in inflammatory bowel disease

Ulcerative colitis (UC) and Crohn's disease (CD), collectively referred to as inflammatory bowel disease (IBD), present with differing histologic and cytokine profiles. While the precise mechanisms underlying the development of IBD are not known, sufficient data have been collected to suggest that it results from a complex interplay of genetic, environmental, and immunologic factors. Animal models of colitis, along with a more detailed understanding of the immune response in the normal bowel, have led to unifying hypotheses regarding the pathogenesis. An inappropriate mucosal immune response to normal intestinal constituents is a key feature, leading to an imbalance in local pro- and anti-inflammatory cytokines. Neutrophil and monocyte influx occurs with subsequent secretion of oxygen radicals and enzymes, leading to tissue damage. Therapy of IBD has improved and expanded as the understanding of disease mechanisms has evolved. Pharmacologic agents such as aminosalicylates, azathioprine/6-mercaptopurine, or steroids are the mainstays of therapy. Newer agents including monoclonal antibodies targeted to specific proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha), have emerged and provide great clinical benefit, but unknown long-term toxicity and immunogenicity may limit their use.

The role of anti-tumor necrosis factor-alpha therapy in Pyoderma gangrenosum associated with inflammatory bowel disease

Pyoderma gangrenosum (PG) is an ulcerative neutrophilic dermatosis seen in 1-5% of patients with inflammatory bowel disease (IBD). The pathogenesis of PG remains unclear, but may be related to abnormal T-cell responses and production of tumor necrosis factor (TNF)-alpha, a powerful proinflammatory cytokine. Although their use is not supported by appropriately controlled trials, corticosteroids and systemic immunosuppressants are the classical cornerstones of treatment of PG, against which they have a nonspecific effect. Successful curative or symptomatic treatment of associated disorders may lead to an improvement in PG. A new era for the management of chronic inflammatory disease began with the advent of biotherapies and particularly anti-TNFalpha therapy, which allows for a specific intervention in the immune cascade. Anti-TNFalpha therapy has improved and broadened the therapeutic options for IBD and, therefore, has brought new perspectives to management of the extra-intestinal manifestations of this disorder, including PG. To date, infliximab, etanercept, and adalimumab have been used in the treatment of PG. Published data have demonstrated that infliximab is highly effective in the treatment of PG, whether associated with IBD or not. This treatment is generally well tolerated, even as long-term therapy. However, rare and serious complications have been reported. Although infliximab is a costly drug, its use should be considered for patients with PG and particularly with corticosteroid-refractory PG associated with IBD. Additional comparative long-term studies are needed to determine the long-term efficacy and safety of anti-TNFalpha therapy and define its role in the management of PG, with or without accompanying IBD.

Infliximab in fistulizing Crohn's disease

The treatment of fistulizing CD has evolved greatly in the last 15 years, largely caused by improvements in medical therapy. Tables 2 and 3 summarize all published controlled and uncontrolled trials of immunomodulator and biologic therapy for the treatment of Crohn's fistulae. The advent of immunomodulators and anti-TNF-alpha agents has transformed the treatment of Crohn's fistulae from almost exclusively surgical to placing a much larger emphasis on medical therapy, either as initial therapy alone, with surgery reserved for refractory cases, or in combination with surgery from the start. For this reason, surgeons and gastroenterologists must work in concert to provide the best care for each patient. Proper fistula management also relies heavily on accurate diagnosis, especially defining the anatomy of the fistula, ascertaining whether abscess formation is present, and determining the location and extent of intestinal inflammation.

Conventional therapy for Crohn’s disease

Crohn’s disease (CD) is a multifactorial disorder of unknown cause. Outstanding progress regarding the pathophysiology of CD has led to the development of innovative therapeutic concepts. Numerous controlled trials have been performed in CD over the last years. However, many drugs have not been approved by regulatory authorities due to lack of efficacy or severe side effects. Therefore, well-known drugs, including 5-ASA, systemic or topical corticosteroids, and immunosuppressants such as azathioprine, are still the mainstay of CD therapy. Importantly, biologicals such as infliximab have shown to be efficacious in problematic settings such as fistulizing or steroid-dependent CD. This review is intended to give practical guidelines to clinicians for the conventional treatment of CD. We concentrated on the results of randomized, placebo-controlled trials and meta-analyses, when available, that provide the highest degree of evidence. We provide evidence-based treatment algorithms whenever possible. However, many clinical situations have not been answered by controlled clinical trials and it is important to fill these gaps through expert opinions. We hope that this review offers a useful tool for clinicians in the challenging treatment of CD.

Maintenance infliximab does not result in increased abscess development in fistulizing Crohn's disease: results from the ACCENT II study

BACKGROUND

Rapid fistula healing may predispose Crohn's disease patients to abscess development.

AIM

Data from ACCENT II were analysed to determine whether fistula-related abscess development is affected by infliximab exposure.

METHODS

Following infliximab 5 mg/kg infusions at weeks 0, 2 and 6, patients were evaluated for fistula response for two consecutive visits at least 4 weeks apart. Patients (N = 282) were randomized at week 14 to either placebo or infliximab 5 mg/kg every 8 weeks through week 46. If response was lost at or after week 22, patients could crossover to a 5 mg/kg higher infliximab dose. Fistula-related abscesses were diagnosed by physical examination or by imaging procedures according to usual practice.

RESULTS

Infliximab exposure was approximately twofold higher for the infliximab maintenance group. Twenty-one (15%) patients in the infliximab maintenance group had at least one newly developed fistula-related abscess compared with 27 (19%) in the placebo maintenance group (P = 0.526). The proportion of patients with a new fistula-related abscess was similar regardless of whether or not patients crossed over to a 5 mg/kg higher infliximab dose. The number of fistula-related abscesses diagnosed over time did not differ between groups.

CONCLUSION

Abscess development in patients with fistulizing Crohn's disease is not dependent on cumulative infliximab exposure.

Perianal fistulas in Crohn's disease are predominantly colonized by skin flora: implications for antibiotic treatment?

In this study we aimed to determine the microorganisms found in perianal fistulas in Crohn's disease and whether treatment with ciprofloxacin affects these microorganisms. Thirteen patients (males/females, 7/6; median age, 34 years; range, 18-61 years) with fistulas were treated with infliximab, 5 mg/kg intravenously, at weeks 6, 8, and 12 and randomized to double-blind treatment with ciprofloxacin, 500 mg bd (n = 6), or placebo (n = 7) for 12 weeks. Samples were taken at baseline and at weeks 6 and 18. In the ciprofloxacin group 10 different genera of microorganisms were identified, while 13 genera could be identified in the placebo group. Gram-negative enteric floras were present in a small minority. The genera found in patients with perianal fistulas were predominantly gram-positive microorganisms. Therefore, antimicrobial treatment should be directed toward these microorganisms.

Crohn's disease--when to operate?

Crohn's disease is a chronic bowel condition, which can present as a number of different clinical and pathological presentations, depending on localization and activity of the inflammatory process. The aethiology of the disease has not been explained. In each case the treatment should be individually tailored depending on the type of the changes. The indications for surgical intervention are continuous bleedings, recurrent ileus, perforation of the intestine, abscesses, fistulas, failure of pharmacological treatment, resistance to steroids and steroid dependence. In case of the mild type of the disease with few symptoms pharmacological treatment is the right choice In case of the mild type of the disease with few symptoms pharmacological treatment is the right choice process. In malign form of Crohn's disease lack of improvement after 7-10 days of intensive treatment is generally accepted indication for surgical treatment. Fulminant form of the disease is still a clear-cut indication for immediate surgical intervention. Decision on surgical intervention is more difficult and controversial when patient presents with series of subileus recurrences subsiding after conservative treatment. Patients with stenotic form of Crohn's disease usually require multiple operations most of which are bowel resections. Patients with stenotic form of Crohn's disease usually require multiple operations most of which are bowel resections therapy. External and internal asymptomatic fistulas should be treated conservatively. The timing of surgical treatment is essential in Crohn's disease however the prevention from recurrences is also fundamental. It is well proved that preventive administration of 5-ASA (especially mesalazine) and metronidazol can reduce the risk of early recurrences after surgery.

Infliximab maintenance treatment reduces hospitalizations, surgeries, and procedures in fistulizing Crohn's disease

BACKGROUND & AIMS

Infliximab is effective in closing fistulas in patients with Crohn's disease. We examined the effect of infliximab maintenance treatment on hospitalizations, surgeries, and procedures in patients with fistulizing Crohn's disease enrolled in the ACCENT II study.

METHODS

After 5 mg/kg infliximab at weeks 0, 2, and 6, a total of 282 patients were separately randomized at week 14 as responders (at least a 50% reduction from baseline in the number of draining fistulas at both weeks 10 and 14) or nonresponders to receive placebo or 5 mg/kg infliximab maintenance every 8 weeks. At week 22 and later, patients who lost response could be treated with a maintenance dose 5 mg/kg higher. Data on Crohn's disease-related hospitalizations, surgeries, and procedures were compared between the treatment groups for responders and all randomized patients.

RESULTS

A total of 282 patients were randomized at week 14, of whom 195 were randomized as responders. Among patients randomized as responders, those who received infliximab maintenance had significantly fewer mean hospitalization days (0.5 vs. 2.5 days; P < .05), mean numbers (per 100 patients) of hospitalizations (11 vs. 31; P < .05), all surgeries and procedures (65 vs. 126; P < .05), inpatient surgeries and procedures (7 vs. 41; P < .01), and major surgeries (2 vs. 11; P < .05), compared with those who received placebo maintenance.

CONCLUSIONS

In patients with fistulizing Crohn's disease, infliximab 5 mg/kg every 8 weeks significantly reduced hospitalizations, surgeries, and procedures compared with placebo.

Long-term oral tacrolimus therapy in refractory to infliximab fistulizing Crohn's disease: a pilot study

AIMS

To evaluate efficacy and safety of oral tacrolimus in cases of fistulizing Crohn's disease (FCD), which is refractory to conventional therapy including infliximab.

METHODS

Patients with fistulas, previously and unsuccessfully treated with all conventional therapy (i.e., antibiotics, azathioprine, or 6-mercaptopurine and infliximab), were enrolled in a prospective, uncontrolled, open-label study of long-term treatment with oral tacrolimus (0.05 mg/kg every 12 h). The evaluation of the clinical response was complemented by use of the perianal Crohn's disease activity index (PCDAI) and magnetic resonance imaging-based score (MRS) with determined periodicity.

RESULTS

Ten patients were included in the study (enterocutaneous fistula, 3 patients; perianal fistula, 4 patients; rectovaginal fistula, 3 patients) with 6 to 24 months of follow-up. Five patients were steroid-dependent, and 4 patients needed maintenance treatment with immunosuppressant agents. Four patients (40%) achieved complete clinical responses, which were verified by PCDAI and MRS. Five patients (50%) achieved partial responses (i.e., important decreases in fistula drainage, size, discomfort, and PCDAI/MRS values). Decreases in both the PCDAI and MRS were statistically significant (P < 0.05). All steroid-dependent patients stopped therapy with prednisone, and concomitant immunosuppressive therapy was tapered. The response was maintained, and no new flare-up of the disease was observed. Only mild adverse events were detected (1 patient withdrew from treatment due to headache), and no case of nephrotoxicity or diabetes was detected. One patient had received no benefit from therapy after 6 months.

CONCLUSIONS

Oral tacrolimus could be an effective and safe treatment for patients with FCD, even if there has been no response to infliximab treatment. Randomized studies are needed to compare oral tacrolimus with infliximab in terms of efficacy, safety, and costs.

Clinical and endosonographic effect of ciprofloxacin on the treatment of perianal fistulae in Crohn's disease with infliximab: a double-blind placebo-controlled study

BACKGROUND

Ciprofloxacin is effective in perianal Crohn's disease but after treatment discontinuation symptoms reoccur. Infliximab is effective but requires maintenance therapy.

AIM

To evaluate the effect of combined ciprofloxacin and infliximab in perianal Crohn's disease.

METHODS

A double-blind placebo-controlled study was conducted. Patients were randomly assigned to receive 500-mg ciprofloxacin twice daily or a placebo for 12 weeks. All patients received 5-mg/kg infliximab in week 6, 8 and 12 and were followed for 18 weeks. Primary end-point was clinical response, defined as a 50% or greater reduction from baseline in the number of draining fistulae. Secondary end-points were the change in Perianal Disease Activity Index and hydrogen peroxide enhanced three-dimensional endoanal ultrasonography findings. Analysis was by intention-to-treat.

RESULTS

Twenty-four patients were included but two discontinued treatment. At week 18, response was 73% (eight of 11) in the ciprofloxacin group and 39% (five of 13) in the placebo group (P = 0.12). Using logistic regression analysis patients treated with ciprofloxacin tended to respond better (OR = 2.37, CI: 0.94-5.98, P = 0.07). The Perianal Disease Activity Index score only improved (P = 0.008) in the ciprofloxacin group. Three-dimensional endoanal ultrasonography improved in three patients with a clinical response.

CONCLUSIONS

A combination of ciprofloxacin and infliximab tended to be more effective than infliximab alone.

Review article: antibiotics and probiotics in inflammatory bowel disease

Treatment with antibiotics in inflammatory bowel disease has a long tradition and is widely used. The indications for antibiotic therapy are wide ranging, from specific situations such as abscesses or fistulae, to patients with severe disease (as an unspecific 'protective' measure), and to address the hypothesis that the enteric flora as a whole, or specific microorganisms such as mycobacteria, are involved in the pathogenesis of inflammatory bowel disease. The best-studied single antibiotic compound is metronidazole. However, overall, the scientific basis for the use of antibiotics is limited, which may reflect a lack of interest from sponsors within the pharmaceutical industry. Despite this weak evidence base, antibiotics are a globally established therapeutic tool in inflammatory bowel disease. Growing evidence from human and animal studies points towards a pivotal pathogenetic role of intestinal bacteria in inflammatory bowel disease. In view of these experimental findings, clinical trials have been undertaken to elucidate the therapeutic effects of probiotics in inflammatory bowel disease. Probiotics are viable nonpathogenic microorganisms which confer health benefits to the host by improving the microbial balance of the indigenous microflora. So far, of the many candidates, one specific strain (Escherichia coli Nissle 1917) and a mixture of eight different bacteria have demonstrated convincing therapeutic efficacy in controlled studies. Maintenance therapy in ulcerative colitis and prevention therapy, as well as the treatment of pouchitis, have emerged as areas in which probiotic therapy offers a valid therapeutic alternative to current treatments. Further investigations may detect additional clinically effective probiotics and other clinical indications.

Antibiotics and azathioprine for the treatment of perianal fistulas in Crohn's disease

BACKGROUND

Antibiotics and thiopurines have been employed in the management of fistulizing Crohn's disease, although evidence of their efficacy is rare.

AIM

To evaluate, in a prospective, open-label study, the influence of antibiotics and azathioprine on the clinical outcome of perianal fistulas in patients with Crohn's disease.

METHODS

Fifty-two patients entered the study, starting with an 8-week regimen of ciprofloxacin (500-1000 mg/day) and/or metronidazole (1000-1500 mg/day). Seventeen patients had already received daily azathioprine (2-2.5 mg/kg) at enrollment, whereas in 14 patients azathioprine was initiated after 8 weeks of antibiotic treatment. Outcome was evaluated by Fistula Drainage Assessment and the Perianal Disease Activity Index at weeks 8 and 20.

RESULTS

Overall, 26 patients (50%) responded to antibiotic treatment, with complete healing in 25% of patients at week 8. The Perianal Disease Activity Index decreased significantly from 8.4 +/- 2.9 to 6.0 +/- 4.0 (P < 0.0001). At week 20, the outcome was assessed in 49 patients (94%), 29 of whom (59%) had received azathioprine. Response was noted in 17 of the 49 patients (35%), with complete healing in nine patients (18%). Patients who received azathioprine were more likely to achieve a response (48%) than those without immunosuppression (15%) (P = 0.03). The Perianal Disease Activity Index was closely associated with treatment response and perianal disease activity.

CONCLUSION

Antibiotics are useful to induce a short-term response in perianal Crohn's disease, and may provide a bridging strategy to azathioprine, which seems to be essential for the maintenance of fistula improvement.