Crohn's Fistulas Research Articles

Erratum to: MR imaging of perianal fistulas in Crohn’s disease: sensitivity and specificity of STIR sequences

Erratum to: MR imaging of perianal fistulas in Crohn’s disease: sensitivity and specificity of STIR sequences

Outcomes of Medical and Surgical Therapy for Entero-urinary Fistulas in Crohn's Disease.

The aims of this study were to evaluate the frequency of entero-urinary fistulas in a cohort of Crohn's disease (CD) patients and to analyse the outcomes of medical and surgical therapy. This multicentre retrospective study included all CD patients with entero-urinary fistulas diagnosed by the presence of clinical symptoms and confirmed at surgery or by radiological or endoscopic techniques. We evaluated outcomes of medical and surgical therapy. We defined remission as absence of clinical symptoms with a radiological confirmation of fistula closure. Cox regression analysis was performed to evaluate factors predictive of achieving remission without need for surgery. Of 6081 CD patients screened, 97 had entero-urinary fistulas (frequency 1.6%). Seventy-five percent of fistulas occurred in men. After a median follow-up of 91 months, 96% of patients were in sustained remission. Thirty-three patients (35%) received anti-tumour necrosis factor (TNF) therapy. Of these, 45% achieved sustained remission (median follow-up 35 months) without needing surgery. More than 80% of patients required surgery, which induced remission (median follow-up 101 months) in 99% of them. Only the use of anti-TNF agents was associated with an increased rate of remission without need for surgery (hazard ratio 0.23, 95% confidence interval 0.12-0.44; p < 0.001). In this large cohort of CD patients, the frequency of entero-urinary fistulas was lower than previously described. More than 80% of patients required surgery, and in all but one of them surgery induced sustained remission. In a selected subgroup of patients, anti-TNF may induce long-term fistula remission and radiographic closure, making it possible to avoid surgery.

A Rare Case of a Complex System of Fistulas in Crohns Disease

Fistulas in Crohn’s disease are a common problem in treatment of the disease. Especially perianal fistulas may cause a loss in patient’s quality of life. They are coincident with an unfavourable development of Crohn’s disease. Because of the frequent young patient's age, they come along with a long life of suffering and high cost for treatment. Therefore a good clinical diagnostic and a balance between drug therapy and surgery is needed. In this report, we present the case of a 28-year old male patient with a complex system of fistula in Crohn’s disease. Based on clinical and radiological findings we performed operative treatment in combination to immunosuppressive therapy as an interdisciplinary collaboration.

Long-term outcome after surgery for Crohn's anal fistula.

Treatment of Crohn's anal fistula remains challenging and little is known about factors associated with healing. The aim of this study was to assess the rate of healing after surgical treatment and analyse clinical variables related to healing. A total of 119 patients [63 women, mean age 36 (±13.7)years] with histopathologically verified Crohn's disease underwent a surgical procedure for anal fistula at four main referral centres in Sweden, January 1998 to December 2009. Baseline and treatment-related variables were recorded and analysed for correlation with fistula healing at a final follow-up after a mean of 7.2 (median 7.1, 1.0-17.5)years. Of the 119 patients 62 (52%) were healed at final follow-up. Fourteen healed after one procedure and the remaining 48 healed after a further median of 4.0 (2-20) procedures. Ten (8%) patients were subjected to a proctectomy. Final healing was more common in patients operated with a procedure aiming at eradicating the fistula (P=0.0001), without proctitis (P=0.02) and a shorter duration of Crohn's disease (P=0.0019). Long-term healing of a Crohn's anal fistula can be expected in about half of the patients, usually after repeated surgical treatment. The probability for cure was higher when a curative operation was performed in a patient without proctitis and with a shorter duration of Crohn's disease. An attempt to close a Crohn's anal fistula is thus often worthwhile.

Mucinous Adenocarcinoma Arising from Perianal Fistulae in Crohn’s Disease: A Rare Case Report and Review of the Literature

Perianal fistula is a common manifestation of Crohn's disease. Adenocarcinoma arising from perianal fistulae in patients with Crohn’s disease is rare. There are only 65 cases in English literature with anorectal adenocarcinoma arising from a perianal fistula in patients with Crohn's disease reported from January 1946 until September 2009. We present a case of 44 year old male diagnosed with Crohn’s disease in 2012. Patient presented with worsening perirectal fistulas and posterior anal mass in 2014. Biopsy of posterior anal mass and right lateral anal margin, revealed mucinous adenocarcinoma. Given the findings of a perianal adenocarcinoma and extensive perianal Crohn’s disease, the patient underwent neoadjuvant treatment, followed by abdominoperineal resection. Tumor size was 4.0 cm, estimated, as a discreet mass was not seen. This moderately differentiated adenocarcinoma was arising from the lining of the perianal fistulae tracts. The malignant cells and mucinous pools were diffusely involving the anal canal and part of the perianal fibroadipose tissue. The tumor demonstrated irregularly shaped tubules lined by cells with basally located, uniform, and hyperchromatic nuclei with abundant mucinous cytoplasm. The positive staining with CK20 and CDX2 in the tumor cells by immunohistochemistry suggests that tumor originated from colonic epithelium lining the fistula tracts. This case is unusual because of the very short duration between the first time diagnosis of Crohn's disease and development of adenocarcinoma in the perianal fistula tracts.

New Imaging in Gastrointestinal Tract.

Pathologies of gastrointestinal tract are various and affect patients of different ages. Both of these conditions influence the imaging modalities of gastrointestinal tract that underwent relevant changes during recent years. Magnetic Resonance (MR) and Computed Tomography (CT) techniques, optimised for gastrointestinal imaging, are playing today an increasing role in the evaluation of gastrointestinal disorders, and several studies have shown the advantage of these techniques over tradition barium fluoroscopic examinations secondary to improvements in spatial and temporal resolution combined with improved bowel distending agents. Based on recent literature and guidelines, there is a change of paradigms regarding the diagnosis of esophagus and gastrointestinal cancer towards CT, whereas for small bowel imaging in inflammatory disease MRI with a new focus on Diffusion Weighted Imaging (DWI) are the most important imaging modalities, because DWI can be easily implemented in standard MRI for routine use to further enhance the diagnostic accuracy in disease assessment [1–4]. CT and MRI play an important role also in functional disorders. In particular, the recent development of faster MRI pulse sequences provides rapid, real-time imaging of the gastrointestinal tract, pinpointing areas of stricture and providing valuable information on motility. This special issue is devoted to current and emerging techniques in gastrointestinal tract, focusing on some selected topics that are both interesting and challenging: neoplastic pathologies, chronic inflammatory diseases, functional pathologies, and nontraumatic emergency causing occlusion. The first section covers cross-sectional imaging of the gastrointestinal tract in neoplastic disease, including lymphoma, both through a review (“Radiological Features of Gastrointestinal Lymphoma” by G. Lo Re et al.) and through an original paper (“Staging of Primary Abdominal Lymphomas: Comparison of Whole-Body MRI with Diffusion-Weighted Imaging and 18F-FDG-PET/CT” by A. Stecco et al.) and small-bowel neoplasms (“Small-Bowel Neoplasms: Role of MRI Enteroclysis” by A. Faggian et al.). The imaging of hepatocellular carcinoma after locoregional treatments is also reviewed (“CT Appearance of Hepatocellular Carcinoma after Locoregional Treatments: A Comprehensive Review” by D. Marin et al.). Cross-sectional imaging modalities are fundamental also in the management of patients with inflammatory bowel disease (IBD) from the first diagnosis and throughout the entire course of the disease. In this sense, MRI, owing to the lack of ionizing radiation, represents the main technique in young patients with IBD who may require multiple studies over a lifetime. New imaging of chronic inflammatory pathologies is focused on Crohn's disease, where the imaging is essential also in scoring the activity of disease (“3D-EAUS and MRI in the Activity of Anal Fistulas in Crohn's Disease” by M. E. Alabiso et al.; “Assessment of Disease Activity in Small Bowel Crohn's Disease: Comparison between Endoscopy and Magnetic Resonance Enterography Using Mria and Modified Mria Score” by A. Scardapane et al.). Some functional pathologies are also discussed: achalasia and pelvic floor disfunction (“Imaging in the Evaluation of Endoscopic or Surgical Treatment for Achalasia” by D. Palladino et al.; “MR Imaging in Diagnosis of Pelvic Floor Descent: Supine versus Sitting Position” by F. Iacobellis et al.). Finally nontraumatic emergency causing occlusion is discussed in three different papers, with emphasis on the role of MDCT and dynamic MRI (“Intussusception in Adults: The Role of MDCT in the Identification of the Site and Cause of Obstruction” by V. Valentini et al.; “A Novel Diagnostic Aid for Detection of Intra-Abdominal Adhesions to the Anterior Abdominal Wall Using Dynamic Magnetic Resonance Imaging” by D. Randall et al.; “Adhesions to Mesh after Ventral Hernia Mesh Repair are Detected by MRI but Are Not a Cause of Long Term Chronic Abdominal Pain” by O. Langbach et al.). The contributions of this special issue could stimulate the spread of new imaging modalities in daily practice, pinpoint technical aspects, and share some strategies to optimise CT and MR protocols. Roberto Grassi Antonio Pinto Lorenzo Mannelli Daniele Marin Maria Antonietta Mazzei

Outcome of Surgery for Coloduodenal Fistula in Crohn’s Disease

BackgroundThis study was conducted to report the short- and long-term outcomes of surgery for coloduodenal fistula in Crohn’s disease and explore the effect of preoperative optimization on surgical outcome. MethodsThis is a retrospective review of 34 patients with coloduodenal fistula complicating Crohn’s disease between Jan 2008 and May 2015. Demographic information, preoperative management, and intraoperative and postoperative outcome data were collected. ResultsPrimary duodenal repair was carried out in 33 patients (13 with duodenal defect >3 cm), and bypass surgery was performed in one patient with duodenal stenosis. Patients undergoing preoperative optimization (n = 25) had decreased postoperative major (24.0 vs. 87.5 %, P = 0.005) and intra-abdominal septic (20.0 vs. 75.0 %, P = 0.008) complications compared to patients with emergent/semi-emergent surgery (n = 8). No duodenal stenosis occurred on a median follow-up of 22.5 months. Patients with duodenum-ileocolic anastomosis fistula had longer postoperative stay (14.0 vs. 10.0 days, P = 0.032) and increased possibility of refistulization of the duodenum on follow-up (30.0 vs. 0 %, P = 0.031) compared with those with spontaneous duodenum-colonic fistula. ConclusionPrimary duodenal repair can be safely performed in coloduodenal fistula in Crohn’s disease provided there was no duodenal stenosis, even for large duodenal defects. Preoperative optimization is associated with reduced postoperative complications. Patients with duodenum-ileocolic anastomosis fistula are more likely to have duodenum fistula recurrence compared to those with spontaneous duodenum-colonic fistula.

MR imaging of perianal fistulas in Crohn's disease: sensitivity and specificity of STIR sequences.

Although some studies proved the role of STIR sequences in the evaluation of perianal fistulas in Crohn's Disease (CD), contrast medium is still injected in many institutions since there is not a validated reference MR protocol. Our purpose was to evaluate the role of the STIR sequence in the detection and characterization of perianal fistulae comparing it to the post-contrast T1 sequence and correlating it with rectal examination under anesthesia. We retrospectively reviewed all clinical records of 31 CD patients, suspected of having perianal fistulas, who had been submitted to an MR study before and after contrast medium injection and surgical exploration under anesthesia within the same month. Perianal fistulas were classified according to the Parks' criteria. Finally, comparison between STIR and post-contrast T1-weighted fat saturated sequences was done. 29 fistulas were detected in 25 patients who underwent an MR study. There was no significant difference between MR imaging and exploration under anesthesia. For the detection of perianal fistulas of any type, there was a perfect statistical agreement between gadolinium-enhanced and STIR sequences (kappa value=1). STIR sequences represent a valid alternative to the T1-weighted sequences acquired after the injection of contrast medium, allowing the identification of the primary fistula, any secondary ramification, and complications of the disease.

Endoscopic Therapy in Crohn's Disease: Principle, Preparation, and Technique.

Stricture and fistula are common complications of Crohn's disease. Endoscopic balloon dilation and needle-knife stricturotomy has become a valid treatment option for Crohn's disease-associated strictures. Endoscopic therapy is also increasingly used in Crohn's disease-associated fistula. Preprocedural preparations, including routine laboratory testing, imaging examination, anticoagulant management, bowel cleansing and proper sedation, are essential to ensure a successful and safe endoscopic therapy. Adverse events, such as perforation and excessive bleeding, may occur during endoscopic intervention. The endoscopist should be well trained, always be cautious, anticipate for possible procedure-associated complications, be prepared for damage control during endoscopy, and have surgical backup ready. In this review, we discuss the principle, preparation, techniques of endoscopic therapy, as well as the prevention and management of endoscopic procedure-associated complications. We propose that inflammatory bowel disease endoscopy may be a part of training for "super" gastroenterology fellows, i.e., those seeking a career in advanced endoscopy or in inflammatory bowel disease.

Managing perianal Crohn's fistula in the anti-TNFα era.

Perianal fistulas in Crohn's disease are common and difficult to treat. Their aetiology is poorly understood. Assessment is clinical, endoscopic and radiological, and management is undertaken by a multidisciplinary team of gastroenterologists, surgeons and radiologists. Surgical drainage of the fistula tract system with the placement of loose setons precedes combined therapy with immunosuppressant and anti-TNFα agents in most patients. Proctitis should be rigorously eliminated where possible. Definitive surgical repair is sometimes possible and diversion or proctectomy are occasionally required. Combined medical and surgical management represents a promising avenue for the future.

Treatment of Crohn’s disease-related high perianal fistulas combining the mucosa advancement flap with platelet-rich plasma: a pilot study

BackgroundHealing rates after surgical closure for high perianal fistula in patients with Crohn’s disease are even more disappointing than in patients with cryptoglandular fistulas. The objective was to improve healing rates by combining the well-known mucosal advancement flap with platelet-rich plasma.MethodsA prospective pilot study was conducted in one tertiary referral centre. Consecutive patients with primary or recurrent Crohn’s disease-related high perianal fistulas, defined as involving the middle and/or upper third parts of the anal sphincter complex, were included. A staged procedure was performed with non-cutting seton treatment for 3 months first, followed by a mucosal advancement flap with injection of platelet-rich plasma into the fistula tract.ResultsTen consecutive patients were operated on between 2009 and 2014. Half (50 %) of the patients had undergone previous fistula surgery. Mean follow-up was 23.3 months (SD 13.0). Healing of the fistula was 70 % (95 % confidence interval, 33–89 %) at 1 year. One (10 %) patient had a recurrence, and in two (20 %) patients, the fistula was persistent after treatment. An abscess occurred in one (10 %) patient. The median post-operative Vaizey score was 8.0 (range 0–21), indicating a moderate to severe continence impairment.ConclusionsThe results of combining the mucosal advancement flap with platelet-rich plasma in patients with Crohn’s disease-related high perianal fistulas are moderate with a healing rate of 70 %. Further investigation is needed to determine the benefits and risks on continence status for this technique in this patient population.

Tu1380 Fistulising Perianal Crohn's Disease - Has Anti-TNF Therapy Improved Outcomes?

Introduction Anti-tumor necrosis factor (TNF) therapies are currently being used to treat fistulising perianal Crohn's disease (CD). We evaluated the clinical and radiological outcomes of patients with perianal Crohn's fistulas who have been treated with immunomodulators alone as compared with those treated with anti-TNF therapies. Methods A local database of 270 consecutive patients with CD anal fistulas treated at our institution between 2000 and 2014 was established. Demographic and clinical data were recorded in addtion to radiological reports. Results Ninety patients were in the non-anti-TNF group and 180 were treated with anti-TNF therapy (Infliximab or Adalimumab). Clinical response rates were significantly higher in the anti-TNF group (74% vs 62%, p=0.04). Similarly, radiological response rates were higher in the anti-TNF group (56% vs 28%, p<0.01). Cox Regression analysis demonstrated fistula duration (p=0.01) and biologic therapy (p=<0.01) to be significant at the univariate level. At the multivariate level, patients on anti-TNF therapy had a faster radiological response over a 6-year follow-up period (OR=2.25, CI= 1.14-4.46, p= 0.02). A short duration of CD (less than 5 years) contributes to a faster time to clinical response (OR=1.77, CI=1.03-3.05, p=0.04). Treatment with anti-TNF therapy is an independent predictor of radiological response (OR 3.55, CI 1.59-7.91, p<0.01). Patients with L1 luminal disease are 3 times more likely not to go into clinical remission on both univaraite and multivariate analyses (OR=3.08, CI=1.47-6.46, p=0.01). The duration of CD is also a poor predictor of clinical response to therapy (p<0.01). Conclusion Patients on anti-TNF therapy have improved clinical and radiological response rates compared with patients without. Anti-TNF therapy is a positive predictor of radiological response to therapy.

Tu1384 Meconium Ileus: Mucin Secretion in the Cystic Fibrosis Ileum

Introduction Anti-tumor necrosis factor (TNF) therapies are currently being used to treat fistulising perianal Crohn's disease (CD). We evaluated the clinical and radiological outcomes of patients with perianal Crohn's fistulas who have been treated with immunomodulators alone as compared with those treated with anti-TNF therapies. Methods A local database of 270 consecutive patients with CD anal fistulas treated at our institution between 2000 and 2014 was established. Demographic and clinical data were recorded in addtion to radiological reports. Results Ninety patients were in the non-anti-TNF group and 180 were treated with anti-TNF therapy (Infliximab or Adalimumab). Clinical response rates were significantly higher in the anti-TNF group (74% vs 62%, p=0.04). Similarly, radiological response rates were higher in the anti-TNF group (56% vs 28%, p<0.01). Cox Regression analysis demonstrated fistula duration (p=0.01) and biologic therapy (p=<0.01) to be significant at the univariate level. At the multivariate level, patients on anti-TNF therapy had a faster radiological response over a 6-year follow-up period (OR=2.25, CI= 1.14-4.46, p= 0.02). A short duration of CD (less than 5 years) contributes to a faster time to clinical response (OR=1.77, CI=1.03-3.05, p=0.04). Treatment with anti-TNF therapy is an independent predictor of radiological response (OR 3.55, CI 1.59-7.91, p<0.01). Patients with L1 luminal disease are 3 times more likely not to go into clinical remission on both univaraite and multivariate analyses (OR=3.08, CI=1.47-6.46, p=0.01). The duration of CD is also a poor predictor of clinical response to therapy (p<0.01). Conclusion Patients on anti-TNF therapy have improved clinical and radiological response rates compared with patients without. Anti-TNF therapy is a positive predictor of radiological response to therapy.

Tu1382 The Role of NHE8 in Intestinal Mucosal Homeostasis

Introduction Anti-tumor necrosis factor (TNF) therapies are currently being used to treat fistulising perianal Crohn's disease (CD). We evaluated the clinical and radiological outcomes of patients with perianal Crohn's fistulas who have been treated with immunomodulators alone as compared with those treated with anti-TNF therapies. Methods A local database of 270 consecutive patients with CD anal fistulas treated at our institution between 2000 and 2014 was established. Demographic and clinical data were recorded in addtion to radiological reports. Results Ninety patients were in the non-anti-TNF group and 180 were treated with anti-TNF therapy (Infliximab or Adalimumab). Clinical response rates were significantly higher in the anti-TNF group (74% vs 62%, p=0.04). Similarly, radiological response rates were higher in the anti-TNF group (56% vs 28%, p<0.01). Cox Regression analysis demonstrated fistula duration (p=0.01) and biologic therapy (p=<0.01) to be significant at the univariate level. At the multivariate level, patients on anti-TNF therapy had a faster radiological response over a 6-year follow-up period (OR=2.25, CI= 1.14-4.46, p= 0.02). A short duration of CD (less than 5 years) contributes to a faster time to clinical response (OR=1.77, CI=1.03-3.05, p=0.04). Treatment with anti-TNF therapy is an independent predictor of radiological response (OR 3.55, CI 1.59-7.91, p<0.01). Patients with L1 luminal disease are 3 times more likely not to go into clinical remission on both univaraite and multivariate analyses (OR=3.08, CI=1.47-6.46, p=0.01). The duration of CD is also a poor predictor of clinical response to therapy (p<0.01). Conclusion Patients on anti-TNF therapy have improved clinical and radiological response rates compared with patients without. Anti-TNF therapy is a positive predictor of radiological response to therapy.

Tu1381 Genome-Wide Association Identifies Multiple Collagenous Colitis Susceptibility Loci

Introduction Anti-tumor necrosis factor (TNF) therapies are currently being used to treat fistulising perianal Crohn's disease (CD). We evaluated the clinical and radiological outcomes of patients with perianal Crohn's fistulas who have been treated with immunomodulators alone as compared with those treated with anti-TNF therapies. Methods A local database of 270 consecutive patients with CD anal fistulas treated at our institution between 2000 and 2014 was established. Demographic and clinical data were recorded in addtion to radiological reports. Results Ninety patients were in the non-anti-TNF group and 180 were treated with anti-TNF therapy (Infliximab or Adalimumab). Clinical response rates were significantly higher in the anti-TNF group (74% vs 62%, p=0.04). Similarly, radiological response rates were higher in the anti-TNF group (56% vs 28%, p<0.01). Cox Regression analysis demonstrated fistula duration (p=0.01) and biologic therapy (p=<0.01) to be significant at the univariate level. At the multivariate level, patients on anti-TNF therapy had a faster radiological response over a 6-year follow-up period (OR=2.25, CI= 1.14-4.46, p= 0.02). A short duration of CD (less than 5 years) contributes to a faster time to clinical response (OR=1.77, CI=1.03-3.05, p=0.04). Treatment with anti-TNF therapy is an independent predictor of radiological response (OR 3.55, CI 1.59-7.91, p<0.01). Patients with L1 luminal disease are 3 times more likely not to go into clinical remission on both univaraite and multivariate analyses (OR=3.08, CI=1.47-6.46, p=0.01). The duration of CD is also a poor predictor of clinical response to therapy (p<0.01). Conclusion Patients on anti-TNF therapy have improved clinical and radiological response rates compared with patients without. Anti-TNF therapy is a positive predictor of radiological response to therapy.

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.

The results of seton drainage combined with anti-TNFα therapy for anal fistula in Crohn's disease.

Combined infliximab and sphincter-sparing surgery can be effective in perianal fistula associated with Crohn's disease (CD). This study aimed to assess the efficacy of local surgery combined with infliximab on sustained fistula closure and to identify predictive factors for response after this combined treatment. Between 2000 and 2010, 81 patients with fistulising perianal CD were included in this observational study. Drainage with a loose seton was followed by infliximab therapy. The primary end-points were the rate of complete fistula closure and time required for this to occur. The fistula was complex in 71 (88%) of the 81 patients. Local proctological surgery was carried out in 77 (95%), including seton drainage in 62 (80.5%) of these. This was continued for a median duration of 3.8months and the patient then received infliximab therapy. The median follow-up after treatment was 64months (2-263). Initial complete closure of the fistula occurred in 71 (88%) cases at a median interval of 12.4months (1-147) from the start of treatment. Recurrence was observed in 29 (41%) patients at a median interval of 38.5months (2-48) from the start of treatment. They were treated again with combined treatment with successful closure in 19 (65.5%) patients. The total rate of closure of the fistula was 75.3%. Female gender, anal stenosis, rectovaginal and complex fistula formation were factors independently associated with failure of combined treatment. Seton drainage for several months combined with infliximab therapy is effective in closing the fistula in 75% of patients with complex perianal fistula formation associated with CD.

What role do bacteria play in persisting fistula formation in idiopathic and Crohn's anal fistula?

The aetiology of Crohn's disease-related anal fistula remains obscure. Microbiological, genetic and immunological factors are thought to play a role but are not well understood. The microbiota within anal fistula tracts has never been examined using molecular techniques. The present study aimed to characterize the microbiota in the tracts of patients with Crohn's and idiopathic anal fistula. Samples from the fistula tract and rectum of patients with Crohn's and idiopathic anal fistula were analysed using fluorescent in situ hybridization, Gram staining and scanning electron microscopy were performed to identify and quantify the bacteria present. Fifty-one patients, including 20 with Crohn's anal fistula, 18 with idiopathic anal fistula and 13 with luminal Crohn's disease and no anal fistula, were recruited. Bacteria were not found in close association with the luminal surface of any of the anal fistula tracts. Anal fistula tracts generally do not harbour high levels of mucosa-associated microbiota. Crohn's anal fistulas do not seem to harbour specific bacteria. Alternative explanations for the persistence of anal fistula are needed.

P634. What Are The Long Term Outcomes of Perianal Crohn's Fistulae Treated with Anti-TNF Therapies?

P634. What Are The Long Term Outcomes of Perianal Crohn's Fistulae Treated with Anti-TNF Therapies?

Segmental sigmoid polyposis as a colonoscopic indicator of an ileosigmoid fistula in Crohn's ileitis.

Ileosigmoid fistulas (ISFs) are frequently undiagnosed prior to surgery. This study was designed to describe a polyp or cluster of polyps limited to the sigmoid colon as a marker of ISF in patients with ileitis. This novel finding will increase a gastroenterologist's opportunity to detect them preoperatively and their prognostic implication of worsening ileitis. The medical records of patients with Crohn's disease and ISF were reviewed to determine whether colonoscopy had revealed polyposis limited to the sigmoid colon and its frequency. Thirty-seven patients with Crohn's ileitis complicated by ISF were identified from our database. Twenty had one or more sigmoid polyps without polyps elsewhere in the colon suggesting the site of fistula exit. Fifteen of the patients had ISF and five had ileorectal fistula (IRF). The fistula was detected by various means, including colonoscopy, sigmoidoscopy, small bowel X-ray series, barium enema, computed tomography, and magnetic resonance enterography. The ISF was generally diagnosed prior to the recognition and significance of the segmental polyps. These polyps were inflammatory or hyperplastic on pathologic review. Most ISFs and IRFs are now found preoperatively by imaging and some are incidental surgical findings. The segmental sigmoid polyps that we describe should help the gastroenterologist to be suspicious of ISF. The polyps are a surrogate marker for the progression of the fistula and the underlying ileitis as they tend to appear after the fistula has matured and lead to increased intensity of medical therapy well before surgical intervention is required.