Does combined medical and surgical treatment improve perianal fistula outcomes in patients with Crohn's disease? A systematic review and meta-analysis.

BACKGROUND: The optimal treatment of perianal fistulizing Crohn's disease (PFCD) is unknown. We performed a systematic review with meta-analysis to compare combined surgical intervention and anti-TNF therapy (combined therapy) vs. either therapy alone. METHODS: MEDLINE, EMBASE, and Cochrane databases were searched systematically through December 2023. Surgical intervention was defined as an exam under anesthesia ± setons. We calculated weighted risk ratios (RR) with 95% confidence intervals (CI) for our co-primary outcomes: fistula response and healing, defined clinically as a reduction in fistula drainage or number of draining fistulas and fistula closure respectively. RESULTS: Thirteen studies were analysed: 515 patients treated with combined therapy, 330 patients with surgical intervention and 406 patients with anti-TNF therapy with follow-up between 10 weeks and 3 years. Fistula response (RR 1.10; 95% CI, 0.93-1.30, p=0.28) and healing (RR 1.06; 95% CI, 0.86-1.31, p=0.58) was not significantly different when comparing combined therapy with anti-TNF therapy alone. In contrast, combined therapy was associated with significantly higher rates of fistula response (1.25; 95% CI, 1.10-1.41, p<0.001) and healing (RR 1.17; 95% CI, 1.00-1.36, p=0.05) compared with surgical intervention alone. Our results remained stable when limiting to studies that assessed outcomes within 1 year and studies where <10% of patients underwent fistula closure procedures. CONCLUSION: Combined surgery and anti-TNF therapy was not associated with improved PFCD outcomes compared with anti-TNF therapy alone. Due to an inability to control for confounding and small study sizes, future, controlled trials are warranted to confirm these findings.

Comparative Efficacy of Advanced Therapies for Achieving Endoscopic Outcomes in Crohn's Disease: A Systematic Review and Network Meta-Analysis.

BACKGROUND & AIMS: We conducted a network meta-analysis to compare the efficacy of advanced therapies for achieving endoscopic outcomes in patients with moderate-to-severely active Crohn's disease. METHODS: MEDLINE, Embase, and Cochrane CENTRAL databases were searched from inception to August 2, 2023 to identify phase II and III randomized controlled trials (RCTs) in adults (≥18 years) with moderate-to-severe Crohn's disease treated with tumor necrosis factor (TNF) antagonists, etrolizumab, vedolizumab, anti-interleukin (IL)12/23p40, anti-IL23p19, or Janus kinase-1 (JAK1) inhibitors, compared with placebo/active comparator, for induction and/or maintenance of remission and reported endoscopic outcomes. Primary outcome was endoscopic response after induction therapy, and endoscopic remission after maintenance therapy. We performed a random-effects network meta-analysis using a frequentist approach, and estimated relative risk (RRs), 95% confidence interval (CI) values, and P score for ranking agents. We used GRADE to ascertain certainty of evidence. RESULTS: A total of 20 RCTs (19 placebo-controlled and 1 head-to-head trial; 5592 patients) were included out of which 12 RCTs reported endoscopic outcomes for the induction phase, 5 reported for the maintenance phase, and 3 reported for both induction and maintenance phases. JAK1 inhibitors (RR, 3·49 [95% CI, 1·48-8·26]) and anti-IL23p19 (RR, 2·30 [95% CI, 1·02-5·18]) agents were more efficacious than etrolizumab (moderate certainty of evidence), and JAK1 inhibitors (RR, 2·34 [95% CI, 1·14-4·80]) were more efficacious than anti-IL12/23p40 agents for inducing endoscopic response (moderate certainty of evidence). JAK1 inhibitors and anti-IL23p19 ranked highest for induction of endoscopic response. There was paucity of RCTs of TNF antagonists reporting endoscopic outcomes with induction therapy. On network meta-analysis of 6 RCTs, all agents except vedolizumab (RR, 1.89 [95% CI, 0.61-5.92]) were effective in maintaining endoscopic remission compared with placebo. TNF antagonists, IL12/23p40, and JAK1 inhibitors were ranked highest. CONCLUSIONS: On network meta-analysis, JAK1 inhibitors and anti-IL23p19 agents may be the most effective among non-TNF-targeting advanced therapies for inducing endoscopic response. Future head-to-head trials will further inform positioning of different therapies for the management of Crohn's disease.

Comparative Effectiveness of Biologic Therapies in Preventing Penetrating Complications in Patients With Crohn's Disease.

BACKGROUND & AIMS: Comparative effectiveness of biologics in preventing penetrating disease (PD) in Crohn's disease (CD) is not well established. We compared the risk of developing luminal and perianal PD (LPD and PPD) between biologics used as first-line therapies. METHODS: Adults (>17 years) with CD who initiated their first biologic (anti-tumor necrosis factor [anti-TNF], ustekinumab [UST], or vedolizumab [VDZ]) were identified from Merative Commercial Database (2006 and 2020). We excluded preexisting PD using a minimum look-back period of 1 year. Cohorts were balanced by inverse probability of treatment weighting based on age, sex, comorbidities, prior CD surgery, and CD severity. Pairwise comparisons were performed by Cox proportional hazards models, adjusted for immunomodulator exposure, and with biologic exposure treated as a time-dependent variable based on a medication possession ratio of 0.8. RESULTS: Our analysis included 40,693 patients: 93% anti-TNF, 3% UST, and 4% VDZ. After inverse probability of treatment weighting all comparisons were well balanced. Anti-TNF was protective against LPD (hazard ratio, 0.66; 95% confidence interval, 0.55-0.78; P < .0001) and PPD (hazard ratio, 0.88; 95% confidence interval, 0.80-0.96; P = .0045) compared with VDZ and LPD (hazard ratio, 0.37; 95% confidence interval, 0.30-0.46; P < .0001) compared with UST. There were no significant differences in the risk of LPD and PPD between VDZ and UST. These results were similar after limiting the study period to after 2016. CONCLUSIONS: Anti-TNF therapy was associated with a lower risk of LPD and PPD compared with VDZ, and lower risk of LPD compared with UST. Further studies are needed to validate these findings and to determine potential reasons for these differences.

Development of an MRI-Based Prediction Model for Anti-TNF Treatment Failure in Perianal Crohn's Disease: A Multicenter Study.

BACKGROUND & AIMS: Clinical and radiologic variables associated with perianal fistula (PAF) outcomes are poorly understood. We developed prediction models for anti-tumor necrosis factor (TNF) treatment failure in patients with Crohn's disease-related PAF. METHODS: In a multicenter retrospective study between 2005 and 2022 we included biologic-naive adults (>17 years) who initiated their first anti-TNF therapy for PAF after pelvic magnetic resonance imaging (MRI). Pretreatment MRI studies were prospectively reread centrally by blinded radiologists. We developed and internally validated a prediction model based on clinical and radiologic parameters to predict the likelihood of anti-TNF treatment failure, clinically, at 6 months. We compared our model and a simplified version of MRI parameters alone with existing imaging-based PAF activity indices (MAGNIFI-CD and modified Van Assche MRI scores) by De Long statistical test. RESULTS: We included 221 patients: 32 ± 14 years, 60% males, 76% complex fistulas; 68% treated with infliximab and 32% treated with adalimumab. Treatment failure occurred in 102 (46%) patients. Our prediction model included age at PAF diagnosis, time to initiate anti-TNF treatment, and smoking and 8 MRI characteristics (supra/extrasphincteric anatomy, fistula length >4.3 cm, primary tracts >1, secondary tracts >1, external openings >1, tract hyperintensity on T1-weighted imaging, horseshoe anatomy, and collections >1.3 cm). Our full and simplified MRI models had fair discriminatory capacity for anti-TNF treatment failure (concordance statistic, 0.67 and 0.65, respectively) and outperformed MAGNIFI-CD (P = .002 and < .0005) and modified Van Assche MRI scores (P < .0001 and < .0001), respectively. CONCLUSIONS: Our risk prediction models consisting of clinical and/or radiologic variables accurately predict treatment failure in patients with PAF.

Pharmacological therapies for the management of fistulising Crohn's disease: A systematic review and meta-analysis.

BACKGROUND: Fistulas are a debilitating complication of Crohn's disease (CD). We conducted a systematic review to assess the efficacy of medical therapies for fistulising CD. METHODS: MEDLINE, Embase, and CENTRAL were searched on May 26, 2022, for randomised controlled trials (RCTs) of pharmacologic therapy in adults with fistulising CD. The primary outcome was induction and maintenance of fistula response. Pooled risk ratios (RRs) and 95% confidence intervals (CI) were calculated. GRADE was used to assess certainty of evidence. RESULTS: Thirty-eight RCTs were included. Nineteen trials (50%) exclusively involved perianal fistula. The remaining studies included some participants with non-perianal fistula. Pooled RRs for anti-tumor necrosis factor (TNF) agents were not statistically significant for induction (RR 1.36, 95% CI 0.97-1.91) or maintenance of fistula response (RR 1.48, 95% CI 0.97-2.27). However, in a sensitivity analysis of studies with fistula response as the primary outcome, anti-TNFs were superior to placebo for induction (RR 1.94, 95% CI 1.10-3.41) and maintenance (RR 1.88, 95% CI 1.23-2.88) of fistula response. Oral small molecules (RR 2.56, 95% CI 1.18-5.53) and mesenchymal stem cell (MSC) therapy (RR 1.26, 95% CI 1.01-1.57) were effective for induction of fistula response. Ustekinumab was associated with maintenance of fistula response (RR 1.80, 95% CI1.04-3.11). Vedolizumab was not superior to placebo. The certainty of evidence ranged from very low to moderate. CONCLUSION: Very low-to-moderate certainty evidence suggests that anti-TNF therapy, oral small molecules, ustekinumab, and MSCs are effective for perianal fistulising CD. Dedicated fistula studies evaluating biologics and small molecules are needed.

Perianal Fistulas Are Associated with Persistently Higher Direct Health Care Costs in Crohn's Disease: A Population-Based Study.

BACKGROUND: The economic impact of perianal fistulas in Crohn's disease (CD) has not been formally assessed in population-based studies in the biologic era. AIM: To compare direct health care costs in persons with and without perianal fistulas. METHODS: We performed a longitudinal population-based study using administrative data from Ontario, Canada. Adults (> 17 years) with CD were identified between 2007 and 2013 using validated algorithms. Perianal fistula positive "cases" were matched to up to 4 "controls" with CD without perianal fistulas based on age, sex, geographic region, year of CD diagnosis and duration of follow-up. Direct health care costs, excluding drug costs from private payers, were estimated annually beginning 5 years before (lookback) and up to 9 years after perianal fistula diagnosis (study completion) for cases and a standardized date for matched controls. RESULTS: A total of 581 cases were matched to 1902 controls. The annual per capita direct cost for cases was similar at lookback compared to controls ($2458 ± 6770 vs $2502 ± 10,752; p = 0.952), maximally greater in the first year after perianal fistulas diagnosis ($16,032 ± 21,101 vs $6646 ± 13,021; p < 0.001) and remained greater at study completion ($11,358 ± 17,151 vs $5178 ± 9792; p < 0.001). At perianal fistula diagnosis, the cost difference was driven primarily by home care cost (tenfold greater), publicly-covered prescription drugs (threefold greater) and hospitalizations (twofold greater), whereas at study completion, prescription drugs were the dominant driver (threefold greater). CONCLUSION: In our population-based cohort, perianal fistulas were associated with significantly higher direct healthcare costs at the time of perianal fistulas diagnosis and sustained long-term.

Venous Thromboembolism After COVID-19 Infection Among People With and Without Immune-Mediated Inflammatory Diseases.

Importance: Immune-mediated inflammatory diseases (IMIDs) and COVID-19 are independently associated with venous thromboembolisms (VTEs). Objective: To determine if individuals with IMIDs are at higher risk of VTE following COVID-19 infection compared with individuals without IMIDs. Design, Setting, and Participants: Population-based matched cohort study using multiple deterministically linked health administrative databases from Ontario, Canada, and including patients testing positive for COVID-19 between January 1, 2020, and December 30, 2021, and followed up until March 31, 2022. Individuals with IMIDs (n = 28 440) who tested positive for COVID-19 were matched with up to 5 individuals without an IMID (n = 126 437) who tested positive for COVID-19. Matching was based on year of birth, sex, neighborhood income, and rural/urban residence. Data analysis was performed from August 6, 2022, to August 21, 2023. Exposure: Diagnosis of an IMID, identified using algorithms based on diagnostic codes, procedures, and specialist visits. Main Outcome and Measure: The main outcome was estimated age- and sex-standardized incidence of VTE. Proportional cause-specific hazard models compared the risk of VTE in people with and without IMIDs. Death was a competing risk. Models adjusted for history of VTE, 2 or more doses of a COVID-19 vaccine 14 or more days prior to COVID-19 diagnosis, and the Charlson Comorbidity Index. Routinely collected health data were used, so the hypothesis tested was formulated after data collection but prior to being granted access to data. Results: The study included 28 440 individuals (16 741 [58.9%] female; 11 699 [41.1%] male) with an IMID diagnosed prior to first COVID-19 diagnosis, with a mean (SD) age of 52.1 (18.8) years at COVID-19 diagnosis. These individuals were matched to 126 437 controls without IMIDs. The incidence of VTE within 6 months of COVID-19 diagnosis among 28 440 individuals with an IMID was 2.64 (95% CI, 2.23-3.10) per 100 000 person-days compared with 2.18 (95% CI, 1.99-2.38) per 100 000 person-days among 126 437 matched individuals without IMIDs. The VTE risk was not statistically significantly different among those with vs without IMIDs (adjusted hazard ratio, 1.12; 95% CI, 0.95-1.32). Conclusions and Relevance: In this retrospective population-based cohort study of individuals with IMIDs following COVID-19, individuals with IMIDs did not have a higher risk of VTE compared with individuals without an IMID. These data provide reassurance to clinicians caring for individuals with IMIDs and COVID-19.

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.

Pancolonic Dye Spray Chromoendoscopy to Detect and Resect Ill-Defined Neoplastic Lesions in Colonic Inflammatory Bowel Disease.

Background: Pancolonic dye spray chromoendoscopy (DCE) is used as an adjunct to white light endoscopy (WLE) to enhance the detection and delineation of ill-defined neoplastic (dysplastic) lesions in persons with colonic inflammatory bowel diseases (cIBD). We evaluated the utility of DCE as follow-up to high-definition WLE (HD-WLE) to "unmask" and/or facilitate endoscopic resection of neoplastic lesions. Methods: We retrospectively studied persons with cIBD who underwent DCE as follow-up to HD-WLE between 2013 and 2020. We describe neoplastic findings and management during HD-WLE and DCE exams and report outcomes from post-DCE surveillance exams. Results: Twenty-four persons were studied (mean age 56.7 ± 13.8 years, 50.0% male, 70.8% ulcerative colitis, mean disease duration 18.0 ± 11.0 years). Overall, 32 visible neoplastic lesions were unmasked during DCE, of which 24 were endoscopically resected. DCE facilitated the diagnosis of two cancers. Among 17 persons referred for evaluation of "invisible" neoplasia (detected in non-targeted biopsies) during HD-WLE, DCE identified neoplastic lesions at the same site in eight persons and a different site in four persons. Among seven persons referred for ill-defined visible neoplasia, DCE facilitated complete endoscopic resection in four individuals, whereas two individuals required colectomy for a diagnosis of cancer. Among 19 individuals with post-DCE surveillance, five developed new visible neoplastic lesions, including one high-grade neoplasia which was completely resected. Conclusions: In our cohort, DCE aided in unmasking invisible neoplasia and facilitated endoscopic resection of ill-defined neoplasia, suggesting that it is a useful surveillance tool in selected persons with cIBD. Large prospective studies are needed to validate these findings.

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

BACKGROUND: Multidisciplinary care involving exam under anesthesia (EUA) and tumor necrosis factor (TNF) inhibitors is recommended for perianal Crohn's disease. However, the impact of this combined approach is not well established. METHODS: We performed a comparative cohort study between 2009 and 2019. Patients with perianal Crohn's disease treated with EUA before anti-TNF therapy (combined modality therapy) were compared with anti-TNF alone. The primary outcome was fistula closure assessed clinically. Secondary outcomes included subsequent local surgery and fecal diversion. Multivariable analysis adjusted for abscesses, concomitant immunomodulators, and time to anti-TNF initiation was performed. RESULTS: Anti-TNF treatment was initiated 188 times in 155 distinct patients: 66 (35%) after EUA. Abscesses (50% vs 15%; P < .001) and concomitant immunomodulators (64% vs 50%; P = .07) were more common in the combined modality group, while age, smoking status, disease duration, and intestinal disease location were not significantly different. Combined modality therapy was not associated with higher rates of fistula closure at 3 (adjusted odds ratio [aOR], 0.7; 95% confidence interval [CI], 0.3-1.8), 6 (aOR, 0.8; 95% CI, 0.4-2.0) and 12 (aOR, 1.0; 95% CI, 0.4-2.2) months. After a median follow-up of 4.6 (interquartile range, 5.95; 2.23-8.18) years, combined therapy was associated with subsequent local surgical intervention (adjusted hazard ratio, 2.2; 95% CI, 1.3-3.6) but not with fecal diversion (adjusted hazard ratio, 1.3; 95% CI, 0.45-3.9). Results remained consistent when excluding patients with abscesses and prior biologic failure. CONCLUSIONS: EUA before anti-TNF therapy was not associated with improved clinical outcomes compared with anti-TNF therapy alone, suggesting that EUA may not be universally required. Future prospective studies controlling for fistula severity are warranted.

This comparative cohort study found that an exam under anesthesia before initiation of anti-tumor necrosis factor therapy in perianal Crohn's disease was not associated with higher rates of fistula closure, suggesting that an exam under anesthesia may not be universally required in patients with perianal Crohn's disease.

Effectiveness of Tofacitinib for Hospitalized Patients with Acute Severe Ulcerative Colitis: Case Series.

BACKGROUND: Treatment options for acute severe ulcerative colitis (ASUC) are limited. Tofacitinib, an approved treatment for moderate to severe ulcerative colitis, could be a potential rescue therapy for ASUC given its rapid onset of action. OBJECTIVE: To evaluate the effectiveness of tofacitinib in hospitalized patients with ASUC refractory to standard therapy in a real-world setting. METHODS: Retrospective observational study of hospitalized adult patients with ASUC treated with tofacitinib between January 2019 and September 2020 at five Canadian centers. We extracted patient demographics, clinical status, biomarkers (C-reactive protein and fecal calprotectin), endoscopic findings, and colectomy-free rate at admission, 30 days, 90 days, and 6 months after tofacitinib initiation. RESULTS: Eight patients with symptoms refractory to standard rescue therapy (corticosteroids ± infliximab if infliximab-naïve prior to admission) were treated with tofacitinib. During index hospitalization, clinical response was observed in 5/8 patients. The median time to discharge post-tofacitinib initiation was 5 days (IQR 5.0-6). At 30 and 90 days, all five responders were in clinical remission. At 6 months, only 3/5 responders remained in clinical remission. The colectomy-free rate was 37.5% during the follow-up period (two colectomies occurred within 30 days; one occurred within 90 days). No drug-related adverse reaction occurred. CONCLUSION: In this small case-series, tofacitinib was an effective rescue therapy in patients with refractory ASUC. These findings need to be evaluated in a randomized controlled trial.

Surgery and the Subtype of Inflammatory Bowel Disease Impact the Risk of Venous Thromboembolism After Hospital Discharge.

BACKGROUND: Surgery for inflammatory bowel disease (IBD) is associated with an increased risk of venous thromboembolism (VTE) during hospitalization. It is unclear whether this association persists after hospital discharge. AIMS: We assessed the association between surgery and VTE following hospital discharge in IBD. METHODS: We conducted a population-based cohort study between 2002 and 2016 in Ontario, Canada. Adults with IBD hospitalized for ≥ 72 h who underwent an intra-abdominal surgery were compared to hospitalized, nonsurgical IBD patients. Multivariable Cox proportional hazard models were used to compare VTE risk within 12 months of discharge. RESULTS: A total of 80,445 hospital discharges were analyzed: 60% Crohn's disease (CD) and 40% ulcerative colitis (UC). The median time to VTE was three times longer for nonsurgical patients with CD and 1.6 times longer for nonsurgical patients with UC. Compared with nonsurgical patients, surgery for CD was associated with a lower cumulative risk of VTE in the 2 weeks after discharge and persisted through to 12 months after discharge (adjusted HR 0.24; 95% CI 0.15-0.40). In contrast, urgent surgery for UC was associated with an increased risk of VTE. The increased risk was greatest at 2 weeks after discharge (aHR, 1.80; 95% CI 1.26-2.57) and declined progressively over the course of 12 months. CONCLUSIONS: Surgery was associated with a greater risk of VTE after hospital discharge in UC but not CD. In patients with UC who have undergone urgent surgery, healthcare providers should consider an extended period of prophylaxis after hospital discharge.

Fecal Diversion for Perianal Crohn Disease in the Era of Biologic Therapies: A Multicenter Study.

BACKGROUND: The natural history of perianal Crohn disease (PCD) after fecal diversion in the era of biologics is poorly understood. We assessed clinical and surgical outcomes after fecal diversion for medically refractory PCD and determined the impact of biologics. METHODS: We performed a retrospective, multicenter study from 1999 to 2020. Patients who underwent fecal diversion for refractory PCD were stratified by diversion type (ostomy with or without proctectomy). Times to clinical and surgical outcomes were estimated using Kaplan-Meier methods, and the association with biologics was assessed using multivariable Cox proportional hazards models. RESULTS: Eighty-two patients, from 3 academic institutions, underwent a total of 97 fecal diversions: 68 diversions without proctectomy and 29 diversions with proctectomy. Perianal healing occurred more commonly after diversion with proctectomy than after diversion without proctectomy (83% vs 53%; P = 0.021). Among the patients who had 68 diversions without proctectomy, with a median follow-up of 4.9 years post-diversion (interquartile range, 1.66-10.19), 37% had sustained healing, 31% underwent surgery to restore bowel continuity, and 22% underwent proctectomy. Ostomy-free survival occurred in 21% of patients. Biologics were independently associated with avoidance of proctectomy (hazard ratio, 0.32; 95% confidence interval, 0.11-0.98) and surgery to restore bowel continuity (hazard ratio, 3.10; 95% confidence interval, 1.02-9.37), but not fistula healing. CONCLUSIONS: In this multicenter study, biologics were associated with bowel restoration and avoidance of proctectomy after fecal diversion without proctectomy for PCD; however, a minority of patients achieved sustained fistula healing after initial fecal diversion or after bowel restoration. These results highlight the refractory nature of PCD.

Strategies to Distinguish Perianal Fistulas Related to Crohn's Disease From Cryptoglandular Disease: Systematic Review With Meta-Analysis.

BACKGROUND: Management of perianal fistulas differs based on fistula type. We aimed to assess the ability of diagnostic strategies to differentiate between Crohn's disease (CD) and cryptoglandular disease (CGD) in patients with perianal fistulas. METHODS: We performed a diagnostic accuracy systematic review and meta-analysis. A systematic search of electronic databases was performed from inception through February 2021 for studies assessing a diagnostic test's ability to distinguish fistula types. We calculated weighted summary estimates with 95% confidence intervals for sensitivity and specificity by bivariate analysis, using fixed effects models when data were available from 2 or more studies. The Quality Assessment of Diagnostic Accuracy Studies tool was used to assess study quality. RESULTS: Twenty-one studies were identified and included clinical symptoms (2 studies; n=154), magnetic resonance imaging (MRI) characteristics (3 studies; n=296), ultrasound characteristics (7 studies; n=1003), video capsule endoscopy (2 studies; n=44), fecal calprotectin (1 study; n=56), and various biomarkers (8 studies; n=440). MRI and ultrasound characteristics had the most robust data. Rectal inflammation, multiple-branched fistula tracts, and abscesses on pelvic MRI and the Crohn's ultrasound fistula sign, fistula debris, and bifurcated fistulas on pelvic ultrasonography had high specificity (range, 80%-95% vs 89%-96%) but poor sensitivity (range, 17%-37% vs 31%-63%), respectively. Fourteen of 21 studies had risk of bias on at least 1 of the Quality Assessment of Diagnostic Accuracy Studies domains. CONCLUSIONS: Limited high-quality evidence suggest that imaging characteristics may help discriminate CD from CGD in patients with perianal fistulas. Larger, prospective studies are needed to confirm these findings and to evaluate if combining multiple diagnostic tests can improve diagnostic sensitivity.

Differentiating between perianal fistulas related to cryptoglandular disease and Crohn's disease is essential to guide disease-specific management. A variety of imaging characteristics from magnetic resonance imaging and ultrasound had high specificity but relatively low sensitivity for predicting perianal fistulas associated with Crohn's disease.

Epidemiology and Natural History of Perianal Crohn's Disease: A Systematic Review and Meta-Analysis of Population-Based Cohorts.

BACKGROUND AND AIMS: Perianal Crohn's disease (pCD) is a potentially severe phenotype of CD. We conducted a systematic review with meta-analysis to estimate cumulative incidence, risk factors, and outcomes of pCD in population-based cohort studies. METHODS: Through a systematic literature review through March 1, 2021, we identified population-based inception cohort studies reporting cumulative incidence of perianal disease (primarily abscess and/or fistula) in patients with CD. We estimated the cumulative incidence of pCD at presentation and 1-, 5-, and 10-year follow-up, and risk factors for perianal disease and outcomes including risk of major (bowel resection, proctectomy, ostomy) and minor perianal (incision and drainage, seton placement, etc.) surgery. RESULTS: In 12 population-based studies, prevalence of pCD was 18.7% (95% confidence interval [CI], 12.5%-27.0%) with 1-, 5-, and 10-year risk of perianal disease being 14.3% (95% CI, 7.9%-24.6%), 17.6% (95% CI, 11.3%-26.5%), and 18.9% (95% CI, 15.0%-23.4%), respectively. Approximately 11.5% of patients (95% CI, 6.7%-19.0%) had perianal disease at or before CD diagnosis. Colonic disease location and rectal involvement were associated with higher risk of pCD. Overall, 63.3% of patients (95% CI, 53.3-72.3) required minor perianal surgery and 6.4% of patients (95% CI, 1.8%-20.6%) required major abdominal surgery for pCD. Use of biologic therapy for pCD is common and has steadily increased throughout the years. CONCLUSIONS: Approximately 1 in 5 patients with CD develops perianal disease within 10 years of CD diagnosis, including 11.5% who have perianal disease at presentation. Approximately two-thirds of patients require perianal surgery, with a smaller fraction requiring major abdominal surgery.

In a systematic review and meta-analysis of 12 population-based cohort studies, we observed that approximately 1 in 5 patients develops perianal disease within 10 years of Crohn's disease diagnosis. Of these, two-thirds require perianal surgery and 6% require major abdominal surgery.

Inflammatory Bowel Disease Increases the Risk of Venous Thromboembolism in Children: A Population-Based Matched Cohort Study.

BACKGROUND AND AIMS: Although venous thromboembolism [VTE] is a well-known complication of inflammatory bowel disease [IBD] in adults, limited data exist on the risk in children. We report the incidence of VTE among children with and without IBD. METHODS: We conducted a matched cohort study within a distributed network of population-based Canadian provincial health administrative databases. Children <16 years diagnosed with IBD were identified using validated algorithms from administrative data in Alberta, Manitoba, Nova Scotia, Ontario and Québec and compared to age- and sex-matched children without IBD. Hospitalizations for VTE within 5 years of IBD diagnosis were identified. Generalized linear mixed-effects models were used to pool province-specific incidence rates and incidence rate ratios [IRR] with 95% confidence intervals [CI]. Hazard ratios [HR] from Cox proportional hazards models were pooled with fixed-effects meta-analysis. RESULTS: The 5-year incidence of VTE among 3593 children with IBD was 31.2 [95% CI 23.7-41.0] per 10 000 person-years [PY] compared to 0.8 [95% CI 0.4-1.7] per 10 000 PY among 16 289 children without IBD [unadjusted IRR 38.84, 95% CI 16.59-90.83; adjusted HR 22.91, 95% CI 11.50-45.63]. VTE was less common in Crohn's disease than ulcerative colitis [unadjusted IRR 0.47, 95% CI 0.27-0.83; adjusted HR 0.52, 95% CI 0.29-0.94]. The findings were similar for deep vein thrombosis and pulmonary embolism when comparing children with and without IBD. CONCLUSIONS: The risk of VTE is much higher in children with IBD than controls without IBD. While the absolute risk is low, we found a higher incidence rate than previously described in the pediatric literature.Conference Presentation: An abstract based on the data included in this paper was presented at Canadian Digestive Diseases Week [Montréal, Canada] in March 2020.

Absence of Day 3 Steroid Response Predicts Colitis-Related Complications and Colectomy in Hospitalized Ulcerative Colitis Patients.

BACKGROUND AND AIMS: Rates and predictors of complications among hospitalized ulcerative colitis (UC) patients requiring high-dose corticosteroids have not been well-characterized, especially in the era of biologics. METHODS: We retrospectively studied consecutive UC admitted for a colitis flare requiring high-dose corticosteroids between April 2006 and December 2016. We evaluated rates and determinants of serious in-hospital complications (colitis-related complications, systemic complications, peri-operative complications and death) and colectomy. We performed multivariable logistic regression analysis to assess the independent association between day 3 steroid response and the risk of incurring in-hospital complications and colectomy. RESULTS: Of 427 consecutive admissions, serious in-hospital complications occurred in 87 cases (20%), while colitis-related complications occurred in 47 cases (11%). There were significantly fewer colitis-related complications during the 2012 to 2016 period as compared to the 2006 to 2011 period (7% versus 16%, P < 0.01), but significantly more systemic complications (16% versus 5%, P = 0.001). In-hospital colectomy occurred in 50 hospitalizations (12%). Day 3 steroid response was achieved in 167 hospitalizations (39%). Day 3 steroid nonresponse was significantly associated with colitis-related complications among males (adjusted odds ratio [aOR] 8.22, 95% confidence interval [CI] 1.77 to 38.17), but not among females (aOR 1.39, 95% CI 0.54 to 3.60). Older age, C. difficile infection and admission to a non-gastroenterology service were also associated with a higher risk of in-hospital complications. Day 3 steroid nonresponse was significantly associated with in-hospital colectomy (aOR 10.10, 95% CI 3.56 to 28.57). CONCLUSION: In our series of UC hospitalizations for a colitis flare, absence of day 3 steroid response was associated with an increased risk of colitis-related complications among males and of in-hospital colectomy. Clinicians should recognize the importance of early steroid response as a marker to guide the need for treatment optimization.

Venous thromboembolic events in inflammatory bowel diseases: A review of current evidence and guidance on risk in the post-hospitalization setting.

Venous thromboembolism (VTE) is a life-threatening, yet potentially preventable, complication of inflammatory bowel disease (IBD). The incidence of VTE in IBD is roughly three-fold greater than in the general population, and results in a 2-fold increased risk of mortality. The absolute risk is highest during hospitalization and has led to consensus guidelines recommending thromboprophylaxis for all admitted patients with IBD in the absence of contraindications. Emerging evidence suggests that the risk of VTE is likely to remain high early after hospital discharge. Despite this, it remains unclear if thromboprophylaxis should be continued after hospitalization. Therefore, this review will synthesize the available literature pertaining to the post-discharge setting with a focus on the incidence of VTE, associated risk factors, and the potential role for extended thromboprophylaxis.

Risk of Venous Thromboembolism After Hospital Discharge in Patients With Inflammatory Bowel Disease: A Population-based Study.

BACKGROUND: Inflammatory bowel disease (IBD) is associated with a high risk of venous thromboembolism (VTE) during hospitalization. It is unclear if this association persists after discharge. We aimed to assess the incidence of postdischarge VTE in IBD patients and to determine if IBD is associated with increased VTE risk. METHODS: We performed a population-based cohort study between 2002 and 2016 using Ontario health administrative data sets. Hospitalized (≥72 hours) adults with IBD were stratified into nonsurgical and surgical cohorts and matched on propensity score to non-IBD controls. Time to postdischarge VTE was assessed by Kaplan-Meier methods, and VTE risk was assessed by Cox proportional hazard models. RESULTS: A total of 81,900 IBD discharges (62,848 nonsurgical and 19,052 surgical) were matched to non-IBD controls. The cumulative incidence of VTE at 12 months after discharge was 2.3% for nonsurgical IBD patients and 1.6% for surgical IBD patients. The incidence increased in the nonsurgical IBD cohort by 4% per year (incidence rate ratio, 1.04; 95% CI, 1.02-1.05). In our propensity score-matched analysis, the risk of VTE at 1-month postdischarge was greater in nonsurgical IBD patients (hazard ratio [HR], 1.72; 95% CI, 1.51-1.96) and surgical patients with ulcerative colitis (HR, 1.68; 95% CI, 1.16-2.45) but not surgical patients with Crohn's disease. These trends persisted through 12 months. CONCLUSIONS: Nonsurgical IBD patients and surgical patients with ulcerative colitis are 1.7-fold more likely to develop postdischarge VTE than non-IBD patients. These findings support the need for increased vigilance and consideration of thromboprophylaxis in this population.