Perianal Crohn’s disease:Still more questions than answers

In this editorial we comment on the article by Pacheco et al published in a recent issue of the World Journal of Gastroenterology.We focus specifically on the burden of illness associated with perianal fistulizing Crohn’s disease(PFCD)and the diagnostic and therapeutic challenges in the management of this condition.Evol-ving evidence has shifted the diagnostic framework for PFCD from anatomical classification systems,to one that is more nuanced and patient-focused to drive ongoing decision making.This editorial aims to reflect on these aspects to help clinicians face the challenge of PFCD in day-to-day clinical practice.

Higher infliximab and adalimumab trough levels are associated with fistula healing in patients with fistulising perianal Crohn’s disease

BACKGROUND Tumor necrosis factor-alpha inhibitors,including infliximab and adalimumab,are effective medical treatments for perianal fistulising Crohn’s disease(CD),but not all patients achieve fistula healing.AIM To determine the correlation between perianal fistula healing and closure with infliximab and adalimumab trough levels.METHODS In this multicentre retrospective study conducted across four tertiary inflammatory bowel disease centres in Australia,we identified CD patients with perianal fistulae on maintenance infliximab or adalimumab who had a trough level within twelve weeks of clinical assessment.Data collected included demographics,serum infliximab and adalimumab trough levels(mg/L)within 12 wk before or after their most recent clinical assessment and concomitant medical or surgical therapy.The primary outcome was fistula healing,defined as cessation in fistula drainage.The secondary outcome was fistula closure,defined as healing and closure of all external fistula openings.Differences between patients who did or did not achieve fistula healing were compared using the chi-square test,t test or Mann-Whitney U test.RESULTS One hundred and fourteen patients(66 infliximab,48 adalimumab)were included.Forty-eight(72.7%)patients on maintenance infliximab achieved fistula healing and 18(27.3%)achieved fistula closure.Thirty-seven(77%)patients on maintenance adalimumab achieved fistula healing and 17(35.4%)achieved fistula closure.Patients who achieved fistula healing had significantly higher infliximab and adalimumab trough levels than patients who did not[infliximab:6.4(3.8-9.5)vs 3.0(0.3-6.2)mg/L,P=0.003;adalimumab:9.2(6.5-12.0)vs 5.4(2.5-8.3)mg/L,P=0.004].For patients on infliximab,fistula healing was associated with lower rates of detectable anti-infliximab antibodies and younger age.For patients on adalimumab,fistula healing was associated with higher rates of combination therapy with an immunomodulator.Serum trough levels for patients with and without fistula closure were not significantly different for infliximab[6.9(4.3-10.2)vs 5.5(2.5-8.3)mg/L,P=0.105]or adalimumab[10.0(6.6-12.0)vs 7.8(4.2-10.0)mg/L,P=0.083].CONCLUSION Higher maintenance infliximab and adalimumab trough levels are associated with perianal fistula healing in CD.

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 shortterm 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.Longterm benefit with infliximab was not proven,at least in patients with anorectal stricture.

Assessment of perianal fistulizing Crohn’s disease activity with endoanal ultrasound: A retrospective cohort study

BACKGROUND Perianal fistulas pose dual challenges to Crohn's disease(CD)patients.Low patient compliance due to the complexity of existing examination methods plagues the treatment and follow-up management of perianal CD.AIM To determine the accuracy of endoanal ultrasound(EUS)and shear wave elastography(SWE)for evaluating perianal fistulizing CD(PFCD)activity.METHODS This was a retrospective cohort study.A total of 67 patients from August 2022 to December 2023 diagnosed with CD were divided into three groups:Non-anal fistula group(n=23),low-activity perianal fistulas[n=19,perianal disease activity index(PDAI)≤4],high-activity perianal fistulas(n=25,PDAI>4)based on the PDAI.All patients underwent assessments including EUS+SWE,pelvic magnetic resonance[pelvic magnetic resonance imaging(MRI)],C-reactive protein,fecal calprotectin,CD activity index,PDAI.RESULTS The percentage of fistulas indicated by pelvic MRI and EUS was consistent at 82%,and there was good consistency in the classification of perianal fistulas(Kappa=0.752,P<0.001).Significant differences were observed in the blood flow Limberg score(χ^(2)=8.903,P<0.05)and shear wave velocity(t=2.467,P<0.05)between group 2 and 3.Shear wave velocity showed a strong negative correlation with magnetic resonance novel index for fistula imaging in CD(Magnifi-CD)score(r=-0.676,P<0.001),a weak negative correlation with the PDAI score(r=-0.386,P<0.05),and a weak correlation between the Limberg score and the PDAI score(r=0.368,P<0.05).CONCLUSION EUS combined with SWE offers a superior method for detecting and quantitating the activity of perianal fistulas in CD patients.It may be the ideal tool to assess PFCD activity objectively for management strategies.

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.

Prevalence and risk factors of depression among patients with perianal fistulizing Crohn’s disease

BACKGROUND Psychological distress,especially depression,associated with perianal fistulizing Crohn’s disease(PFCD)is widespread and refractory.However,there is a surprising paucity of studies to date that have sought to identify the prevalence and risk factors of depression associated with PFCD.AIM To estimate the prevalence of depressive symptoms and investigate the depression-related risk factors in patients with PFCD.METHODS The study was conducted in the form of survey and clinical data collection via questionnaire and specialized medical staff.Depressive symptoms,life quality,and fatigue severity of patients with PFCD were assessed by Patient Health Questionnaire-9,Inflammatory Bowel Disease Patient Quality of Life Questionnaire(IBDQ),and Inflammatory Bowel Disease(IBD)Fatigue Patient Self-assessment Scale.The basic demographic information,overall disease features,perianal clinical information,and laboratory inflammation indicators were also gathered.Multivariate regression analysis was ultimately used to ascertain the risk factors of depression associated with PFCD.RESULTS A total of 123 patients with PFCD were involved,and 56.91%were suffering from depression.According to multivariate logistic regression analysis,Perianal Disease Activity Index(PDAI)score[odds ratio(OR)=0.69,95%confidence interval(CI):0.50 to 0.95],IBDQ score(OR=0.93,95%CI:0.88 to 0.97),modified Van Assche index(OR=1.24,95%CI:1.01 to 1.53),and IBD Fatigue score(OR=1.72,95%CI:1.23 to 2.42)were independent risk factors of depression-related prevalence among patients with PFCD(P<0.05).Multiple linear regression analysis revealed that the increasing perianal modified Van Assche index(βvalue=0.166,95%CI:0.02 to 0.31)and decreasing IBDQ score(βvalue=-0.116,95%CI:-0.14 to-0.09)were independently associated with the severity of depression(P<0.05).CONCLUSION Depressive symptoms in PFCD patients have significantly high prevalence.PDAI score,modified Van Assche index,quality of life,and fatigue severity were the main independent risk factors.

Predicting short-term major postoperative complications in intestinal resection for Crohn’s disease:A machine learning-based study

BACKGROUND Due to the complexity and numerous comorbidities associated with Crohn’s disease(CD),the incidence of postoperative complications is high,significantly impacting the recovery and prognosis of patients.Consequently,additional stu-dies are required to precisely predict short-term major complications following intestinal resection(IR),aiding surgical decision-making and optimizing patient care.AIM To construct novel models based on machine learning(ML)to predict short-term major postoperative complications in patients with CD following IR.METHODS A retrospective analysis was performed on clinical data derived from a patient cohort that underwent IR for CD from January 2017 to December 2022.The study participants were randomly allocated to either a training cohort or a validation cohort.The logistic regression and random forest(RF)were applied to construct models in the training cohort,with model discrimination evaluated using the area under the curves(AUC).The validation cohort assessed the performance of the constructed models.RESULTS Out of the 259 patients encompassed in the study,5.0%encountered major postoperative complications(Clavien-Dindo≥III)within 30 d following IR for CD.The AUC for the logistic model was 0.916,significantly lower than the AUC of 0.965 for the RF model.The logistic model incorporated a preoperative CD activity index(CDAI)of≥220,a diminished preoperative serum albumin level,conversion to laparotomy surgery,and an extended operation time.A nomogram for the logistic model was plotted.Except for the surgical approach,the other three variables ranked among the top four important variables in the novel ML model.CONCLUSION Both the nomogram and RF exhibited good performance in predicting short-term major postoperative complic-ations in patients with CD,with the RF model showing more superiority.A preoperative CDAI of≥220,a di-minished preoperative serum albumin level,and an extended operation time might be the most crucial variables.The findings of this study can assist clinicians in identifying patients at a higher risk for complications and offering personalized perioperative management to enhance patient outcomes.

Role of gut microbiota in Crohn’s disease pathogenesis:Insights from fecal microbiota transplantation in mouse model

BACKGROUND Inflammatory bowel disease,particularly Crohn’s disease(CD),has been associated with alterations in mesenteric adipose tissue(MAT)and the phenomenon termed“creeping fat”.Histopathological evaluations showed that MAT and intestinal tissues were significantly altered in patients with CD,with these tissues characterized by inflammation and fibrosis.AIM To evaluate the complex interplay among MAT,creeping fat,inflammation,and gut microbiota in CD.METHODS Intestinal tissue and MAT were collected from 12 patients with CD.Histological manifestations and protein expression levels were analyzed to determine lesion characteristics.Fecal samples were collected from five recently treated CD patients and five control subjects and transplanted into mice.The intestinal and mesenteric lesions in these mice,as well as their systemic inflammatory status,were assessed and compared in mice transplanted with fecal samples from CD patients and control subjects.RESULTS Pathological examination of MAT showed significant differences between CDaffected and unaffected colons,including significant differences in gut microbiota structure.Fetal microbiota transplantation(FMT)from clinically healthy donors into mice with 2,4,6-trinitrobenzene sulfonic acid(TNBS)-induced CD ameliorated CD symptoms,whereas FMT from CD patients into these mice exacerbated CD symptoms.Notably,FMT influenced intestinal permeability,barrier function,and levels of proinflammatory factors and adipokines.Furthermore,FMT from CD patients intensified fibrotic changes in the colon tissues of mice with TNBS-induced CD.CONCLUSION Gut microbiota play a critical role in the histopathology of CD.Targeting MAT and creeping fat may therefore have potential in the treatment of patients with CD.

Crohn’s disease as the intestinal manifestation of pan-lymphatic dysfunction:An exploratory proposal based on basic and clinical data

Crohn’s disease(CD)is caused by immune,environmental,and genetic factors.It can involve the entire gastrointestinal tract,and although its prevalence is rapidly increasing its etiology remains unclear.Emerging biological and small-molecule drugs have advanced the treatment of CD;however,a considerable proportion of patients are non-responsive to all known drugs.To achieve a breakthrough in this field,innovations that could guide the further development of effective therapies are of utmost urgency.In this review,we first propose the innovative concept of pan-lymphatic dysfunction for the general distribution of lymphatic dysfunction in various diseases,and suggest that CD is the intestinal manifestation of pan-lymphatic dysfunction based on basic and clinical preliminary data.The supporting evidence is fully summarized,including the existence of lymphatic system dysfunction,recognition of the inside-out model,disorders of immune cells,changes in cell plasticity,partial overlap of the underlying mechanisms,and common gut-derived fatty and bile acid metabolism.Another benefit of this novel concept is that it proposes adopting the zebrafish model for studying intestinal diseases,especially CD,as this model is good at presenting and mimicking lymphatic dysfunction.More importantly,the ensuing focus on improving lymphatic function may lead to novel and promising therapeutic strategies for CD.

Duodenal Crohn’s disease:Case report and systematic review

BACKGROUND Inflammatory bowel disease,including ulcerative colitis,microscopic colitis,and Crohn’s disease(CD),has a global impact.This review focuses on duodenal CD(DCD),a rare subtype affecting the duodenum.DCD’s rarity and asymptomatic nature create diagnostic challenges,impacting prognosis and patient well-being.Delayed diagnosis can worsen DCD outcomes.AIM To report a rare case of DCD and to discuss the diagnostic challenges and its implications on prognosis.METHODS A systematic literature search,following the PRISMA statement,was conducted.Relevant studies were identified and analysed using specific Medical Subject Terms(MeSH)from PubMed/MEDLINE,American Journal of Gastroenterology,and the University of South Wales database.Data collection included information from radiology scans,endoscopy procedures,biopsies,and histopathology results.RESULTS The review considered 8 case reports and 1 observational study,involving 44 participants diagnosed with DCD,some of whom developed complications due to delayed diagnosis.Various diagnostic methods were employed,as there is no gold standard workup for DCD.Radiology scans[magnetic resonance imaging(MRI),computed tomography(CT),and upper gastrointestinal X-ray],endoscopy procedures(colonoscopy and esophagogastroduodenoscopy),biopsies,and clinical suspicions were utilized.CONCLUSION This review discusses DCD diagnosis challenges and the roles of CT,MRI,and fluoroscopy.It notes their limitations and compares findings with endoscopy and histopathology studies.Further research is needed to improve diagnosis,emphasizing scan interpretation,endoscopy procedures,and biopsies,especially in high-risk patients during routine endoscopy.

Diagnostic performance of texture analysis in the differential diagnosis of perianal fistulising Crohn’s disease and glandular anal fistula

BACKGROUND Perianal fistulising Crohn's disease(PFCD)and glandular anal fistula have many similarities on conventional magnetic resonance imaging.However,many patients with PFCD show concomitant active proctitis,but only few patients with glandular anal fistula have active proctitis.AIM To explore the value of differential diagnosis of PFCD and glandular anal fistula by comparing the textural feature parameters of the rectum and anal canal in fat suppression T2-weighted imaging(FS-T2WI).METHODS Patients with rectal water sac implantation were screened from the first part of this study(48 patients with PFCD and 22 patients with glandular anal fistula).Open-source software ITK-SNAP(Version 3.6.0,http://www.itksnap.org/)was used to delineate the region of interest(ROI)of the entire rectum and anal canal wall on every axial section,and then the ROIs were input in the Analysis Kit software(version V3.0.0.R,GE Healthcare)to calculate the textural feature parameters.Textural feature parameter differences of the rectum and anal canal wall between the PFCD group vs the glandular anal fistula group were analyzed using Mann-Whitney U test.The redundant textural parameters were screened by bivariate Spearman correlation analysis,and binary logistic regression analysis was used to establish the model of textural feature parameters.Finally,diagnostic accuracy was assessed by receiver operating characteristic-area under the curve(AUC)analysis.RESULTS In all,385 textural parameters were obtained,including 37 parameters with statistically significant differences between the PFCD and glandular anal fistula groups.Then,16 texture feature parameters remained after bivariate Spearman correlation analysis,including one histogram parameter(Histogram energy);four grey level co-occurrence matrix(GLCM)parameters(GLCM energy_all direction_offset1_SD,GLCM entropy_all direction_offset4_SD,GLCM entropy_all direction_offset7_SD,and Haralick correlation_all direction_offset7_SD);four texture parameters(Correlation_all direction_offset1_SD,cluster prominence_angle 90_offset4,Inertia_all direction_offset7_SD,and cluster shade_angle 45_offset7);five grey level run-length matrix parameters(grey level nonuniformity_angle 90_offset1,grey level nonuniformity_all direction_offset4_SD,long run high grey level emphasis_all direction_offset1_SD,long run emphasis_all direction_offset4_SD,and long run high grey level emphasis_all direction_offset4_SD);and two form factor parameters(surface area and maximum 3D diameter).The AUC,sensitivity,and specificity of the model of textural feature parameters were 0.917,85.42%,and 86.36%,respectively.CONCLUSION The model of textural feature parameters showed good diagnostic performance for PFCD.The texture feature parameters of the rectum and anal canal in FS-T2WI are helpful to distinguish PFCD from glandular anal fistula.

Physician-dependent diagnosis delay in Crohn's disease:A pseudoproposition or not?

The challenge of diagnosis delay in inflammatory bowel disease(IBD)has emerged as a significant concern for both patients and healthcare professionals.The widely accepted notion that there is an extended time frame from the onset of symptoms to the definitive diagnosis is often attributed to the heterogeneity of IBD and the non-specificity of clinical manifestations.Specific to patients with Crohn’s disease,the issue of delayed diagnosis appears to be more pronounced across different regions globally.The intricate interplay of real-world factors has led to debates regarding the primary contributors to these diagnostic delays.Drawing a comparison solely between patients and physicians and implicating the latter as the predominant influence factor may fall into a simplistic either-or logical trap that may obscure the truth.This letter,grounded in published evidence,explores areas for improvement in a forthcoming paper within the field,hoping to pinpoint the culprit behind the diagnosis delay issue for IBD patients rather than simply attributing it to so-called“physician-dependent factors”.Our objective is to motivate healthcare providers and policymakers in relevant fields to reflect on strategies for addressing this problem to reduce diagnostic delays and enhance patient outcomes.

Pediatric stricturing Crohn's disease

Crohn’s disease(CD)is a chronic inflammatory disease of the digestive tract.The incidence of pediatric CD is increasing and is currently 2.5-11.4 per 100000 world-wide.Notably,approximately 25%of children with CD develop stricturing CD(SCD)that requires intervention.Symptomatic stricturing diseases refractory to pharmacological management frequently require non-pharmacological interventions.Non-pharmacological therapeutic strategies include endoscopic balloon dilatation,stricturoplasty,and surgical resection of the strictured seg-ment.However,strictures tend to recur postoperatively regardless of treatment modality.The lifetime risk of surgery in patients with childhood SCD remains at 50%-90%.Thus,new and emerging strategies,advanced diagnostic tools,and minimally invasive approaches are under investigation to improve the outcomes and overall quality of life of pediatric patients with SCD.

Differential diagnosis of Crohn’s disease and intestinal tuberculosis based on ATR-FTIR spectroscopy combined with machine learning

BACKGROUND Crohn’s disease(CD)is often misdiagnosed as intestinal tuberculosis(ITB).However,the treatment and prognosis of these two diseases are dramatically different.Therefore,it is important to develop a method to identify CD and ITB with high accuracy,specificity,and speed.AIM To develop a method to identify CD and ITB with high accuracy,specificity,and speed.METHODS A total of 72 paraffin wax-embedded tissue sections were pathologically and clinically diagnosed as CD or ITB.Paraffin wax-embedded tissue sections were attached to a metal coating and measured using attenuated total reflectance fourier transform infrared spectroscopy at mid-infrared wavelengths combined with XGBoost for differential diagnosis.RESULTS The results showed that the paraffin wax-embedded specimens of CD and ITB were significantly different in their spectral signals at 1074 cm^(-1) and 1234 cm^(-1) bands,and the differential diagnosis model based on spectral characteristics combined with machine learning showed accuracy,specificity,and sensitivity of 91.84%,92.59%,and 90.90%,respectively,for the differential diagnosis of CD and ITB.CONCLUSION Information on the mid-infrared region can reveal the different histological components of CD and ITB at the molecular level,and spectral analysis combined with machine learning to establish a diagnostic model is expected to become a new method for the differential diagnosis of CD and ITB.

Washed microbiota transplantation for Crohn’s disease:A metagenomic,metatranscriptomic,and metabolomic-based study

BACKGROUND Fecal microbiota transplantation(FMT)is a promising therapeutic approach for treating Crohn’s disease(CD).The new method of FMT,based on the automatic washing process,was named as washed microbiota transplantation(WMT).Most existing studies have focused on observing the clinical phenomena.However,the mechanism of action of FMT for the effective management of CD-particularly in-depth multi-omics analysis involving the metagenome,metatranscriptome,and metabolome-has not yet been reported.AIM To assess the efficacy of WMT for CD and explore alterations in the microbiome and metabolome in response to WMT.METHODS We conducted a prospective,open-label,single-center clinical study.Eleven CD patients underwent WMT.Their clinical responses(defined as a decrease in their CD Activity Index score of>100 points)and their microbiome(metagenome,metatranscriptome)and metabolome profiles were evaluated three months after the procedure.RESULTS Seven of the 11 patients(63.6%)showed an optimal clinical response three months post-WMT.Gut microbiome diversity significantly increased after WMT,consistent with improved clinical symptoms.Comparison of the metagenome and metatranscriptome analyses revealed consistent alterations in certain strains,such as Faecalibac-terium prausnitzii,Roseburia intestinalis,and Escherichia coli.In addition,metabolomics analyses demonstrated that CD patients had elevated levels of various amino acids before treatment compared to the donors.However,levels of vital amino acids that may be associated with disease progression(e.g.,L-glutamic acid,gamma-glutamyl-leucine,and prolyl-glutamine)were reduced after WMT.CONCLUSION WMT demonstrated therapeutic efficacy in CD treatment,likely due to the effective reconstruction of the patient’s microbiome.Multi-omics techniques can effectively help decipher the potential mechanisms of WMT in treating CD.

Treat to target in Crohn’s disease:A practical guide for clinicians

A treat-to-target(T2T)approach applies the principles of early intervention and tight disease control to optimise long-term outcomes in Crohn's disease.The Selecting Therapeutic Targets in Inflammatory Bowel Disease(STRIDE)-II guidelines specify short,intermediate,and long-term treatment goals,documenting specific treatment targets to be achieved at each of these timepoints.Scheduled appraisal of Crohn’s disease activity against pre-defined treatment targets at these timepoints remains central to determining whether current therapy should be continued or modified.Consensus treatment targets in Crohn’s disease comprise combination clinical and patient-reported outcome remission,in conjunction with biomarker normalisation and endoscopic healing.Although the STRIDE-II guidelines endorse the pursuit of endoscopic healing,clinicians must consider that this may not always be appropriate,acceptable,or achievable in all patients.This underscores the need to engage patients at the outset in an effort to personalise care and individualise treatment targets.The use of non-invasive biomarkers such as faecal calprotectin in conjunction with cross-sectional imaging techniques,particularly intestinal ultrasound,holds great promise;as do emerging treatment targets such as transmural healing.Two randomised clinical trials,namely,CALM and STARDUST,have evaluated the efficacy of a T2T approach in achieving endoscopic endpoints in patients with Crohn’s disease.Findings from these studies reflect that patient subgroups and Crohn’s disease characteristics likely to benefit most from a T2T approach,remain to be clarified.Moreover,outside of clinical trials,data pertaining to the real-world effectiveness of a T2T approach remains scare,highlighting the need for pragmatic real-world studies.Despite the obvious promise of a T2T approach,a lack of guidance to support its integration into real-world clinical practice has the potential to limit its uptake.This highlights the need to describe strategies,processes,and models of care capable of supporting the integration and execution of a T2T approach in real-world clinical practice.Hence,this review seeks to examine the current and emerging literature to provide clinicians with practical guidance on how to incorporate the principles of T2T into routine clinical practice for the management of Crohn’s disease.

Early proactive monitoring of DNA-thioguanine in patients with Crohn’s disease predicts thiopurine-induced late leucopenia in NUDT15/TPMT normal metabolizers

BACKGROUND Thiopurine-induced leucopenia significantly hinders the wide application of thiopurines.Dose optimization guided by nudix hydrolase 15(NUDT15)has significantly reduced the early leucopenia rate,but there are no definitive biomarkers for late risk leucopenia prediction.AIM To determine the predictive value of early monitoring of DNA-thioguanine(DNATG)or 6-thioguanine nucleotides(6TGN)for late leucopenia under a NUDT15-guided thiopurine dosing strategy in patients with Crohn’s disease(CD).METHODS Blood samples were collected within two months after thiopurine initiation for detection of metabolite concentrations.Late leucopenia was defined as a leukocyte count<3.5×10^(9)/L over two months.RESULTS Of 148 patients studied,late leucopenia was observed in 15.6%(17/109)of NUDT15/thiopurine methyltransferase(TPMT)normal and 64.1%(25/39)of intermediate metabolizers.In patients suffering late leucopenia,early DNATG levels were significantly higher than in those who did not develop late leucopenia(P=4.9×10^(-13)).The DNATG threshold of 319.43 fmol/μg DNA could predict late leucopenia in the entire sample with an area under the curve(AUC)of 0.855(sensitivity 83%,specificity 81%),and in NUDT15/TPMT normal metabolizers,the predictive performance of a threshold of 315.72 fmol/μg DNA was much more remarkable with an AUC of 0.902(sensitivity 88%,specificity 85%).6TGN had a relatively poor correlation with late leucopenia whether in the entire sample(P=0.021)or NUDT15/TPMT normal or intermediate metabolizers(P=0.018,P=0.55,respectively).CONCLUSION Proactive therapeutic drug monitoring of DNATG could be an effective strategy to prevent late leucopenia in both NUDT15/TPMT normal and intermediate metabolizers with CD,especially the former.

Global geoepidemiology of gastrointestinal surgery rates in Crohn’s disease

BACKGROUND Data regarding the worldwide gastrointestinal surgery rates in patients with Crohn’s disease(CD)remains limited.AIM To systematically review the global variation in the rates of surgery in CD.METHODS A comprehensive search analysis was performed using multiple electronic databases from inception through July 1,2020,to identify all full text,randomized controlled trials and cohort studies pertaining to gastrointestinal surgery rates in adult patients with CD.Outcomes included continent based demographic data,CD surgery rates over time,as well as the geoepidemiologic variation in CD surgery rates.Statistical analyses were conducted using R.RESULTS Twenty-three studies spanning four continents were included.The median proportion of persons with CD who underwent gastrointestinal surgery in studies from North America,Europe,Asia,and Oceania were 30%(range:1.7%-62.0%),40%(range:0.6%-74.0%),17%(range:16.0%-43.0%),and 38%respectively.No clear association was found regarding the proportion of patients undergoing gastrointestinal surgery over time in North America(R^(2)=0.035)and Europe(R^(2)=0.100).A moderate,negative association was seen regarding the proportion of patients undergoing gastrointestinal surgery over time(R^(2)=0.520)in Asia.CONCLUSION There appears to be significant inter-continental variation regarding surgery rates in CD.Homogenous evidencebased guidelines accounting for the geographic differences in managing patients with CD is prudent.Moreover,as a paucity of data on surgery rates in CD exists outside the North American and European continents,future studies,particularly in less studied locales,are warranted.

New anti-mesenteric delta-shaped stapled anastomosis: Technical report with short-term postoperative outcomes in patients with Crohn’s disease

BACKGROUND Medical treatment for Crohn’s disease(CD)has continuously improved,which has led to a decrease in surgical recurrence rates.Despite these advancements,25%of patients will undergo repeat intestinal surgery.Recurrence of CD com-monly occurs on the mesentery side of the anastomosis site.AIM To compare the new anti-mesenteric side-to-side delta-shaped stapled anasto-mosis(DSA)with the conventional stapled functional end-to-end anastomosis(CSA).METHODS This retrospective study included CD patients who underwent ileo-ileal or ileo-colic anastomosis between January 2020 and December 2023.The DSA technique employed a stapler to maintain the concept of anti-mesentery side-to-side ana-stomosis by performing a 90°vertical closure of the open window compared with the CSA technique.At the corner where the open window is closed,the DSA avoids forming a pouch and creates an anastomosis resembling a delta shape within the intestinal lumen.We compared demographics,preoperative condition,operative findings,and operative outcomes for the two techniques.RESULTS The study included 175 patients,including 92 in the DSA group and 83 in the CSA group.The two groups were similar in baseline characteristics,preoperative medical treatment,and operative findings except for the Montreal classification location.The 30-days postoperative complication rate was signi-ficantly lower in the DSA group compared with the CSA group(16.3%vs 32.5%,P=0.009).Ileus incidence was significantly lower in the DSA group than in the CSA group(4.3%vs 14.5%,P=0.033),and the hospital stay was shorter in the DSA group than in the CSA group(5.67±1.53 days vs 7.39±3.68 days,P=0.001).CONCLUSION The DSA technique was feasible and showed comparable postoperative outcomes with lower short-term complic-ations compared with the CSA technique.Further studies on CD recurrence and long-term complications are warranted.

Can serious postoperative complications in patients with Crohn’s disease be predicted using machine learning?

The routine introduction of novel anti-inflammatory therapies into the mana-gement algorithms of patients with Crohn’s disease over the last 2 decades has not substantially changed the likelihood of ultimate surgery.Rather it has delayed the operative need and altered the presentation phenotype.The prospect of complic-ations continues to remain high in this modern era but depending upon the cohort assessed,it remains difficult to make strict comparisons between individual spe-cialist centres.Those patients who present rather late after their diagnosis with a septic complication like an intra-abdominal abscess and a penetrating/fistulizing pattern of disease are more likely to have a complicated course particularly if they have clinical features such as difficult percutaneous access to the collection or multilocularity both of which can make preoperative drainage unsuccessful.Eq-ually,those cases with extensive adhesions where an initial laparoscopic approach needs open conversion and where there is an extended operative time,unsur-prisingly will suffer more significant complications that impact their length of hospital stay.The need for a protective stoma also introduces its own derivative costs,utilizing a range of health resources as well as resulting in important alte-rations in quality of life outcomes.Having established the parameters of the pro-blem can the statistical analysis of the available data identify high-risk cases,promote the notion of centralization of specialist services or improve the allo-cation of disease-specific health expenditure?