Analysis Of Prognostic Value Of Pan-enteric Mucosal Healing In Non-stricturing And Non-penetrating Crohn’s Disease

Background and aims:Mucosal healing(MH)identified by ileocolonoscopy(IC)has been a major therapeutic goal in Crohn’s disease(CD).However,only a very limited part of the small bowel can be explored by IC.In patients achieving IC-identified MH,endoscopic inflammation of the entire intestine has rarely been reported.In current clinical guidelines,all patients with newly diagnosed CD should undergo further investigation of the entire intestine,irrespective of the findings at IC.However,it remains unclear whether pan-enteric MH should be evaluated at the follow-up visits.Thus far,the relationship between IC-identified MH and pan-enteric MH remains unknown,and the role of pan-enteric MH in CD still needs to be investigated.In this study,we aimed to evaluate the relationship between IC-identified MH and pan-enteric MH in patients with non-stricturing and non-penetrating CD,and further to analyze whether pan-enteric MH was associated with patients’ long-term outcomes.Objects and methods:This was a retrospective study conducted in our hospital between January 2011 and June 2019.Inclusion criteria were as follows:(1)patients had active disease identified by both IC and capsule endoscopy(CE)at diagnosis,(2)patients underwent re-examination of both IC and CE(the first follow-up endoscopic examination)within one year after diagnosis,and(3)patients achieved clinical remission,a normal level of C-reactive protein(CRP),and IC-identified MH at the first follow-up endoscopic examination.Exclusion criteria were as follows:(1)patients with intestinal stenosis,fistula,or abscess at diagnosis,(2)patients with a follow-up period less than 1 year after the first follow-up endoscopic examination.According to the inclusion and exclusion criteria,all patients included in our study had achieved clinical remission and IC-identified MH at the first follow-up endoscopic examination,and were followed up after that for at least 1 year.The primary outcome was treatment failure,defined by clinical recurrence,CD-related hospitalization,or CD-related surgery.Cox regression analysis was used to investigate the predictors of treatment failure.Results:A total of 529 patients with active disease identified by IC were screened.To prevent CE retention,134 patients with stricturing or penetrating disease identified by IC or cross-sectional imaging did not undergo CE.Two hundred and ninety-three patients underwent CE at diagnosis.Sixteen patients with intestinal stenosis identified by CE and 25 patients without active disease identified by CE were excluded.A total of 252 patients with non-stricturing and non-penetrating CD had active disease identified by both IC and CE at diagnosis.At the first follow-up endoscopic examination,86 patients achieved clinical remission,a normal level of CRP,and IC-identified MH.Of these,50 patients(58.1%)achieved both IC-identified MH and CE-identified MH,namely pan-enteric MH(group 1),whereas 36(41.9%)still had active inflammation identified by CE(group 2).After a median 28-months follow-up,clinical recurrence,CD-related hospitalization,and CD-related surgery occurred in 16(group 1=6,group 2=10),18(group 1=4,group 2=14),and 3(all in group 2)patients,respectively.The Kaplan-Meier curve showed that compared with patients only achieving IC-identified MH,patients achieving pan-enteric MH had a significant lower cumulative probability of clinical recurrence(P=0.016),CD-related hospitalization(P<0.001),and CD-related surgery(P=0.040).Pan-enteric MH was the only independent factor associated with a decreased risk for treatment failure in multivariate Cox regression analysis[hazard ratio(HR),0.23;0.09-0.61;P=0.003].Conclusion:In non-stricturing and non-penetrating CD,IC-identified MH dose not represent pan-enteric MH,and pan-enteric MH is associated with improved long-term outcomes.Compared with patients only achieving IC-identified MH,patients achieving pan-enteric MH had a lower cumulative probability of clinical recurrence,CD-related hospitalization and CD-related surgery.Thus,we suggest that pan-enteric MH should be evaluated at the follow-up visits in patients with non-stricturing and non-penetrating CD.