title: Transmural inflammation is not pathognomonic for Crohn's disease of the pouch.
abstract: BACKGROUND
  Transmural inflammation shown by imaging and histology has been considered a hallmark of Crohn's disease (CD). However, the diagnostic and prognostic value of this feature in CD of the pouch has not been evaluated. This study aimed to evaluate the clinical utility of transmural inflammation in patients with ileal pouch-anal anastomosis (IPAA) using in vivo optical coherence tomography (OCT) and histopathology.
  
  
  METHODS
  All the patients were recruited from the subspecialty Pouchitis Clinic. The study consisted of two parts: (1) a prospective study with in vivo through-the-scope OCT for the evaluation of transmural disease in patients with normal or diseased pouches and (2) a retrospective pathology re-review for transmural inflammation in excised pouch specimens of CD and chronic pouchitis.
  
  
  RESULTS
  This prospective OCT study enrolled 53 patients: 11 (20.8%) with normal pouches or irritable pouch syndrome, 10 (18.9%) with acute pouchitis, 11 (20.8%) with chronic antibiotic-refractory pouchitis (CARP), and 21 (39.6%) with CD of the pouch. Transmural inflammation, characterized by the loss of layered structure on OCT, was detected in 16 patients (30.2%): 4 with chronic pouchitis and 12 with CD of the pouch. None of the patients with normal pouches, irritable pouch syndrome, or acute pouchitis had transmural disease shown on OCT. Of the 26 patients with pouch failure who had pouch excision, the surgical specimens showed transmural disease in 30% of the CARP patients (3/10) and 12.5% (2/16) of those with CD of the pouch.
  
  
  CONCLUSIONS
  Transmural disease in the setting of IPAA is not pathognomonic of CD. Transmural inflammation shown by imaging or histopathology was seen in both CD and CARP. Transmural inflammation of the pouch appeared to be associated with poor pouch outcome.
authors.affiliation: Department of Gastroenterology, Affiliated Hospital of Nantong University, Jiangsu, China.
authors.forename: Zhao-xiu
authors.initials: ZX
authors.lastname: Liu
authors.forename: Tom
authors.initials: T
authors.lastname: Deroche
authors.forename: Feza H
authors.initials: FH
authors.lastname: Remzi
authors.forename: Jefferey P
authors.initials: JP
authors.lastname: Hammel
authors.forename: Victor W
authors.initials: VW
authors.lastname: Fazio
authors.forename: Run-zhou
authors.initials: RZ
authors.lastname: Ni
authors.forename: John R
authors.initials: JR
authors.lastname: Goldblum
authors.forename: Bo
authors.initials: B
authors.lastname: Shen
mesh_terms: D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002908:Chronic Disease; D003424:Crohn Disease / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D003937:Diagnosis, Differential; D016099:Endoscopy, Gastrointestinal; D005260:Female; D006801:Humans; D007249:Inflammation; D008297:Male; D008875:Middle Aged; D019449:Pouchitis / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D041623:Tomography, Optical Coherence
chemical_list: D000900:Anti-Bacterial Agents