title: Does ablative therapy for Barrett esophagus affect the depth of subsequent esophageal biopsy as compared with controls?
abstract: BACKGROUND
  Photodynamic therapy (PDT) and radiofrequency ablation (RFA) are associated with high rates of complete eradication of Barrett esophagus (BE). However, if ablation were to induce fibrosis in the regenerated squamous epithelium, then postablation biopsies may not penetrate deeply enough to detect subsquamous intestinal metaplasia (SSIM) and, therefore, complete response rates could be over-estimated.
  
  
  OBJECTIVE
  To assess the depth of esophageal biopsies from the squamous epithelium of ablation-naive controls and from the neosquamous epithelium of post-PDT and post-RFA patients to determine if prior ablation results in a reduced proportion of biopsies containing lamina propria (LP) as compared with controls.
  
  
  METHODS
  Review of archived esophageal specimens from a prospective multicenter cohort study (post-RFA) and 2 retrospective consecutive case series (ablation-naive controls, post-PDT).
  
  
  METHODS
  Eight US centers and 1 US gastrointestinal pathology laboratory.
  
  
  METHODS
  Ablation-naive controls with GERD, dyspepsia, and/or BE. Post-PDT and post-RFA BE patients with biopsies more than 6 months after achieving complete eradication of BE.
  
  
  METHODS
  Review of endoscopic biopsies from ablation-naive controls, post-PDT patients, and post-RFA patients.
  
  
  METHODS
  One GI pathology lab processed all tissue and slides. One expert GI pathologist, blinded to cohort, graded the depth of each esophageal specimen as: partial epithelium, full epithelium, LP, muscularis mucosae, or submucosa. Each specimen was also evaluated for SSIM.
  
  
  RESULTS
  There were 82 patients [ablation-naive (12), post-PDT (10), post-RFA (60)] with 899 biopsy specimens. The proportion of specimens containing "LP or deeper" was similar between groups: ablation-naive (88%), post-PDT (88%), post-RFA (91%) (P>0.05). No SSIM was detected in any group.
  
  
  CONCLUSIONS
  There is no difference in esophageal biopsy depth between ablation-naive squamous epithelium and post-PDT/post-RFA neo-squamous epithelium, thus refuting the concern of ablation-induced mucosal resistance to procurement of adequate biopsy specimens. Most biopsies (88% to 91%) from both ablation cohorts were deep enough to detect SSIM, in that they included "LP or deeper."
authors.affiliation: Gastrointestinal Associates, Knoxville, TN, USA.
authors.forename: Bergein F
authors.initials: BF
authors.lastname: Overholt
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Dean
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Galanko
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Lightdale
mesh_terms: D000368:Aged; D001471:Barrett Esophagus / Q000473:pathology / Q000628:therapy*; D001706:Biopsy; D016022:Case-Control Studies; D017115:Catheter Ablation / Q000009:adverse effects; D002986:Clinical Trials as Topic; D004564:Electrocoagulation / Q000009:adverse effects; D004945:Esophagoscopy; D004947:Esophagus / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D009092:Mucous Membrane / Q000473:pathology / Q000601:surgery; D015337:Multicenter Studies as Topic; D010778:Photochemotherapy / Q000009:adverse effects; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D016896:Treatment Outcome; D014481:United States