Endoscopic scar assessment after colorectal endoscopic mucosal resection scars: when is biopsy necessary (EMR Scar Assessment Project for Endoscope (ESCAPE) trial): When is biopsy necessary (EMR Scar Assessment Project for Endoscope (ESCAPE) trial)

Pujan Kandel, Eelco Christiaan Brand, Joe Pelt, Colleen T. Ball, Wei Chung Chen, Ernest P. Bouras, Victoria Gomez, Massimo Raimondo, Timothy A. Woodward, Michael B. Wallace*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

OBJECTIVE: It is unclear whether endoscopic assessment of scars after colorectal endoscopic mucosal resection (EMR) has to include biopsies, even if endoscopy is negative. Vice versa, endoscopic diagnosis of recurrent adenoma may not require biopsy before endoscopic reinterventions. We prospectively analysed various endoscopic modalities in the diagnosis of recurrence following EMR.

DESIGN: We conducted a prospective study of patients undergoing colonoscopy after EMR of large (≥20 mm) colorectal neoplasia. Endoscopists predicted recurrence and confidence level with four imaging modes: high-definition white light (WL) and narrow-band imaging (NBI) with and without near focus (NF). Separately, 26 experienced endoscopists assessed offline images.

RESULTS: Two hundred and thirty patients with 255 EMR scars were included. The prevalence of recurrent adenoma was 24%. Diagnostic values were high for all modes (negative predictive value (NPV) ≥97%, positive predictive value (PPV) ≥81%, sensitivity ≥90%, specificity ≥93% and accuracy ≥93%). In high-confidence cases, NBI with NF had NPV of 100% (95% CI 98% to 100%) and sensitivity of 100% (95% CI 93% to 100%). Use of clips at initial EMR increased diagnostic inaccuracy (adjusted OR=1.68(95% CI 1.01 to 2.75)). In offline assessment, specificity was high for all imaging modes (mean: ≥93% (range: 55%-100%)), while sensitivity was significantly higher for NBI-NF (82%(72%-93%)%)) compared with WL (69%(38%-86%); p<0.001), WL-NF (68%(55%-83%); p<0.001) and NBI (71%(59%-90%); p<0.001).

CONCLUSION: Our study demonstrates very high sensitivity and accuracy for all four imaging modalities, especially NBI with NF, for diagnosis of recurrent neoplasia after EMR. Our data strongly suggest that in cases of high confidence negative optical diagnosis based on NBI-NF, no biopsy is needed to confirm absence of recurrence during colorectal EMR follow-up. A high confidence positive optical diagnosis can lead to immediate resection of any suspicious area. In all cases of low confidence, biopsy is still required.

TRIAL REGISTRATION NUMBER: NCT02668198.

Original languageEnglish
Pages (from-to)1633-1641
Number of pages9
JournalGut
Volume68
Issue number9
Early online date11 Jan 2019
DOIs
Publication statusPublished - Sept 2019

Keywords

  • colonoscopy
  • endoscopic procedures
  • Neoplasm Recurrence, Local/diagnostic imaging
  • Predictive Value of Tests
  • Colorectal Neoplasms/diagnostic imaging
  • Endoscopic Mucosal Resection
  • Prospective Studies
  • Follow-Up Studies
  • Cicatrix/pathology
  • Humans
  • Middle Aged
  • Male
  • Unnecessary Procedures
  • Colonoscopy/methods
  • Narrow Band Imaging/methods
  • Biopsy
  • Sensitivity and Specificity
  • Aged, 80 and over
  • Adult
  • Female
  • Aged
  • Observer Variation

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