CC BY-NC-ND 4.0 · Endosc Int Open 2018; 06(01): E43-E50
DOI: 10.1055/s-0043-120829
Original article
Eigentümer und Copyright ©Georg Thieme Verlag KG 2018

Acetic acid-guided biopsies in Barrett’s surveillance for neoplasia detection versus non-targeted biopsies (Seattle protocol): A feasibility study for a randomized tandem endoscopy trial. The ABBA study

Fergus Chedgy1, Carole Fogg2, Kesavan Kandiah1, Hugh Barr3, Bernard Higgins2, Mimi McCord4, Ann Dewey2, John De Caestecker5, Lisa Gadeke1, Clive Stokes3, David Poller1, Gaius Longcroft-Wheaton1, Pradeep Bhandari1
  • 1Portsmouth Hospitals NHS Trust, Portsmouth, UK
  • 2University of Portsmouth, Portsmouth
  • 3Royal Gloucestershire Hospital, Gloucester, Gloucestershire, UK
  • 4Heartburn Cancer UK, Basingstoke, Hampshire, UK
  • 5Leicester General Hospital, Leicester, UK
Further Information

Publication History

submitted 16 January 2017

accepted after revision: 30 June 2017

Publication Date:
12 January 2018 (online)


Background and study aims Barrett’s esophagus is a potentially pre-cancerous condition, affecting 375,000 people in the UK. Patients receive a 2-yearly endoscopy to detect cancerous changes, as early detection and treatment results in better outcomes. Current treatment requires random mapping biopsies along the length of Barrett’s, in addition to biopsy of visible abnormalities. As only 13 % of pre-cancerous changes appear as visible nodules or abnormalities, areas of dysplasia are often missed. Acetic acid chromoendoscopy (AAC) has been shown to improve detection of pre-cancerous and cancerous tissue in observational studies, but no randomized controlled trials (RCTs) have been performed to date.

Patients and methods A “tandem” endoscopy cross-over design. Participants will be randomized to endoscopy using mapping biopsies or AAC, in which dilute acetic acid is sprayed onto the surface of the esophagus, highlighting tissue through an whitening reaction and enhancing visibility of areas with cellular changes for biopsy. After 4 to 10 weeks, participants will undergo a repeat endoscopy, using the second method. Rates of recruitment and retention will be assessed, in addition to the estimated dysplasia detection rate, effectiveness of the endoscopist training program, and rates of adverse events (AEs). Qualitative interviews will explore participant and endoscopist acceptability of study design and delivery, and the acceptability of switching endoscopic techniques for Barrett's surveillance.

Results Endoscopists’ ability to diagnose dysplasia in Barrett’s esophagus can be improved. AAC may offer a simple, universally applicable, easily-acquired technique to improve detection, affording patients earlier diagnosis and treatment, reducing endoscopy time and pathology costs. The ABBA study will determine whether a crossover “tandem” endoscopy design is feasible and acceptable to patients and clinicians and gather outcome data to power a definitive trial.