A feasibility trial of Acetic acid-targeted Biopsies versus nontargeted quadrantic biopsies during BArrett's surveillance: the ABBA trial.

Background The aims of this study were to compare neoplasia detection rates for nontargeted biopsies (Seattle protocol) versus acetic acid-targeted biopsies (Portsmouth protocol) during Barrett's surveillance and to explore feasibility, patient/clinician experience, acceptance, and barriers/enablers to study participation and implementation of the acetic acid technique. Methods This was a mixed-methods feasibility study including a pilot multicenter, randomized, crossover trial with qualitative interviews. Patients under Barrett's surveillance with no history of neoplasia were included. Patients underwent two endoscopies, one with each protocol, 8 weeks apart. Outcomes included recruitment and retention rates, neoplasia yield, and number of biopsies. Results 200 patients were recruited from 6 centers, and 174 (87.0%) underwent both procedures. Neoplasia prevalence was 4.7% (9/192). High grade dysplasia and cancer were detected with both protocols. Five low grade dysplasias were detected (two with acetic acid, four with nontargeted biopsies; one lesion was detected with both techniques). A total of 2139 biopsies were taken in the nontargeted arm and 226 in the acetic acid arm. Both patients and clinicians found the acetic acid technique acceptable. Based on these data, a noninferiority, tandem, crossover trial would require an estimated 2828 patients. Conclusions We demonstrated the feasibility of performing a crossover endoscopy trial in Barrett's surveillance. Low neoplasia yield makes this design necessary and qualitative results demonstrated patient and clinician acceptance. The reduced numbers of biopsies suggest that the acetic acid technique could result in cost savings, providing the lack of missed pathology can be proven in a fully powered definitive trial.