Can the 1.8 mm transnasal biopsy forceps instead of standard 2.2 mm alter rapid urease test and histological diagnosis?

Background and Aim: Biopsy specimens are taken during transnasal esophagogastroduodenoscopy with 1.8 mm forceps. The aims of this study were to compare the concordance of the Campylobacter-like organism (CLO) test and histological diagnoses between biopsies taken with 1.8 mm and 2.2 mm forceps and to determine whether the concordance of the CLO test could be improved by increasing the number of specimens using 1.8 mm forceps. Methods: A total of 200 patients were enrolled. We first performed the CLO test twice using each sample taken with both forceps in 100 patients. The CLO test was conducted three times again after confirming the difference in the CLO test between two forceps: (i) one sample with 1.8 mm forceps; (ii) two with 1.8 mm; and (iii) one with 2.2 mm in the other 100 patients. Additionally, each specimen was taken from the same gastric lesions in 200 patients for the histological diagnosis using both forceps types. Results: The concordance rate of the CLO test between each sample with 1.8 mm and 2.2 mm forceps was 83% (?-value, 0.64), and that between two samples with 1.8 mm and one with 2.2 mm was 92% (?-value, 0.83). The concordance rate of the histological diagnosis with 1.8 and 2.2 mm was 97% (?-value, 0.84). Conclusions: At least two samples using 1.8 mm forceps might be needed to obtain similar results on the CLO test using 2.2 mm. But, the size difference between two forceps did not influence the histological diagnosis.