Supplementary Material for: One-to-One Correspondence Locations of Resected Polyps after Endoscopic Resection Using Catcher Tagged Method: A Randomized Prospective Study

Background/Aims: Multiple colorectal polyps with a diameter in the range of 10–19 mm are unable to be retrieved through a 3-mm endoscopic channel by the aspiration method. This study aims to assess the usefulness of Catcher Tag retrieval, which not only allows the accurate identification of the resected location but also enables the easiest retrieval in a short time without any special device. Methods: One hundred thirty five patients (483 polyps) were diagnosed with colorectal neoplasm, and 64 patients (225 polyps) were enrolled and randomly allocated into the Net forceps group (NET) and the Catcher Tagged group (TAG). In TAG, 3 types of colored ring-threads were used to retrieve resected polyps. After local injection of natural saline, ring-threads were placed close to polyps. The primary outcome was the number of one-to-one correspondence locations (UMIN000020826). Results: There was significant difference in one-to-one correspondence (p = 0.004). The average retrieval procedure time was 13.56 ± 3.47 (min) in NET and 3.55 ± 1.68 in TAG (p = 0.006). In NET, 1 polyp in each of 4 cases was lost during endoscopic mucosal resection and 2 polyps were lost in 1 case. In TAG, no polyp was lost (p = 0.016). Conclusion: The Catcher Tagged method is very useful for accurate one-to-one correspondence locations and pathological evaluation, and easy-to-retrieve multiple resected specimens.