Usefulness of three dimensional endoscopic ultrasonography assisting at endoscopic resection for rectal carcinoids

Background: Recent progress in colonoscopic examination has facilitated the diagnosis of many rectal carcinoids. Rectal carcinoids less than or equal to 1cm in diameter and the depth of invasion to submucosal layer are perfomed local excision adequate. Endoscopic complete resection of rectal carcinoids is difficult during conventional endoscopic polypectomy. This problem stimulated an exploration of new endoscopic technique, such as two-channel endosope method, aspiration lumpectomy, band-snare resection and so on. Though we treated rectal carcinoids by endoscopic mucosal resection with a ligation device (EMR-L), a few cases were not complet resection. So we perfomed EMR-L assisted with three dimensional endoscopic ultrasonography (3D EUS) at saline injection into the submucosal layer and before snaring resection. Aim: We evaluated the usefulness of assisting the 3D EUS when rectal carcinoids were resected by EMR-L. Patients and Method: We perfomed endoscopic resection 26 rectal carcinoids during Mar 1998 through Dec 2005. 12 lesions were resected by EMR-L not assited with 3D EUS. 14 lesions were resected by EMR-L assited with 3D EUS. 3D EUS was carried out using 3D ultrasonic probe at 12MHz or 20MHz and 3D display software (MAJ1330, Olympus). Results: There were no differences between the two groups in terms of age, gender, or tumor size. For three patients (25%) in EMR-L not assited with 3D EUS group, there was tumor involvement at margin of resection specimen. Whereas all tumors removed by EMR-L assisted with 3D EUS had histopathologically proven negative margins (P<0.05). There was no complication of any procedure. For all lesions, the depth of invasion by 3D EUS and by pathological diagnosis were corresponding. Conclucion: It was useful to assist 3D EUS at EMR-L for small rectal carcinoids and diagnose the depth of invasion.