Matsuda et al. recently carried out a large prospective study of 4215 lesions in 3029 consecutive patients between 1998 and 2005 at the National Cancer

Center Hospital, Tokyo. All lesions were detected via the conventional endoscopic view and assessed using magnifying chromoendoscopy for evidence of invasive features according to pit pattern evaluation. They showed that 99.4% of lesions diagnosed endoscopically as ‘non-invasive’ were adenoma, high-grade dysplasia or adenocarcinoma with submucosal invasion less than 1000 µm. Among lesions diagnosed DNA Damage inhibitor with ‘invasive’ pattern, 87% were cancers with submucosal invasion deeper than 1000 µm. This is the first large-scale prospective study to validate the use of magnifying chromoendoscopy as a highly effective method in the prediction of invasion depth of colorectal neoplasms.64 ESD is an appealing prospect for treatment of certain this website lesions of the GIT in the West, such as superficial carcinomas of the esophagus, high-grade dysplasia in Barrett’s mucosa and large flat non-granular tumors of the colorectum. There are, however, a number of limitations to widespread use of ESD outside Japan. Firstly, selection of appropriate lesions for ESD is crucial, and the diagnostic skills to facilitate this, including determination of lesion characteristics, are of great importance. Whilst optical magnification is used in Japan allowing up to 150× image enlargement,

digital magnification is more commonly available in the West, providing views with less resolution. Chromoendoscopy is also a routine modality in GI lesion assessment in Japan, but rarely used outside specialist units in the West. Consequently, the ability to analyze lesion surface vascularity and pit pattern in detail and therefore lesion selection for ESD is limited. These assessment techniques are considered Chloroambucil crucial in Japan to enable correct diagnosis of lesion type, depth and amenability to endoscopic treatment. Successful application of ESD in the West will certainly require a change in diagnostic technique and close reference to Japanese literature in selection of lesions for resection. Secondly, ESD

is a technically demanding procedure requiring a high level of endoscopic skill and intensive training. The learning curve is steep and involves animal model work in the first instance. Unlike Western countries, facilities for animal model training are readily available in Japan and materials such as the isolated pig stomach can be supplied at low cost. Initial ESD training in patients entails removal of small gastric lesions in the antrum under close expert supervision, and generally, at least 30 procedures are required to reach basic proficiency.65 The likelihood of major complications for ESD of lesions in this position is low, even for endoscopists with less experience. The large lumen allows easy maneuvering and the risk of perforation is reduced due to the relative thickness of the gastric wall.