[Recent progress in endoscopic treatment for colorectal tumors]

Endoscopic mucosal resection (EMR) is indicated for the treatment of superficial, early-stage colorectal cancer because of its minimal invasiveness and excellent results in terms of clinical outcomes. Conventional EMR techniques currently used for the resection of laterally spreading tumors (LSTs), however, are inadequate for the en-bloc resection of flat lesions > or =20 mm because both incomplete removal and local recurrence have been observed and reported on occasion. Endoscopic submucosal dissection (ESD) is widespread as a minimally invasive treatment for early gastric cancer, however, it is not as widely used in the colorectum because of its technical difficulty and complication risk.

Based on clinicopathological analyses of LSTs, the indication for colorectal ESD is an LST non-granular type (LST-NG) >20 mm. LST granular type (LST-G) >30 mm or 40 mm are possible candidates for ESD because they have a higher submucosal (SM) invasion rate and are difficult to treat even by endoscopic piecemeal mucosal resection (EPMR).

ESD procedures were performed using a ball tip bipolar needle knife (B-knife) and an insulation-tip knife (IT knife) with carbon dioxide (CO2) insufflation. Glycerol and 0.4% hyaluronic acid were used as an SM injection solution in order to provide longer lasting SM elevation.

ESD is an effective technique for treating colorectal IST-NGs>20 mm and LST-Gs>30 mm providing a higher en-bloc resection rate as well as being less invasive than surgery.