Endocytoscopy and Colorectal Neoplasia

Colonoscopies will be performed as per routine practice. When a colorectal lesion is found that would normally require biopsy or polypectomy; the lesion will be evaluated by chromoendoscopy with the application of 10 ml 1% methylene blue followed by the inspection with the endocytoscope at both magnifications (450X and 1100X). The endocytoscopic images of the abnormal area will be recorded prior to biopsy or removal of the suspicious tissue. For each lesion, a matching endocytoscopy image from normal adjacent tissue will also be obtained, at least 5cm away from the suspect site, but within the same segment of intestine (e.g. ascending colon). No biopsy will be obtained from normal tissue, and this will be assumed to be normal. Following image acquisition, the lesion will be biopsied or removed as per standard clinical care.

The endocytoscopes, prototype I and prototype II will be used during the study along with the standard colonoscopes. The endocytoscope is a soft catheter type endoscope, with an outside diameter of 3.4 mm at the distal end and 3.2 at the shaft, and total length of 380 cm (working length of 250 cm) which uses a lens system for magnification. The Prototype 1 endocytoscope (low resolution type) has a magnification capability of x 450, depth of field of 50 um, field of view of 300X 300 um with a spatial resolution of 1.7 um. The Prototype 2 (high resolution) has a magnification capability of x1125, depth of field of 5um, field of view of 120X 120 um, and a spatial resolution of 4.2 um, The ECS system can be passed through the working channel of a standard colonoscope.