In situ measurement of colorectal polyps to compare video and fiberoptic endoscopes.

The present study was performed to test the reliability of in situ measurements of colorectal polyps when comparing videoendoscopes with fiberoptic endoscopes. In 25 small rectosigmoid polyps 3-12 mm) removed endoscopically, in situ diameters were measured before polypectomy using both video- and fiberoptic endoscopes. Polaroid and videoprint pictures were taken for computerised analysis of the area of the polyps on the pictures. The results showed a good correlation between the polyp diameter measured with the videoendoscope and fiberoptic endoscope (r = 0.97), with no significant difference by parametric testing. The diameter and weight of the removed polyp also correlated well with the diameter measured in situ using videoendoscopes (r = 0.92 and 0.77, respectively) or fiberoptic endoscopes (r = 0.90 and 0.81, respectively). Furthermore, the weight of the removed polyp correlated reasonably well to the computerised area measurement, the correlation coefficient being r = 0.90 for fiberoptic endoscopes and r = 0.75 for videoendoscopes. We conclude that in situ polyp diameter measurements using videoendscopes and fiberoptic endoscopes are similarly reliable and sensitive, and both instruments can be used interchangeably in follow-up studies of polyp growth.