The researchers determined the anatomic location and histologic type of colorectal polyps observed at colonoscopy, in a study conducted over a 10-year period at the endoscopy unit of the Sir Charles Gairdner Hospital, Perth.
The team reports their findings in the September issue of the Journal of Clinical Gastroenterology.
Endoscopy profiles of 2,578 patients were reviewed, with the polyp/lesion histology and location (left, right, or both) determined in 2,553 cases.
Of all polyps observed, 1,310 (51%) were left-sided, 510 (20%) were right-sided, and 733 (29%) were synchronous.
Adenomas were found to be present in 1,659 cases (65%). Of these, 734 (44%) were left-sided only and 405 (24.5%) were right-sided only.
Carcinoma was observed in 189 (7%) cases, of which 71 (37.5%) were left-sided only.
The researchers found that there was an increased right-sided prevalence of adenoma or carcinoma with age.
Dr Keyur Patel concluded on behalf of fellow authors, "This was not a screening study, but it has shown that a significant number of adenomas and carcinomas lie proximal to the splenic flexure.
| Location of colorectal polyps:|
- Left-sided 51%
- Right-sided 20%
- Synchronous 29%
|Journal of Clinical Gastroenterology |
"Thus, in the absence of left-sided lesions, it is expected that examination of the colon limited to the splenic flexure would miss 23% of such lesions.
"The increasing right-sided prevalence of these lesions with age suggests that evaluation of the proximal bowel is particularly important in older people."