Accuracy of colonoscopic localization

The objective of this study was to evaluate the accuracy of preoperative colonoscopic localization of colonic lesions. Localization of the colonic lesion plays a key role in determining the type of operation a patient may require. Inaccurate localization may result in removal of the wrong segment of colon and/or a change in the operation performed.

A retrospective review of patients who had a colon resection by a single surgeon after preoperative colonoscopic localization between 1991 and 2008 was performed. A comparison of the preoperative colonoscopic localization and the final intraoperative localization was made. Clinical and demographic information was gathered to determine accuracy rates and identify predictive factors.

Three hundred and seventy-four patients were included and 184 (49%) were male. The mean age was 61.6 years. Three hundred and sixty-two (97%) patients underwent colon resection for cancer. Fifteen (4%) patients had nonconcordant colonoscopic and intraoperative findings. Fourteen of the 15 (93%) were resected for cancer and 1 for inflammatory bowel disease (IBD). Seven (47%) lesions were inaccurately localized in the sigmoid colon, four (27%) in the descending colon, two (13%) in the ascending colon, one (7%) in the rectum, and one (7%) lesion was not visualized preoperatively. Eleven of the 15 (73%) patients with nonconcordant localization had a modification of their planned procedure. Ten patients underwent a different segmental colectomy and one patient had an extended resection.

Preoperative colonoscopic localization of colorectal lesions was reasonably accurate (96%) in this large series. The majority of inaccurately identified lesions occurred in the sigmoid and descending colon. Erroneous localization, even though not common, can result in significant changes in the intraoperative plan and the ultimate outcome. Therefore, every effort should be made to localize the lesion before surgery, especially when thought to be in the left or sigmoid colon, to reduce the need for intraoperative localization efforts, the need for an intraoperative change in procedure, and the risk of a surprise for the patient after surgery.