Colonoscopy and computerized tomography scan are not sufficient to localize right-sided colonic lesions accurately

Accurate preoperative localization of colonic lesions is critical especially in laparoscopic colectomy where tactile localization is absent particularly in screen-detected tumours. The study aimed to evaluate the accuracy of colonoscopy and double-contrast computerized tomography (CT) scan to localize lesions treated by right hemicolectomy.

A retrospective chart review was performed of patients treated by right hemicolectomy under the colorectal service between July 2003 and October 2006. Preoperative tumour location determined by CT scan and colonoscopy was compared with the intra-operative and histopathological findings.

Out of 101 patients, 73 (73%) were for adenoma or cancer, with a final diagnosis of adenocarcinoma in 59 (58%). Preoperative localization was inaccurate in 29% of lesions using both CT and colonoscopy. In the transverse colon, colonoscopy alone was only 37.5% accurate, increasing to 62.5% when information from the CT scan was added.

Preoperative localization of right-sided colon cancers using colonoscopy and CT scanning is unreliable in at least 29% of cases. Inaccurate localization of transverse colon tumours risks inadequate lymphadenectomy with an adverse cancer outcome. Preoperative abdominal CT scan improves accuracy but endoscopic tattoo localization should be employed routinely especially in patients undergoing laparoscopic resection.