Improving lesion localisation at colonoscopy: an analysis of influencing factors.

Purpose: Colonoscopy detects colorectal cancer and determines lesion localisation that influences surgical planning. However, published work suggests that the accuracy of lesion localisation can be low as 60%, with implications for both the surgeon and the patient. This work aims to identify potential influencing factors at colonoscopy that could lead to improved lesion localisation accuracy.

Methods: A multi-centred, prospective, observational study was performed that identified patients who were undergoing planned curative resection for a colorectal lesion. Localisation of a lesion at colonoscopy was compared to the intra-operative lesion localisation to determine accuracy of colonoscopic localisation. Patient factors and colonoscopic factors were recorded to determine any influencing factors on lesion localisation at colonoscopy.

Results: One hundred and eleven patients were analysed: mean age 67.4 years (range 27-89); male:female ratio 1.3:1; symptomatic referrals (n = 78, 70.3%); and previous abdominal surgery in 27 patients (24.3%). Complete colonoscopy was recorded in 78 patients (70.3%). In 88 patients (79.3%), colonoscopic lesion localisation matched the intra-operative location. Pre-operative CT imaging was unable to identify the tumour in 24 cases (21.8%). Potential influencing patient and colonoscopic factors on accurate lesion localisation at colonoscopy found complete colonoscopy to be the only significant factor (p = 0.008).

Conclusion: Colonoscopic lesion localisation was found to be inaccurate in 79.3% cases, and with pre-operative CT unable to detect all lesions, this study confirms that accurate lesion localisation in the modern era is increasingly reliant on colonoscopy. Incomplete colonoscopy was the only significant factor that influenced inaccurate lesion localisation at colonoscopy.