Accuracy of preoperative tumor localization in large bowel using 3D magnetic endoscopic imaging: randomized clinical trial

BACKGROUND: Laparoscopic surgery has become the standard treatment for colorectal cancer. A tumor that does not involve serosa is invisible intraoperatively, and manual palpation of the tumor during laparoscopy is not possible. Therefore, accurate localization of the neoplastic infiltrate remains one of the most important tasks prior to elective laparoscopic surgery. The aim of this study was to evaluate the utility of a magnetic endoscopic imaging (MEI) for precise preoperative endoscopic localization of neoplastic infiltrate within the large bowel. MATERIALS AND METHODS: The study enrolled 246 patients who underwent elective surgery for colorectal cancer in 2012–2015 with accurate preoperative colonoscopic localization of the tumor. The analysis concerned patients with neoplastic infiltrate localized more than 30 cm from the anal verge. For evaluative purposes and accuracy of localization, the intestine was divided anatomically into 13 parts. Colonoscopic examinations were conducted with two types of endoscopes: group I—with MEI and group II—without MEI. Patients were assigned to the groups by random allocation. Ultimate confirmation of the tumor localization was accomplished by intraoperative evaluation. RESULTS: Group I involved 127 patients and group II 129. The two groups were compared in terms of age, sex, BMI and frequency of previous abdominal procedures. Proper localization of the lesion was confirmed in 95.23 % of group I patients and in 83.19 % of group II patients (p < 0.05). The greatest discrepancy in localization occurred in 8.9 % of patients from group I and 20 % of patients from group II in which the lesion was assessed primarily in the distal sigmoid. CONCLUSIONS: A magnetic endoscopic imaging allows more accurate localization of neoplastic infiltrate within the large intestine compared to standard colonoscopy alone, especially within the sigmoid colon. This method can be particularly useful in planning and performing laparoscopic procedures to diminish the likelihood of improper bowel segment resection. CLINICALTRIALS.GOV NUMBER: NCT01688557 ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00464-016-5203-4) contains supplementary material, which is available to authorized users.