Accuracy of preoperative tumor localization in large bowel using 3D magnetic endoscopic imaging

Miroslaw K Szura, PhD, Artur Pasternak, PhD, Rafal Solecki, PhD, Andrzej Matyja, PhD. Jagiellonian University

Laparoscopic surgery becomes the standard treatment for colorectal cancer. A tumor not investing serosa is invisible intraoperatively, while manual palpation of the tumor during laparoscopy is not possible. Therefore, accurate localization of neoplastic infiltrate remains one of the most important tasks prior to elective surgery.

The aim of this study is to evaluate the usability of magnetic positioning system (MPS) for preoperative endoscopic localization of neoplastic infiltrate within the large intestine.

Material 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. Analysis concerned patients with neoplastic infiltrate localized above 30 cm from the anal verge. For evaluative purposes and accuracy of localization, the intestine was divided anatomically into 13 parts. The colonoscopic examinations were performed with two types of endoscopes: group I – with MPS, group – without MPS. Patients were assigned to groups by a random allocation. The ultimate confirmation of the tumor localization was done by intraoperative evaluation. ClinicalTrials.gov number, NCT01688557

Results: Group I involved 127 patients and group II – 129. The mean age of the participants was 65.7 years (SD±11,5). Both groups were compared in terms of age, sex, BMI and frequency of previous abdominal procedures. The proper localization of the lesion in group I was confirmed in 95.23% of patients, and in group II – in 83.19% (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 distal sigmoid.

Conclusions: Magnetic positioning system of the endoscope allows for more accurate localization of neoplastic infiltrate within the large intestine as compared to standard colonoscopy alone, especially within the sigmoid colon. This method can be particularly useful in planning and performing the laparoscopic procedure in order to diminish the likelihood of improper bowel segment resection.