Magnetic Endoscopic Imaging for routine colonoscopy – do we need it?

Background: Routine colonoscopy is a ubiquitously practised procedure, but can be uncomfortable for patients and demanding in terms of time and staff requirements. Looping of the colonoscope produces patient discomfort due to mesenteric stretching and necessitates countermeasures such as change of patient position and external abdominal compression by assistant personnel which in turn increases patient stress and consumes time. Magnetic endoscope imaging (MEI) is a technique for direct visualisation of endoscope configuration inside the colon. MEI can help in the prevention of loop formation by giving direct visual feedback of endoscope movement. The aim of this study was the evaluation of (1) the total time needed to advance the colonoscope tip to the cecum, (2) the total duration of abdominal compression by an assistant nurse, (3) the degree of force applied on the patient, (4) the number of turn maneuvers to perform complete diagnostic colonoscopy and (5) the frequency of involvement of a second assistant nurse, each with and without guidance by MEI. Methods: Consecutive patients undergoing complete routine colonoscopy were randomised to two groups: in group A, MEI was used until cecal intubation was performed, in group B, the procedure was performed without magnetic imaging. Sedation was performed according to local standards. In both groups time needed to reach the cecum and the frequency of turn maneuvers and involvement of a second assistant nurse were recorded. Duration of abdominal compression was graded on a scale from 1–4 according to the timespan, intensity of compression was objectified using a scale from 1–3 according to compression form and patient reaction. Results: 350 patients were randomized (group A with MEI, n=174; group B without MEI, n=176) and complete colonoscopy was performed. In group A, median time to cecal intubation was shorter (347s vs. 391s), the duration of abdominal compression was less (without compression: 58 vs. 42%; <1min: 21 vs. 19%; 1–3min: 12 vs. 24%; >3min 9 vs. 15%). The intensity of abdominal compression was less in group A (low intensity: 46 vs. 36%; medium intensity: 39 vs. 42%; high intensity: 15 vs. 22%). There were fewer turn maneuvers per patient (mean 0,77 vs. 1,13) and less need for a second assistance (1,7 vs. 5,6%) in group A. Conclusions: Magnetic endoscopic imaging accelerates colonoscope advancement to the cecum with a moderate overall effect. The use of it significantly reduces both the force and the duration of abdominal compression applied by assistant personnel, thus minimising patient discomfort and decreasing the need for additional staff. The reduction in turn maneuvers per patient and in the use of a second assistant for abdominal compression further illuminates the advantages of MEI.

Keywords: colonoscopy, magnetic endoscopic imaging, routine endoscopy