Optimizing the performance of magnet-controlled capsule endoscopy based on radiological and gastroscopic modeling

Routine use of magnet-controlled capsule endoscopy of the stomach has been limited by the inadequate views of specific stomach regions. In the present study, radiology and upper gastrointestinal endoscopy (UGIE) were used to determine optimal subject body positioning and suitable external control magnet placement for capsule endoscopy. Healthy adult volunteers were subjected to upper gastrointestinal X-ray radiography (n=5), spiral computed tomography with volume reconstruction (n=4) or UGIE (n=1). Stomach fundus-to-body (FB) and body-to-antrum (BA) angles were compared when subjects were supine, prone, lying on their left side and on their right side, and when they were standing upright. Vertical distances from the surface of the body to the distal points of the fundus and antrum were also compared in this range of subject positions. Obtuse angles were considered the most beneficial for capsule movement and short vertical distances were considered desirable for optimizing magnetic force. The FB angle was sharply acute in the supine position, relatively open where subjects were on their side, and almost 180° in the standing position. The BA angle was obtuse in the standing position but acute in all other positions. With the subject in any position, the left lower lateral chest had the shortest distance to the fundus, while the ventral wall was closest to the antrum. The present modeling analysis indicates that standing is superior to all decubitus positions for magnetic-capsule endoscopy, including the commonly used supine position. Both the abdominal anterior wall and left lateral lower chest appeared to be advantageous locations for external control magnet placement.