Novel approach for colonic insufflation via an untethered capsule (with video).

would alter the angle of the pulled papilla. With minor adjustments, cannulation can be achieved. In conclusion, when a hooded major papilla is encountered at ERCP, traction of the papilla by the use of forceps may be useful. Application of clips during ERCP: a new anchoring method for redundant Kerckring's fold covering the duodenal papilla. Capsule endoscopy has quickly become a cornerstone for evaluation of the small intestine. Implementing this technology successfully for evaluation of the human colon has been challenging because of numerous factors. One factor is the need for safe, controlled, reliable insufflation. Carbon dioxide (CO 2) for the purpose of colonic insuffla-tion has been advantageous over traditional air insufflation because it is readily absorbed through the colon, thereby reducing patient discomfort caused by the effect of colonic distention. Our team has developed a novel approach for untethered controlled CO 2 insufflation for use in colon capsule endoscopy. To create CO 2 for wireless untethered colon insuffla-tion, a safe and controlled chemical reaction was developed. This reaction uses sodium bicarbonate (NaHCO 3) and citric acid (C 6 H 8 O 7) in the presence of water (H 2 O) to yield the products of sodium citrate (Na 3 C 6 H 5 O 7), carbon dioxide (CO 2), and water. All the reactants and products are described as safe for human use/consumption by the US Food and Drug Administration. 1 Although the required amount of water can be found within the intestine in physiologic conditions, sodium bi-carbonate and citric acid, in solid state, can be loaded inside a swallowable capsule with a magnetic controlled drug release system (internal volume 2 mL). 2 To quantify the quantity of gas generated and the dynamics of the proposed reactions under ideal conditions, bench-top tests were performed under conditions similar to those in vivo (T ϭ 37°C). Ten trials at 37°C yielded a mean CO 2 volume of 455.30 Ϯ 10.17 mL at 4 minutes (t 50). The pH of the reaction was 6.5. Ex-vivo trials were then performed by use of a fresh porcine colon that was submerged in a tank of 9 L water maintained at 37°C. No animals were killed specifically for the purpose of obtaining tissues. A total of 9 fiducials were spaced at 2-cm intervals along the colon wall and sutured in place. The reactants were then loaded into the swal-lowable capsule, which was activated inside the …