Lengthening Bowel Endoscopically: Hydrogel-Enabled Endoscopic Spring-Mediated Distraction Enterogenesis.

We evaluated the feasibility to lengthen small bowel endoscopically utilizing a spring device constrained by an engineered, slow biodegrading, hyaluronan and elastin-like protein (HELP) hydrogel as a potential treatment for short bowel syndrome. While we previously demonstrated that the HELP hydrogel could provide device confinement and enable non-invasive device removal, here we demonstrate that the HELP hydrogel can also be designed to be catheter-injectable while still being stiff enough to achieve device confinement. Six pigs underwent endoscopic spring-mediated distraction enterogenesis (ESMDE), the lengthening of existing intestine using axial mechanical force. A compressed spring that was encapsulated in gelatin was placed into pig jejunum via enterotomy. The spring was confined on each end by endoscopic catheter-injection of HELP gel into the intestinal submucosa to cause transient luminal narrowing. The gelatin capsule rapidly biodegrades to deploy the spring, while the HELP gel slowly biodegrades to transiently constrain the device, applying tension to the bowel segment. On postoperative day 7, of the six pigs that underwent ESMDE, four had successful bowel lengthening, up to 172% of the initial length. None of the animals experienced any complications such as obstruction or perforation, and there were no mortalities. In this proof-of-concept study, we demonstrate that a hydrogel can be designed with the appropriate catheter-injection properties, stiffness, and biodegradation rate to achieve hydrogel-enabled, endoscopic spring-mediated distraction enterogenesis, making it a possible future treatment for short bowel syndrome.