Biomechanics of small intestine during distraction enterogenesis with an intraluminal spring

Biomechanical Force Prediction for Lengthening of Small Intestine during Distraction Enterogenesis

“…Previously, we developed a method of distraction enterogenesis using an intraluminal spring (Figure 1) where an axial mechanical force was applied within the lumen of the intestine to lengthen the intestine, and this approach has been performed successfully in several animal models [10][11][12]15,[18][19][20][21][22]. Our studies confirmed that mechanical perturbations in the axial direction of the intestinal tract trigger signaling pathways that cause tissue thickening in the radial direction within the distracted segment, as well as adaptive responses in the areas adjacent to the distracted segment [23][24][25].…”

“…Previously, we developed a method of distraction enterogenesis using an intraluminal spring (Figure 1) where an axial mechanical force was applied within the lumen of the intestine to lengthen the intestine, and this approach has been performed successfully in several animal models [10][11][12]15,[18][19][20][21][22]. Our studies confirmed that mechanical perturbations in the axial direction of the intestinal tract trigger signaling pathways that cause tissue thickening in the radial direction within the distracted segment, as well as adaptive responses in the areas adjacent to the distracted segment [23][24][25]. To deliver a safe and efficient outcome for distraction enterogenesis using the self-expanding intraluminal spring, we need to scale the applied mechanical force based on intestinal size to ensure that the delivered physical force is customizable based on the physical characteristics of the small intestine for each subject.…”

“…As previously described [23,24], biocompatible nickel-titanium (nitinol) springs were created where a 0.02 inch gauge nitinol wire (McMaster-Carr, Santa Fe Springs, CA, USA) was wrapped around a 1.3 cm diameter mold, heated to 500 • C for 30 min, rapidly cooled under water. Springs were cut to 7.5 cm in length, and spring constants measured (Figure 1A).…”

“…To deliver a safe and efficient outcome for distraction enterogenesis using the self-expanding intraluminal spring, we need to scale the applied mechanical force based on intestinal size to ensure that the delivered physical force is customizable based on the physical characteristics of the small intestine for each subject. We previously showed the general scalability of our method between different animal models (mouse, rat and pig) [16,23,25,26]. In this study, we further investigated these criteria with a focus on human subjects.…”

“…We then performed mechanical characterization of the intestinal tissue, where these findings were used for our computational modeling efforts. We previously developed a computational modeling platform to study and predict the small intestinal tissue response to applied mechanical force [23]. Here, we further extended the computational model specifically for human subjects and developed a series of models for any potential size of human small intestine.…”