Vascular Cast to Program Antistenotic Hemodynamics and Remodeling of Vein Graft

Abstract

The structural stability of medical devices is established by managing stress distribution in response to organ movement. Veins abruptly dilate upon arterial grafting due to the mismatched tissue property, resulting in flow disturbances and consequently stenosis. Vascular cast is designed to wrap the vein‐artery grafts, thereby adjusting the diameter and property mismatches by relying on the elastic fixity. Here, a small bridge connection in the cast structure serves as an essential element to prevent stress concentrations due to the improved elastic fixity. Consequently, the vein dilation is efficiently suppressed, healthy (laminar and helical) flow is induced effectively, and the heathy functions of vein grafting are promoted, as indicated by the flow directional alignment of endothelial cells with arterialization, muscle expansion, and improved contractility. Finally, collaborative effects of the bridge drastically suppress stenosis with patency improvement. As a key technical point, the advantages of the bridge addition are validated via the computational modeling of fluid–structure interaction, followed by a customized ex vivo set‐up and analyses. The calculated effects are verified using a series of cell, rat, and canine models towards translation. The bridge acted like “Little Dutch boy” who saved the big mass using one finger by supporting the cast function.

Body-Shaping Membrane to Regenerate Breast Fat by Elastic Structural Holding

“…S2 ). The stress management of membrane with consequent resistance to structural deformation under an average daily pressure (3 N) in the range of 1.3 to 5.6 N upon standing and lying was reported previously [ 35 , 36 ]. The results from the 2D flat models were confirmed, as the lower range of stress distribution was managed by the strut (+) membrane over the entire structure in both lying and standing positions unlike in the strut (−) membrane (Fig.…”

“…S3 C ). Alternatively, T m of elastomer can be adjusted by adjusting the crosslinking degree upon alteration of the ratio between PCL and PGMA as reported previously [ 34 – 36 ]. The crosslinking decrystallizes the polymer, resulting in reduction of T m because the endothermic heat energy decreases.…”