Shape memory materials have been successfully applied to minimally invasive implantation of medical devices. However, organ-movement-specific shape programing at a microscale level has never been demonstrated despite significant unmet needs. As vein-to-artery grafting induces vein dilation and stenosis, a polymeric self-enclosable external support (SES) is designed to wrap the vascular out-wall. Its micropores are programmed to increase sizes and interconnections upon dilation. Vessel dilation promotes venous maturation, but overdilation induces stenosis by disturbed blood flow. Therefore, the unique elastic shape-fixity of SES provides a foundation to enable a stable microscale shape transition by maintaining the vein dilation. The shape transition of micropore architecture upon dilation induces beneficial inflammation, thereby regenerating vasa vasorum and directing smooth muscle cell migration toward adventitia with the consequent muscle reinforcement of veins. This game-changer approach prevents the stenosis of vein-to-artery grafting by rescuing ischemic disorders and promoting arterial properties of veins.
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http://dx.doi.org/10.1002/smll.202007297 | DOI Listing |
J Craniofac Surg
August 2024
Department of Plastic and Reconstructive Surgery, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
Despite the rich blood supply to the scalp, postoperative skin necrosis at the surgical site sometimes occurs, and unresolved defects often present a significant challenge for the surgeon. When planning a free flap for scalp reconstruction, distant anastomoses may be necessary if local recipient vessels are unavailable due to previous surgery. This study presents the authors' treatment strategy, which includes extending the pedicle length with arteriovenous bundle interposition grafts.
View Article and Find Full Text PDFJ Vasc Access
May 2024
Department of Nephrology, The First Affiliated Hospital of Soochow University, Suzhou, China.
Objective: Low primary patency rate is a major problem of radio-cephalic arteriovenous fistula (RC-AVF) creation. Radial artery deviation and reimplantation (RADAR) is associated with low juxta-anastomotic stenosis rate. However, inflow artery stenosis is prominent with RADAR.
View Article and Find Full Text PDFSci Rep
June 2021
Vascular Surgery Biomedical Research Laboratory, Washington University School of Medicine, Saint Louis, MO, 60613, USA.
Arteriovenous grafts are routinely placed to facilitate hemodialysis in patients with end stage renal disease. These grafts are conduits between higher pressure arteries and lower pressure veins. The connection on the vein end of the graft, known as the graft-to-vein anastomosis, fails frequently and chronically due to high rates of stenosis and thrombosis.
View Article and Find Full Text PDFSmall
May 2021
Department of Medical Engineering, Yonsei University College of Medicine, 50-1 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
Shape memory materials have been successfully applied to minimally invasive implantation of medical devices. However, organ-movement-specific shape programing at a microscale level has never been demonstrated despite significant unmet needs. As vein-to-artery grafting induces vein dilation and stenosis, a polymeric self-enclosable external support (SES) is designed to wrap the vascular out-wall.
View Article and Find Full Text PDFJ Surg Res
October 2020
Department of Pathology and Laboratory Medicine, McAllister Heart Institute, University of North Carolina, Chapel Hill, North Carolina. Electronic address:
Background: Vein graft stenosis is a major complication of coronary artery bypass surgery and peripheral arterial bypass procedures. Experimental models of this clinical complication have used in vivo grafting procedures, relying on the relatively modest neointimal thickening in these models as a surrogate for clinical graft stenosis without regard to the donor site origin of the vein graft.
Materials And Methods: In a standard rat model of vein grafting, three different donor sites were used to supply veins used as interpositional grafts to the femoral artery: the superficial inferior epigastric vein, the common femoral vein, and the posterior facial vein (distal branch of the jugular vein).
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