Multifunctional small-diameter vascular graft for real-time stenosis detection and anticoagulation

• Bilayered small diameter graft integrates stenosis detection and anticoagulation. • Conductive hydrogel outlayer enables stenosis sensing and vessel matched mechanics. • Zwitterionic hydrogel lumen provides robust anticoagulation under low shear flow. • Graft withstands ten year equivalent cyclic pressure without mechanical failure. • Long term patency and sensing stability validated in rabbit and porcine models. Small-diameter vascular graft replacements are particularly susceptible to postoperative stenosis, primarily due to their limited lumen diameter and reduced blood flow velocity. Managing the failure of such replacements requires complex surgical procedures. The incorporation of a real-time monitoring system enables early and accurate detection of stenosis, allowing for timely and safer therapeutic strategies. We report a bilayered small-diameter vascular graft (MSVG), in which the outer P NAGA @Mxene layer combines flexible Mxene-based electronics with a poly(N-acryloyl glycinamide) hydrogel to enable real-time stenosis detection and provide mechanical properties compatible with native vessels, while the inner P SBMA layer is tailored to enhance anticoagulation. The MSVG demonstrated dynamic stability under pulsatile pressure for 380 million cycles (equal to a service life of 10 years in vivo ). The MSVG provided excellent sensitivity to pressure change and stenosis within the range of blood pressure in a rabbit carotid artery model. In addition, in a porcine carotid model, the MSVG enabled real-time electrical readouts that synchronized with pharmacologically modulated blood pressure, further confirming its in vivo sensing feasibility in large animals. Notably, the MSVG demonstrated outstanding anticoagulant performance and preserved excellent morphological stability throughout the 3-week and 3-month implantation periods in rabbit and porcine carotid artery models, respectively.