Bioabsorbable Stent with Mixed Material Apices for Vessel Protection

The patent applies parameter changes by transitioning the stent material from non-biodegradable metal to biodegradable materials (such as poly-L-lactide, poly-D-lactide, or their copolymers) that change their mechanical properties over time. The stent maintains sufficient strength during the critical healing period and then gradually degrades, allowing the vessel to return to its natural state without long-term foreign body presence.

The patent implements dynamics through the time-dependent degradation behavior of the biodegradable stent. The stent structure evolves from a rigid, high-strength state during deployment and healing to a gradually softening state as the material degrades via hydrolysis and enzymatic breakdown, ultimately becoming fully resorbed by macrophages and osteoclasts.

The patent employs composite materials by combining biodegradable polymer matrices with reinforcing elements such as metal meshes, ceramic coatings, or natural fiber reinforcements. This composite structure provides the initial mechanical strength and radial support needed for vessel patency while maintaining the biodegradable nature of the stent, allowing gradual degradation without sacrificing critical performance characteristics during the healing period.

The patent applies local quality by creating stents with non-uniform material distribution, such as varying the crystallinity, molecular weight, or cross-linking density in different regions of the stent. This allows different parts of the stent to degrade at different rates, with the structure maintaining strength where needed while allowing degradation in other areas, thereby optimizing both performance and biodegradability.

The patent applies preliminary action through pre-deployment treatments such as balloon expansion, self-expansion mechanisms, or shape memory alloy activation that establish the stent's radial configuration and mechanical strength before degradation begins. The stent is designed to achieve its full structural integrity and provide immediate vessel support upon deployment, with degradation processes initiated only after the vessel has healed and stabilized.

The patent implements beforehand cushioning by incorporating degradation delay mechanisms such as protective coatings, cross-linked polymer networks, or crystalline structures that slow down the degradation process. These features act as a cushion, maintaining structural integrity during the critical early healing period and then gradually transitioning to degradation mode once the vessel has sufficiently recovered.