Tissue engineered heart valves for transcatheter aortic valve implantation: current state, challenges, and future developments.

The establishment of transcatheter aortic valve implantation (TAVI) has revolutionized the treatment of severe aortic stenosis. However, with TAVI being approved for low-risk patients, valve durability is becoming of central importance. Here, we summarize how tissue engineered heart valves (TEHVs) may provide a clinically-relevant durable valve replacement compatible with TAVI. Since its introduction, TAVI prostheses have advanced in design and development. However, TAVI bioprostheses are based on fixed xenogeneic materials prone to progressive degeneration. Transcatheter TEHVs may have the potential to overcome the drawbacks of current TAVI bioprostheses, with their remodeling, self-repair, and growth capacities. So far, performance and remodeling of transcatheter TEHV with in-situ regenerative potential were demonstrated in the low-pressure system, with acute performance proved in the systemic circulation. However, several challenges remain to be solved to ensure a safe clinical translation of TEHVs for TAVI approaches. With TAVI rapidly evolving, the establishment of long-term valve durability represents the top priority to reduce the rate of patient re-interventions, remove the associated risks and adverse events, and improve patients' life quality worldwide. With long-term performance and remodeling proved, TEHVs may represent the next-generation technology for a life-long TAVI prosthesis.