新しい生体吸収性組織工学ステントグラフトの生体適合性：ブタモデルを用いた実現可能性のパイロットスタディ

Endovascular aneurysm repair (EVAR) is a widely accepted treatment for aortic pathologies owing to its minimally invasive nature. However, long-term complications, such as stent graft migration and infection, remain unresolved, primarily due to the persistent presence of synthetic materials and limited tissue integration. This pilot study evaluated the feasibility of a novel tissue-engineered stent graft (TESG) combining a bioresorbable poly-L-lactic acid (PLLA) stent with decellularized porcine veins. The veins were processed using a sodium dodecyl sulfate and the Triton X-100 decellularization protocol. Histological and ultrastructural analyses confirmed effective cell removal while preserving extracellular matrix components. Quantitative deoxyribonucleic acid (DNA) analysis showed a > 97% reduction in DNA content. The TESGs were assembled by suturing the decellularized veins into bioresorbable PLLA stents and implanted into porcine iliac arteries (n = 3). Commercially available prosthetic grafts were used as control implants to evaluate differences in tissue responses. Graft patency and morphology were assessed at implantation and on postoperative day 14 using angiography and intravascular ultrasonography. All TESGs remained patent, with no evidence of thrombosis or aneurysmal changes. Histological analysis revealed early endothelialization and smooth muscle cell infiltration within the TESG wall, in contrast to the prosthetic graft controls, which lacked comparable cellular integration. This study demonstrated the short-term feasibility and biological compatibility of a fully bioresorbable TESG. Although long-term outcomes remain to be established, these results support further development of TESG to reduce late complications through improved tissue integration and avoidance of permanent synthetic materials.