摘要
背景:自体细胞心脏瓣膜组织工程(TE)已在体外实验中获得成功。本文报道应用自体内皮祖细胞(EPC)作为种子细胞的组织工程肺动脉瓣(PV)的首次临床植入以及3.5年的随访结果。方法和结果:人PV同种异体移植物经脱细胞化(胰蛋白酶/EDTA),可致从血液中分离的外周单核细胞种植于支架。
BACKGROUND -Tissue engineering(TE) of heart valves reseeded with autologous cells has been successfully performed in vitro. Here, we report our first clinical implantation of pulmonary heart valves(PV) engineered with autologous endothelial progenitor cells(EPCs) and the results of 3.5 years of follow-up. METHODS AND RESULTS -Human PV allografts were decellularized(Trypsin/EDTA) and resulting scaffolds reseeded with peripheral mononuclear cells isolated from human blood. Positive stain for von Willebrand factor, CD31, and Flk-1 was observed in monolayers of cells cultivated and differentiated on the luminal surface of the scaffolds in a dynamic bioreactor system for up to 21 days, indicating endothelial nature. PV reseeded with autologous cells were implanted into 2 pediatric patients(age 13 and 11) with congenital PV failure. Postoperatively, a mild pulmonary regurgitation was documented in both children. Based on regular echocardiographic investigations, hemodynamic parameters and cardiac morphology changed in 3.5 years as follows: increase of the PV annulus diameter(18 to 22.5 mm and 22 to 26 mm, respectively), decrease of valve regurgitation(trivial/mild and trivial, respectively), decrease(16 to 9 mm Hg) or a increase(8 to 9.5 mm Hg) of mean transvalvular gradient, remained 26 mm or decreased(32 to 28 mm) right-ventricular end-diastolic diameter. The body surface area increased(1.07 to 1.42 m2 and 1.07 to 1.46 m2, respectively). No signs of valve degeneration were observed in both patients. CONCLUSIONS -TE of human heart valves using autologous EPC is a feasible and safe method for pulmonary valve replacement. TE valves have the potential to remodel and grow accordingly to the somatic growth of the child.
