Matsubayashi Keiji, Fedak Paul W M, Mickle Donald A G, Weisel Richard D, Ozawa Tsukasa, Li Ren-Ke
Department of Surgery, Division of Cardiovascular Surgery, Shiga University of Medical Science, Shiga, Japan.
Circulation. 2003 Sep 9;108 Suppl 1:II219-25. doi: 10.1161/01.cir.0000087450.34497.9a.
Recurrent ventricular dilatation can occur after surgical repair of a left ventricular (LV) aneurysm. Use of an autologous bioengineered muscle graft to replace resected scar tissue may prevent recurrent dilatation and improve cardiac function.
Vascular smooth muscle cells (SMCs, 5 x 10(6) cells) from rat aortas were seeded onto synthetic PCLA (sponge polymer of epsilon-caprolactone-co-L-lactide reinforced with knitted poly-L-lactide fabric) patches and cultured for 2 weeks to allow tissue formation. Syngenic rats underwent proximal left coronary artery ligation to create a transmural myocardial scar. Four weeks after coronary ligation, cell-seeded patches (n=15) or unseeded patches (n=12) were used for a modified endoventricular circular patch plasty (EVCPP) repair of the infarct area. Ligated controls (n=14) and nonligated normal rats (n=10) had sham surgeries without EVCPP. Cardiac function was assessed by echocardiography and isolated Langendorff heart perfusion. Graft histology and morphology was also assessed.
After 8 weeks in vivo, seeded patches were thicker (P<0.05) and smaller in area (P<0.003) than unseeded patches. Only seeded patches had prominent elastic tissue formation (P<0.001) in association with SMCs. LV systolic function by echocardiography was improved in the seeded group compared with both unseeded (P<0.002) and control groups (P<0.0001). LV volumes in both patch repair groups were comparable but were significantly smaller (P<0.05) than controls. LV distensibility tended toward improvement in the seeded group as compared with unseeded hearts, but the difference did not achieve statistical significance (P=0.06).
Surgical repair with muscle-cell seeded grafts reduced abnormal chamber distensibility and improved LV function after myocardial infarction as compared with unseeded grafts. Bioengineered muscle grafts may be superior to synthetic materials for the surgical repair of LV scar.
左心室（LV）动脉瘤手术修复后可能会出现反复的心室扩张。使用自体生物工程肌肉移植物替代切除的瘢痕组织可能会预防反复扩张并改善心脏功能。
将来自大鼠主动脉的血管平滑肌细胞（SMCs，5×10⁶个细胞）接种到合成的PCLA（用针织聚-L-丙交酯织物增强的ε-己内酯-co-L-丙交酯海绵聚合物）补片上，并培养2周以形成组织。同基因大鼠接受左冠状动脉近端结扎以形成透壁心肌瘢痕。冠状动脉结扎4周后，将接种细胞的补片（n = 15）或未接种细胞的补片（n = 12）用于梗死区域的改良心室内环形补片成形术（EVCPP）修复。结扎对照组（n = 14）和未结扎的正常大鼠（n = 10）接受了不进行EVCPP的假手术。通过超声心动图和离体Langendorff心脏灌注评估心脏功能。还评估了移植物的组织学和形态。
在体内8周后，接种细胞的补片比未接种细胞的补片更厚（P < 0.05）且面积更小（P < 0.003）。只有接种细胞的补片与SMCs相关联有明显的弹性组织形成（P < 0.001）。与未接种细胞的组（P < 0.002）和对照组（P < 0.0001）相比，接种细胞组通过超声心动图评估的左心室收缩功能得到改善。两个补片修复组的左心室容积相当，但明显小于对照组（P < 0.05）。与未接种细胞的心脏相比，接种细胞组的左心室扩张性有改善的趋势，但差异未达到统计学意义（P = 0.06）。
与未接种细胞的移植物相比，用接种肌肉细胞的移植物进行手术修复可减少心肌梗死后异常的心室扩张并改善左心室功能。生物工程肌肉移植物在左心室瘢痕的手术修复方面可能优于合成材料。
