Kim Kwan-Chang, Kim Soo-Hwan, Kim Yong-Jin
Department of Thoracic and Cardiovascular Surgery, School of Medicine, Ewha Womans University, Korea.
Korean J Thorac Cardiovasc Surg. 2011 Apr;44(2):99-107. doi: 10.5090/kjtcs.2011.44.2.99. Epub 2011 Apr 14.
Calcification is the most frequent cause of clinical failure of bioprosthetic tissues fabricated from GA-fixed porcine valves or bovine pericardium. A multi-factorial approach using different mechanisms was recently developed to reduce the calcification of bioprosthetic tissues. The purpose of the present study was to evaluate the synchronized synergism of using L-arginine and NaBH(4), compared with ethanol and L-lysine, in glutaraldehyde treated porcine pericardium from the standpoint of calcification and tissue elasticity.
Porcine pericardium was fixed at 0.625% GA (7 days at room temperature after 2 days at 4℃). An interim step of ethanol (80%; 1 day at room temperature) or L-lysine (0.1 M; 2 days at 37℃) or L-arginine (0.1 M; 2 days at 37℃) was followed by completion of the GA fixation. A final step of NaBH(4) (0.1 M; 2 days at room temperature) was followed. Their tensile strength, thickness, and thermal stability were measured. Treated pericardia were implanted subcutaneously into three-week-old Sprague-Dawley rats for 8 weeks. Calcium content was assessed by atomic absorption spectroscopy and histology.
L-arginine and NaBH(4) pretreatment (1.81±0.39 kgf/5 mm p=0.001, 0.30±0.08 mm p<0.001) significantly increased tensile strength and thickness compared with the control (0.53±0.34 kgf/5 mm, 0.10±0.02 mm). In a thermal stability test, L-arginine and NaBH(4) pretreatment (84.25±1.12℃, p=0.023) caused a significant difference from the control (86.25±0.00℃). L-lysine and NaBH(4) pretreatment (183.8±42.6 ug/mg, p=0.804), and L-arginine and NaBH(4) pretreatment (163.3±27.5 ug/mg, p=0.621) did not significantly inhibit calcification compared to the control (175.5±45.3 ug/mg), but ethanol and NaBH(4) pretreatment did (38.5±37.3 ug/mg, p=0.003).
The combined pretreatment using L-arginine and NaBH(4) after GA fixation seemed to increase the tensile strength and thickness of porcine pericardium, fixed with GA. Additionally, it seemed to keep thermal stability. However it could not decrease the calcification of porcine pericardium fixed with GA. NaBH(4) pretreatment seemed to decrease the calcification of porcine pericardium fixed with GA, but only with ethanol.
钙化是由戊二醛固定的猪瓣膜或牛心包制成的生物假体组织临床失效的最常见原因。最近开发了一种使用不同机制的多因素方法来减少生物假体组织的钙化。本研究的目的是从钙化和组织弹性的角度评估与乙醇和L-赖氨酸相比，使用L-精氨酸和硼氢化钠（NaBH₄）在戊二醛处理的猪心包中的同步协同作用。
猪心包用0.625%戊二醛固定（4℃放置2天后，室温放置7天）。在戊二醛固定完成之前，先进行乙醇（80%；室温放置1天）或L-赖氨酸（0.1M；37℃放置2天）或L-精氨酸（0.1M；37℃放置2天）的中间步骤。接着进行硼氢化钠（0.1M；室温放置2天）的最后一步。测量其拉伸强度、厚度和热稳定性。将处理过的心包皮下植入3周龄的Sprague-Dawley大鼠体内8周。通过原子吸收光谱法和组织学评估钙含量。
与对照组（0.53±0.34kgf/5mm，0.10±0.02mm）相比，L-精氨酸和硼氢化钠预处理（1.81±0.39kgf/5mm，p = 0.001，0.30±0.08mm，p < 0.001）显著提高了拉伸强度和厚度。在热稳定性测试中，L-精氨酸和硼氢化钠预处理（84.25±1.12℃，p = 0.023）与对照组（86.25±0.00℃）有显著差异。与对照组（175.5±45.3μg/mg）相比，L-赖氨酸和硼氢化钠预处理（183.8±42.6μg/mg，p = 0.804）以及L-精氨酸和硼氢化钠预处理（163.3±27.5μg/mg，p = 0.621）没有显著抑制钙化，但乙醇和硼氢化钠预处理有显著抑制作用（38.5±37.3μg/mg，p = 0.003）。
戊二醛固定后使用L-精氨酸和硼氢化钠的联合预处理似乎增加了用戊二醛固定的猪心包的拉伸强度和厚度。此外，它似乎保持了热稳定性。然而，它不能降低用戊二醛固定的猪心包的钙化。硼氢化钠预处理似乎降低了用戊二醛固定的猪心包的钙化，但仅与乙醇联合时有效。
