Lockie K J, Fisher J, Juster N P, Davies G A, Watterson K
Department of Mechanical Engineering, University of Leeds, United Kingdom.
J Thorac Cardiovasc Surg. 1994 Dec;108(6):1037-42.
The biomechanics and function of fresh porcine aortic roots and valves have been compared with those of glutaraldehyde-treated roots prepared in a conventional manner without dilation of the elastic aortic root and with glutaraldehyde-treated roots prepared with permanent predilation during fixation. The glutaraldehyde-treated aortic walls were significantly less extensible than fresh walls, with a mean dilation of only 6% compared with 45% for the fresh root at 120 mm Hg pressure. Permanent predilation of the aortic root during fixation allowed the total dilation of the fixed root to be increased to 19% at 120 mm Hg pressure. The effective orifice area of the fresh root and valve was significantly greater than those of the fixed roots and valves, with permanent predilation fixation producing a significantly greater orifice area than conventional fixation. The open-leaflet bending deformations were found to be lower in the valves fixed after permanent predilation than in the standard fixed valves. The glutaraldehyde-treated porcine root and valve does not reproduce the biomechanics and function of the fresh/root, because of the reduced extensibility of the fixed aortic wall. Permanent predilation during fixation helps to partially overcome the shortcomings of the fixed root, producing better function than a standard fixed valve.
已将新鲜猪主动脉根部和瓣膜的生物力学及功能，与以传统方式制备的未经弹性主动脉根部扩张的戊二醛处理根部，以及在固定过程中进行永久性预扩张制备的戊二醛处理根部进行了比较。戊二醛处理的主动脉壁的可扩展性明显低于新鲜壁，在120毫米汞柱压力下，平均扩张率仅为6%，而新鲜根部为45%。在固定过程中对主动脉根部进行永久性预扩张，可使固定根部在120毫米汞柱压力下的总扩张率增加到19%。新鲜根部和瓣膜的有效开口面积明显大于固定根部和瓣膜，永久性预扩张固定产生的开口面积明显大于传统固定。发现永久性预扩张后固定的瓣膜中的开放瓣叶弯曲变形低于标准固定瓣膜。由于固定主动脉壁的可扩展性降低，戊二醛处理的猪根部和瓣膜无法重现新鲜根部的生物力学和功能。固定过程中的永久性预扩张有助于部分克服固定根部的缺点，产生比标准固定瓣膜更好的功能。
