David T E, Pollick C, Bos J
Division of Cardiovascular Surgery, Toronto Western Hospital, Ontario, Canada.
J Thorac Cardiovasc Surg. 1990 Jan;99(1):113-8.
Twenty-nine patients were entered in a clinical trial on aortic valve replacement with a stentless glutaraldehyde-fixed porcine aortic valve. This bioprosthesis is secured to the aortic root by the same technique used for aortic valve replacement with aortic valve homografts. The functional results obtained from this operation have been most satisfactory. To assess the hemodynamic benefit of eliminating the stent of a porcine aortic valve, we matched 22 patients with a stentless porcine bioprosthesis for age, sex, body surface area, valve lesion, and bioprosthesis size to 22 patients who had aortic valve replacement with a Hancock II bioprosthesis. Mean and peak systolic gradients across the aortic bioprosthesis and effective aortic valve areas were obtained by Doppler studies. Gradients across the stentless bioprosthesis were significantly lower than gradients across the Hancock II valve for every bioprosthesis size. Effective aortic valve areas of the stentless bioprosthesis were significantly larger than the valve areas of the Hancock II valve. Our data demonstrate that the hemodynamic characteristics of a glutaraldehyde-fixed porcine aortic bioprosthesis are greatly improved when the aortic root is used as a stent for the valve. This technique of implantation is expected to enhance the durability of the bioprosthesis, because the aortic root may dampen the mechanical stress to which the leaflets are subjected during the cardiac cycle.
29例患者参与了一项关于使用无支架戊二醛固定猪主动脉瓣进行主动脉瓣置换的临床试验。这种生物假体通过与使用主动脉瓣同种异体移植物进行主动脉瓣置换相同的技术固定于主动脉根部。该手术获得的功能结果非常令人满意。为了评估去除猪主动脉瓣支架的血流动力学益处，我们将22例使用无支架猪生物假体的患者与22例使用汉考克II型生物假体进行主动脉瓣置换的患者，在年龄、性别、体表面积、瓣膜病变和生物假体尺寸方面进行了匹配。通过多普勒研究获得了主动脉生物假体上的平均和峰值收缩期梯度以及有效主动脉瓣面积。对于每种生物假体尺寸，无支架生物假体上的梯度显著低于汉考克II型瓣膜上的梯度。无支架生物假体的有效主动脉瓣面积显著大于汉考克II型瓣膜的瓣膜面积。我们的数据表明，当将主动脉根部用作瓣膜的支架时，戊二醛固定猪主动脉生物假体的血流动力学特性会得到极大改善。这种植入技术有望提高生物假体的耐久性，因为主动脉根部可能会减轻瓣叶在心动周期中所承受的机械应力。
