González-Juanatey J R, García-Acuña J M, Vega Fernandez M, Amaro Cendón A, Castelo Fuentes V, García-Bengoechea J B, de la Peña M G
Department of Cardiology, Galician General Hospital, Spain.
J Thorac Cardiovasc Surg. 1996 Aug;112(2):273-80. doi: 10.1016/s0022-5223(96)70249-0.
Discussion of aortic valve replacement has primarily concerned the choice between tissue and mechanical prostheses. Less emphasis has been placed on prosthesis size. Despite technical advances increasing prosthesis orifice area, small valves implanted in the unenlarged aortic root may not be significantly less obstructive than the stenotic native valves they replace.
In this work we studied 52 patients (31 women, 21 men; mean age 59.2 years) in whom valve prostheses sized 19, 21, 23, or 25 mm (30 bioprostheses and 22 tilting disc valves) had been implanted to replace stenotic aortic valves. Most patients with 19 or 21 mm prostheses were women. Doppler and conventional echocardiographic studies were performed in the 10 days preceding the operation and between 10 and 40 months (mean 18 months) after the operation. The patients receiving larger valve sizes had significantly larger body surface areas than those receiving smaller valve sizes (mainly women).
No significant differences were observed between preoperative and postoperative diameters or left ventricular systolic function parameters, but left ventricular mass and mass index decreased in all four groups (albeit nonsignificantly in the 19 mm group, and with less statistical significance in the 21 mm group than in the 23 and 25 mm groups). Postoperative peak and mean transvalvular pressure drops were significantly greater in the 19 mm group than in the other groups, and the 21 mm group had significantly greater transvalvular pressure drops than the 25 mm group. Postoperative effective valve area was significantly smaller in the 19 mm group than in the 21 mm group, and significantly smaller in the 21 mm group than in the 23 and 25 mm groups.
We conclude that despite undeniable recent improvements in the design of artificial heart valves, 19 mm aortic prostheses continue to create significant obstruction of the left ventricular outflow tract and, possibly as a consequence of this, fail to bring about significant reduction in left ventricular hypertrophy.
关于主动脉瓣置换术的讨论主要集中在组织瓣膜和机械瓣膜之间的选择上。对瓣膜尺寸的重视程度较低。尽管技术进步增加了瓣膜开口面积，但植入未扩大主动脉根部的小瓣膜可能并不比它们所替代的狭窄天然瓣膜的梗阻性小很多。
在这项研究中，我们研究了52例患者（31名女性，21名男性；平均年龄59.2岁），这些患者植入了尺寸为19、21、23或25毫米的瓣膜假体（30个生物瓣膜和22个倾斜盘式瓣膜）以置换狭窄的主动脉瓣。大多数植入19或21毫米假体的患者为女性。在手术前10天以及手术后10至40个月（平均18个月）进行了多普勒和传统超声心动图检查。接受较大瓣膜尺寸的患者的体表面积明显大于接受较小瓣膜尺寸的患者（主要是女性）。
术前和术后直径或左心室收缩功能参数之间未观察到显著差异，但所有四组的左心室质量和质量指数均下降（尽管19毫米组下降不显著，且21毫米组的统计学意义低于23和25毫米组）。19毫米组术后的跨瓣膜峰值和平均压力阶差明显大于其他组，21毫米组的跨瓣膜压力阶差明显大于25毫米组。19毫米组术后的有效瓣膜面积明显小于21毫米组，21毫米组明显小于23和25毫米组。
我们得出结论，尽管近期人工心脏瓣膜设计有了不可否认的改进，但19毫米的主动脉假体继续对左心室流出道造成明显梗阻，可能因此未能使左心室肥厚显著减轻。
