Caimmi Philippe Primo, Diterlizzi Marco, Grossini Elena, Kapetanakis Emmanouil Ioannis, Gavinelli Matteo, Carriero Alessandro, Vacca Giovanni
Department of Cardiac Surgery, Medical School, University of Eastern Piedmont A. Avogadro, Novara, Piedmont, Italy.
Ann Thorac Surg. 2009 Sep;88(3):740-4. doi: 10.1016/j.athoracsur.2009.04.069.
The circumference of the aortic annulus adjusts proportionally with changes in left ventricular volume. These dimensional changes in the aortic annulus improve the left ventricular outflow tract (LVOT) hemodynamics and enhance the anterior mitral valve leaflet (AML) movement. In this study, we investigated the impact of circumferential and partial circumference prosthetic mitral rings on aortomitral apparatus function.
Forty patients who underwent coronary artery bypass graft surgery and restrictive annuloplasty of the mitral valve annulus through either a partial circumference flexible ring (group A = 20 patients) or a circumferential rigid ring (group B = 20 patients) were evaluated using cardiac magnetic resonance imaging. Imaging was performed at the end of a 2-year follow-up period. Variations in LVOT diameter, transmitral valve gradient, and effective mitral valve area were measured and compared.
Mean variation in LVOT diameter was significantly higher in group A compared with group B (12.7% +/- 4% versus 3.6% +/- 5%, p = 0.0005). Transmitral valve gradient was higher in group B than in group A (6.2 +/- 3 mm Hg versus 4.6 +/- 2 mm Hg, p = 0.007), whereas effective mitral valve area was larger in group A than group B (3.9 +/- 4 cm(2) versus 3.1 +/- 6 cm(2), p = 0.009). The long-axis cardiac magnetic resonance imaging of patients in group B demonstrated that movement at the base of the AML was hindered with the AML pivotal point appearing to shift posteriorly.
This study demonstrated that the use of circumferential annular rings significantly impairs overall aortomitral apparatus function by reducing outflow diameter and AML movement.
主动脉瓣环周长随左心室容积变化而成比例调整。主动脉瓣环的这些尺寸变化改善了左心室流出道（LVOT）血流动力学，并增强了二尖瓣前叶（AML）运动。在本研究中，我们调查了圆周和部分圆周人工二尖瓣环对主动脉二尖瓣装置功能的影响。
40例接受冠状动脉旁路移植手术并通过部分圆周柔性环（A组 = 20例患者）或圆周刚性环（B组 = 20例患者）进行二尖瓣环限制性成形术的患者，使用心脏磁共振成像进行评估。成像在2年随访期结束时进行。测量并比较LVOT直径、跨二尖瓣压差和有效二尖瓣面积的变化。
A组LVOT直径的平均变化显著高于B组（12.7%±4%对3.6%±5%，p = 0.0005）。B组跨二尖瓣压差高于A组（6.2±3 mmHg对4.6±2 mmHg，p = 0.007），而A组有效二尖瓣面积大于B组（3.9±4 cm²对3.1±6 cm²，p = 0.009）。B组患者的心脏磁共振成像长轴显示，AML基部的运动受到阻碍，AML枢轴点似乎向后移位。
本研究表明，使用圆周环形环通过减小流出道直径和AML运动，显著损害了主动脉二尖瓣装置的整体功能。
