Fikani Amine, Craiem Damian, Boulogne Cyrille, Soulat Gilles, Mousseaux Elie, Jouan Jerome
Department of Cardiothoracic and Vascular Surgery, University Medical Center Hôtel-Dieu de France Hospital, Faculty of Medicine, Saint-Joseph University of Beirut, Beirut, Lebanon.
XLIM UMR CNRS 7252, Limoges, France.
JTCVS Tech. 2024 Jul 1;27:60-67. doi: 10.1016/j.xjtc.2024.06.012. eCollection 2024 Oct.
To evaluate the role of 4-dimensional (4D; 3-dimensional [3D] + time) analysis using multiphase cardiac computed tomography (MCCT) in the description of the aortic annulus (AA) of bicuspid aortic valves (BAV) with regard to the latest expert consensus classification.
Electrocardiography-gated MCCT of 15 patients with BAV were analyzed using in-house software and compared to 15 patients with normal tricuspid aortic valve (TAV). The AA border was pinpointed on 9 reconstructed planes, and the 3D coordinates of the 18 consecutive points were interpolated in 3D using a cubic spline to calculate 3D areas, perimeters, diameters, eccentricity indexes, and global height. Measurements were repeated throughout the cardiac cycle (10 phases). Three additional planes were generated at the level of the left ventricular outflow tract (LVOT), the sinus of Valsalva, and the sinotubular junction.
The annulus area was significantly larger in BAV compared to TAV (mean indexed 3D area, 5.64 ± 0.84 cm/m vs 4.3 ± 0.38 cm/m, respectively; < .001). The AA was also larger in BAV in terms of perimeter, diameters, and height ( < .001). The Valsalva sinuses and sinotubular junction also were significantly larger in BAV compared to TAV (mean area in end-diastole, 6.06 ± 1.00 cm vs 4.69 ± 1.00 cm [ < .001] and 5.13 ± 1.62 cm vs 3.62 ± 0.99 cm [ < .001], respectively). In BAV, 3D AA shape analysis helps distinguish the 3 types of BAV: the 2-sinus type (symmetrical), the fused type, and the partial-fusion type or "form fruste" (both asymmetrical). It also allows determination of the position and height of the nonfunctional commissure. In symmetrical BAV, the nonfunctional commissure was significantly lower than the other commissures (6.01 ± 4.27 mm vs 18.24 ± 3.20 mm vs 17.15 ± 3.60 mm; < .001), whereas in asymmetrical BAV, the 3 commissures were of comparable height (16.38 ± 0.86 mm vs 15.88 ± 1.69 mm vs 15.37 ± 0.88 mm; = .316). There was no difference in AA eccentricity indices between TAV and BAV in all phases of the cardiac cycle; however, there was a spectrum of ellipticity for the other components of the aortic root among the different types of valves: going from TAV to asymmetrical BAV to symmetrical BAV, at end-diastole, the LVOT became more circular and the sinuses of Valsalva became more elliptical.
3D morphometric analysis of the BAV using MCCT allows identification of the type of BAV and the position and height of the nonfunctional commissure. There are significant differences in the morphology of the aortic root between TAV and the different types of BAV. Further studies are needed to evaluate the impact of 3D analysis on the procedural planning for pathologic BAV.
根据最新专家共识分类，评估使用多期心脏计算机断层扫描（MCCT）进行四维（4D；三维[3D]+时间）分析在描述二叶式主动脉瓣（BAV）主动脉瓣环（AA）中的作用。
使用内部软件分析15例BAV患者的心电图门控MCCT，并与15例正常三尖瓣主动脉瓣（TAV）患者进行比较。在9个重建平面上确定AA边界，并使用三次样条在3D中对18个连续点的3D坐标进行插值，以计算3D面积、周长、直径、偏心指数和整体高度。在整个心动周期（10个阶段）重复测量。在左心室流出道（LVOT）、主动脉窦和窦管交界处水平生成另外三个平面。
与TAV相比，BAV的瓣环面积明显更大（平均索引3D面积分别为5.64±0.84cm/m²和4.3±0.38cm/m²；P<0.001）。BAV的AA在周长、直径和高度方面也更大（P<0.001）。与TAV相比，BAV的主动脉窦和窦管交界处也明显更大（舒张末期平均面积分别为6.06±1.00cm²和4.69±1.00cm²[P<0.001]以及5.13±1.62cm²和3.62±0.99cm²[P<0.001]）。在BAV中，3D AA形状分析有助于区分3种类型的BAV：双窦型（对称）、融合型和部分融合型或“不完全型”（均不对称）。它还允许确定无功能瓣叶联合的位置和高度。在对称BAV中，无功能瓣叶联合明显低于其他瓣叶联合（6.01±4.27mm对18.24±3.20mm对17.15±3.60mm；P<0.001），而在不对称BAV中，3个瓣叶联合高度相当（16.38±0.86mm对15.88±1.69mm对15.37±0.88mm；P=0.316）。在心动周期的所有阶段，TAV和BAV之间的AA偏心指数没有差异；然而，在不同类型的瓣膜中，主动脉根部其他组件的椭圆率存在差异：从TAV到不对称BAV再到对称BAV，在舒张末期，LVOT变得更圆，主动脉窦变得更椭圆。
使用MCCT对BAV进行3D形态测量分析可识别BAV的类型以及无功能瓣叶联合的位置和高度。TAV和不同类型的BAV之间主动脉根部形态存在显著差异。需要进一步研究来评估3D分析对病理性BAV手术规划的影响。
