Holzamer Andreas, Sitka Emanuel, Hengstenberg Christian, Schmid Christof, Debl Kurt, Maier Lars, Camboni Daniele, Husser Oliver, Hilker Michael
Klinik und Poliklinik für Herz-, Thorax- und herznahe Gefäßchirurgie, University of Regensburg Medical Center, Regensburg, Germany
Klinik und Poliklinik für Herz-, Thorax- und herznahe Gefäßchirurgie, University of Regensburg Medical Center, Regensburg, Germany.
Eur J Cardiothorac Surg. 2015 Dec;48(6):879-85; discussion 885-6. doi: 10.1093/ejcts/ezv095. Epub 2015 Mar 29.
We demonstrate a multislice computed tomography (MSCT)-based method to calculate the prediction of the so-called 'line of perpendicularity' (LOP) and the 'implanter's views' (IVs) for transcatheter aortic valve implantation (TAVI) procedures. The LOP represents all possible angiographic angulations that result in an orthogonal view to the aortic annulus plane. The IVs allow visual confirmation of correct implantation planes, and are crucial for the commissural aligned implantation of second-generation TAVI prostheses.
The LOP and IVs of 335 concomitant patients were prospectively analysed using multiple plane reconstruction (MPR) of the patient's MSCT scans. Exclusion criteria were bicuspid valves (n = 18) and valve-in-valve TAVI (n = 15). In the MPRs, the aortic cusps' lowest points were marked. With the marker's three-dimensional coordinates, the graph of the LOP with the IVs was calculated and plotted using vector mathematics. In the last 244 cases, the IV with the right coronary cusp in front was chosen for the first aortic root angiogram of the TAVI procedure. The finally used angulation was confirmed by aortic angiogram prior to the valve implantation. Solid angle differences that show the combined left anterior oblique/right anterior oblique and cranio/caudal movement of the C-arm allow quantification of corrections as well as demonstrate interindividual variations.
There is a broad interindividual variation of the aortic valve's topology with solid angle variations of up to 74°. The shape of the LOPs is extremely varying, especially regarding the slope of the curve that indicates differences in valve orientations. Among the 244 patients for whom we used the prediction for the procedure, the first angiogram was considered perfect for implantation without further corrections in 97% (n = 237) of them. In case of the 7 patients with subsequent corrections, the mean solid angle between the prediction and the final angiogram prior to implantation was 6.2° (±5°); the largest correction was 14°.
Prediction of the implantation plane by analysing the patient's MSCT is highly reliable in achieving an adequate view of the aortic annulus in TAVI. The analysis of LOPs showed the large interindividual differences that permit using a standard implantation plane. Therefore, we strongly recommend determining the LOP and IVs during the patient's screening process in each single TAVI case.
我们展示一种基于多层螺旋计算机断层扫描（MSCT）的方法，用于计算经导管主动脉瓣植入术（TAVI）中所谓的“垂直性线”（LOP）和“植入者视角”（IVs）的预测值。LOP代表所有可能的血管造影角度，这些角度可形成与主动脉瓣环平面正交的视图。IVs可用于直观确认正确的植入平面，对于第二代TAVI假体的瓣叶对齐植入至关重要。
使用患者MSCT扫描的多平面重建（MPR）对335例同期患者的LOP和IVs进行前瞻性分析。排除标准为二叶式瓣膜（n = 18）和瓣中瓣TAVI（n = 15）。在MPR图像中，标记主动脉瓣叶的最低点。利用标记点的三维坐标，使用向量数学计算并绘制带有IVs的LOP图形。在最后244例病例中，TAVI手术的首次主动脉根部血管造影选择右冠状动脉瓣叶在前的IV。最终使用的角度在瓣膜植入前通过主动脉血管造影进行确认。显示C形臂的左前斜/右前斜和头侧/尾侧联合运动的立体角差异可用于量化校正，并展示个体间差异。
主动脉瓣拓扑结构存在广泛的个体间差异，立体角变化可达74°。LOP的形状变化极大，尤其是指示瓣膜方向差异的曲线斜率方面。在我们对手术进行预测的244例患者中，97%（n = 237）的首次血管造影被认为非常适合植入，无需进一步校正。在7例随后需要校正的患者中，预测值与植入前最终血管造影之间的平均立体角为6.2°（±5°）；最大校正角度为14°。
通过分析患者的MSCT预测植入平面在TAVI中获得主动脉瓣环的充分视图方面高度可靠。对LOP的分析显示出个体间的巨大差异，这使得可以使用标准植入平面。因此，我们强烈建议在每例TAVI病例的患者筛查过程中确定LOP和IVs。
