Abu Saleh Walid K, Goswami Rajiv, Chinnadurai Ponraj, Al Jabbari Odeaa, Barker Colin M, Lin C Huie, Kleiman Neal, Reardon Michael J, Ramlawi Basel
J Heart Valve Dis. 2015 Jul;24(4):420-5.
Direct aortic access for transcatheter aortic valve replacement (DA-TAVR) is an important alternative approach in patients with hostile ileo-femoral vessels. Planning the transaortic puncture site and an 'ideal' trajectory towards the annulus plane is important for safe and successful valve implantation. The feasibility of three-dimensional (3D) planning and real-time fluoroscopic image guidance for DA-TAVR was evaluated using pre-procedural multi-detector computed tomography (MDCT) and intra-procedural Dyna CT co-registration approaches.
Between May 2012 and August 2014, a total of 44 patients (40 mini-sternotomies, four mini-thoracotomies) was selected for DA-TAVR using the authors' MDCT-Dyna CT co-registration approach (32 CoreValve, 12 SAPIEN). Pre-procedural contrast-enhanced multi-slice CT (MSCT) and intra- procedural non-contrast Dyna CT images were co-registered based on cardiac outline and aortic root calcifications. Using a prototype software, the aortic root was segmented and relevant landmarks identified automatically. The intersection of a virtual perpendicular trajectory from the annulus with the greater curvature of the aorta was marked as the planned DA puncture site. The planned DA puncture site, trajectory and relevant landmarks were overlaid onto real-time fluoroscopic images for image guidance during DA-TAVR.
Real-time fluoroscopic overlay of planned trajectory was feasible in all 44 cases of DA-TAVR. The mean 2D projection distance error between the actual and planned aortic puncture sites was 1.60 +/- 1.1 cm. The mean angular difference error (measure of co-axiality) between actual and planned DA trajectory was 11.86 +/- 9.3. Errors in distance and co-axiality were lower with the mini-thoracotomy than with the mini-sternotomy approach. The Multi-Slice CT (MSCT)-Dyna CT co-registration technique resulted in significantly less contrast usage, and trended towards shorter fluoroscopy and operative times. There was also a trend towards a reduction in acute kidney injury, but no difference was identified in the degree of paravalvular regurgitation or mortality.
3D access planning and real-time image guidance for DA-TAVR is feasible using an MDCT/non-contrast Dyna CT image co-registration-based approach. Such image co-registration strategies improve the accuracy of case planning and safety of valve deployment with a direct aortic approach. Further studies are necessary to determine if these enhancements translate into an improvement in clinical outcomes.
对于髂股血管条件不佳的患者，经导管主动脉瓣置换术（TAVR）的直接主动脉入路（DA-TAVR）是一种重要的替代方法。规划经主动脉穿刺点以及朝向瓣环平面的“理想”路径对于安全、成功地植入瓣膜至关重要。使用术前多排螺旋计算机断层扫描（MDCT）和术中Dyna CT配准方法，评估了DA-TAVR的三维（3D）规划和实时荧光透视图像引导的可行性。
2012年5月至2014年8月期间，共有44例患者（40例行微创胸骨切开术，4例行微创开胸术）采用作者的MDCT-Dyna CT配准方法接受DA-TAVR（32例使用CoreValve瓣膜，12例使用SAPIEN瓣膜）。基于心脏轮廓和主动脉根部钙化，对术前增强多层螺旋CT（MSCT）图像和术中非增强Dyna CT图像进行配准。使用原型软件对主动脉根部进行分割，并自动识别相关标志点。将从瓣环引出的虚拟垂直轨迹与主动脉大弯的交点标记为计划的DA穿刺点。在DA-TAVR过程中，将计划的DA穿刺点、轨迹和相关标志点叠加到实时荧光透视图像上以进行图像引导。
在所有44例DA-TAVR病例中，计划轨迹的实时荧光透视叠加均可行。实际与计划的主动脉穿刺点之间的平均二维投影距离误差为1.60±1.1厘米。实际与计划的DA轨迹之间的平均角度差异误差（同轴度测量值）为11.86±9.3。与微创胸骨切开术相比，微创开胸术的距离和同轴度误差更小。多层螺旋CT（MSCT）-Dyna CT配准技术显著减少了造影剂用量，并且在透视时间和手术时间方面有缩短趋势。急性肾损伤也有减少趋势，但瓣周反流程度或死亡率方面未发现差异。
使用基于MDCT/非增强Dyna CT图像配准的方法，DA-TAVR的3D入路规划和实时图像引导是可行的。这种图像配准策略提高了病例规划的准确性以及直接主动脉入路瓣膜植入的安全性。需要进一步研究以确定这些改进是否能转化为临床结果的改善。
