Abstract：
BACKGROUND: Successful transcatheter aortic valve replacement (TAVR) requires an understanding of how a prosthetic valve will interact with a patient\'s anatomy in advance of surgical deployment. To improve this understanding, we developed a benchtop workflow that allows for testing of physical interactions between prosthetic valves and patient-specific aortic root anatomy, including calcified leaflets, prior to actual prosthetic valve placement.
METHODS: This was a retrospective study of 30 patients who underwent TAVR at a single high volume center. By design, the dataset contained 15 patients with a successful annular seal (defined by an absence of paravalvular leaks) and 15 patients with a sub-optimal seal (presence of paravalvular leaks) on post-procedure transthoracic echocardiogram (TTE). Patients received either a balloon-expandable (Edwards Sapien or Sapien XT, n = 15), or a self-expanding (Medtronic CoreValve or Core Evolut, n = 14, St. Jude Portico, n = 1) valve. Pre-procedural computed tomography (CT) angiograms, parametric geometry modeling, and multi-material 3D printing were utilized to create flexible aortic root physical models, including displaceable calcified valve leaflets. A 3D printed adjustable sizing device was then positioned in the aortic root models and sequentially opened to larger valve sizes, progressively flattening the calcified leaflets against the aortic wall. Optimal valve size and fit were determined by visual inspection and quantitative pressure mapping of interactions between the sizer and models.
RESULTS: Benchtop-predicted \"best fit\" valve size showed a statistically significant correlation with gold standard CT measurements of the average annulus diameter (n = 30, p < 0.0001 Wilcoxon matched-pairs signed rank test). Adequateness of seal (presence or absence of paravalvular leak) was correctly predicted in 11/15 (73.3%) patients who received a balloon-expandable valve, and in 9/15 (60%) patients who received a self-expanding valve. Pressure testing provided a physical map of areas with an inadequate seal; these corresponded to areas of paravalvular leak documented by post-procedural transthoracic echocardiography.
CONCLUSIONS: We present and demonstrate the potential of a workflow for determining optimal prosthetic valve size that accounts for aortic annular dimensions as well as the active displacement of calcified valve leaflets during prosthetic valve deployment. The workflow\'s open source framework offers a platform for providing predictive insights into the design and testing of future prosthetic valves.
METHODS: This was a retrospective study of 30 patients who underwent TAVR at a single high volume center. By design, the dataset contained 15 patients with a successful annular seal (defined by an absence of paravalvular leaks) and 15 patients with a sub-optimal seal (presence of paravalvular leaks) on post-procedure transthoracic echocardiogram (TTE). Patients received either a balloon-expandable (Edwards Sapien or Sapien XT, n = 15), or a self-expanding (Medtronic CoreValve or Core Evolut, n = 14, St. Jude Portico, n = 1) valve. Pre-procedural computed tomography (CT) angiograms, parametric geometry modeling, and multi-material 3D printing were utilized to create flexible aortic root physical models, including displaceable calcified valve leaflets. A 3D printed adjustable sizing device was then positioned in the aortic root models and sequentially opened to larger valve sizes, progressively flattening the calcified leaflets against the aortic wall. Optimal valve size and fit were determined by visual inspection and quantitative pressure mapping of interactions between the sizer and models.
RESULTS: Benchtop-predicted \"best fit\" valve size showed a statistically significant correlation with gold standard CT measurements of the average annulus diameter (n = 30, p < 0.0001 Wilcoxon matched-pairs signed rank test). Adequateness of seal (presence or absence of paravalvular leak) was correctly predicted in 11/15 (73.3%) patients who received a balloon-expandable valve, and in 9/15 (60%) patients who received a self-expanding valve. Pressure testing provided a physical map of areas with an inadequate seal; these corresponded to areas of paravalvular leak documented by post-procedural transthoracic echocardiography.
CONCLUSIONS: We present and demonstrate the potential of a workflow for determining optimal prosthetic valve size that accounts for aortic annular dimensions as well as the active displacement of calcified valve leaflets during prosthetic valve deployment. The workflow\'s open source framework offers a platform for providing predictive insights into the design and testing of future prosthetic valves.
摘要：
背景：成功的经导管主动脉瓣置换术（TAVR）需要在手术部署之前了解人工瓣膜如何与患者的解剖结构相互作用。为了提高这种认识,我们开发了一个台式工作流程，可以测试人工瓣膜和患者特定的主动脉根解剖结构之间的物理相互作用，包括钙化的小叶,在实际人工瓣膜放置之前。
方法：这是一项对30例患者进行的回顾性研究，这些患者在单个高容量中心接受了TAVR。根据设计，数据集包含15例成功环形密封的患者(定义为无瓣周漏)和15例术后经胸超声心动图(TTE)显示次优密封的患者(有瓣周漏).患者接受了球囊扩张（EdwardsSapien或SapienXT，n=15),或自我扩张(美敦力CoreValve或核心Evolut，n=14，圣裘德门廊，n=1)阀门。术前计算机断层扫描(CT)血管造影,参数化几何建模,多材料3D打印用于创建柔性主动脉根物理模型，包括可移位的钙化瓣膜小叶。然后将3D打印的可调尺寸装置放置在主动脉根模型中，并依次打开更大的瓣膜尺寸，逐渐变平钙化小叶对主动脉壁。通过目视检查和大小器与模型之间的相互作用的定量压力映射来确定最佳瓣膜尺寸和配合。
结果：基准预测的“最佳拟合”瓣膜尺寸与平均瓣环直径的金标准CT测量值具有统计学意义（n=30，p<0.0001Wilcoxon匹配对符号秩检验）。在接受球囊扩张瓣膜的11/15（73.3%）患者中正确预测了密封的充分程度（存在或不存在瓣周漏）。以及9/15（60％）接受自膨式瓣膜的患者。压力测试提供了密封不足区域的物理图；这些对应于术后经胸超声心动图记录的瓣周漏区域。
结论：我们提出并证明了确定最佳人工瓣膜尺寸的工作流程的潜力，该工作流程考虑了主动脉瓣环尺寸以及人工瓣膜部署过程中钙化瓣膜小叶的主动移位。工作流的开源框架提供了一个平台，为未来人工瓣膜的设计和测试提供预测性见解。
方法：这是一项对30例患者进行的回顾性研究，这些患者在单个高容量中心接受了TAVR。根据设计，数据集包含15例成功环形密封的患者(定义为无瓣周漏)和15例术后经胸超声心动图(TTE)显示次优密封的患者(有瓣周漏).患者接受了球囊扩张（EdwardsSapien或SapienXT，n=15),或自我扩张(美敦力CoreValve或核心Evolut，n=14，圣裘德门廊，n=1)阀门。术前计算机断层扫描(CT)血管造影,参数化几何建模,多材料3D打印用于创建柔性主动脉根物理模型，包括可移位的钙化瓣膜小叶。然后将3D打印的可调尺寸装置放置在主动脉根模型中，并依次打开更大的瓣膜尺寸，逐渐变平钙化小叶对主动脉壁。通过目视检查和大小器与模型之间的相互作用的定量压力映射来确定最佳瓣膜尺寸和配合。
结果：基准预测的“最佳拟合”瓣膜尺寸与平均瓣环直径的金标准CT测量值具有统计学意义（n=30，p<0.0001Wilcoxon匹配对符号秩检验）。在接受球囊扩张瓣膜的11/15（73.3%）患者中正确预测了密封的充分程度（存在或不存在瓣周漏）。以及9/15（60％）接受自膨式瓣膜的患者。压力测试提供了密封不足区域的物理图；这些对应于术后经胸超声心动图记录的瓣周漏区域。
结论：我们提出并证明了确定最佳人工瓣膜尺寸的工作流程的潜力，该工作流程考虑了主动脉瓣环尺寸以及人工瓣膜部署过程中钙化瓣膜小叶的主动移位。工作流的开源框架提供了一个平台，为未来人工瓣膜的设计和测试提供预测性见解。
