Park Matthew H, Marin-Cuartas Mateo, Sellke Mark, Pandya Pearly K, Zhu Yuanjia, Wilkerson Robert J, Holzhey David M, Borger Michael A, Woo Y Joseph
Department of Cardiothoracic Surgery, Stanford University, Stanford, Calif.
Department of Mechanical Engineering, Stanford University, Stanford, Calif.
JTCVS Tech. 2023 Apr 18;20:45-54. doi: 10.1016/j.xjtc.2023.03.022. eCollection 2023 Aug.
An increasing number of high-risk patients with previous mitral valve annuloplasty require transcatheter mitral valve replacement due to recurrent regurgitation. Annulus dilation with a transcatheter balloon is often performed before valve-in-ring transcatheter mitral valve replacement, which is believed to reduce misalignment and paravalvular leakage, yet little evidence exists to support this practice. Our objective was to generate intuitive annuloplasty ring analyses for improved valve-in-ring transcatheter mitral valve replacement planning.
We generated a mathematical model that calculates image-tracked differential ring curvature to build quantifications for improved planning for valve-in-ring procedures. Carpentier-Edwards Physio M24 and M30 (n = 2 each), Physio II M24 and M26 (n = 3 each), LivaNova AnnuloFlex M26 (n = 2), and Edwards Geoform M28 (n = 2) rings were tested with a 30-mm Toray Inoue balloon inflated to maximum rated pressures.
Curvature variance reduces with larger ring sizes, indicating that larger rings are initially more circular than smaller ones. Evaluated semi-rigid and rigid rings showed little to no difference between pre- and post-dilation states. Annuloflex rings (flexible band) showed a postdilation variance reduction of 32.83% ( < .001) followed by an increase after 10 minutes of relaxation that was still reduced by 19.62% relative to the initial state ( < .001).
We discovered that balloon dilation does not significantly deform evaluated semi-rigid or rigid rings at maximum rated balloon pressures. This may mean that dilation for these conditions before valve-in-ring transcatheter mitral valve replacement is unnecessary. Our mathematical approach creates a foundation for extended classification of this practice, providing meaningful quantification of ring geometry.
越来越多曾接受二尖瓣环成形术的高危患者因反流复发需要经导管二尖瓣置换术。在环内瓣膜经导管二尖瓣置换术前，常采用经导管球囊进行瓣环扩张，人们认为这可减少瓣膜错位和瓣周漏，但几乎没有证据支持这种做法。我们的目标是生成直观的瓣环成形环分析，以改进环内瓣膜经导管二尖瓣置换术的规划。
我们建立了一个数学模型，该模型计算图像跟踪的差分环曲率，以建立量化指标，用于改进环内手术的规划。使用充气至最大额定压力的30毫米东丽伊诺埃球囊对Carpentier-Edwards Physio M24和M30（各2个）、Physio II M24和M26（各3个）、LivaNova AnnuloFlex M26（2个）以及Edwards Geoform M28（2个）环进行测试。
曲率方差随环尺寸增大而减小，表明较大的环最初比较小的环更接近圆形。评估的半刚性和刚性环在扩张前后状态之间几乎没有差异。Annuloflex环（柔性带）扩张后方差降低了32.83%（P<0.001），在放松10分钟后有所增加，但相对于初始状态仍降低了19.62%（P<0.001）。
我们发现，在最大额定球囊压力下，球囊扩张不会使评估的半刚性或刚性环发生显著变形。这可能意味着在环内瓣膜经导管二尖瓣置换术前，针对这些情况进行扩张是不必要的。我们的数学方法为这种做法的扩展分类奠定了基础，提供了有意义的环几何形状量化指标。
