Project description:Valve-in-mitral annular calcification presents a great challenge with a risk of left ventricular outflow tract obstruction (LVOTO). We demonstrate the first-in-human experience of performing percutaneous electrosurgery-guided perforation and balloon dilation of the anterior mitral valve leaflet followed by transcatheter valve implantation to prevent LVOTO.
Project description:Rationale: Ischemic mitral regurgitation (IMR) is frequently observed following myocardial infarction (MI) and is associated with higher mortality and poor clinical prognosis if left untreated. Accumulating evidence suggests that mitral valve (MV) leaflets actively remodel post-MI, yet the cellular mechanisms underlying these responses and how this affects tissue function remain largely unknown. Objective: We sought to elucidate MV remodeling post-MI at the tissue, cellular, and transcriptomic levels. Methods and Results: The mechanical behavior of ovine MV leaflets pre-MI and 8 weeks post-MI reveal a significant decrease in radial direction extensibility, which essentially eliminated the mechanical anisotropy typically observed in healthy MVs. Quantitative histology and ultrastructural assessment by transmission electron microscopy revealed altered leaflet composition and architecture at 8 weeks post-MI. Assessment of the MV interstitial cell (MVIC) nuclear aspect ratio, a metric of cellular deformation, revealed that MVICs were on average rounder following MI. RNA sequencing (RNA-seq) indicated that YAP-induced genes were elevated at 4 weeks post-MI and genes related to extracellular matrix organization were some of the most downregulated in sheep with IMR compared to sheep without IMR at 4 weeks post-MI. Additionally, RNA-seq revealed the possible recruitment of immune cells in this remodeling process due to the drastic elevation of CXCL9 and CLEC10A. Conclusions: This multiscale assessment revealed significant mechanical and microstructural changes due to MI. RNA-seq provided a baseline for global gene expression changes in response to MI with and without IMR and suggests YAP-induced mechanotransduction, altered expression of ECM-related genes, and recruitment of immune cells as mechanisms contributing to altered MV biomechanics post-MI. Conclusions: This multiscale assessment revealed significant mechanical and microstructural changes due to MI. RNA-seq provided a baseline for global gene expression changes in response to MI with and without IMR and suggests YAP-induced mechanotransduction, altered expression of ECM-related genes, and recruitment of immune cells as mechanisms contributing to altered MV biomechanics post-MI.
Project description:ObjectivesWe present our surgical management of a mechanical transcatheter aortic valve replacement (TAVR) complication of an anterior mitral valve leaflet (AML) perforation with infective endocarditis.Key stepsManagement consisted of surgical TAVR explantation, transaortic patch plasty of the AML perforation, patch plasty of an aortic laceration by the TAVR valve, and surgical aortic valve replacement.Potential pitfallsIn cases of high operative risk in a technically demanding surgical situation, the surgeon should aim to operate early and avoid extensive surgical trauma and long operation time by addressing the mitral valve through the aorta and choosing repair instead of replacement for AML perforation.Take-home messagesPoor positioning of TAVR valves can result in severe structural and subsequent infectious complications. Early surgical treatment in high-risk older adult patients can be successfully performed, with favorable outcomes. Scrupulous asepsis and prophylactic perioperative antibiotic therapy are the most important prophylactic measures for prosthetic valve endocarditis.