Medizinische Klinik und Poliklinik II, Universitätsklinikum Bonn, Bonn, Germany.
J Am Coll Cardiol. 2013 Jul 2;62(1):11-20. doi: 10.1016/j.jacc.2013.02.088. Epub 2013 May 1.
Paravalvular aortic regurgitation (PAR) negatively affects the prognosis after transcatheter aortic valve replacement (TAVR) with dramatically increased morbidity and mortality in patients with more than mild PAR. Because transcatheter heart valves are implanted in a sutureless fashion using oversizing to anchor the prosthesis stent frame at the level of the virtual aortic annulus, stent frame underexpansion due to heavily calcified cusps, suboptimal placement of the prosthesis, and/or annulus-prosthesis-size mismatch due to malsizing can contribute to paravalvular leakage. In contrast to open heart surgery, TAVR does not offer the opportunity to measure the aortic annulus under direct vision during the procedure. Therefore, the dilemma before each TAVR procedure is the appropriate sizing of the dimensions of the aortic annulus and to choose not only the size but also the transcatheter heart valve type (self-expanding vs. balloon-expandable) that fits the given anatomy best. Because precise echocardiographic quantification of PAR in patients with TAVR remains challenging especially in the acute implantation situation, a multimodal approach for the evaluation of PAR with the use of hemodynamic measurements and imaging modalities is imperative to precisely quantify the severity of aortic regurgitation immediately after valve implantation and to identify patients who will benefit from corrective measures such as post-dilation or valve-in-valve implantation. Every measure has to be taken to prevent or reduce PAR to provide a satisfying long-term clinical outcome.
瓣周主动脉瓣反流 (PAR) 对经导管主动脉瓣置换术 (TAVR) 后的预后有负面影响,对于 PAR 程度超过轻度的患者,其发病率和死亡率显著增加。由于经导管心脏瓣膜采用无缝线方式植入,通过过大尺寸将假体支架框架固定在虚拟主动脉瓣环水平,因此重度钙化瓣叶、假体位置不当和/或因尺寸不当导致瓣环-假体不匹配导致支架框架扩张不足,可能导致瓣周漏。与心脏直视手术不同,TAVR 术在手术过程中无法直视测量主动脉瓣环。因此,每次 TAVR 手术前都面临着一个困境,即如何正确测量主动脉瓣环的尺寸,不仅要选择合适的尺寸,还要选择最适合特定解剖结构的经导管心脏瓣膜类型(自扩张型与球囊扩张型)。由于 TAVR 患者的 PAR 经超声心动图精确量化仍然具有挑战性,尤其是在急性植入情况下,因此需要采用血流动力学测量和影像学相结合的多模态方法来评估 PAR,以便在植入瓣膜后立即精确量化主动脉瓣反流的严重程度,并确定需要采取何种矫正措施(如后扩张或瓣中瓣植入)的患者。必须采取一切措施预防或减少 PAR,以提供满意的长期临床效果。