Grunau Gilat Linn, Blanke Philipp, Leipsic Jonathon
Department of Medical Imaging, St Paul's Hospital, University of British Columbia, Vancouver, BC, Canada.
J Thorac Imaging. 2015 Nov;30(6):341-8. doi: 10.1097/RTI.0000000000000166.
Aortic stenosis (AS) is a common disorder that affects nearly 5% of individuals over 75 years of age. Many patients with AS are unable to undergo surgical valve replacement (SAVR) as they are commonly deemed to be of very high risk. Transcatheter aortic valve implantation (TAVI), introduced in 2002, is a new method for treatment of these patients. Computed tomography (CT) is becoming the gold standard imaging modality for preprocedural planning, including assessment of annular size and access. Since 2002, >100,000 procedures have been performed with either a balloon-expandable valve (Edwards SAPIEN valve) or the self-expanding valve (Medtronic CoreValve). A growing body of evidence supporting the effectiveness and safety of TAVI includes the PARTNER trial and the CoreValve pivotal trial. These have found significantly better survival for the TAVI arm compared with SAVR (CoreValve). There were no significant differences in all-cause mortality between TAVI and SAVR, whereas significantly reduced all-cause mortality was observed for TAVI when compared with standard therapy (PARTNER). Paravalvular regurgitation is increased in TAVI compared with SAVR; however, integration of CT into valve selection has shown to improve outcomes. There is conflicting evidence regarding increased risk for stroke after TAVI, and occurrence of conduction disturbances and the need for a pacemaker after TAVI remain a concern. Upcoming trials are focusing on assessing outcomes for use of TAVI in intermediate-operative risk patients. The future will likely include an increased choice of devices, smaller access sites, and further integration of CT for preprocedure planning.
主动脉瓣狭窄（AS）是一种常见疾病，影响着近5%的75岁以上人群。许多AS患者因通常被认为风险极高而无法接受外科瓣膜置换术（SAVR）。2002年引入的经导管主动脉瓣植入术（TAVI）是治疗这些患者的一种新方法。计算机断层扫描（CT）正成为术前规划的金标准成像方式，包括评估瓣环大小和入路。自2002年以来，已经使用球囊扩张瓣膜（爱德华兹SAPIEN瓣膜）或自膨胀瓣膜（美敦力CoreValve）进行了超过10万例手术。越来越多支持TAVI有效性和安全性的证据包括PARTNER试验和CoreValve关键试验。这些试验发现，与SAVR（CoreValve）相比，TAVI组的生存率显著更高。TAVI和SAVR之间的全因死亡率没有显著差异，而与标准治疗相比（PARTNER），TAVI的全因死亡率显著降低。与SAVR相比，TAVI的瓣周反流增加；然而，将CT纳入瓣膜选择已显示可改善预后。关于TAVI后中风风险增加存在相互矛盾的证据，TAVI后传导障碍的发生和起搏器的需求仍然是一个令人担忧的问题。即将进行的试验重点是评估TAVI在中等手术风险患者中的疗效。未来可能会有更多的器械选择、更小的入路部位，以及进一步将CT用于术前规划。
