Accuracy of Using 2D Transesophageal Echocardiography Compared to Balloon Sizing in Determining Valve Size During Transcatheter Aortic Valve Implantation

The method of transcatheter aortic valve implantation (TAVI) introduced in 2002 by Alain Cribier et al. has offered new prospects for patients with severe aortic stenosis and multiple comorbidities, who are at high operative risk(1). The PARTNER series of randomized controlled trials has firmly established the role of TAVI with the balloon-expandable Edwards Sapien valve in patients with severe symptomatic aortic stenosis (AS) at prohibitive risk of surgery (PARTNER IA), high risk for surgery (PARTNER IB), and intermediate risk for surgery (PARTNER 2).(2) Also PARTNER 3 and Evolut Low Risk trial strongly suggest that TAVI is not only a suitable alternative and may be superior to surgical aortic valve replacement ( SAVR) in low-risk patients.(2) The accurate determination of the size of the implant is dependent on pre-procedural imaging. Annular measurements are important in the TAVI as inaccurate estimation can lead to complications e.g paravalvular leakage .(3) Transthoracic echocardiography (TTE), transoesophageal echocardiography (TOE), multidetector computed tomography (MDCT) and magnetic resonance imaging (MRI) have been extensively studied with respect to pre-procedural aortic annular sizing.(3). However, even with some of the evidence returning a discrepancy in annular measurements between techniques, the literature to date does not clarify whether TOE undersizes inappropriately or appropriately with respect to MDCT.(3) In a recent study, 29.5% of patients would have been deemed ineligible for TAVI because of overestimation of annular measurements by MDCT, a figure reduced to 1.3% with the use of TOE (4) In a recent small retrospective study, TOE, MDCT and MRI all performed comparatively well with device sizing. (5) Balloon aortic valvuloplasty (BAV) dilatation before TAVI is considered a mandatory procedural step in the early years of TAVR. BAV is used to confirm annular sizing and to enhance trans-catheter heart valve (THV) deliverability.(6) However till now there is no comparison of annular measurement by 2D transesophgeal echocardiography with balloon sizing.