Transcatheter Aortic Valve Implantation

Abstract

S urgical aortic valve replacement (AVR) is the conventional treatment for severe aortic stenosis (AS). However, a high operative mortality of 7% to 10% is well recognized in high-risk groups. 1,2 Risk of AVR is increased by a number of factors, including increasing age, and comorbidities, such as heart failure, respiratory and renal disease, prior cardiac surgery, and need for concomitant coronary revascularization. 3 As a result, 30% to 40% of elderly patients do not have surgery because of 1 or more of the following reasons: (1) The patient is not referred for AVR by the cardiology team, (2) the patient is not accepted for an operation by the cardiothoracic team, and (3) the patient declines AVR. 4,5 Additionally, surgery is more likely to be denied in patients who are elderly and who have left ventricular (LV) dysfunction or multiple comorbidities 5 and is contraindicated in cases of porcelain aorta, radiation dermatitis, and liver cirrhosis. 6 However, conservative management of patients with severe AS is known to have a poor prognosis. 7 Transcatheter aortic valve implantation (TAVI) was developed to address this unmet need. After the demonstration of feasibility of TAVI in 2002, 8 it is now widely practiced, with Ͼ20 000 patients treated worldwide, and the technique has been recommended as an alternative strategy for patients in high-risk surgical groups. 9 Currently, there are 2 CE marked devices with some similar fundamental design features: the self-expanding CoreValve ReValving system (Medtronic Inc; Minneapolis, MN) and the balloon-expandable Edwards SAPIEN prosthesis (Edward Lifesciences Inc; Irvine, CA), which is now available as the new generation, smaller profile, balloonexpandable Edwards SAPIEN XT prosthesis. The CoreValve is available in 2 inflow diameter sizes, 26 and 29 mm, whereas the Edwards SAPIEN and Edwards SAPIEN XT valves are available in 23-and 26-mm diameters. Transfemoral, transapical, and transaxillary/subclavian delivery routes have been developed. Both the transfemoral and the transaxillary/subclavian routes involve a retrograde approach, whereas the transapical route involves an anterograde approach. More recently, the transaortic route also has been introduced, allowing direct aortic access. 10 The transfemoral route is the first choice for both prostheses in the majority of patients; however, in patients in whom the transfemoral route is contraindicated, the transapical route can be considered for Edwards SAPIEN or Edwards SAPIEN XT valve implantation, and the transaxillary/subclavian route is an alternative for implantation of the CoreValve.Multiple trials have assessed the efficacy of TAVI in terms of procedural success, early mortality, and short-term clinical outcomes. [11][12][13][14][15] More recently, medium-term outcomes have been reported for the Edwards SAPIEN, 16 with the longest published follow-up at 3 years 17 ; more comprehensive longterm survival data are awaited.Selection criteria have a crucial influence on complication rates and clinical outcomes after TA...

Robot-assisted real-time magnetic resonance image–guided transcatheter aortic valve replacement

“…34 rtMRI guidance may be useful for TAVR patients with renal insufficiency, which is a contraindication to the procedure. 18, 35 …”

Real-time magnetic resonance imaging–guided transcatheter aortic valve replacement

“…41 Utilizing rtMRI guidance may allow the use of TAVR in patients with renal insufficiency, which is a contraindication to the procedure. 15,49 …”

Transcatheter aortic valve insertion (TAVI): a review

“…7 Because of these varied options, it is difficult to provide absolute parameters, which would render a transfemoral approach impossible, although increasing calcification and the ratio of vascular sheath to femoral artery diameter .1.05 seem predictive for important complications. 48 The smallest delivery catheter was previously 18 French gauge (6 mm), and the largest 24 French (8 mm), such that vessels of these sizes are considered to be the limits for a transfemoral approach by many authorities, 49 although smaller sheaths are now available. At our centre, we report vessels of ,6 mm as being unlikely to be suitable for transfemoral approach, 6-8 mm as possibly suitable and .8 mm as usually suitable, dependent on vessel calcification and tortuosity.…”