Cath Lab Digest

Abstract

The Edwards-SAPIEN aortic valve (Edwards Lifesciences, Irvine, California) transapical approach was introduced into clinical practice in 2005. After feasibility studies, CE mark was obtained by the end of 2007. It is applied in operations on high-risk patients with calcific aortic valve stenosis, and allows for a less invasive replacement of the diseased native valve. Initially, patients were placed on cardiopulmonary bypass as a safety net, but improvements in periprocedural management soon allowed for truly off-pump implantation of these prostheses.
The follow-up results of the large multicenter trials showed 30-day mortality rates ranging between 10.4% and 19% in high-risk patients with logistic EuroSCORES ranging from 26–35%. The 12-month mortality rates range from 39–43.5%.

The purpose of this article is to provide a description of transapical aortic valve implantations with the Edwards-SAPIEN prosthesis.

VASCULAR DISEASE MANAGEMENT 2010;7:E61–E65

Key words: transapical aortic valve implantation

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Introduction

Transapical aortic valve implantations have found their way into clinical practice in Europe. Currently, the only device on the market is the Edwards-SAPIEN prosthesis (Edwards Lifesciences, Irvine, California). The implantation procedure has been standardized by extensive teaching and proctoring programs.
Antegrade access to the aortic valve is conducted through the left ventricular apex. A small anterolateral thoracotomy allows for safe placement of delivery sheaths and the catheter-based Edwards-SAPIEN prosthesis. Deployment of the valve is performed under rapid ventricular pacing. Both fluoroscopy and transesophageal echocardiography (TEE) are employed to place the valve. For optimal results, a multidisciplinary team of cardiac surgeons, interventional cardiologists and anesthetists are necessary. The procedures are ideally performed in a hybrid operating room. This technology warrants careful preoperative patient screening with regard to native aortic valve anatomy, dimensions and degree of calcifications. Furthermore, patient-related risk factors need to be evaluated.

Initial experimental studies and early clinical cases of transapical aortic valve implantation (TAP-AVI) were typically performed with the use of cardiopulmonary bypass (CPB) to avoid ejection of the heart in systole, thus reducing the likelihood of embolization of the valve across the annulus.^1–5

From the percutaneous experience of Cribier and colleagues and others, we learned that unloading of the heart can be effectively achieved by rapid ventricular pacing.^6–11 However, there are distinct differences between the transfemoral versus transapical aortic valve implantation in terms of patient selection and technical aspects regarding the individual procedure. In general, patients referred to cardiac surgeons for TAP-AVI consideration were previously screened by cardiologists and were not deemed suitable candidates for the transfemoral approach. There may be several reasons for this, including a higher-risk profile with the presence of peripheral vascular disease. The presence of peripheral vascular disease of course not only prevents the introduction of the delivery sheath for AVI, but also increases the risk of complications following cannulation of the groin, including leg ischemia. In contrast to the transfemoral approach, TAP-AVI requires the transventricular placement of a rather large sheath (typically 26 Fr, initially 32 Fr), thereby partly immobilizing the left ventricular anterior wall. This immobilization may further predispose the ventricle to hemodynamic deterioration following rapid pacing. These differences explain why all of the first centers in which TAP-AVI was successfully introduced into clinical practice initially decided to perform the procedure using the additional safety net of CBP. With increasing experience, the use of CPB during TAP-AVI was safely and consistently avoided without compromising postoperative outcomes.

The purpose of this article is to provide a description of transapical aortic valve implantations with the Edwards-SAPIEN prosthesis.

TAP-AVI Experience at Our Center

Patient selection.Inclusion criteria. High-risk patients with severe symptomatic aortic stenosis and an aortic valve orifice area of < 0.8 cm² are considered for this procedure. High-risk is defined by a logistic EuroSCORE predicted risk for mortality > 20%.^3,4,12,13 Additional inclusion criteria are an age of ≥ 75 years, echocardiographically measured aortic annulus diameter of > 24 mm, as well as symmetrically distributed calcification of the stenotic native aortic valve cusps.

Exclusion criteria The presence of one or more of the following comorbidities is considered a contraindication for TAP-AVI: echocardiographically measured aortic annulus diameter of > 25 mm, non-calcified aortic stenosis, subvalvular aortic stenosis, bicuspid aortic valve; intracardiac thrombus or vegetation; endocarditis; untreated symptomatic coronary artery disease; myocardial infarction within < 1 months; ejection fraction < 20%; recent stroke; and hypertrophic obstructive cardiomyopathy.