Transapical Aortic Valve Implantation (TAVI)

Abstract

Aortic stenosis is a common valvular heart diseases. It affects nearly 5% of individuals over 75 years of age. Aortic stenos is may be caused by degenerative calcification, congenital malformations, or rheumatic fever. Severe symptomatic calcific aortic valve stenosis (AS) is aproven indication for valve replacement according to the current guidelines. Aortic valve replacement (AVR) utilizing the open surgical techniques with the use of cardiopulmonary bypass (CPB) remains the standard of care for symptomatic patients with severe aortic stenosis (AS). Certain patients, however, cannot take advantage of this option due to co morbidities and/or hemodynamic conditions rendering them at high risk for surgery. In the EURO HEART Survey, 31.8 % of all patients indicated for surgical valve replacement were accordingly rejected. Several risk stratification systems have been developed for perioperative mortality risk assessment. The Euro Score is awidely used, web based, easy applicable such tool. It includes patient based, cardiac and operative related factors such as age, sex, renal insufficiency, left ventricular (LV) dysfunction, pulmonary hypertension and peripheral arteriopathy. Alogistic Euro Score of ≥1 5 % designates high risk. But now a novel alternative approach to surgical aortic valve replacement among critically ill patients with severe aortic valve stenosis has been finally introduced by Cribier–the aortic valve replacement. Transapical aortic valve implantation(TAVI) has emerged as an alternative treatment for patients with severe AS considered at high Summary 67 surgical risk with promising early and mid term results. In contrast to surgical replacement, this method forms amuchless invasive approach, which therefore may be safely offered for high risk surgical patients. Many reports have shown the safety and efficacy of (TAVI) approaches. However, a significant number of patients have poor vascular access due to either small size vessels or severe peripheral vascular disease and are only amenable to treatment with the T A approach. Two independent TAVI systems have gathered data of safety and feasibility in human trials; the Edwards SAPIEN valve (Edwards Life sciences Corporation, Irvine, CA) and Core Valve Re Valving System (CRS, Medtronic, Luxembourgh ).The major difference between both systems lies in the expansion mechanism of the stent mounted valve: balloon expandable or self expandable, respectively. The CRSisa self expandable, biological, nitinol stent mounted aortic valve prosthesis which has first been introduced in 2005. Since March 2007, this prosthesis became CE-Mark certified and commercially available.