Transcatheter aortic valve-in-surgical aortic valve implantation: current status and future perspectives

Abstract

During the last decade, the relative use of surgical bioprosthetic valves has increased by nearly 80%, an observation likely explained by improved surgical techniques, valve durability, avoidance of anticoagulation and patient’s preference [1]. Nevertheless, surgical bioprosthetic valves are known to fail; actuarial freedom from reoperation for a failing bioprosthetic valve is 95, 90 and 70% at 5, 10 and 15 years, respectively [2, 3]. The lifetime risk of reoperation actually decreases with increasing patient age at the time of the index procedure. For example, a 50and a 60-year old patient undergoing surgical bioprosthetic aortic valve replacement will have a lifetime risk of reoperation of 45 and 25%, respectively [4]. The gold-standard treatment for a failing surgical bioprosthetic valve is a redo operation. The operative mortality following an elective redo operation in low-to-intermediate risk patients is 2–7% [5, 6]. In high surgical risk or non-elective cases, however, the mortality can be as high as 30% [7]. Even in low-risk and elective redo scenarios, the risks of wound infection, blood transfusions, postoperative pain and delayed functional recovery are not negligible. Transcatheter aortic valve-in-surgical aortic valve (TAV-in-SAV) implantation was first reported in 2007, and since then, numerous case series and registries have demonstrated its safety and efficacy [8, 9]. Since TAV-in-SAV avoids sternotomy and cardiopulmonary bypass, it can improve resource utilization by accelerating patient recovery and by reducing the length of hospital stay. Furthermore, it may obviate or reduce the number of repeat surgical procedures in a patient’s lifetime.