Transcatheter Tricuspid and Pulmonary Valve Repair and Replacement.

Severe tricuspid regurgitation (TR) is associated with significant mortality and morbidities. Currently, surgical tricuspid repair with annuloplasty is the gold standard treatment. However, the prohibitive risks of open surgery and increasing evidence that severe TR should be intervened on early has led to an outburst in the development and evolution of transcatheter tricuspid valve interventions (TTVI). These technologies are broadly categorized into direct suture annuloplasty devices, minimally invasive annuloplasty, direct ring annuloplasty devices, coaptation-based strategies, edge-to-edge repair devices, and transcatheter valve replacement. Each has its own set of advantages and limitations and have been tried, to varying degrees of success, in a myriad of pathoanatomic scenarios. Challenges faced in TTVI device and trial designs include heterogeneous patient populations, the need for quality imaging, variations of imaging requirements and anatomic criteria by device, hard-to-define clinical endpoints, and the poor prognosis carried by significant residual TR. Similar to tricuspid valve disease, pulmonic valve (PV) disease can occur on its own or secondary to a congenital heart defect, most commonly tetralogy of Fallot. Many patients with pulmonic stenosis or insufficiency often require repeat surgical interventions for other cardiac problems, highlighting the importance of developing transcatheter approaches to reduce the number of repeat open-heart surgeries required. Transcatheter PV replacement (TPVR) is growing in use and is the procedure of choice in patients with failed bioprostheses via valve-in-valve implantation. The Melody (Medtronic Inc., Minneapolis, Minnesota) and SAPIEN XT (Edwards Lifesciences Inc., Irvine, California) devices are the currently available TPVR technologies. Current limitations here include device kinking, the risk of stent fracture, anatomic difficulties, such as asymmetric right ventricular outflow tracts leading to poor landing zones and procedural risks of coronary artery and aortic root compression.