A Novel Approach to an Anatomical Adapted Stent Design for the Percutaneous Therapy of Tricuspid Valve Diseases

Abstract

Tricuspid valve regurgitation mostly occurs as result of dilation of the right ventricle, secondary to left heart valve diseases. Until recently, little attention has been given to the development of percutaneous therapeutic tools exclusively designed for tricuspid valve disease. A new approach to the interventional therapy of tricuspid regurgitation, in particular, the design of a conceptual new valve-bearing, self-expansible stent, is presented here. A three-dimensional computer model of a right porcine heart was developed to gain a realistic anatomical geometry. The new design consists of two tubular stent elements, one inside the superior vena cava and the other inside the tricuspid valve annulus after being eventually equipped with a biological valve prosthesis, which are connected by struts. Anchoring to the heart structure is provided primarily by the vena cava stent, strengthened by the struts. The stents are designed to be cut from a 10 mm tube and later expanded to their designated diameter. Simulation software analyzing the expansion process with respect to the intended geometrical design is used in an iterative process. A validation of the anatomical geometry and function of the stent design inside a silicone model within in vitro tests and a random porcine heart shows an accurate anatomical fitting.

Transatrial Intrapericardial Tricuspid Annuloplasty

“…Despite the adoption of transcatheter aortic and mitral valve interventions, there remains an unmet need for transcatheter tricuspid valve repair (16), particularly because untreated TR after aortic or mitral surgery confers a poor outcome. Percutaneous orthotopic (17,18) or heterotopic (19,20) prosthetic tricuspid valve replacement has been described, but these risk thrombosis without anticoagulation. TRAIPTA would not require anticoagulation because the implant is extravascular, although some patients may have other indications (e.g., atrial fibrillation).…”

Development of a Transcatheter Tricuspid Valve Prosthesis Through Steps of Iterative Optimization and Finite Element Analysis

“…The postprocessing to extract all relevant distances and diameters was described in Pott et al. . The three‐dimensional (3‐D) stent design was revised from a 72° symmetry to a 60/120° symmetry for improved leaflet connection to the TVA‐stent (Fig.…”

“…Both stents and struts are manufactured from nitinol to use the advantages of shape‐memory alloys. For the expansion and crimping simulations, the super‐elastic nitinol model incorporated in Abaqus was used as it was optically validated and obtained satisfactory results in previous simulations. The austenite and martensite elasticity were 40 and 32 GPa, respectively, the austenite and martensite Poisson's ratio was 0.33, the start and end of transformation loading were 440 and 540 MPa, respectively and the start and end of transformation unloading were 250 and 140 MPa, respectively.…”

“…Pott et al. gave an overview about some novel percutaneous approaches for the tricuspid valve implantation found in literature . Some devices designed for the orthotopic position reached the state of in vivo animal trials .…”

“…Possibly because of the underestimated risk of TR and the difficult anchoring of devices in orthotopic position, up to date there have been few reports about percutaneous devices designed especially for the tricuspid position. Pott et al gave an overview about some novel percutaneous approaches for the tricuspid valve implantation found in literature (9). Some devices designed for the orthotopic position reached the state of in vivo animal trials (10)(11)(12)(13).…”