ABSTRACT
Introduction With the advent of transcatheter pulmonary and aortic valve replacement, attempts have been ongoing to extend this technology to both atrioventricular valves. Percutaneous tricuspid valve replacement (TVR) was described as early as 2005 by Boudjemline and colleagues in an animal model.2 ey devised a self-fabricated selfexpandable stent formed of two disks separated by a tubular part. e ventricular disk was covered by a polytetrauoroethylene (PTFE) membrane to ensure complete annular sealing, and the atrial disk was le uncovered to prevent occlusion of the coronary sinus. e diameter of the two disks was chosen to be slightly larger than the diameter of the tricuspid annulus to allow for anchoring. Mechanical xation was ensured by trapping the annulus between the two disks. An 18 mm bovine jugular vein valve was sutured in the tubular part of the device. e device was tested in native tricuspid valves. However, one problem related to the orthotopic position was sucient xation of the valve in the highly dynamic tricuspid annulus. e second issue was the fact that tricuspid regurgitation (TR) in humans is usually secondary to the right heart dilation and so it is a challenge to rely on the annular size. Bai et al.3 described in sheep the use of a self-fabricated stented valve comprising a unidirectional semilunar valve of porcine pericardium that was sutured onto a ring and mounted on a double-edge nitinol stent. PTFE was not used to cover the stent, which enabled the delivery system to be as compact as a 14 F delivery system. Again, the major limitation was that these valved stents were <18 mm diameter whereas pathologic TR in humans results in tricuspid annular dilation up to 30-40 mm. Lauten et al.4 evaluated the concept of heterotopic TVR via implantation of self-expanding valves in the superior vena cava (SVC) and inferior vena cava (IVC) of sheep. is allowed for sucient valve xation and carried low risk to cardiac structures. However, although this reduces the amount of venous regurgitation,
it does not reduce the right ventricular and atrial volume overload. Although stable transcatheter stent-valve delivery is routine across the native aortic valve with calcic aortic stenosis, the remaining locations have largely required prosthetic material to provide support for the stent-valve complex and thus, reported transcatheter TVR to date in humans has been limited to patients with previous TVR.
