Stanton J. Rowe

Transapical endovascular implantation of neochordae using a suction and suture device

OBJECTIVE Neochordae implantation is a standard method for treatment of mitral valve prolapse. We describe a transcatheter technology enabling transapical endovascular chordal implantation. METHODS Six adult pigs were anesthetized. Two 10F sheaths were introduced in the femoral vessels for monitoring and intracardiac echo. After midline sternotomy, the pericardium was opened, the apex was punctured inside two 2-0 polypropylene purse strings. A 0.035 in J tipped guidewire was introduced in the left ventricle and an ultra stiff 14F sheath (guide catheter) inserted through the apex. A suction-and-suture device was introduced in the left ventricle. The mitral valve was crossed under echo guidance. Using suction, either the anterior (two cases) or posterior (four cases) leaflet was captured and a loop of 4-0 polypropylene was thrown at the edge of the leaflet. The loop, with a pledget, was exteriorized through the introducer. The introducer was removed and the purse-string tied. Under echo guidance, the neochordae suture was pulled and tied over a pledget to evoke leaflet tethering. The animals were sacrificed and gross anatomy reviewed. RESULTS Leaflet capture was feasible in the intended location in all cases. Following suture tethering, variable degrees of MR were obtained. At gross anatomy, the neochordae were positioned at 1-4mm from the leaflet free edge, and were firmly attached to the leaflets. CONCLUSIONS Transcatheter endovascular neochordae implantation is feasible. A prolapse model is needed to further demonstrate feasibility under pathologic conditions. The apical approach allows easy and direct route to transcatheter beating heart minimally invasive mitral repair.

Evolving strategies for the treatment of valvular heart disease: Preclinical and clinical pathways for percutaneous aortic valve replacement

To decrease the morbidity associated with conventional surgery for calcific aortic stenosis, there has been increasing interest in catheter‐based treatment using a stent or frame mounted bioprosthetic valve. Critical to its success is knowledge of pathoanatomy, risk of embolization of calcific debris, and issues associated with device anchoring and paravalvular leaks. In the absence of a chronic animal model of aortic stenosis, development of a catheter‐based device has been an iterative process based on experimental and early clinical data gathered abroad, where marketing may be permitted with less clinical data than required in the United States. This process has persuaded many companies to circumvent the time delays occasioned by the FDA regulatory validation of iterative design changes by performing initial studies outside the United States. Because percutaneous aortic valve replacement is considered a Class III device, premarket approval, including defining the patient population, inclusion and exclusion criteria, control population, and interpretable clinical endpoints, is required. In the early clinical experience, percutaneous aortic valve replacement has been directed at high‐risk patients who were considered “very poor” or “non‐surgical” candidates. Defining and identifying patients for the clinical trial may be challenging, in part because of the difficult selection of an appropriate control group, e.g., conventional aortic valve replacement, best medical management, and/or balloon valvuloplasty.