Preclinical evaluation of a transcatheter aortic valve replacement system for patients with rheumatic heart disease.

AIMS: Cardiac surgery in middle-income countries differs significantly from that in high-income countries regarding prevailing heart valve pathologies and access to cardiac surgery. Typically, rheumatic aortic regurgitation in the absence of calcification by far outweighs stenosis. As such, entirely different transcatheter aortic valve implantation (TAVI) concepts are required for these regions. The aim of the study was to evaluate the five-month performance of the SAT (Strait Access Technologies, Cape Town, South Africa) pericardial TAVI system in the orthotopic aortic position of juvenile sheep. METHODS AND RESULTS: A self-homing, non-occlusive balloon-expandable TAVI system comprising a hollow balloon, stabilising locator trunks, a scalloped CoCr stent with elevating anchorage arms and decellularised, sandwich-crosslinked pericardium was compared with control surgical valves (Edwards PERIMOUNT) in sheep. The implantation period was five months. The tactile placement of the TAVI valves was accomplished without the need for rapid pacing. At termination, no structural degeneration was observed in either group. The TAVIs were well healed with the stent struts largely embedded in tissue. Correlating with sheep growth (weight gain of 40.4±13.0%) during the implantation period, mean transvalvular gradients increased from 3.08±1.95 mmHg to 8.50±5.38 mmHg (p=0.044) after five months. CONCLUSIONS: A single-stage, balloon-expandable, easy to place TAVI system with antigen-depleted and antigen-masked bioprosthetic leaflets promises to address the distinct needs of low- and middle-income countries with regard to TAVI better than conventional systems.

Quadruple valve replacement in a patient with severe rheumatic heart disease.

SummaryWe present a patient with rheumatic heart disease involving all the heart valves. An intraoperative transoesophageal echocardiography confirmed severe mitral stenosis, severe aortic regurgitation, severe tricuspid regurgitation and stenosis, and severe pulmonary stenosis. The patient underwent successful quadruple valve replacement during a single operation at the Groote Schuur Hospital, Cape Town, South Africa. LEARNING POINTS: Rheumatic heart disease can affect all the heart valves including the pulmonary valve.Intraoperative transoesophageal echocardiography is key for diagnosis, monitoring and confirmation of successful surgical result during heart valve surgery.Combined surgical procedure of all four valves is possible though associated with long procedural time.