When Transcatheter Therapy Moves to the "Forgotten Valve"

Percutaneous treatment of tricuspid regurgitation: A new therapeutic horizon

Functional tricuspid regurgitation is a prevalent disease, especially among patients with other valve disorders, and is associated with significant morbidity and mortality. Its management is challenging, and many patients deemed at high surgical risk are managed conservatively. Despite optimization of pharmacological treatment, many patients continue to be symptomatic, thus leading to interest in percutaneous interventional techniques. The Mitralign system has recently been used for the treatment of functional tricuspid regurgitation, with favorable clinical and imaging results. We report the first case in Portugal to our knowledge of percutaneous tricuspid regurgitation treatment with the Mitralign system.

Effects of Cinching Force on the Tricuspid Annulus: A Species Comparison

PURPOSE

Tricuspid annuloplasty rings are commonly used to cinch an enlarged tricuspid annulus back to its original shape and size in patients with severe functional tricuspid regurgitation. However, the invasive operation is contraindicated for patients at risk for reoperation. Fortunately, transcatheter repair procedures, currently in the development process, are minimally invasive alternatives to current repair techniques. This study aims to determine the species-dependence of cinching force with the potential of informing transcatheter repair design by quantifying the minimum required cinching force necessary to reduce tricuspid regurgitation.

METHODS

The cinching force necessary to reduce the septal-lateral diameter of a dilated annuls was quantified and compared in ten ovine hearts and nine porcine hearts. Additionally, a deparaffinization protocol and Verhoeff-Van Gieson stain were used to compare the microscopic structure of tissue samples at different stages of the experimental procedure in the two species.

RESULTS

The maximum annulus dilation observed for the porcine was 11.2%, and the maximum cinching force was 0.40 ± 0.12 N. As previously demonstrated, ovine hearts yielded a maximum annulus dilation and cinching force of 8.82% and 0.38 ± 0.09 N respectively. Histological stains revealed no gross tissue differences between ovine and porcine septal or free wall tissues.

CONCLUSION

The cinching force was not species dependent between ovine and porcine models. This study is an essential first step for determining which animal model should be utilized for the development of transcatheter devices.