First-in-human experience with a heterotopic cross-caval transcatheter tricuspid valve replacement

Severe tricuspid regurgitation (TR) is a growing clinical challenge, particularly among elderly and comorbid populations. Untreated TR is associated with excess morbidity and mortality irrespective of ventricular or pulmonary pressures. Conventional surgery for isolated TR remains high risk1, and contemporary transcatheter repair or replacement therapies are frequently limited by anatomical constraints or technical complexity. Caval valve implantation (CAVI) has therefore emerged as an alternative, aiming to mitigate systemic venous congestion rather than eliminating TR per se2. We report the first-in-human multicentre experience with the Unica system (Innoventric), a novel heterotopic cross-caval stent hosting two opposing porcine pericardial bioprosthetic valves designed for the superior (SVC) and inferior vena cava (IVC).

From January 2023 to January 2024, 8 patients across 7 European and Canadian centres underwent Unica implantation under compassionate use. Inclusion criteria are shown in Supplementary Table 1. Preprocedural planning included computed tomography (CT)-based simulation, patient-specific silicone models, and catheter laboratory training. CT-specific criteria are shown in Supplementary Table 2.

Implantation was performed transfemorally under fluoroscopy alone, without general anaesthesia or transoesophageal echocardiography, using a 24 Fr...