JVS - Vascular Science (Jan 2024)
Technical and analytical approach to biventricular pressure-volume loops in swine including a completely endovascular, percutaneous closed-chest large animal model
Abstract
Pressure-volume (PV) loop analysis is a sophisticated invasive approach to quantifying load-dependent and independent measures of cardiac function. Biventricular (BV) PV loops allow left and right ventricular function to be quantified simultaneously and independently, which is important for conditions and certain physiologic states, such as ventricular decoupling or acute physiologic changes. BV PV loops can be performed in an entirely endovascular, percutaneous, and closed-chest setting. This technique is helpful in a survival animal model, as a percutaneous monitoring system during endovascular device experiments, or in cases where chest wall compliance is being tested or may be a confounder. In this article, we describe the end-to-end implementation of a completely endovascular, totally percutaneous, and closed-chest large animal model to obtain contemporaneous BV PV loops in 40 to 70 kg swine. We describe the associated surgical and technical challenges and our solutions to obtaining endovascular BV PV loops, closed-chest cardiac output, and stroke volume (including validation of the correction factor necessary for thermodilution), as well as how to perform endovascular inferior vena cava occlusion in this swine model. We also include techniques for data acquisition and analysis that are required for this method. : Clinical Relevance: This article describes the end-to-end implementation of a completely endovascular, percutaneous, and closed-chest large animal model for obtaining biventricular pressure-volume loops in swine. This will allow researchers to obtain contemporaneous, continuous left and right ventricular physiology through a minimally invasive procedure that animals can survive and does not alter chest wall compliance. This model may be used to better quantify the physiology during clinical scenarios of ventricular decoupling, during procedures such as transcatheter aortic valve repair or those that alter left ventricular (LV) function, or during the initiation of resuscitative endovascular balloon occlusion of the aorta or extracorporeal cardiopulmonary resuscitation when LV and right ventricular filling become misaligned.
