The Quintessential Ventricular Cannula

Antaki, James

Abstract

Chronic mechanical circulatory support has been progressively migrating towards the use of turbo-dynamic blood pumps. For many reasons, these """"""""second-"""""""" and """"""""third-generation"""""""" devices offer advantages over the current pulsatile generation of ventricular assist devices. However, ventricular unloading with dynamic blood pumps can be markedly affected by the geometry of the cannula within the ventricular chamber. Due to the ability of these pumps to develop negative inflow pressure, existing cannula designed for passively-filling blood pumps can be predisposed to inflow occlusion by intraventricular anatomic structures, and deleterious hemodynamic flow patterns. The consequences may be catastrophic: causing thrombosis, and attendant morbidity and mortality. This project aims to develop a novel """"""""trumpet"""""""" mouth cannula to overcome several of the limitations of existing cannula. Previous research by the P.I. has demonstrated the effectiveness of a trumpet shape to stent the ventricular apex, assure placement of the tip opening relative to the endocardial surface, and streamline the blood drainage through the inflow tract. The practical, clinical implementation of this cannula requires additional development, specifically concentrating on the means of deployment. This Phase-l effort will therefore seek to develop an efficient, practical, reliable cannulation method by systematic evaluation of two alternative deployment strategies. The design will be performed with the assistance of computer-aided engineering tools, and will be evaluated in vitro using flexible casts of both human and bovine ventricles. Final evaluation will be performed within transparent casts by flow visualization to select a cannula that accommodates a wide range of ventricular anatomies, avoids blood stagnation at the apex, and minimally interferes with the papillary structures. The final deliverable will be an optimized design suitable for in-vivo testing and preparation for mass production in a subsequent Phase-ll effort.