Ex Vivo Assessment of a Parabolic-Tip Inflow Cannula for Pediatric Continuous-Flow VADs. Issue 5 (September 2016)

• Record Type: Journal Article
• Authors: Griffin, Michael T.; Grzywinski, Matthew F.; Voorhees, Hannah J.; Kameneva, Marina V.; Olia, Salim E.
• Is Part Of: ASAIO journal. Volume 62:Issue 5(2016)
• Publication Date: 2016-09
• Subjects: mechanical circulatory support -- rotary blood pump -- inflow cannula -- pediatric ventricular assist device; Artificial organs -- Periodicals; 617
• DOI: 10.1097/MAT.0000000000000411
• Languages: English
• ISSNs: 1058-2916

Abstract

Abstract : To address the challenge of unloading the left ventricle during pediatric mechanical circulatory support using next-generation rotary blood pumps, a novel inflow cannula was developed. This unique inflow cannula for pediatric, continuous-flow, left ventricular assist devices (VADs) with a parabolic-shaped inlet entrance was evaluated alongside a bevel-tip and fenestrated-tip cannula via an ex vivo, isolated-heart experimental setup. Performance was characterized using two clinical scenarios of over-pumping and hypovolemia, created by varying pump speed and filling preload pressure, respectively, at ideal and off-axis cannula placement to assess ventricular unloading and positional sensitivity. Quantitative and qualitative assessments were performed on the resultant hemodynamics and intra-ventricular boroscopic images to classify conditions of nonsuction, partial, gradual or severe entrainment, and ventricular collapse. The parabolic-tip cannula was found to be significantly less sensitive to placement position ( p < 0.001) than the bevel-tip cannula under all conditions, while not statistically different from the fenestrated cannula. Visual analysis of the parabolic-tip cannula showed complete resistance to entrainment, whereas the fenestrated-tip had partial entrainment in 90% and 87% of the over-pumping and hypovolemic studies, respectively. We conclude that future pediatric VAD designs may benefit from incorporating the parabolic-tip inflow cannula design to maximize unloading of the left ventricle in ideal and nonoptimal conditions.