Fontan pump: Advanced preclinical development.

Abstract

Late Fontan failure and attrition is an increasingly prevalent problem for which there is no primary therapy. A Fontan circulation is a circulation that lacks a subpulmonary pump. We are developing a technology that can safely and reliably restore subpulmonary pump function in a Fontan circulation to reverse the Fontan paradox and maintain normal circulatory health. A rotary pump scaled for adolescent and adult use was developed for implantation to physiologically augment flow in the total cavopulmonary connection (TCPC). Design objectives include 30/70% SVC/IVC inflow draw over a broad range of performance, and no obstruction in the event of device failure. Hydrodynamic and hemodynamic performance were characterized in vitro in a Fontan mock circulatory loop using blood analog. Hemolysis was characterized in blood. The pump augments TCPC flow (SVC/IVC inflow; LPA/RPA outflow) at +6-10 mmHg, ranging to +18 mmHg at 3K RPM. Performance is consistent over a wide range of cardiac output. Power requirement is low (1W) at +6 mmHg pressure rise. Hemolysis is comparable to other commercially available pumps. Cavitation or suction was not observed. In the stalled condition (0 RPM), gradient is ≤1 mmHg. A Fontan pump can safely reverse the Fontan paradox. Features include a fail-safe contingency that is clinically manageable. The technology may prevent progression of Fontan failure in the setting of preserved systemic ventricular systolic function. As a surgical strategy of long-term biventricular health maintenance, it may improve quality and duration of life for patients with single ventricle heart disease.