The standard palliative surgery for a single ventricle defect is a total cavopulmonary connection (TCPC), which
separates the pulmonary and systemic circulations. This Fontan circulation eventually fails with high long-term
mortality. A failing Fontan includes cavopulmonary failure (CPF) and/or ventricular failure. No cavopulmonary
assist (CPA) device is available for CPF. Our ultimate goal is to develop a percutaneous CPA system for total
ambulatory support of CPF patients. Our enabling technology is a CPA dual lumen cannula (DLC) with paired
membrane umbrellas. Via ony 1 venous cannulation, this DLC connects the TCPC to an external pump without
major surgery. This system provided total CPA and reversed CPF hemodynamics/renal dysfunction in our
lethal CPF sheep model, enabling 96 hr survival. To move our CPA DLC toward clinical application, the
following specific aims were developed: Specific Aim 1: To design, optimize, and fabricate a new CPA
DLC for least thrombogenic/ hemolytic potential and smooth installation/deployment. Two membrane
umbrellas ensure efficient/reliable performance. Slipknots ensure easy DLC installation/umbrella deployment.
Validated computational fluid dynamics will be used for design optimization. The CPA DLC body will be made
of ultrathin reinforced polyurethane (PU) with a PU membrane sleeve infusion lumen. The two membrane
umbrellas will be molded onto DLC. Specific Aim 2: [To assess the anatomic fittingness of the CPA DLC
in patient specific TCPC silicone models and evaluate the potential of reversing pathophysiology in
CPF patients using our established mathematical model validated with CPF patients’ comprehensive
hemodynamic data]. Patient specific silicone TCPC models will be made from MRIs in our Fontan database.
A mock loop with these models will assess the CPA DLC for: 1) ability to fit/function well; 2) flow stasis/high
shear stress areas. Our patient specific Fontan simulation platform will quantify CPA flow rates that mitigate
liver congestion. Specific Aim 3: To evaluate final CPA DLC prototype in a [patient specific TCPC mock
loop] for performance, reliability, and 30 day durability. This mock loop with 37% glycerin will test CPA
DLC for: 1) flow efficiency/reliability at 360° [axial] rotation/8 cm dislocation, and 2) 30 day durability at 4 L/min
flow. Specific Aim 4: To evaluate the CPA DLC prototype for in vivo performance, reliability, and ease of
installation/deployment in a CPF sheep model. Ease of installation/deployment and performance/reliability
will be assessed in 6 hr studies (n=15). A 2-week preclinical study (n=15) will confirm full reversal of CPF
hemodynamics/end-organ dysfunction and will assess biocompatibility.
