Construction and Evaluation of a Bio-Engineered Pump to Enable Subpulmonary Support of the Fontan Circulation: A Proof-of-Concept Study

Our objective was to create a bio-engineered pump (BEP) for subpulmonary Fontan circulation support capable of luminal endothelialization and producing a 2-6 mmHg pressure gradient across the device without flow obstruction. To accomplish this, porcine urinary bladder submucosa was decellularized to produce a urinary bladder matrix (UBM) which produced acellular sheets of UBM. The UBM was cultured with human umbilical vein endothelial cells producing a nearly confluent monolayer of cells with the maintenance of typical histologic features demonstrating UBM to be a suitable substrate for endothelial cells. A lamination process created bilayer UBM sheets which were formed into biologic reservoirs. BEPs were constructed by securing the biologic reservoir between inlet and outlet valves and compressed with a polyurethane balloon. BEP function was evaluated in a simple flow loop representative of a modified subpulmonary Fontan circulation. A BEP with a 92-mL biologic reservoir operating at 60 cycles per minute produced pulsatile downstream flows without flow obstruction and generated a favorable pressure gradient across the device, maintaining upstream pressure of 6 mm Hg and producing downstream pressure of 13 mm Hg. The BEP represents potential long-term assistance for the Fontan circulation to relieve venous hypertension, provide pulsatile pulmonary blood flow and maintain cardiac preload.