Pulsatile ventricular assist device with pericardial inner lining.

Abstract

Preserved pericardium in contact with blood is not thrombogenic, therefore avoiding the use of anticoagulants, and has excellent mechanical properties. Our objective is to take advantage of these characteristics and build a pulsatile ventricular assist device (VAD) with pericardium used as the inner lining of the blood chamber. A mold is used for the tanning of the pericardium, rendering it with an exact shape. A flexible polymeric structure is designed to serve as a base for the pericardium, guiding it and limiting its rate of strain. It consists of two halves, which when outfitted with the interior pericardium lining and connected to each other, form the blood chamber. This assembly is housed in rigid polyvinyl chloride (PVC) shells making up the air chamber for the pneumatic activation. Valves are likewise made of pericardium. Sealing of the chambers was tested statically up to 300 mm Hg with no air or fluid leakage. The device was tested for 60 continuous days in a mock loop, demonstrating hydrodynamic performance adequate for ventricular assist. Micrographs (confocal laser and scanning electron microscopy) were obtained of several pericardium areas, especially on the flexing regions that are a transition between the wet and dry regions. No sign of damage to the pericardium was observed either with the naked eye or at the microscopic level. From the hydraulic performance and materials viewpoints, a completely pericardium-lined pulsatile VAD displaying a polymeric structure that avoids unpredictable bending and limits strain is feasible. The results warrant further studies regarding biocompatibility and strength advantages.