Implantation of one piece biventricular assist device by left thoracotomy in an ovine model

In this report, we describe an operative procedure for our implantable 1 pi ece biventricular assist device (BiVAD) based on a moving actuator mechanis m, using an ovine model. Our implantable BiVAD is a volumetric coupled 1 pi ece unit including right and left blood sacs and an actuator assembly based on the moving actuator mechanism. The BiVAD was controlled by fixed rate c ontrol with 75 bpm for the most part. Both the left and the right full ejec tion modes with the maximum stroke angle were selected to minimize blood st asis in the blood sacs because of low assist flow condition. Three Corrieda le sheep were used for the device implantation by a left thoracotomy incisi on. Cannulation was successfully performed in all cases. Although exposabil ity of the right atrial appendage varied from animal to animal, the inserti on of the cannula was easily performed. The cannulas were connected to the pump-actuator assembly in the preperitoneal pocket. All 3 animals survived the experimental procedure. During implantation of the device, in the 1 mon th survival animal, pump flow was maintained between 2.0 L/min and 2.5 L/mi n, mean aortic pressure was 90-110 mm Hg, and mean pulmonary artery pressur e was 20-30 mm Hg. The left and right atrial pressure were maintained betwe en 0 and 5 mm Hg. In conclusion, this ovine model for implantation of the 1 piece BiVAD can be an effective alternative for testing in vivo biocompati bility of the device although it needs more consideration for anatomical fi ttability for future human application.