Twenty-four-hour normothermic perfusion of isolated ex vivo hearts using plasma exchange

Objective: Cross-circulation of plasma from a paracorporeal animal allows successful ex vivo heart perfusion (EVHP) for 3 days. Little is known about the feasibility of prolonged EVHP without a paracorporeal animal. These experiments evaluated plasma exchange (PX) that infuses fresh plasma, whereas an equal amount is removed to replace paracorporeal cross-circulation. Methods: Ten hearts were procured from 8 to 10 kg piglets and maintained with EVHP. The EVHP circuit was primed with platelet- and leukocyte-reduced blood. Plasma obtained from stored porcine blood (4°C for ≤7 days) was infused and removed with a plasma separator at 1 mL/h/g cardiac tissue (n = 5) in the PX group. Controls (n = 5) used the same EVHP without PX. Antegrade aortic perfusion was adjusted to reach physiologic coronary flow of 0.7 to 1.2 mL/min/g, normothermia (37°C), and hemoglobin ≥8 g/dL. Viability was assessed by hemodynamic metrics, metabolic assays, and histopathology. Results: All PX hearts remained viable for 24 hours compared with only 1 control (P = .015). Coronary resistance was higher in the PX versus controls (1.06 ± 0.06 mm Hg/mL/min; 0.58 ± 0.02 mm Hg/mL/min [P .05). In mixed effect models, oxygen consumption was higher with PX (P < .05). Histopathologic evaluation confirmed extensive myocardial degeneration and worse interstitial edema in controls. Conclusions: These results demonstrate that EVHP can be successfully maintained for at least 24 hours using continuous PX. This eliminates the need for a paracorporeal animal and provides an important step toward clinical application.http://deepblue.lib.umich.edu/bitstream/2027.42/177122/2/1-s2.0-S0022522320333353-main.pdfPublished versionDescription of 1-s2.0-S0022522320333353-main.pdf : Published versio