title: Long-term animal model of venovenous extracorporeal membrane oxygenation with atrial septal defect as a bridge to lung transplantation.
abstract: This study evaluated the effectiveness of an atrial septal defect (ASD) with venovenous extracorporeal membrane oxygenation (vv-ECMO) as a bridge to transplantation. Sheep (56 ± 3 kg; n = 7) underwent a right-sided thoracotomy to create the ASD (diameter = 1 cm) and place instrumentation and a pulmonary artery (PA) occluder. After recovery, animals were placed on ECMO, and the PA was constricted to generate a twofold rise in right ventricular (RV) systolic pressure. Sheep were then maintained for 60 hours on ECMO, and data were collected hourly. Five sheep survived 60 hours. One sheep died because of a circuit clot extending into the RV, and another died presumably because of an arrhythmia. Mean right ventricular pressure (mRVP) was 19 ± 3 mm Hg at baseline, averaged 27 ± 7 mm Hg over the experiment, but was not statistically significant (p = 0.27) due to one sheep without an increase. Cardiac output was 6.8 ± 1.2 L/min at baseline, averaged 6.0 ± 1.0 L/min during the experiment, and was statistically unchanged (p = 0.34). Average arterial oxygen saturation and PCO2 over the experiment were 96.8 ± 1.4% and 31.8 ± 3.4 mm Hg, respectively. In conclusion, an ASD combined with vv-ECMO maintains normal systemic hemodynamics and arterial blood gases during a long-term increase in RV afterload.
authors.affiliation: *Department of Cardiothoracic Surgery, University Hospital Regensburg, Regensburg, Germany; †Department of Surgery, University of Michigan, Ann Arbor, Michigan; and ‡Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan.
authors.forename: Daniele
authors.initials: D
authors.lastname: Camboni
authors.forename: Alvaro
authors.initials: A
authors.lastname: Rojas
authors.forename: Peter
authors.initials: P
authors.lastname: Sassalos
authors.forename: David
authors.initials: D
authors.lastname: Spurlock
authors.forename: Kelly L
authors.initials: KL
authors.lastname: Koch
authors.forename: Sarah
authors.initials: S
authors.lastname: Menchak
authors.forename: Jennifer
authors.initials: J
authors.lastname: Singleton
authors.forename: Erika
authors.initials: E
authors.lastname: Boothman
authors.forename: Jonathan W
authors.initials: JW
authors.lastname: Haft
authors.forename: Robert H
authors.initials: RH
authors.lastname: Bartlett
authors.forename: Keith E
authors.initials: KE
authors.lastname: Cook
mesh_terms: D000818:Animals; D054087:Atrial Septum / Q000601:surgery*; D004195:Disease Models, Animal; D015199:Extracorporeal Membrane Oxygenation / Q000379:methods*; D006439:Hemodynamics / Q000502:physiology*; D016040:Lung Transplantation; D008297:Male; D012756:Sheep