title: Validation of a rat model of cardiopulmonary bypass with a new miniaturized hollow fiber oxygenator.
abstract: Cardiopulmonary bypass (CPB) is an essential component of cardiac surgery, with still unknown device/patient interactions. To evaluate the response of CPB to hemodynamic, biochemical, inflammatory, as well as thermo-pharmacodynamic interactions, a novel miniaturized oxygenator with controlled and standardized specifications has been developed together with an improved surgical central cannulation technique. A hollow-fiber small priming volume (6.3 ml) oxygenator was manufactured according to specifications resulting from engineering, heart surgery and perfusion expertise (Dideco-Sorin Group, Italy) with the following characteristics: Gas Exchange Surface--450 cm2, and Heat Exchange Surface--16 cm2. The oxygenator was tested in vitro and in vivo in five anesthetized, ventilated, open-chest rats using a miniaturized roller pump. Pressures were monitored in the animal before and after the oxygenator. Central venous cannulation through the superior vena cava and aortic cannulation through the carotid artery were used. In vitro: blood oxygenation increased 10-fold (from room air to 100% O2) and PCO2 removal was 2.5-fold. In vivo: CPB was performed without blood prime for 90 minutes (no ventilation) maintaining stable hemodynamics. A maximal blood flow rate of 124 ml/min/kg was obtained. Arterio-venous PO2 gradients were 10-fold (O2 100%) with only small variations when changing blood flow rates. This new, standardized and miniaturized hollow fiber oxygenator, new cannulation technique and CPB circuit achieved optimal gas transfer with small asanguinous priming volumes. This study opens new potentials for various CPB-related study protocols in the small animal.
authors.affiliation: Division of Cardiac Surgery, University of Verona, Verona, Italy.
authors.forename: Giovanni Domenico
authors.initials: GD
authors.lastname: Cresce
authors.forename: Beat H
authors.initials: BH
authors.lastname: Walpoth
authors.forename: Damiano
authors.initials: D
authors.lastname: Mugnai
authors.forename: Francesco
authors.initials: F
authors.lastname: Innocente
authors.forename: Alessio
authors.initials: A
authors.lastname: Rungatscher
authors.forename: Giovanni Battista
authors.initials: GB
authors.lastname: Luciani
authors.forename: Andrea
authors.initials: A
authors.lastname: Zaniboni
authors.forename: Gabriele
authors.initials: G
authors.lastname: Battistuzzi
authors.forename: Maddalena
authors.initials: M
authors.lastname: Tessari
authors.forename: Afksendiyos
authors.initials: A
authors.lastname: Kalangos
authors.forename: Alessandro
authors.initials: A
authors.lastname: Mazzucco
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Faggian
mesh_terms: D000818:Animals; D002315:Cardiopulmonary Bypass / Q000295:instrumentation* / Q000379:methods; D015199:Extracorporeal Membrane Oxygenation / Q000295:instrumentation*; D008297:Male; D008904:Miniaturization / Q000295:instrumentation / Q000379:methods; D023421:Models, Animal; D010107:Oxygenators, Membrane; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results