Use of the Cobra catheter for targeted temperature management during cardiopulmonary bypass in swine.

Background: The purpose of this investigation was to determine whether temperatures of the aortic arch and descending aortic circulations could be controlled independently during cardiopulmonary bypass with a cannula possessing an endoaortic baffle (Cobra; Cardeon, Cupertino, Calif).

Methods: After Institutional Animal Care and Use Committee approval, 12 pigs weighing 60 kg were started on bypass through a sternotomy. A dual-lumen endoaortic cannula with a deployable baffle was used for arterial cannulation. Bypass was initiated at 37 degrees C, and control measurements were obtained. The baffle was then inflated with saline solution, segmenting blood flow along the greater and lesser curvatures of the aortic arch. Parallel heat exchangers were used to independently control temperature of the arch and descending aortic perfusates. Cerebral and systemic temperatures were recorded continuously.

Results: During cardiopulmonary bypass, mean flow and arterial pressure were maintained at 2.4 to 2.6 L x min(-1) x m(-2) and 60 to 70 mm Hg, respectively. With aortic flow distributed by the baffle, a 5 degrees C temperature differential between brain (30 degrees C) and body (35 degrees C) was established in a mean of 5 +/- 2 minutes. Mean brain and corporeal temperatures of 27 degrees C and 35 degrees C were then maintained over 60 minutes. Relative to control, internal jugular and inferior vena cava oxygen saturations increased during targeted temperature control with the device.

Conclusions: The Cobra cannula allows for independent control of brain and body temperature while providing satisfactory hemodynamics. Application of this temperature management strategy may offer cerebral protection and the advantages of warm systemic bypass temperature.