Magnetic resonance imaging to detect acute cerebral events in on-pump and hybrid-pump patients.

BACKGROUND Conventional cardiopulmonary bypass results in cerebral ischemic sequelae that may be reduced with hybrid pump technologies, such as the CardioVention system (CardioVention, Santa Clara, CA, USA). CardioVention differs from conventional bypass in that it has a novel air elimination module and reduced membrane surface area and priming volume. This preliminary study tested whether this pump confers neurological safety advantages over conventional bypass. METHODS Ten patients were studied, with 6 assigned to on-pump coronary artery bypass grafting and 4 to the CardioVention system. No patients had any stroke history. Within 72 hours postsurgery, each underwent diffusion-weighted magnetic resonance imaging, a sensitive test for cerebral ischemic events. RESULTS Two on-pump patients (33%) had postoperative findings on imaging, but none of the CardioVention patients demonstrated comparable changes ( P =.47). No patients had symptoms of acute stroke. CONCLUSION Postoperative magnetic resonance imaging showed a trend toward a greater rate of ischemic events in patients undergoing traditional on-pump surgery. These preliminary findings suggest that hybrid pump technologies, such as the CardioVention system, may attenuate the risk of short-term neurological complications. Future studies are indicated to confirm these subclinical ischemic changes and to correlate them with long-term neurocognitive changes.