Methods: This prospective, randomized study included a total of 40 patients (36 males, 4 females; mean age 60.0±8.5 years; range 43 to 75 years) who underwent elective coronary artery bypass grafting between January 2015 and December 2015. The patients were divided into two groups by block randomization using the sealed envelope technique. In group 1, non-integrated arterial filter membrane oxygenators and, in group 2, integrated arterial filter membrane oxygenators were used. Near-infrared spectroscopy was used to assess the cerebral oxygenation intraoperatively in all patients. Cranial diffusion-weighted magnetic resonance imaging was performed 2-4 days before and after the surgical procedure. Cognitive functions were evaluated using the Montreal Cognitive Assessment at the postoperative one month.

Results: Eleven patients in the non-integrated group and seven patients in the integrated group had new lesions in the diffusion-weighted magnetic resonance imaging. The mean pre- and postoperative total Montreal Cognitive Assessment scores were 27.9±3.3 vs 28.1±3.4 and 26.2±3.1 vs 26.8±3, respectively, in the non-integrated and integrated groups. There were no statistically significant differences between the two groups in terms of the number of new lesions, the near-infrared spectroscopy findings, and the Montreal Cognitive Assessment scores.

Conclusion: Membrane oxygenators with integrated arterial filters do not seem to offer a significant advantage over those without integrated arterial filters in terms of neurocognitive outcomes in patients undergoing coronary artery bypass grafting.