Monitoring of antegrade selective cerebral perfusion for aortic arch surgery with transcranial Doppler ultrasonography and near-infrared spectroscopy

Objective To evaluate the safety and efficacy of antegrade selective cerebral perfusion (ASCP) during aortic arch surgery as a means of extending the safe period of systemic circulatory arrest using multimodality neuromonitoring to objectively quantify the physiologic responses Methods In twenty two patients (all less than age 60) scheduled for repair of an aortic arch aneurysm, preoperative verification of effective collateral perfusion through both the carotid and vertebrobasilar arterial systems was documented with transcranial Doppler ultrasonography (TCD) During cardiopulmonary bypass, the sole arterial inflow from the pump was via the right subclavian artery The magnitude of ASCP was quantified by TCD using peak middle cerebral artery velocity, while flow adequacy was measured by continuous regional cerebrovenous oxygen saturation (rSO 2) using dual wavelength spatially resolved near infrared spectroscopy Results All patients experienced an uneventful recovery Flow in the middle cerebral artery became undetectable at ASCP < 5?ml·kg 1 ·min 1 , so adjustments from a 15-20?ml·kg 1 ·min 1 baseline were used to maintain rSO 2 above 50% Furthermore, ASCP flow was highly correlated ( P <0 01) with both peak middle cerebral artery velocity and rSO 2 ( r =0 86 and 0 96, respectively) Conclusion Neuromonitoring guided ASCP may be expected to extend the safe period and is at least partly responsible for the absence of neurologic complications in this patient cohort

Cerebral Metabolic Profiling of Hypothermic Circulatory Arrest with and Without Antegrade Selective Cerebral Perfusion： Evidence from Nontargeted Tissue Metabolomics in a Rabbit Model

Background： Antegrade selective cerebral perfusion （ASCP） is regarded to perform cerebral protection during the thoracic aorta surgery as an adjunctive technique to deep hypothermic circulatory arrest （DHCA）. However, brain metabolism profile after ASCP has not been systematically investigated by metabolomics technology. Methods： To clarify the metabolomics profiling of ASCP, 12 New Zealand white rabbits were randomly assigned into 60 min DHCA with （DHCA＋ASCP [DA] group, n = 6） and without （ DHCA [D] group, n = 6） ASCP according to the random number table. ASCP was conducted by cannulation on the right subclavian artery and cross-clamping of the innominate artery. Rabbits were sacrificed 60 min after weaning off cardiopulmonary bypass. The metabolic features of the cerebral cortex were analyzed by a nontargeted metabolic profiling strategy based on gas chromatography-mass spectrometry. Variable importance projection values exceeding 1.0 were selected as potentially changed metabolites, and then Student＇s t-test was applied to test for statistical significance between the two groups. Results： Metabolic profiling of brain was distinctive significantly between the two groups （Q2y = 0.88 for partial least squares-DA model）. In comparing to group D, 62 definable metabolites were varied significantly after ASCP, which were mainly related to amino acid metabolism, carbohydrate metabolism, and lipid metabolism. Kyoto Encyclopedia of Genes and Genomes analysis revealed that metabolic pathways after DHCA with ASCP were mainly involved in the activated glycolytic pathway, subdued anaerobic metabolism, and oxidative stress. In addition, L-kynurenine （P = 0.0019）, 5-methoxyindole-3-acetic acid （P = 0.0499）, and 5-hydroxyindole-3-acetic acid （P = 0.0495） in tryptophan metabolism pathways were decreased, and citrulline （P - 0.0158） in urea cycle was increased in group DA comparing to group D. Conclusions： The present study applied metabolomics analysis to identify the cerebral metabolic profiling in rabbits with ASCP, and the results may shed new lights that cerebral metabolism is better preserved by ASCP compared with DHCA alone.