SRS91 Patey Prize Entrant - INTERCEPTevar trial- flushing of thoracic aortic stents with carbon dioxide versus saline to reduce neurological injury; results of S100B neuroglial biomarker ELISA

TEVAR is associated with a 3–8% risk of stroke and 63–81% risk of 'silent brain infarcts'. Solid emboli have long been recognised as a cause for this, but the role of gaseous emboli due to inadequately flushed stents has become increasingly recognised. Carbon dioxide is more dense than air, less toxic and also more soluble in blood, making it a good purging agent. 85 patients were randomised in the UK, USA and New Zealand to carbon dioxide and saline flushing, versus saline flushing alone. Of these patient 45 had bloods taken pre-operatively, immediately post operatively, and then 24 h later. These were analysed using ELISA techniques to assess for S100B levels, a marker of neuroglial injury. This found that the rise in S100B post-operatively could be reduced in the carbon dioxide arm, +222.93 pg/ml versus +488.92 pg/ml in the saline arm. This was a statistically significant result with a p value of 0.022. This result suggests that through the use of carbon dioxide flushing in thoracic stents, we can reduce neuroglial injury. This could reduce the risk of silent brain infarcts and potentially stroke.