2.Retrograde cerebral perfusion (RCP)
This technique was first described by Ueda (23) and aims at prolonging the safe duration of HCA, flushing embolic debris and air out of the brain vessels and removing toxic metabolites. A few years later it was demonstrated in different animals that RCP does not result in effective cerebral perfusion (24,25): RCP does not provide adequate nutritive delivery to meet cerebral metabolic demands. Also Ehrlich demonstrated ineffective cerebral flow during RCP (26). Despite the lack of any benefit in outcome using RCP, some surgeons still today use it throughout their aortic arch replacements because some large clinical series demonstrated good results (27). On the other hand the group of Birmingham UK could not demonstrate a cerebral metabolic, neurologic of neuropsychological outcome benefit using RCP related to arch surgery (28,29). A potential disadvantage is increasing brain oedema exacerbating cerebral injury (30). RCP seems to be fading away gradually nowadays.