4.Which is the best cerebral protection strategy in type A
aortic dissection?
Technically surgery for acute and chronic type A aortic dissection is
complex and has to be extended at least into the proximal arch,
sometimes further downstream. This demands for opening the arch and
arresting the circulation. There is a lack of randomized controlled
trials comparing the three aforementioned cerebral protection
techniques. HCA appears safe for short arrest durations but if the
anticipated arrest time is longer than 20 to 25 minutes (which is too
short to perform complex arch repair in a setting of acute type A
dissection), most surgeons will rely on ASCP due to the superior
outcomes. In a large meta-analysis Tian et al. clearly showed that
moderate hypothermic circulatory arrest in combination with selective
antegrade cerebral perfusion is the most optimal way to protect the
brain in arch surgery (41). Therefore we advocate in type A dissection a
modification of this technique: we cool the patient first to 20° C core
temperature, then arrest the circulation and install ASCP. This dual
protection strategy allows for a very extended and safe time period in
which the arch can be tackled minimizing cerebral damage, eventually
anticipating technical difficulties with an almost zero risk of spinal
and renal function problems. It further allows for meticulous surgical
technique and the benefits of this will be translated in less
haemostatic problems at the end and therefore not necessarily an extra
prolongation of ECC-time.
AUTHOR CONTRIBUTIONS
Marc Schepens: concept/design, drafting, revision
Eric Graulus: drafting, revision