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