Hypothermic circulatory arrest during ascending and aortic arch surgery: the theoretical impact of different cerebral perfusion techniques and other methods of cerebral protection

Abstract

Operations on the thoracic aorta using hypothermic circulatory arrest are still associated with significant morbidity and mortality due to neurological complications. During the last decades, different cerebral protection techniques have been introduced into clinical practice to reduce the incidence of such complications. Furthermore clinical as well as basic researches have been performed to improve the outcome after these operations. Currently different cerebral perfusion methods are in clinical use and the superiority of one or the other method is a matter of controversial discussion. This review has been undertaken to evaluate the theoretical impact of these different methods of cerebral protection. Based on the experience of the authors the pros and cons are discussed with clinical and experimental reports from the literature.

Neurologic Injury Following Hypothermic Circulatory Arrest

“…Reductions in CMRO 2 and the duration of DHCA reduce the risk of neurologic injury. The length of time on CPB might be a better predictor of postoperative death and stroke than the duration of DHCA time (Hagl et al, 2003). Aortic procedures requiring hypothermic circulatory arrest have been specifically correlated with increased risk of both stroke and mortality in all patients.…”

Thoracic aortic surgery with circulatory arrest and cold cerebral perfusion

“…Dabei wird ein streng standardisiertes Protokoll verwendet, welches die bereits oben erwähnten Vorteile der kalten Temperaturen für das Gehirn mit den moderaten Temperaturen für den restlichen Körper vereint [12].…”

“…B. bei hämody-namischer Instabilität des Patienten unter Reanimation die HLM etabliert werden kann, ohne dass es hierbei zu einer Unterbrechung der Thoraxkompressionen kommen muss [9]. Die Kanülierung der Aorta ascendens/des Aortenbogens ist ein Verfahren, das in dem vorliegenden Patientengut größtenteils angewendet wurde [12]. Unserer Erfahrung nach bietet dieses Verfahren nicht nur bei elektiven Eingriffen, sondern auch bei akuten Aortendissektionen einen sicheren und schnellen Zugangsweg mit einer antegraden Versorgung von Gehirn und restlichem Körper [23].…”

Hypothermic circulatory arrest with and without cold selective antegrade cerebral perfusion: impact on neurological recovery and tissue metabolism in an acute porcine model1

“…On the basis, that clinical as well as experimental data on the value of retrograde cerebral perfusion (RCP) techniques are still a matter of controversial discussion [2,3], selective antegrade cerebral perfusion (SACP) methods became increasingly popular. Recent reports from clinical studies clearly demonstrate a favourable outcome [4,5] in those patients, but prospective controlled studies are still missing.…”

“…Recent reports from clinical studies clearly demonstrate a favourable outcome [4,5] in those patients, but prospective controlled studies are still missing. Reviewing data from the literature, there are a number of technical details how SACP can be used [3]. These techniques include different cannulation techniques, variable levels of general hypothermia and diverse protocols regarding antegrade flow and temperature.…”