New frontiers in aortic therapy: focus on deep hypothermic circulatory arrest.

There is currently a paradigm shift in the conduct of adult aortic arch repair. Although deep hypothermic circulatory arrest has been the classic perfusion platform for adult aortic arch repair, recent developments have challenged this aortic arch paradigm. There has been a gradual clinical drift towards moderate, and even mild, hypothermic circulatory arrest combined with antegrade cerebral perfusion. This paradigm shift appears to be associated with equivalent clinical outcomes, and in certain settings, with improved outcomes. The advent of endovascular therapy has challenged even further the concept that circulatory arrest is required for adult aortic arch repair. These dramatic advances have resulted in the emergence of an international aortic arch surgery study group that aims to advance this dynamic field through consensus statements, meta-analysis, clinical database analysis, prospective registries, and randomized controlled trials.

Current conduct of deep hypothermic circulatory arrest in China.

INTRODUCTION: Deep hypothermic circulatory arrest for adult aortic arch repair is still associated with significant mortality and morbidity. Furthermore, there is still significant variation in the conduct of this complex perioperative technique. This variation in deep hypothermic circulatory arrest practice has not been adequately characterized and may offer multiple opportunities for outcome enhancement. The hypothesis of this study was that the current practice of adult deep hypothermic circulatory arrest in China has significant variations that might offer therapeutic opportunities for reduction of procedural risk. METHODS: An adult deep hypothermic circulatory arrest questionnaire was developed and then administered at a thoracic aortic session at the International Cardiothoracic and Vascular Anesthesia Congress convened in Beijing during 2010. The data was abstracted and analyzed. RESULTS: The majority of the 56 respondents were anesthesiologists based in China at low-volume deep hypothermic circulatory arrest centers. The typical aortic arch repair had a prolonged deep hypothermic circulatory arrest time at profound hypothermia. The target temperature for deep hypothermic circulatory arrest was frequently measured distal to the brain. The most common perfusion adjunct was antegrade cerebral perfusion, typically monitored with radial arterial pressure and cerebral venous oximetry. The preferred neuroprotective agents were steroids and propofol. CONCLUSIONS: The identified opportunities for outcome improvement in this delineated deep hypothermic circulatory arrest model include nasal/tympanic temperature measurement and routine cerebral perfusion, preferably with unilateral antegrade cerebral perfusion monitored with radial artery pressure and cerebral oximetry. Development and dissemination of an evidence-based consensus would enhance these practice-improvement opportunities.