Ascending aorta and aortic arch surgery is currently one of the most complex surgical interventions in the spectrum of cardiac surgery, where cardiac and circulatory arrest play an important role in the post-surgical success and patient survival. Our case met the main recommendation criteria of the European Association for Cardio-Thoracic Surgery and the European Society for Vascular Surgery for open treatment of TAA (high risk of retrograde dissection with ascending aorta > 45 mm, aneurysmal extension involving aortic root and extending to the aortic arch) .
Despite this, the open approach involves a wide variety of techniques such as circulatory arrest with cerebral perfusion, allowing us to obtain greater surgical safety with less risk of systemic and cerebral ischemia. These techniques require adequate planning and strict control of the times of ischemia, hypothermia, and cerebral perfusion.
For this reason, TCADHCP-AB was used through the right axillary and left carotid artery, providing constant perfusion to the brain during arch surgery and minimally reducing cerebral ischemic time; likewise, we associated it with profound hypothermia (< 28 °C) that allowed an acceptable alteration of the internal environment, less bleeding and greater neuroprotection. It is known that on average the Cerebral Oxygen Metabolic Rate (COMO2) decreases 7% for every 1 °C reduction in temperature from 37 °C, allowing us to perform the surgical procedure safely until 45′–55′ before the occurrence of the significant neurological and multisystem side effects .
Recent studies describe a lower incidence of ischemic brain lesions demonstrated by magnetic resonance imaging with the use of TCADHCP-AB in relation to the same technique with moderate hypothermia (p < 0.01) ; however, others describe an incidence of 19.1% of transient ischemic attacks (OR 1.88, p = 0.23) when this strategy exceeds 25′–30′ associated with a survival of 61.8% at 10 years (57.8–65.8%, 95% CI, p < 0.05) .
Another effective method for adequate monitoring of cerebral perfusion in TCADHCP-AB is continuous cerebral oximetry (NIRS), used in more than 65% of the hospital institutions that perform this type of surgery, and allows the capture of regional oxygen saturation of the tissues corresponding to the perfusion territories of the anterior and middle cerebral arteries. Its main advantage is that it is not affected by the degree of anesthetic depth or by hypothermia, and in the case of an acute brain injury, its value is directly related to the COMO2 and decreases proportionally to the severity of the injury .
From a hemodynamic and flowmetric point of view, open surgical reconstruction of the aortic arch presents serious advantages over endovascular and hybrid, with 100–200% less pressure drop in regions of supra-aortic vessels with a uniformly distributed flow and with a nominal wall shear stress of 417 dyne/cm2. This fact has still demonstrated the hemodynamic supremacy of open aortic arch correction over the other options .
The repair of an ATAA with compromised aortic arch that respects the anatomical and hemodynamic principles described, with TCADHCP-AB support and optimal NIRS monitoring, should lead to low morbidity and mortality rates (< 25%) . However, disorders of the internal environment that produce profound hypothermias, perioperative bleeding, and systemic/cerebral ischemia time are the main predictors of postoperative survival in the short and long term.
Current evidence describes that the use of TCADHCP-AB in the context of aortic arch surgery in centers with high volume of patients, survival to the first year is 89% (79–94%, 95% CI, p < 0.05), 78% at 5 years (66–86%, 95% CI, p < 0.05) and 73% at 10 years (59–82%, 95% CI, p < 0.05) . Despite the aforementioned findings, our case is added to the list of the first to be performed at our hospital headquarters, and we are aware that evaluating survival in the medium and long term will be the subject of future research.
Recently, various combined endovascular treatments for ATA and aortic arch pathologies have been disseminated; however, they were only evaluated in isolated cases, not showing great benefits and presenting serious risks (stroke, endoleaks, myocardial infarction, embolism, etc.…) over standard open treatment .