Challenges in thoracic aortic aneurysm and dissection

Simplified total arch reconstruction with a stented graft for extended aortic arch dilation

BACKGROUND

Reconstruction of the aortic arch and its three supra-aortic vessels remains a great surgical challenge with postoperative complications. We present a simplified total arch reconstruction with a modified stent graft (s-TAR) and compared its operative outcomes with conventional total arch replacement (c-TAR).

METHODS

This retrospective analysis of prospectively collected data from all consecutive patients who had ascending aortic aneurysm with extended aortic arch dilation and underwent simultaneous ascending aorta replacement and aortic arch reconstruction with the s-TAR or c-TAR between 2018 and 2021. The indication for intervention was maximum diameter of ascending aorta >55 mm and aortic arch in zone II >35 mm.

RESULTS

A total of 84 patients were analyzed: 43 in the s-TAR group and 41 in the c-TAR group. No inter-group differences were found for sex, age, comorbidities, or EuroSCORE II results. All patients were successfully treated with s-TAR or c-TAR, and none died intraoperatively. Cardiopulmonary bypass, selective cerebral perfusion, and lower-body circulatory arrest time were significantly shorter in the s-TAR group, which also had a lower incidence of prolonged ventilation and transient neurologic dysfunction. No patient in either group experienced permanent neurologic dysfunction. The incidence of recurrent laryngeal nerve injury and paraplegia was markedly increased in the c-TAR group; however, no such events were observed in the s-TAR group. Both perioperative blood loss and the incidence of reoperation for bleeding were significantly lower in the s-TAR group. The in-hospital mortality rate was 0% in the s-TAR group and 4.9% in the c-TAR group. The s-TAR group had significantly shorter intensive care unit (ICU) stay and lower total hospitalization costs.

CONCLUSIONS

The s-TAR technique is a safe and effective alternative for total arch reconstruction with shorter operation time, lower rate of postoperative complications and lower total hospitalization costs compared with c-TAR.

Oxidative stress in genetically triggered thoracic aortic aneurysm: role in pathogenesis and therapeutic opportunities

Background: The primary objective of this review was to explore the contribution of oxidative stress to the pathogenesis of genetically-triggered thoracic aortic aneurysm (TAA). Genetically-triggered TAAs manifest substantial variability in onset, progression, and risk of aortic dissection, posing a significant clinical management challenge. There is a need for non-invasive biomarkers that predict the natural course of TAA and therapeutics that prevent aneurysm progression.

Methods: An online systematic search was conducted within PubMed, MEDLINE, Scopus and ScienceDirect databases using keywords including: oxidative stress, ROS, nitrosative stress, genetically triggered thoracic aortic aneurysm, aortic dilatation, aortic dissection, Marfan syndrome, Bicuspid Aortic Valve, familial TAAD, Loeys Dietz syndrome, and Ehlers Danlos syndrome.

Results: There is extensive evidence of oxidative stress and ROS imbalance in genetically triggered TAA. Sources of ROS imbalance are variable but include dysregulation of redox mediators leading to either insufficient ROS removal or increased ROS production. Therapeutic exploitation of redox mediators is being explored in other cardiovascular conditions, with potential application to TAA warranting further investigation.

Conclusion: Oxidative stress occurs in genetically triggered TAA, but the precise contribution of ROS to pathogenesis remains incompletely understood. Further research is required to define causative pathological relationships in order to develop therapeutic options.