From the Guidelines
The arch of aorta is a critical anatomical structure with significant clinical importance, particularly in the context of aortic aneurysms, dissections, and other thoracic vascular pathologies, where its involvement can impact morbidity, mortality, and quality of life. The arch of aorta serves as the origin for three major arteries supplying the head, neck, and upper limbs: the brachiocephalic trunk, left common carotid artery, and left subclavian artery. Clinically, the aortic arch is relevant in several conditions including aortic aneurysms, aortic dissection, aortic coarctation, and atherosclerosis, as noted in the 2022 ACC/AHA guideline for the diagnosis and management of aortic disease 1. Aortic arch anomalies can cause tracheal or esophageal compression, leading to dysphagia or respiratory difficulties.
During surgical procedures involving the thorax, identifying and preserving the arch and its branches is crucial to prevent catastrophic bleeding or ischemic complications, with techniques such as hemiarch procedures being considered for proximal aneurysmal aortic disease extending to the level of the innominate artery or further into the arch 1. The left recurrent laryngeal nerve loops around the arch, making it vulnerable during thoracic surgeries. Radiologically, the aortic arch serves as an important landmark on chest X-rays, where widening may indicate pathology. Aortic arch syndrome (Takayasu arteritis) involves inflammation of the arch and its branches, causing diminished pulses in the upper extremities.
Understanding the arch's anatomy is essential for interpreting imaging studies, planning interventional procedures, and managing thoracic vascular pathologies, with guidelines suggesting operative treatment for asymptomatic patients when the diameter of the arch exceeds 5.5 cm, and reimaging at 6- or 12-month intervals for aneurysms of smaller diameters 1. Key considerations include:
- The size and growth rate of aortic arch aneurysms
- The presence of symptoms such as hoarseness, dysphagia, dyspnea, and chest or back pain
- The need for neuroprotective strategies during surgical procedures
- The importance of preserving the arch and its branches during thoracic surgeries.
Given the most recent and highest quality evidence from the 2022 ACC/AHA guideline 1, operative treatment is reasonable for asymptomatic patients with aortic arch aneurysms exceeding 5.5 cm in diameter, and a hemiarch procedure may be considered for proximal aneurysmal aortic disease extending into the arch.
From the Research
Clinical Significance of Arch of Aorta
The arch of aorta plays a crucial role in the cardiovascular system, and its clinical significance can be understood through various studies related to aortic dissection.
- Aortic dissection is a serious condition where the inner layer of the aorta tears, causing blood to flow between the layers of the aorta 2, 3, 4.
- The management of acute type A aortic dissection involves initial temporizing medical therapy followed by urgent surgical repair, which is the definitive treatment 4.
- The use of beta-blockers has been shown to be effective in reducing mortality and stroke in patients with type B thoracic aortic dissection 3.
- Statin treatment has also been associated with higher long-term survival in medically managed patients with aortic dissection 2.
- Anticoagulant and anti-thrombotic therapy in acute type B aortic dissection is a complex issue, and current guidelines do not provide clear recommendations 5.
- A study comparing clevidipine and sodium nitroprusside as adjunct agents to esmolol for blood pressure management in aortic dissection found that clevidipine was a less costly and reasonable alternative to sodium nitroprusside 6.
Key Findings
- Beta-blockers and statins are effective in reducing mortality and improving outcomes in patients with aortic dissection 2, 3.
- Surgical repair is the definitive treatment for acute type A aortic dissection 4.
- Anticoagulant and anti-thrombotic therapy in acute type B aortic dissection requires careful consideration of individual patient factors 5.
- Clevidipine is a viable alternative to sodium nitroprusside for blood pressure management in aortic dissection 6.