Shaggy and calcified aorta: surgical implications

Abstract

Atheroembolism is an emerging problem in cardiovascular surgery, especially in elderly patients. Severe atherosclerosis of the thoracic aorta usually reflects systemic atherosclerosis. Aggressive preoperative and intraoperative evaluation of the aorta using enhanced CT, transesophageal echocardiography and epiaortic ultrasound is important in elderly patients as well as those with systemic atherosclerosis. To prevent atheroembolism, it is important to select an adequate arterial perfusion site and to avoid touching the diseased aorta until circulatory arrest. In atherosclerotic aortic arch aneurysm, central cannulation under ultrasound guidance and directing the dispersive cannula toward the aortic root is a simple and effective perfusion strategy. Axillary perfusion is useful as an alternative to central cannulation in atherosclerotic aortic disease, but special care is necessary to avoid complications when the patient has a small axillary artery or flail atheroma around the arch vessels. In femoral artery perfusion, retrograde perfusion may induce paradoxical cerebral embolism, but the incidence of stroke is comparable with axillary perfusion when there is adequate preoperative screening using transesophageal echography. Circulatory arrest with/without cerebral perfusion is another important strategy when the aorta has severe atherosclerosis. Recent literature has shown that mild hypothermia may be safe for anterior cerebral perfusion during circulatory arrest, but optimal flow rates and time limitations are unknown. A simple calcified aorta called "porcelain aorta" may be managed by circulatory arrest, local debridement and the clamp method. Several surgical options are proposed for this clinical entity but their use will diminish in the future because of transcatheter valve replacement.

Porcelain Aorta

“…The exact definition of PA varied between authors, but the common denominator that best describes the clinical problem is aortic calcification that interferes with aortic cannulation, aortic clamping, aortotomy, or central coronary bypass anastomosis, necessitating modification of the surgical technique to avoid complications. 15 Diverse modalities are used for the diagnosis of PA, and there is a lack of clear definition for how PA should be diagnosed. Not uncommonly, PA is recognized by manual palpation performed after sternotomy and exposure of the aorta at the time of cardiac surgery.…”

“…The presence of a heavily calcified atheromatous aorta is associated with a significantly increased risk of embolic stroke and peripheral embolism during conventional cardiac surgery. 6,15,41 On the other hand, when calcification of the aorta is limited to the tunica media, it excludes a significant source of embolization because the intima is relatively intact without exophytic lesions but precludes safe cross-clamping or cannulation of the aorta. Nonetheless, the currently available diagnostic methods used to detect TAC, including CT, do not discriminate intimal from medial calcification, thus precluding a clear, clinically valuable separation between patients with PA.…”

“…15 Seyahi et al 53 evaluated the presence of TAC in 47 patients with TA, 43 patients with SLE, and 70 healthy control subjects using multidetector CT. TAC was present in 21 patients with TA (45%). In 8 patients, it was diffuse and extended from the ascending to the descending aorta.…”

“…6,41 Severe AAC interferes with aortic cannulation, aortic clamping, aortotomy, and central coronary bypass anastomosis, necessitating modification of the surgical technique to avoid complications such as aortic dissection, surgically unreconstructable ascending aorta, or release of thromboembolic material that may cause periprocedural stroke. 12,15,82 Several modifications have been used in isolated CABG procedures to avoid cannulation and clamping of the diseased ascending aorta. The most common modification is a "no touch" technique that totally avoids manipulation of the ascending aorta.…”

Transapical aortic perfusion using a deep hypothermic procedure to prevent dissecting lung injury during re-do thoracoabdominal aortic aneurysm surgery

“…Later, a technique for changing the blood temperature and the perfusion rate selectively in the upper and lower body depending on the purpose of the protected organs was also reported [8]. The ascending aorta and thoracic descending aorta are frequently selected as the cannulation route for perfusing the upper body, but this route is not appropriate in patients with profound atherosclerotic changes, such as a shaggy and calcified aorta [9]. Shiiya et al reported using antegrade perfusion by transapical aortic cannulation to prevent debris scattering due to retrograde perfusion from the femoral artery in a patient undergoing thoracoabdominal aortic repair by left thoracotomy [7], and Takemura et al reported the usefulness of transapical cannulation in preventing malperfusion during a deep hypothermic procedure to repair an acute traumatic descending aortic rupture [10].…”