Coral reef aorta

Coral reef aorta (CRA) is a rare disease, described as hard calcifications involving the arterial wall which protrude into the lumen. It predominantly involves the posterior thoracic and abdominal aorta. CRA luminal lesions can cause significant aortic stenosis.

Epidemiology

Patients usually present at around 50 years of age, which is younger than most patients suffering from other arterial occlusive diseases. The frequency of CRA is estimated to be 6 in 1,000 (0.6%) .

Clinical presentation

Patients present with arterial occlusion-like symptoms such as intermittent claudication and visceral ischemia such as bowel involvement causing diarrhea, weight loss, and abdominal pain. Renovascular arterial hypertension symptoms are also common .

Pathology

The pathophysiology of CRA is not well understood. It often occurs in patients that have traditional atherosclerotic risk factors: hypertriglyceridemia, hypercholesterolemia, tobacco smoking, diabetes, and hypertension . There may be a calcification regulation defect secondary to lack of serum fetuin-A (also known as alpha-2-Heremans-Schmid glycoprotein) which acts to inhibit ectopic calcification .

Radiographic features

CT

Non-contrast CT demonstrates dense, serpiginous, exophytic, calcifications of the aortic wall which protrude into the aortic lumen. This is in contrast to the typical appearance of atherosclerosis which follows the curve of the vessel wall. These lesions are located typically at the suprarenal and/or juxtarenal aorta causing significant occlusion. Lesions demonstrate a coral reef shape .

Recognition of the extensive endoluminal calcifications can have important implications for planning interventions and treatment, particularly for vascular surgeons and interventional radiologists .

Treatment and prognosis

Typically treatment is invasive surgery, most commonly thromboendarterectomy. Other techniques include aortoiliac and aortofemoral bypass. Relative postoperative complications include acute ischemia of the lower extremities and viscera such as the bowel .

Differential diagnosis

• severe aortic atherosclerosis: different from CRA by having calcific plaques involving the aortic wall without luminal projections

History and etymology

The term coral reef aorta was coined in 1984 by Qvarfordt et al .