| How is aortic anatomy? | Ascending thoracic aorta, aortic arch, descending thoracic aorta, abdominal aorta
Stress of aorta: • The aorta has continuous exposure to high pulsatile pressure and shear stress.
• The aorta is more prone to rupture than any other vessel especially with the development of aneurysmal dilatation.
Types of aneurysms: • True aneurysm
- Saccular
- Fusiform
• False aneurysm or pseudoaneurym |
| How are types of aneurysms? | • True aneurysm involves all three layers of the vessel.
- A fusiform aneurysm affects the entire circumference of segment of the vessel resulting in a diffusely dilated lesion.
- A saccular aneurysm involves only a portion of the circumference resulting in an outpouching of the vessel wall.
• False aneurysms involve the inner layers of the aorta. It is a partial rupture of the aorta, contained by the adventitia |
| How is etiology of fusiform aortic aneurysms? | • The most common pathologic condition associated with aortic aneurysm is Atherosclerosis.
• Cystic medial necrosis is the degeneration of collagen and elastic fibers in the tunica media of the aorta.
• It affects the proximal part of the aorta causing a fusiform aneurysm.
• The fusiform aneurysm is particularly prevalent in patients with: (Marfan’s syndrome. Pregnant women. Hypertensive patients., Valvular heart disease patients. )
• Syphyllis is an uncommon cause of aortic aneurysm.
• Tuberculous and mycotic aneurysms are rare conditions.
• Vasculitis.
• Spondyloarthropathies.
• Traumatic.
• Congenital aortic anuerysms (usually associated with bicuspid aortic valve or aortic coartation). |
| How are thoracic aortic aneurysms? | Thoracic aortic aneurysms (• The average growth of the aneurysm is 0.1 to 0.4 cm/year. The risk of rupture is related to the size of the aneurysm especially when > 55 mm in diameter for the ascending aorta and > 60 mm for the descending aorta
• Most often is asymptomatic.
• Compression or erosion of adjacent tissue may
cause chest pain, dyspnea, cough, hoarseness, dysphagia.
• Congestion of head, neck and upper extremities secondary to compression of the superior vena cava.
• Dilated aortic root with aortic valve regurgitation.
• Congestive heart failure secondary to aortic regurgitation
• Imaging includes: Chest X-ray (might show mediastinal enlargement). Echocardiogram: trans-thoracic, trans-esophageal, or both. CT angio-scanner (Gold Standard). Magnetic Resonance Imaging (MRI). |
| How are abdominal aortic aneurysms? | • It occurs in males more than females.
• The incidence increases with age.
• Atherosclerosis affects more than 90% of the aneurysms > 40 mm in diameter.
• Most of them are below the renal arteries.
• The 5 year risk of rupture for aneurysms < 50 mm is 1 to 2%.
• The 5 year risk of rupture for aneurysm > 50 mm is 20 to 40%.
• The formation of mural thrombi within the aneurysm may predispose to peripheral embolization.
• AAA produces no symptoms and it is usually detected on routine examination as a palpable pulsatile and non tender mass.
• It is usually an incidental finding during an abdominal CT scanner or ultrasound performed for other reasons.
• If AAA expands, it may produce severe pain in the abdomen, or lower back due to mass effect.
• Aneurysmal pain is an emergency because it is an early sign of rupture |
| What is aortic dissection? | • Blood violates aortic intimal and adventitial layers
• False lumen is created
• Dissection may extend proximally, distally, or in both directions
Effects on aortic root Aortic valve and Coronary arteries
flails
Classifications: • DeBakey and co-workers classification
- Type I: The intimal tear occurs in the ascending aorta but which involves the descending aorta as well. (60%)
- Type II: The dissection is limited to the ascending aorta. (10-15%)
- Type III: The tear is located in the descending thoracic aorta (25-30%) |
| How are Debakey's classifications of aortic dissection? | . |
| What are etiologies of aortic dissection? | • Hypertension (known or misdiagnosed).
• Connective tissue diseases:
- Marfan syndrom.
- Ehlers-Danlos syndrom.
• Congenital malformations:
- Bicuspid aortic valve.
- Coarctation of the aorta
• Traumatic (car accident: frontal shock).
• Iatrogenic:
- arterial catheterism.
- during or after cardiac surgery.
• Pregnancy (rare). |
| How is presentation of aortic dissection? | Typical:
• Acute chest pain.
• Abrupt onset.
• Stabbing pain.
• Irradiating pain to the back.
• Migrating pain to the lower back.
• Tearing sensation.
• Hypertensive patient.
Atypical:
• Neurological deficit or syncope: complete or partial obstruction of carotid arteries.
• Hypotension: cardiac tamponade or massive bleeding.
• Shortness of breath: hemothorax
• Acute limb ischemia, acute mesenteric ischemia, acute renal artery obstruction renal failure |
| How is PE of aortic dissction? DD? | • Examine 4 limbs:
- Asymetric pulses (not always present).
- Asymetric blood pressure values (not always present), > 20 mmHg if present.
• Heart auscultation: Diastolic aortic murmur due to aortic valve regurgitation (not always present)
DD: • Myocardial infarction:
- perform ECG and cardiac enzymes.
• Cerebro-vascular accident:
- perform carotid ultrasound and/or brain angio-scanner.
• Pulmonary embolism:
- perform a chest angio-scanner.
• Pericarditis or Pericardial effusion and tamponade:
- perform a cardiac ultrasound and/or a chest angio-scanner |
| How is management of aortic aneurysms? | • Blood pressure Control:
- measure BP in 4 limbs and consider the highest.
- if high, administer IV anti-hypertensive drugs (Loxen, Isoket, Ebrantyl, etc…).
- if low, administer IV fluids.
• Pain Control:
- administer IV morphine, to lower pain, and secondarily to lower BP
Imaging (CXR [if stable pt, see wide mediastinum sometimes], Angioscanner of thorax, abdopelvis, cardiac US if stable pt to see intimal flap/ AR/ pericardial effusion/tamponade, MRI can be performed but time consuming, arteriography not to be done when doubtful dx due to risk of rupture |
| How is management after dx? | Type A (• Call the Open Heart team for an emergent surgery.
• Mortality increases by 2% each hour for total mortality rate of 95%
Restore normal anatomy of aortic root, commissural resuspension and glueing of dissecton layers, aortic valve reimplantation [David Operation]) |
| How is cardiac coarctation correction? | . |
