AORTIC EVALUATION ASSESSMENT.pdf, Lecture notes of Biology

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GROUP 4  CINDY WANGUI  JARED OWUOCHA  VINCENT JOWAUR  ANTONY MAINA  SUPERVISED BY: MR.MASESE  LECTURER: MR MASESE  DATE 28/02/

PRESENTATION ON DISESASES OF

THE

AORTA

• (^) Aorta is the conduit through which blood ejected from the left ventricle is delivered to the systemic arterial bed.
• (^) In adults, its diameter is approximately 3 cm at the origin and in the ascending portion, 2.5 cm in the descending portion in the thorax, and 1.8–2 cm in the abdomen.
• (^) The aortic wall consists of a thin intima composed of endothelium, subendothelial connective tissue, and an internal elastic lamina; a thick tunica media composed of smooth muscle cells and extracellular matrix; and an adventitia composed primarily of connective tissue enclosing the vasa vasorum and nervi vascularis.

• (^) In addition to the conduit function, it distends during systole to allow a portion of the stroke volume and elastic energy to be stored, and recoils during diastole so that blood continues to flow to the periphery.
• (^) Because of its continuous exposure to high pulsatile pressure and shear stress, the aorta is particularly prone to injury and disease resulting from mechanical trauma.

• (^) Aortic aneurysm
• (^) Acute aortic syndromes (aortic dissection, acute intramural hematoma, penetrating atherosclerotic ulcer)
• (^) Aortic occlusion
• (^) Aortitis DISEASES OF AORTA

AORTIC

ANEURYSM

• (^) An aneurysm is defined as a pathologic dilation of a segment of a blood vessel ie. 1.5 times to that of expected normal diameter
• (^) A fusiform aneurysm affects the entire circumference of a segment of the vessel, resulting in a diffusely dilated artery
• (^) Saccular aneurysm involves only a portion of the circumference, resulting in an outpouching of the vessel wall .

ETIOLOGY(CONTINUATION)

 (^) Marfan syndrome  (^) Genetic or developmental  (^) Loveys-Dietz syndrome  (^) Ehlers-Danlos syndrome type IV  (^) Familial  (^) Bicuspid aortic valve

 (^) Inflammatory Disorders These occur in isolation or in the context of systemic disorders such as inflammatory vasculitis. They include infectious (Syphilis) and noninfectious causes (Giant Cell Arteritis, Takayasu’s Arteritis ankylosing spondylitis, rheumatoid arthritis)

THORACIC AORTIC ANEURYSM

• (^) Cystic medial necrosis is the most common pathology associated with ascending aortic aneurysms, whereas atherosclerosis is the condition most frequently associated with aneurysms of the aortic arch and descending thoracic aorta.
• (^) Risk of rupture is 2–3% per year for thoracic aortic aneurysms <4.0 cm whereas 7% per year for those > cm in diameter.
• (^) Most thoracic aortic aneurysms are asymptomatic

• (^) Large ascending aortic aneurysms may cause superior vena cava obstruction manifesting as distended neck veins
• (^) Ascending aortic aneurysms also may develop aortic insuffi ciency, with widened pulse pressure or a diastolic murmur, and heart failure
• (^) Arch aneurysms may cause hoarseness, which results from stretching of the recurrent laryngeal nerves
• (^) Descending thoracic aneurysms and thoracoabdominal aneurysms may compress the trachea or bronchus and cause dyspnea, stridor, wheezing, or cough

• (^) Erosion into surrounding structures may result in hemoptysis, hematemesis, or GI bleeding
• (^) Erosion into the spine may cause back pain or instability
• (^) Spinal cord compression or thrombosis of spinal arteries may result in neurologic symptoms of paraparesis or paraplegia
• (^) Descending thoracic aneurysms may thrombose or embolize clot and atheromatous debris distally to visceral, renal, or lower extremities