VASCULAR PATHOLOGIES BY Dr Abiodun Mark . A

Hyaline arteriolosclerosis Hyaline arteriolosclerosis, also arterial hyalinosis refers to thickening of the walls of arterioles by the deposition of homogeneous pink hyaline material. Lesions reflect leakage of plasma components across vascular endothelium and excessive extracellular matrix production by smooth muscle cells, usually secondary to hypertension It is associated with aging, hypertension, diabetes mellitus and may be seen in response to certain drugs (calcineurin inhibitors).

Hyperplastic arteriolosclerosis Hyperplastic arteriolosclerosis is a type of arteriolosclerosis involving a narrowed lumen. The term "onion-skin" is sometimes used to describe this form of vessel with thickened concentric smooth muscle cell layer and thickened, duplicated basement membrane. In malignant hypertension these hyperplasic changes are often accompanied by fibrinoid necrosis of the arterial intima and media. These changes are most prominent in the kidney(Renovascular hypertension) and can lead to ischemia and acute renal failure.

Atherosclerosis  Atherosclerosis is a specific form of arteriosclerosis in which an artery wall thickens as a result of the accumulation of calcium and fatty materials such as cholesterol and triglyceride i.e artheroma. It reduces the elasticity of the artery walls and therefore allows less blood to travel through. Atherosclerosis is a potentially reversible process. The process of reversal can be summarized as follows: eat fewer total calories and exercise more.

Artherogenesis.

Normal coronary artery This is a normal coronary artery with no atherosclerosis and a widely patent lumen that can carry as much blood as the myocardium requires. There is no impediment to blood flow.

Coronary atherosclerosis. The degree of atherosclerosis is much greater in this coronary artery, and the lumen is narrowed by half. The fatty deposit is separated from the vessel lumen (L) by the cap, formed by connective tissue and smooth muscle cells

Aneurysm An aneurysm "dilation", is a localized, blood-filled balloon-like bulge in the wall of a blood vessel. Aneurysms may be classified by type, morphology, or location. A true aneurysm is one that involves all three layers of the wall of an artery (Intima, media and adventitia). A false aneurysm, or pseudo-aneurysm, is a collection of blood leaking completely out of an artery or vein, but confined next to the vessel by the surrounding tissue.

Aneurysms. Morbidity and death due to aneurysms is due to the following: Rupture. Impingement on adjacent structures. Embolism from a mural thrombus.

Pathogenesis of aneurysms. Arteries maintain their integrity by constantly synthesizing ,degrading and repairing damage to their ECM constituents. Aneurysms occur when the structure/function of the CT within the vascular wall is compromised: -:Decreased synthesis of CT e.g: Marfan’s syndrome. -:Increased degradation of CT. -:Weakened vascular wall through loss of smooth muscle cells.

Abdominal aortic aneurysm Abdominal aortic aneurysm (also known as AAA,) is a localized dilatation of the abdominal aorta exceeding the normal diameter by more than 50 percent, and is the most common form of aortic aneurysm. The 2 most common causes of aortic aneurysm are atherosclerosis and cystic medial degeneration. Approximately 90 percent of abdominal aortic aneurysms occur infrarenally (below the kidneys). Abdominal aortic aneurysms occur most commonly in individuals between 65 and 75 years old and are more common among men and smokers. 

Thoracic aortic aneurysm A thoracic aortic aneurysm is an aortic aneurysm that presents primarily in the thorax. An thoracic aortic aneurysm is the "ballooning" of the upper aspect of the aorta, below the rib cage. Untreated or unrecognized they can be fatal  TAA in pts younger than 40 is associated with CT disorders like Marfan’s and Ehlers Danlos syndrome. Thoracic aneurysms are less common than an abdominal aortic aneurysm

A Dacron graft is a man-made (synthetic) material that is used to replace normal body tissues. It is usually made in a tube form to replace or repair blood vessels

Aortic dissection Aortic dissection occurs when a tear in the inner wall of the aorta causes blood to flow between the layers of the wall of the aorta, forcing the layers apart. This is usually due to hypertension in older people and caused by C.T disorders in younger people. In most cases this is associated with a tearing/excruciating chest pain that usually begins in the anterior chest wall and radiates to the back and downwards as the dissection continues. Aortic dissection is a medical emergency and can quickly lead to death

VASCULITIS.

Large vessel Vasculitis.

Giant-cell arteritis Giant-cell arteritis (temporal arteritis or) is an inflammatory disease of blood vessels most commonly involving large and medium arteries  of the head, predominantly the branches of the external carotid artery. The most serious complication of GCA is permanent blindness, though this can be prevented by prompt treatment with corticosteroids. The name (giant cell arteritis) reflects the type of inflammatory cell involved as seen on a biopsy.

What do you see here? Takayasu

Medium size vessel vasculitis

PAN. Polyartheritis nodosa is a systemic vasculitis of small and medium sized arteries. Classic PAN is characterized by segmental transmural necrotizing inflammation of the small to medium sized arteries. About 30% of patients with PAN have hepatitis B antigen antibody complexes in the affected vessels. Classic PAN is not associated with P-ANCA.

N.B: Perinuclear pattern of antineutrophil cytoplasmic antibodies (p-ANCA) - is present in a form of the disease affecting smaller blood vessels, known as microscopic polyangiitis or leukocytoclastic angiitis

Kawasaki disease.

Small vessel vasculitis.

Thromboangitis obliterans Thromboangitis obliterans (Buerger disease) is caused by small blood vessels that become inflamed and swollen. The blood vessels then narrow or become completely blocked by blood clots (thrombosis). Blood vessels of the hands and feet are especially affected. Arteries are more affected than veins. This condition mostly affects young men ages 20 - 40, who are heavy smokers or chew tobacco.

What is the pathology here?

RAYNAULDS DISEASE. This is a paroxysmal pallor/cyanosis of the hand or foot digits(and infrequently the tips of the nose and ears) caused by intense vasospasm of local arterioles and small arteries. Raynaulds disease occurs in young and healthy adults mostly. CREST SYNDROME.

Varicose veins. Superficial dilated tortuous veins secondary to valvular incompetency. Risk factors include: long standing jobs female sex. Obesity family history. Pregnancy.

Superior vena cava syndrome Superior vena cava syndrome (SVCS), is usually the result of the direct obstruction of the superior vena cava by malignancies. The most common malignancy associated with SVCS are bronchogenic carcinoma and mediastinal lymphoma. Cerebral edema is rare, but if it occurs it may be fatal

Capillary hemangioma A capillary hemangioma (also known as "Strawberry hemangioma",).Capillary hemangioma is a vascular anomaly. This is the most common variant of hemangioma which appears as a raised, red, lumpy area of flesh anywhere on the body, though 83% occur on the head or neck area. These marks occur in about 10% of all births, and usually appear between one and four weeks after birth. It may grow rapidly, before stopping and slowly fading. Some are gone by the age of 2, about 60% by 5 years, and 90–95% by 9 years.

Summary. Vascular disorders and their downstream sequelae are responsible for more morbidity and mortality than any other category of human disease. Vascular pathology results in disease via 2 principal mechanisms : 1) Narrowing or complete vessel lumen occlusion. 2) weakening of vessel wall causing dilation or rupture.

Muchas gracias …Al final.