12. Pathology of BVs Overview (Burke) 8/26

Question 1

endothelial cell function

Answer 1

○ Mediate
§ Vasoconstriction and thrombosis
§ Maintain capillary integrity
§ Regulate inflammation
○ Studied mostly in context of atherosclerosis
○ “Endothelial activation” via endotoxin, decreased shear stress, oxidized LDL, AGE, complement

Permeability increases w/inflammation, histamine, following edema and extravasation of inflamm cells

Question 2

intimal thickening

Answer 2

○ Normal arterial intima = BM, ground substance, and endothelial cells within IEL (internal elastic lamina)

Initial accumulation of smooth muscle cells and fibroblasts to non-specific response to injury

Question 3

hypertensive vascular disease

Answer 3

• Most susceptible small vessels
  ○ Renal: small muscular arteries and arterioles
  § Arterionephrosclerosis (hypertensive renovascular disease) -> hyaline arteriorlar sclerosis or concentric thickening w/elastosis of muscualr arteries (onion skinning) in malignant hypertension
• retinal arteries
• cerebral arteries
• pulmonary arteries

Question 4

arteriosclerosis

Answer 4

arterial thickening of any type
- renovascular changes
Atherosclerosis
- Intimal disease of elastic and muscular arteries
- Aorta, iliacs, carotid, coronary arteries most susceptible
○ Small arteries -> blockages (eg acute MI due to blockage of coronary artery or peripheral vascular disease due to blockage of vessel in knee)
- Endothelial damage initiating event
○ Increased risk factors: heredity, serum cholesterol, inflammatory markers, diabetes, smoking
- Denotes more than intimal thickening: addition of lipid material (atheroma)
- Early atherosclerosis
○ Activated Ecs allow adhesion and migration of macrophages and lymphocytes
○ Oxidized LDL enters intima via scavenger and LDL receptors
○ Foam cell macrophages and lymphocytes stimulate proliferation of SMCs
○ Apoptotic cell death allows for accum of cell debris (atheroma)
- Later atherogenesis
○ Angiogenesis in growing atheroma
§ Leaking red cells and fibrin into core
○ Endoth damage results in small luminal thrombi
○ Large thrombi result in rupture of fibrous cap (“plaque rupture”) or erosion of large areas of denuded endoth.
○ Acute coronary syndromes generally based on sudden narrowing by thrombus
- Medial calcification (of Monckeberg)

Question 5

intravascular stenting

Answer 5

• Common PCI (percutaneous intervention) to open athersclerotic coronary arteries
  
  • 2 types
    ○ DES: drug eluting
    ○ BMS: bare metal
  • Major complications:
    ○ Restenosis
  • Uncommon complications:
    ○ Dissections, perforations, acute thrombosis

Question 6

abdominal aortic aneurysm

Answer 6

• Increasing in incidence
  
  • RFs: cigarette smoking, HTTN
  • Etiology? Collagenase, elastase, alpha1-antitrypsin defic, decreased metalloproteases
  • Most common location: distal to renal arteries
  • Complication: rupture if >5 cm

Question 7

dissecting aortic aneurysm

Answer 7

§ Usual site: ascending/thoracic aorta
§ Triad of predisposing factors
	□ HTTN
	□ Marfan's
	□ Bicuspid aortic valve
§ Other predisposing factors:
	□ Previous valve surgery
	□ Pregnancy
- Classification
   Type 2: distension not beyond aortic arch
   Type 1: distension beyond aortic arch
   Type 3: extension of false lumen to renal artery
- hemopericardium can lead to cardiac tapenade

Question 8

PE

Answer 8

PE
§ .2-5% of all deaths
§ 3-5% hospital deaths
§ Usu from leg veins
§ RFs:
	□ DVT
	□ Trauma, post op
	□ Obesity
	□ Malignancy
	□ Chronic heart disease
	□ Genetic factors: Protein C,S defic; resistance to activated protein C
§ Acute
	□ DVT
§ Chronic

Makes pulmonary artery HUGE

Question 9

SVC thrombosis

Answer 9

SVC thrombosis = superior vena cava syndrome

- Occlusion of SVC
- Edema of face and neck
- Usu lung cancer, lymphoma
- Radiation therapy provide sx relief
- 90% mortality 2.5 years

Question 10

IVC thrombosis

Answer 10

thrombosis of the inferior vena cava
- Usu caused by tumors infiltrating the lumen
○ Renal cell carcinoma
○ Hepatocellular carcinoma
○ Testicular germ cell tumors
- Lower extremity edema, proteinuria if involving renal vein

Question 11

Budd-Chiari syndrome

Answer 11

Budd-Chiari Syndrome = thrombosis of hepatic vein
- Occlusion of mesenteric and hepatic circulation
- Liver failure, massive ascites, hepatosplenomegaly
- Causes
○ Idiopathic, tumor (HCC), thrombotic states (polycythemia vera)

Question 12

portal vein thrombosis

Answer 12

- Caused by infections
		○ Pylephlebitis
		○ Appendicitis
		○ Diverticulitis
		○ Umbilical cord infections (neonates)
	- Frequent in cirrhosis
	- Portal hypertension results