Warren- Diseases of Blood Vessels Flashcards
What is nephrosclerosis?
Renal pathology associated w/ sclerosis of RENAL ARTERIOLES AND SMALL ARTERIES
What is seen microscopically with nephrosclerosis?
HYALINE ARTERIOSCLEROSIS>
narrows lumen>
ischemic atrophy w/ tubular atrophy
What does Nephrosclerosis look like grossly?
surface has fine even granularity
What is the pathogenesis of nephrosclerosis?
Aging, genetics, hemocynamic changes>
medial/intimal thickening>
hyaline deposition in arterioles d/t endothelial cell injury
Does nephrosclerosis typically cause renal insufficiency?
Not really
What pts is nephrosclerosis commonly observed in?
DM
black
Severe HTN
WHat is malignant nephrosclerosis?
Renal disease associated w/ malignant HTN
1-5% of pts w/ HTN get it
Who do you commonly see malignant nephrosclerosis in?
Young black men
What is observed grossly with malignant nephrosclerosis?
petechial hemorrhages (flea bitten)
What is observed microscopically with malignant nephrosclerosis?
FIBRINOID NECROSIS of the arterioles
ONION SKINNING OF VESSELS (cocentric proliferation of smth muscle cells and collagen; correlates w/ renal failure)
Describe the clinical course of malignant nephrosclerosis.
HA, N/V, Visual impairement (scotomas)
High Diastolic pressure, papilledema, encephalopathy
Proteinuria/hematuria EARLY>
rapid renal failure
What is renal artery stenosis?
2-5% of HTN>
unilateral renal artery stenosis>
renin secretion
How do you diagnose renal artery stenosis?
bruit on kidney ausculation
high plasma/renal vein renin
What does a kidney w/ renal artery stenosis look like? How does the non-ischemic kidney appear?
Ischemic SMALL kidney w/ some atrophy
Hyaline arteriosclerosis (subjected to systemic HTN)
What can cause RAS?
70% d/t occlusion of RA by atheromatous plaque
Fibromuscular dysplasia
What are thrombotic microangiopathies?
Group of disorders characterized by THROMBOSIS in capillaries and arterioles in the body
What is seen clinically in pts w/ thrombotic microangiopathies?
- MAHA (shistocytes- RBC fight way through small vessels)
- Thrombocytopenia)- low platelets b/c they’re utilized in multiple clots)
- RF
What are the thrombotic microangiopathies?
typical HUS
atypical HUS
familial HUS
Idiopathic TTP
What causes HUS/TTP
Endothelial cell injury>
reveals thrombogenic tissue>
clotting cascase>
decrease PG I2 and NO
Platelet activation and aggregation
What causes Typical HUS and why does this make you NOT want to drink non-pasteurized milk?
75% d/t intestinal infection by verocytotoxin producing E. Coli>
sudden onset bleeding, oliguria, hematuria
What does verocytotoxin do?
causes endothelial lysis, increased endothelin, decreased NO
What happens to most pts w/ typical HUS?
Recover w/in weeks w/ dialysis
What is atypical HUS?
Unclear mechanism
- Pregnancy- post partum renal failure
- vascular renal disease
- CYCLOSPORINE
What causes familial HUS? What is the mortality rate?
Def of the copmlement regulatory protein Factor H
Factor H>
protects cells form uncontrolled complement activation
HIGH- 50%
What causes Idiopathic TTP?
Acquired/genetic defect in protease that cleaves large von Willebrand multimers
What is the classic pentad of sxs for TTP?
Fever neurologic MAHA thrombocytopenia RF
Who is commonly affected by TTP?
Women
Pts < 40
How do you differentiate TTP and HUS?
TTP- neurologic features (sometimes renal involvement)
HUS- significant renal involvement and may not have neurologic features
How do you treat TTP?
plasma exchange and corticosteroids
Microscopically, a pt has deposits of FIBRIN in the capillary lumen, subendothelially and in the mesangium. They also have fibrinoid necrosis of the arterioles. What do they have?
HUS/TTP
What causes most renal infarcts?
Emboli
25% CO to kidneys>
limited colateral circulation
What is the difference between acute and chronic renal infarcts grossly? What is seen micro?
acute: solitary WHITE infarcts
chronic: depressed, gray-white scars w/ a V shape
coagulative necrosis
What does obstructive uropathy lead to?
Hydronephrosis
renal atrophy
How does hydronephrosis appear grossly?
obstruction of urine flow> DILATION of the renal pelivs and calyces> atrophy of the kidney> massive enlargement> thin walles cyst
How does an acute obstruction present?
Pain and sxs related to underlying cause (renal colic form calculus)
How does unilateral hydronephrosis present?
Can be silent for a long time b/c other kidney compensates
How does bilateral partial obstruction present?
Inability to concentrate urine>
polyuria/nocturia
How does bilateral complete obstruction present?
anuria
What percent of americans have stones? M vs. F? Peak age?
5-10%
Men
20-30 y/0
What primarily causes urolithiasis?
inborn errors of metabolism> stone formation
gout
cystinuria
primary hyperoxaluria
What are the 4 main types of calculi?
70% Ca oxalate and Ca phosphate
15% Struvite (Mg NH4 PO)
5-10% UA
1-2% cystine stones
What stones are radiolucent on x ray?
UA stones
What causes Struvite stones?
Magnesium Ammonium Phospahte Stones
Formed after infection by UREA SPLITTING BACTERIA (proteus and staph)>
convert urea to ammonia>
alkaline urine
What causes some of the largest “staghorn” stones?
Urea splitting bacteria (proteus/staph)