Chapter 20.3 Vascular Diseases Flashcards
(66 cards)
1
Q
Renal vascular diseases can be categorized in what ways?
A
- Small vessel disease
- Large vessel disease
- Thrombotic microangiopathies
- Other
2
Q
Nephrosclerosis, commonly assx with _____, is defined by prescense of varying degrees of
A
Nephrosclerosis, commonly assx with HTN, is defined by prescene of varying degrees of
- glomerulsclerosis
- interstitial fibrosis and tubular atrophy
- arteriosclerosis
- arteriolosclerosis
3
Q
In nephrosclerosis, what happens as the lumen narrows?
A
- contributes to glomerulosclerosis (global and segmental), which can cause interstitial fibrosis and tubular atrophy.
4
Q
What is Benign Nephrosclerosis.
A
- Hyaline sclerosis of the renal arterioles and small arteries d/t benign HTN=> multi-focal ischemia of kidney parenchyma that the sclerotic vessels supply
5
Q
Is Benign Nephrosclerosis is a general process or a specific Dx?
A
General process
6
Q
Benign Nephrosclerosis is strongly associated with _________
and it will occur more in who?
A
- HTN
- Blacks, increasing age and DM
7
Q
What 2 microscopic processes occur in benign nephrosclerosis?
A
- Medial and intimal thickening (fibroelastic hyperplasia) due to hemodynamic changes, aging => narrowing of lumen
- Hyaline protein depositions in arteriolar walls (hyaline arteriolosclerosis) => homogenous and eosinophillic thickening
8
Q
How does the cortical surface of the kidney appear in Benign Nephrosclerosis?
A
- Granular, leather appearance due to scarring and shrinking => causing a reduction in cortical mass
9
Q
Ischemia that occurs in Benign Nephrosclerosis causes what?
A
- patchy ischemic atrophy of tubules and glomeruli
10
Q
Benign nephrosclerosis can progress to what?
A
- glomerulosclerosis
- chronic tubulointerstitial injury (tubular atrophy & interstitial fibrosis)
11
Q
Does Benign nephrosclerosis cause renal failure/renal insufficiecy.
A
No. Obny in 3 cases:
- African-Americans
- Severe HTN
- Diabetic Nephropathy
12
Q
Malignant Nephrosclerosis typically occurs most often in whom?
A
Younger men, black
13
Q
- Malignant Nephrosclerosis is a renal disease with typical arterial changes associated with ______________
A
Malignant or accelerated HTN
14
Q
What type of HTN is a clinical syndrome and a medical emergency?
A
Malignant HTN
15
Q
What is the pathogenesis of malignant HTN?
A
- Injured endothelium (d/t hemodynamic changes) => ↑ permeability to fibrinogen and plasma proteins,
- => Irreversible endothelial injury => focal vascular cell death and platelet deposition
- This will lead to:
- fibrinoid necrosis of arterioles and small arteries,
- activation of platelets and coagulation factors causing intravascular hemorrhage** and **thombosis
- Fibrinoid necrosis leads to hyperplastic arteriolitis/onion skinning (malignant arteriolar sclerosis), causes
- Ischemic kidneys d/t lumen narrowing.
- RAAS => Elevated plasma renin
- This creates a self-perpetuating cycle of damage and HTN
16
Q
What do we see as a result of the fibrinoid necrosis and hyaline arteriolitis seen in malignant nephrosclerosis?
A
Ischemic kidneys and high plasma renin
- Lumen narrowing causes ischemic kidneys
-
+ RAASs ==> high plasma renin
*
17
Q
High plasma renin results in what in Malignant Nephrosclerosis?
A
self-perpetuating cycle of damage and HTN
18
Q
What are the morphological manifestations of malignant HTN.
A
Malignant arteriolosclerosis/malignant nephrosclerosis
19
Q
How does the cortical surface of the kidney appear in Malignant Nephrosclerosis?
A
“Flea-bitten”; small, pinpoint petechial hemorrhages
20
Q
What are the histological manifestation of malignant nephrosclerosis?
A
- Fibrinoid necrosis of arterioles
- Hyperplastic arteriolitis (collagen + proteoglycans and plasma proteins), indicative of renal failure
21
Q
The full-blown syndrome of Malignant HTN is characterized by what BP, and other serious clinical manifestations?
A
- BP: >180/>120,
- Papilledema,
- Retinal hemorrhages,
- Encephalopathy
- CV abnormalities
- Renal failure
22
Q
Early symptoms of Malignant HTN are due to what?
A
↑ ICP
23
Q
Large vessel disease: Unilateral renal artery stenosis causes ____________ and is important to recognize. Why?
A
- Unilateral renal artery stenosis causes 2-5% of HTN cases and is important to recognize because it is curable by surgery.
24
Q
Renal artery stenosis is a cause of _____ due to what?
A
HTN
Due to an increasing production of renin from an ischemic kidney
25
What perpetuates HTN in **renal artery stenosis?**
**Accumulation of Na+**
26
**Renal artery stenosis** is most commonly due to what?
**1. Atherosclerosis (70%)**
**2. Fibromuscular dysplasia (**medial\*\* (most common), intimal and adventitial hyperplasia)
27
**Atherosclerosis** is more common in
1. **Men**
2. **Increasing age**
3. **DM**
28
Which cause of **renal artery stenosis** is more often seen in **younger age groups** (3rd-4th decades) and is more common in **woman**?
**Fibromuscular dysplasia** of the **renal artery**
29
Which cause of **renal artery stenosis** is more often seen in **older people**?
**atherosclerosis;**
30
What is the classic appearance on arteriography of **renal artery stenosis** due to f**ibromuscular dysplasia?**
**"String of beads"**
31
In general pts w/ **renal artery stenosis** present clinically similar to what other disorder?
How can it be diagnosed?
- Resemble those w/ **essential HTN**
- Occasionally **bruit** can be heard over kidney on ausculation (rare)
- **High renin levels**, **response to ACE inhibitors,** **renal scans**, and **IV pyelography** may all aid in Dx
- Need **arteriography** to localize stenotic lesion
32
What is the arteriolosclerosis like in the **ischemic kidney in renal artery stenosis** vs. **non-ischemic (functional) kidney**?
- **Ischemic kidney: decrease size** and show signs of **diffuse ischemic necrosis**
- **Contralateral kidney (healthy)** may show **more severe arteriolosclerosis**, depending on severity of the HTN!
\*Think the ischemic kidney w/ stenosis is essentially shut off from the blood supply, while the functional kidney is getting rocked by extremely high/persistent BP
33
What are the 2 important **thrombotic microangiopathies?**
* 1. HUS **(Hemolytic-uremic syndrome)**
* 2. TTP (**thrombotic** **thrombocytopenic purpura)**
34
**Thrombotic microangiopathy** are a diverse set of conditions that all lead to
* Insults that cause **excessive activation of platelets,** forming **thrombi** in capillaries and arterioles in various tissue beds, including the **kidneys**.
35
What are the 3 major findings in the Thrombotic Microangiopathies (HUS and TTP)?
- **Thrombi** in capillaries and arterioles
- **Microangiopathic hemolytic anemia**
- **Thrombocytopenia** (low platelet count)\*\*\*\* (big clue in a question stem!)
36
**Thrombocytopenia** that occurs in HUS and TTP causes what?
1. Results in **flow abnormalities** that **shear red cells**
2. Causes **microangiopathic hemolytic anemia** and **microvascular occlusions**
3. **Causes ischemia** and **organ dysfunction.**
37
The **primary cause/inciting** event that causes thrombi formation in **HUS** differs from **TTP** how as far as pathogenesis?
- HUS = **injury to endothelial cells** and **platelet** **activation ==\> intravascular thrombosis**
- TTP = **platelet activation** --\> **aggregation**
38
What are triggers of injury to **endothelial cells?**
1. bacterial toxins
2. cytokines
3. viruses
4. certain meds
5. anti-endothelial antibodies
39
In **HUS**, what is a result of damage to the endothelial cells?
1. **Decrease prostaglandin I2 and NO**, which i**nhibit aggregation of platelets**
2. **Increased endothelin,** which causes **vasoconstriction**
40
What is the trigger for **platelet activation and thrombosis** in **typical HUS** vs. **atypical HUS?**
- **Typical HUS** - **Shiga**-**like** toxin (from E.coli) after eating food
- **Atypical HUS** - inherited mutation of proteins that cause excessive activation of complement
41
**Typical HUS** is associated with what synonyms?
**1. Epidemic**
**2. Classic**
**3. Diarrhea +**
42
**Atypical HUS** is associated with what synonyms?
* **Non-epidemic**
* **Diarrhea negative**
43
Who is most often affected by **Typical HUS?**
How is this form treated/managed and prognosis?
- **Children**
- Renal failure is managed w/ **dialysis** and most pts recover normal renal function within weeks
- Long-term prognosis is variable due to renal damage
44
What are the 2 common inherited mutations which cause **Atypical HUS?**
1. **factor H** mutation
2. **Factor I and CD46** mutation
45
Besides inherited mutations, what else can cause **Atypical HUS?**
- **Antiphospholipid syndrome**, either 1° or 2° to SLE
- **Pregnancy** --\> postpartum renal failure
- **Vascular diseases of kidney:** systemic sclerosis and malignant HTN
- **Chemotherapy** and **immunosupprants**
- **Irradiation** of kidney
46
What has a **worse** prognosis: Typical or Atypical HUS?
**Atypical,** due to underlying conditions
47
**Thrombotic Thrombocytopenic Purpura (TTP)** is classically manifested by what pentad, what is the dominant feature?
1) **Neurological sx's = Dominant feature**
2) Fever
3) Microangiopathic hemolytic anemia
4) Thrombocytopenia
5) Renal failure
48
**TTP** and **Atypical HUS** both appear more commonly in **adults**, occassionally having similar sx's. How are they distinguished from one another?
**Atypical** has of **normal ADAMTS13** in plasma
49
**TTP** is associated with **inherited** or **acquired** **deficiencies** in what?
The most common cause is due to what?
- **ADAMTS13** = negative regulator of vWF, which forms large multimers of vWF =\> activate platelets
- **Inhibitory autoantibodies against ADAMTS13** = MOST COMMON!
50
Who is most often affected by **TTP** and it typically presents before what age?
- **Woman**
- Presents **before 40 yo**
51
What is the **course** of TTP and **treatment**?
* **Relapsing** and **remitting course**
* **Plasma exchange** to remove autoAB to ADAMTS13
52
Light microscopy of chronicdisease associated with **atypical HUS/TTP** will show what?
- Mildy HYPERcellular glomeruli
- Thickened capillary walls
- Splitting/reduplication of BM ("tram-tracks")
- "Onion-skinning" of arterial walls
53
What are the morphological characteristics seen on micrcoscopy in both HUS/TTP?
Which arteries will show necrosis? (quiz question!)
- In acute, active dz, the kidney shows **patchy or diffuse CORTICAL necrosis** and **subscapular petechiae**
- **Thrombi** occluded glomerular capillaries
- **Mesangiolysis**
- **Interlobular arteries** w/ **fibrinoid necrosis** of wall and occlusive thrombi
54
When is **life stress** related to **atherosclerosis**?
When pt has **unhealthy coping mechanisms**
55
**Bilateral renal artery disease** (aka **atherosclerotic ischemic renal disease)** is a common cause of what in older individuals?
**Chronic ischemia** _w/ renal insufficiency,_ sometimes w/o HTN
56
How is **bilateral renal artery disease** definitively diagnosed?
Treatment?
- **Arteriography**
## Footnote
**- Surgical revascularization**
57
**Atheroembolic renal disease** is caused by what?
Most often seen in whom and when?
- **Fragments of atheromatous plaques** from aorta or renal artery embolize into intrarenal vessels,
- Most commonly in **older adults** w/ **severe** **atherosclerosis**, esp. following **surgery** on AAA repaire, aortography, or intra-aortic cannulization
58
What occurs when **atheroembolism** throws?
to a **sudden obstruction of blood flow** in the **renal artery** or their main segmental branches and to **ischemia** of kidney =\> **infarction w/ renal dysfunction** of failure
59
Hemorrhagic renal infarcts are due to what?
**renal vein thrombosis**
60
What is the most common cause of **renal infarct?**
**Embolism** from **mural thrombus on left side of heart**
61
**Renal infarct** occurs when what?
* Decreased blood flow (25% of CO)
* End-organ vascular supply
* Lack of collateral circulation
62
What are OTHER sources of **emboli** leading to **renal infarcts?**
* - Mural thrombosis from left atrium/ventricle due to MI
* - Vegetative endocarditis
* - Aortic aneurysms
* - Aortic atherosclerosis
63
Due to the lack of collateral blood supply, how do **renal infarcts** appear morphologically?
Shape?
- Sharply demarcated, pale, yellow-white areas of **coagulative necrosis**
- **Wedge-shaped**
64
* **_Sickle Cell Nephropathy is seen both the disease and can manifest with sickle trait as well._**
* What are the sx?
1. **Hematuria**
2. **Hyposthenuria**
3. 30% will have **sub-nephrotic proteinuria**
65
How does **sickle cell nephropathy** alter the kidney?
1. **Patchy papillary necrosis**
2. Cortex is pale d/t **diffuse ischemic**
3. **Vascular disruption**
66
* **Diffuse Cortical Necrosis** is what?
* Caused by?
* Can lead to?
* **Coagulative necrosis** of both **glomeruli** and **tubules**
* Obstetic MRGENCIES, septic shock, surgery complications
* Systemic hypoperfusion or hypoxia
