Vascular Pathology Flashcards
What is Vasculitis ?
Inflammation of a blood vessel wall (artery/vein)
What does Vasculitis cause?
Inflammation weakens the blood vessel —> causes aneurysm
Causes fibrosis of vessel wall and reduces lumen size —> can cause Ischemia
What are the layers of blood vessels?
Intima, Media, Adventitia
Tunica Intima
Keeps the blood flowing smoothly- Regulates blood pressure, prevents blood clots and keeps toxins out of your body
Media
SMOOTH MUSCLE
Contains elastic fibres that keep blood flowing in one direction
Adventitia
CONNECTIVE TISSUE
Helps delivers oxygen and nutrients from your blood to your cells and helps remove waste
What is the etiology of Vasculitis
Unknown
Is Vasculitis infectious
No
What are the non specific symptoms of Vasculitis ?
Fever, Fatigue, Weight Loss, Myalgia (This shows an inflammation is occurring)
Symptoms of organ ischemia due to:
- Thrombus Formation (damage of endothelium which exposes tissue factor and collagen that stimulates clot formation)
- Reduced lumen size (injury and healing of vessel wall causes fibrosis that reduces lumen size of the vessel)
Aneurysm- Inflammation and necrosis of vessel wall weakens it leading to aneurysm
What does Large Vessel Arteritis affect?
Aorta and it’s major branches
What does Medium Vessel Arteritis affect?
Muscular arteries that supplies organs (renal artery, coronary artery)
What does Small Vessel Artery affect?
Arterioles, Capillaries and Venules
What are the 2 diseases of Large Vessel Vasculitis
-Temporal GIANT CELL Arteritis
-Takayasu Arteritis (PULSELESS DISEASE)
What are the 3 diseases of Medium Vessel Vasculitis?
-Polyarteritis Nodosa
-Kawasaki Disease
-Buerger Disease
What are the 4 diseases of Small Vessel Vasculitis ?
-Wegner Granulomatosis
-Microscopic Polyangitis
-Churg Strauss
-Henoch Schonlein
Who is usually affected by Temporal Giant Cell Arteritis
Vasculitis of old people (avg age 72)- Usually affects females
What is the classic location of Temporal Giant Cell Arteritis?
Branches of carotid artery
Old people with new onset of headache
Vasculitis of Temporal Artery
Visual Disturbance
Vasculitis of Opthalmic Artery
Jaw Claudication
Vasculitis of Arteries of Jaw
What would you expect the ESR to be for a patient with temporal giant cell arteritis
Elevated > 100
What clinical feature is Polymyalgia with flu like symptoms associated with ?
Temporal Giant Cell Arteritis
How is Temporal Arteritis diagnosed?
Vessel Biopsy- should see an inflamed vessel wall with giant cells and Intimal fibrosis
How is the vessel affected for temporal arteritis?
Segmentally so a long segment is taken out for biopsy
How do we treat temporal arteritis ?
Corticosteroids- Treat asap because risk of blindness due to involvement of ophthalmic artery
Who is affected by Takayasu Arteritis?
Mainly adults >50. Classic Pt is young Asian female
What disease affects aortic arch at branch point?
Takayasu Arteritis
What clinical findings do we see with Takayasu Arteritis?
-Visual and neurologic symptoms
-Weak or absent pulse in upper extremity (therefore disease called pulseless disease)
-ESR is elevated, vasculitis is granulomatous
-Treat with corticosteroids
What type of Medium Vessel Arteritis is a necrotising Vasculitis that affects vessels in many organs EXCEPT the lungs
Polyarteritis Nodosa
What are the clinical findings of Polyarteritis Nodosa?
Classic pt is young adults
Symptoms depend on vessel involved-
-Renal artery involvement cause hypertension
-Mesenteric arteries - abdominal pain with melena
-CNS arteries - neurologic disturbances
-Skin lesions
What chemical is associated with Polyarteritis Nodosa
Serum HbsAg
What is the pearl on string appearance of Polyarteritis Nodosa?
Early character of disease is that it creates
fibrinoid necrosis that makes the vessel lumen wide (as dead vessel is weak, aneurysms occur). Late character of disease is that it creates thick fibrosis that narrows the lumen. Therefore imaging gives a “string-of-pearl” appearance with alternate thick and thin sections.
How can we treat Polyarteritis Nodosa?
Corticosteroids & Cyclophosphamide
Fatal if not treated
Classic Pt is Asian child under 4
Kawasaki Disease
What is the clinical presentation of Kawasaki Disease?
- Very non specific viral like infection
-Fever>5 days
-Shrieking irritability - extremely irritable kid
-Conjunctivitis sparring area right next to iris
-Erythematous rash of palms and soles and any mucocutaenous membrane (ex - strawberry tongue)
-Enlarged cervical lymph nodes
What artery is affected with Kawasaki Disease
Coronary Artery
What are the complications of Kawasaki Disease?
Thrombosis with MI- Due to endothelial damage and exposure of collagen and tissue factor
Aneurysm with rupture
What is the treatment of Kawasaki Disease?
Aspirin- Prevents Thrombosis (Antiplatelet drug- Prevents formation of thromboxans A2)
IVIG (Intravenous Immunoglobulin)
Why can we not give kids aspirin when they have a viral disease?
As they can get Rye Syndrome- Encephalopathy and massive liver necrosis
What is Buerger Disease
Necrotising Vasculitis involving digits. Presents with ulceration, gangrene and auto amputation of fingers and toes
What can Buerger Disease be associated with?
Raynaud Phenomenon- Pale to blue to red colour change in digits due to exposure to cold. Pale and blue colour is due to vasopasm; red is due to return of circulation
What can Buerger Disease also be associated with?
Smoking- Smoking cessation = treatment
What 3 diseases can lead to RPGN?
Wegner Granulomatosis, Microscopic Polyangitis, Chug-Strauss
Wegner Granulomatosis is …
C-ANCA +
What affects Nasopharynx, Lungs and Kidney?
Wegner Granulomatosis
What is the treatment of Wegner Granulomatosis?
Cyclophosphamide and Corticosteroids
Relapse common
Microscopic Polyangitis is…
P-ANCA +
What affects lungs, kidney and other organs?
Microscopic Polyangitis
What is the treatment of Microscopic Polyangitis?
Cyclophosphamide and Corticosteroids
Relapse is common
Churg Strauss is …
P-ANCA+
Affects multiple organs including lungs and heart
Churg Strauss
What causes Palpable purpura in buttocks pathogenic?
Henoch Schonlein Palpura
Henoch Schonlein Palpura is shown after a
Upper respiratory infection
How can we treat Henoch Schonlein Palpura?
With steroids
What affects middle aged males
Wegner Granulomatosis
Presentation of Wegner Granulomatosis?
Sinusitis or Nasopharyngeal Ulceration
Hemoptysis with bilateral modular lung infiltrates
Hematuria due to RPGN
Serum C-ANCA level correlates with disease
How can we diagnose Wegner Granulomatosis?
Pt. Is C-ANCA +
A biopsy would show large necrotising granuloma with adjacent necrotising vasculitis
How can we treat Wegner Granulomatosis?
Cyclophosphamide and Corticosteroids
Does Microscopic Polyangitis involve Nasopharyngeal?
No
Serum P-ANCA is associated with
Microscopic Polyangitis
In C-ANCA, anticytoplasmic antibodies mainly target
Cytoplasm away from Nucleus
In P-ANCA, anticytoplasmic antibodies mainly target
Cytoplasm in Perinuclear area
What 3 features distinguish Microscopic Polyangitis from Churg Strauss?
Necrotising granulomatous vasculitis with eosinophils.
Involves multiple organs, especially lungs and heart.
Asthma and peripheral eosinophila.
Churg Strauss
• Necrotizing granulomas with eosinophils present
• Peripheral eosinophila and asthma present
• Involves heart and lung
• P-ANCA correlate with disease activity
What Vasculitis is due to IgA immune complex deposition and most common in children?
Henoch-Schonlein Purpura
Presentation of Henoch-Schonlein Purpura?
-Palpable Purpura on buttocks and legs
-GI Involvement (GI Pain and Bleeding)
-IgA nephropathy leads to Hematuria
-Usually after an upper respiratory infection (The infection generates IgA as IgA protects mucosal site. Too much IgA causes deposition and disease)
How is Henoch-Purpura treated?
Self-Limited
Treat with steroids if severe
What is Hypertension?
Increase in blood pressure
What are 2 types of hypertension?
Pulmonary
Systemic
What is the finding for systemic HTN?
BP > 140/90
What is the etiology for primary HTN?
We don’t know
Risk factors for primary HTN
Age
Race
Obesity
Stress
High Salt Diet
Lack of Physical Activity
How does high sodium cause HTN?
-Systolic BP is a function of stroke volume
-Diastolic BP is a function of total peripheral resistance
-Sodium increases blood volume and peripheral resistance so increases both systolic and diastolic
How does renal artery stenosis cause secondary HTN?
Low blood flow to juxtaglomerular apparatus causes release of renin.
Renin converts angiotensin to angiotensin I
Angiotensin I is converted to Angiotensin II by ACE in lung endothelium
Angiotensin II increases BP by 2 ways:
- Powerful vasoconstrictor (increases diastolic BP)
- Stimulates adrenal medulla to secrete aldosterone (it increases sodium reabsorption and potassium excretion from DCT. Water follows sodium and nobody will have more water- increases systolic BP
Clinical presentation of Renal Artery Stenosis
Atrophy of the stenoses kidney
Increases blood renin
Important causes of RAS
Atherosclerosis
Fibromuscular Dysplasia
What is benign HTN?
Mild/Moderate increase in BP
Clinically silent
Vessels and organs are damaged over time
What is malignant HTN?
Severe increase in BP 200/120 mm Hg
Can arise from pre-existing benign HTN
Pt. Presents with acute end organ damage
What is arteriosclerosis?
Hardening of arterial wall
Atherosclerosis
Thickening of intima due to plaque (occurs in medium and large sized vessels)
Arteriosclerosis
Thickening of small vessels
Hyaline Arteriolosclerosis leads to
Diabetes, Benign HTN
Hyper-plastic Arteriolosclerosis leads to
Malignant HTN
What is mockenberg medial sclerosis
When media is calcified but doesn’t affect lumen size
Histology of Artherosclerosis?
Intimal plaque that obstructs blood flow, contains necrotic lipid core with a fibromuscular wall
4 most common sites for Artherosclerosis
Abdominal aorta
Coronary arteries
Popliteal artery
Internal carotid artery
Modifiable key risk factors for Atherosclerosis
HTN
Hypercholesteremia
Smoking
Diabetes
Non-Modifiable Key risk factors for Artherosclerosis?
Age
Gender
Genetics
Pathogenesis of Atherosclerosis
-Intima is damaged –> lipids gets between intima and media –>lipid is oxidized and then
phagocytozed by macrophage –> this makes fatty streak. Fatty streak is seen as early as
teenagers.
-Inflammation, healing and increased deposition of lipid occurs. A fibromuscular cap occurs due to
inflammation and healing
What are complications of Atherosclerosis
Asymptomatic until occlusion is >70%
Stenosis of medium sized vessels
Peripheral vascular disease (popliteal A)
Angina (coronary A)
Ischemia bowel disease (mesenteric A)
Plaque rupture with thrombosis
MI (coronary A)
Stroke (MCA)
Plaque rupture with embolisation
Results in Artherosclerotic emboli (hallmark is cholesterol cleft in emboli)
Aneurysm due to weak wall
Atrophic ballooning of the wall
Arteriolosclerosis
Narrowing of small Arterioles
Causes of Arteriolosclerosis
Deposition of hyaline or hyperplastic media
What is hyaline Arteriolosclerosis
Proteins leaking into vessel wall causes vascular thickening
Seen as pink hyaline in microscopy
What are 2 causes of Hyaline Arteriolosclerosis?
Benign HTN- High pressure forces protein into the vessel wall
Diabetes- Non enzymatic glycosides ion of basement membrane makes vessel wall leaky and protein leaks in. This is how diabetes can cause nephrotic syndrome
What is key consequence of hyaline Arteriolosclerosis?
Reduced vessel diameter leads to end organ ischemia
Classically produces glomerular scarring which progresses to chronic renal failure
What is Hyperplastic Arteriolosclerosis
Vessel wall thickens due to hyperplasia of smooth muscle
Onion skin like appearance
What causes hyperplastic arteriosclerosis
Malignant HTN which leads to acute renal failure and fibrinoid necrosis of vessel
Consequences of hyperplastic arteriosclerosis
-Reduced vessel diameter leads to end organ ischemia
- Malignant HTN may lead to fibrinoid necrosis of vessel wall (another cause of fibrinoid necrosis is
vasculitis)
- Classically causes ARF with ‘flea-bitten’ appearance - flea-bitten necrosis is due to pin point
hemorrhages (HY)
Aortic Dissection
Blood leaks into the media through a break in Intima and it rips the media in half
What 2 things are needed for aortic dissection?
Stress
Pre-existing weakness of media
How does HTN weaken media and lead to aortic dissection?
Leads to hyaline Arteriolosclerosis of vaso vasorum. Media weakens due to low supply of blood
What is the most common cause of aortic dissection
HTN
What connective tissue disorders can lead to dissection?
- Marfan syndrome - mutation in fibrillin-1 protein. Fibrillin is the base on which elastic fibers are
laid down. Media has lots of elastic fibers - Ehlers-Danlos syndrome - mutation in collagen or proteins that interact with collagen
Clinical picture of aortic dissection?
- Presents with tearing chest pain that radiates to the back
- Most common cause of death is cardiac tamponade. Other causes include aorta bursting open and
obstruction of arteries that branch off aorta.
2 classic locations of Aneurysm
Thoracic and Abdominal aneurysm
Classic cause of thoracic aneurysm
- Tertiary syphilis- syphilis is end arteritis disease. It affects vaso vasorum and poor blood supply
weakens aortic wall. Weak vessel wall leads to aneurysm - Tree bark appearance of aorta is classic finding - as vaso vasorum is affected, poor blood supply leads to fibrosis and scarring
Complications of thoracic aneurysm
- Aortic insufficiency (HY) - as aorta dilates, the valves are pulled apart and can’t close well
- Compression of mediastinal structures
- Thrombosis in wall of aneurysm due to disruption in laminar blood flow. It can embolize.
Common site of abdominal aortic aneurysm
Below the renal arteries and above aortic bifurcation
Presentation of AAA
60 year old male smoker with HTN
Pulsatile abdominal mass that grows with time
Complications of AAA
Rupture especially when < 5cm in diameter
Presents with triad of hypotension, pulsatile abdominal pain, and flank pain
What is a hemangioma?
Benign tumour compromised of blood vessels
Present at birth- regresses during childhood
Involves skin and liver
If pressed it would blanch
What is a Angiosarcoma?
Malignant proliferation of endothelial cells
Highly aggressive
What is Kaposi Sarcoma
Will NOT blanch
Low grade malignant proliferation of endothelial cells
HHV-8 virus that drives the tumour
Presents as purple patches, plaques/nodules on skin
Involves visceral organ
