This document describes diseases of blood vessels. It begins by describing the basic structure and types of blood vessels. It then discusses various pathologies that can affect blood vessels including congenital anomalies, arteriosclerosis, hypertension, vasculitides, aneurysms, dissections, problems with veins and lymphatics, and tumors. Specific conditions discussed in more detail include abdominal aortic aneurysms, thoracic aortic aneurysms, berry aneurysms, aortic dissections, varicose veins, and various vasculitides such as Takayasu arteritis, polyarteritis nodosa, Kawasaki disease, Wegener's granulomatosis, microscopic polyangiitis, and Churg-Strauss

1. Diseases of blood vessels
Dr Manisha T

2. Structure and function of blood
vessels
• 5 main types
– Arteries – carry blood AWAY from the heart
– Arterioles
– Capillaries – site of exchange
– Venules
– Veins – carry blood TO the heart

3. Basic structure
3 layers or tunics
1. Tunica interna (intima)
2. Tunica media
3. Tunica externa

4. Structure
• Tunica interna (intima)
– Inner lining in direct contact with blood
– Endothelium continuous with endocardial lining of heart
– Active role in vessel-related activities
• Tunica media
– Muscular and connective tissue layer
– Greatest variation among vessel types
– Smooth muscle regulates diameter of lumen
• Tunica externa
– Elastic and collagen fibers
– Vasa vasorum
– Helps anchor vessel to surrounding tissue

5. Structure

6. Arteries
3 layers of typical blood vessel
– Thick muscular-to-elastic tunica media
– High compliance – walls stretch and expand in
response to pressure without tearing
– Vasoconstriction – decrease in lumen diameter
• Vasodilation – increase in lumen diameter

7. Veins
• Structural changes not as distinct as in arteries
• In general, very thin walls in relation to total
diameter
• Same 3 layers
• Tunica interna thinner than arteries
• Tunica interna thinner with little smooth muscle
• Tunica externa thickest layer
• Not designed to withstand high pressure
Valves – folds on tunica interna forming cusps
• Aid in venous return by preventing backflow

8. Pathology
Congenital Anomalies
Arteriosclerosis
HTN
Vasculitides ( inflammations)
Aneurysms & Dissections
Veins & Lymphatics
Tumors

9. Aneurysms
• Localized abnormal dilatation of blood
vessel or the wall of the heart that may be
congenital or acquired.
• True aneurysm: an aneurysm is bounded by
arterial wall components or the attenuated
wall of the heart.
• Atherosclerosis, Syphilitic & congenital
vascular aneurysms & left ventricular
aneurysm that can follow MI.

10. Aneurysm
• False/Pseudo aneurysm: it is the breach in the
vascular wall leading to an extravascular
hematoma that freely communicates with the
intravascular space ( “pulsating hematoma”).
OR
• Having fibrous wall & occuring often from
trauma to the vessel.
• Post-myocardial infarction rupture that has
been contained by a pericardial adhesion.

11. Aneurysms
Depending upon the shape classified as
• Fusiform having slow spindle shaped dilatation.
• Saccular : having large spherical outpouching.
• Dissecting: arises when blood enters the wall of artery, as a hematoma
dissecting b/w its layers.
• Cylindrical: with a continuous parallel dilatation.
• Serpentine or varicose: Has tortuous dilatation of vessel.
• Racemose or circoid: having mass of inter communicating small
arteries & veins.
• Berry aneurysm: small dilatations ( circle of willis in the base of brain)
• Complications:
– Thrombosis
– Embolism
– Rupture

12. Aneurysms

13. Aneurysms
• Based on pathogenic mechanism
• Atherosclerotic
• Syphilitic
• Dissecting
• Mycotic

14. Aneurysms

15. Pathogenesis : aneurysms
1. The intrinsic quality of the vascular wall CT is poor.
Example:
Marfan syndrome: defective synthesis on protein
fibrillin- weakning of elastic tissue.
Ehlers –Danlos syndrome: defective type III
collagen synthesis.
loeys- dietz syndrome: mutations in TGF-beta
receptors- defective synthesis of elastin & collagens
I & II.

16. Pathogenesis : aneurysms
2. The balance of collagen degradation &
synthesis is altered by inflammation &
associated proteases
3. Vascular wall is weakened through loss 9of
smooth muscle cells or synthesis of
noncollagenous or nonelastic extracellular
matrix.

17. Aortic aneurysms
• Causes:
• Atherosclerosis
• cystic medial degeneration of the arterial
media.
• Trauma( traumatic aneurysms or
Arteriovenous anuerysms)
• Congenital defects ( berry)
• Infections: mycotic
• syphilis

18. Berry Aneurysms

19. Abdominal aortic aneurysm ( AAA)
• Occuring as a consequences of atherosclerosis.
• Abdominal aorta & common iliac arteries.
• Common in men & in smokers.
• Rarely developing before age 50.
• Positioned below renal arteries & above
bifurcation of aorta.
• Saccular/ fusiform : 15cm in diameter & 25cm
in length.

20. Abdominal aortic aneurysm ( AAA)
• There is severe complicated atherosclerosis,
destruction & thinning of aortic media, containing
bland, laminated ,poorly organized mural thrombosis.
• Variants of AAA
1. Inflammatory AAA: younger patients, back pain,
elevated inflammatory markers (increased C-reactive
protein)
• Lymphoplasmacytic inflammation with many
macrophages. Periaortic scarring.
• Cause: localized immune response.

21. Mycotic aneurysms
• Infection of major artery that weakens its wall
give rise to mycotic aneurysm.
• Originate either
1.From embolization & arrest of septic embolus
at some point in the vessel( as a complication
of infective endocarditis)
2.As an extension of an adjacent suppurative
process
3.By circulating organisms directly infecting the
arterial wall.

22. Aneurysms

23. Thoracic Aortic aneurysm
• Associated with HT.
• Marfans syndrome & loeys- dietz syndrome.

24. Syphilitic ( luetic aneurysms)
• cardiovascular syphilis causes arteritis:
syphilitic aortitis and cerebral arteritis.
• The obliterative endarteritis characteristic of
the tertiary syphilis ( lues) , predilection for
small vessels.
• Syphilitic involvement of vasa vasorum of
thoracic aorta can lead to aneurysmal
dilatation.

25. Tree bark appearance

26. Syphilitic ( luetic aneurysms)
• Syphilitic aneurysm Occurs in 3 rd stage
syphilis –
• Obliterative endarteritis
• Involvement of vasa vasorum of the aorta –
Results in ischaemic medial injury
• Leading to aneurysmal dilation of the aorta
and aortic annulus- eventually valvular
insufficiency.

27. Aortic Dissection (Dissecting
hematoma)
• It is a catastrophic illness characterized by
dissection of blood between and along the
laminar planes of the media.
• With the formation of a blood- filled channel
within the aortic wall that often ruptures
outwards, causing massive hemorrhage /
cardiac tamponade.
• May or may not associated with marked
dilatation of the aorta.

28. Aortic Dissection
• Aortic Dissection – Prominent cause of sudden
death
• Violation of intima that allows blood to enter
media and dissect b/w intimal and adventitial
layers
• Common site is ascending aorta at ligamentum
arteriosum .
• Unusual in the presence of substantial
Atherosclerosis, syphilis ( medial scarring
obstruct the advancement of dissection)

29. Aortic Dissection
• Occurs mainly in 2 groups of patients
1. Men 40-60 years of age with antecedent HT ( 90% of
cases)
2. Usually younger Systemic or localized abnormality
of connective tissue that affect the aorta. Eg: Marfan
syndrome
3.Iatrogenic- complication of arterial cannulation
4.Congenital heart disease
5.Pregnancy

30. Pathogenesis: Aortic Dissection
• HT is the major risk factor for aortic dissection
• Medial hypertrophy of the vasa vasorum asso. With
degenerative changes such as loss of medial smooth muscle
cells & disorganized ECM.
• Pressure related mechanical injury and / or ischemic injury
Other rare causes include
• Inherited or acquired CT disorders causing abnormal vascular
ECM
Marfan syndrome ( elongated axial bones, lens subluxation,
cardiovascular manifestations)
Vit C deficiency Copper metabolic defects

31. Aortic Dissection
• Once the tear has occurred, blood flow under
systemic pressure dissects through the media
Fostering progression of the medial hematoma.
• In some cases, disruption of the vaso vasorum
can give rise to an intramural hematoma
without an intimal tear.

32. Aortic Dissection
• Morphology:
• Cystic medial degeneration
• Inflammation is absent.

33. Aortic Dissection
• Clinical Features
• The risk and nature of serious complications
depend strongly on the level of the aorta
affected.
• Most serious complications with the
involvement of aorta from the aortic valve to
the arch .

34. Aortic Dissection
• 85% abrupt, severe pain in chest or b/w scapula –
50% ripping or tearing – Pain in anterior chest
• ascending aorta (70%) – Back pain (less
common)
• descending aorta (63%) – If dissection into
carotid classic neurological symptoms
• 40% with neurologic sequelae (ex. paraplegia) –
Nausea, vomiting, diaphoresis – Most have sense
of impending doom

35. Classification: Aortic Dissection
• Stanford Classification
• Type A ( proximal and dangerous) -involves –
Ascending aorta only or – ascending aorta, arch &
descending aorta
• Type B –involves descending aorta
DeBakey Classification
Type I –ascending only
Type II –ascending, arch & descending aorta
Type III –descending only

36. Aortic Dissection
• cause of death is rupture of the dissection outwards
into the body cavity.
• Retrograde dissection into the aortic root causes
disruption of the aortic valvular apparatus – Cardiac
tamponade – Aortic insufficiency – MI –
• Transverse myelitis (compression of spinal artery)
• Critical vascular obstruction( extension of the
dissection into the great arteries)

37. Varicose veins
• Abnormal diffuse dilatation of veins.
• Lower limbs- common
• Congenital or acquired
• Pathogenesis:
– Damage to valves
– Stagnation
– Increased pressure  dilatation.
• Chronic ulcers.

38. Varicose veins

39. Vasculitides
• Vasculitides = Inflammation of Blood Vessels
• Present with Non-Specific/ systemic/Vague complaints
• Fever, Myalgia, Artharlgia, Malaise, etc.,
Types : Based on
– Size of Vessels involved
– Site of involvement
– Characteristic Features

40. Pathogenic Mechanisms
Immune –
1. Immune complex : Hypersensitivity (to Drugs),
Following Viral Infections (PAN & HBV)
2. ANCA Positive
• (Anti Neutrophil Cytoplasmic Antibodies) C- ANCA
(Ab Against Proteinase -3) :Wegener's
– P- ANCA ( Ab against MPO) : mPAN, Chaurg –
Straus
3. Anti – Endothelial Cell antibodies: SLE, Kawasaki’s
4. Autoreactive T cells.
Infectious –
• Less Common, Direct Trauma is the cause, can be
Bacterial or fungal

41. Giant cell ( Temporal) arteritis
• Systemic Vasculitis: chronic
inflammatory disorder of large to
small-sized arteries.
• Sites : Temporal ( Head ache &
Facial Pain), Vertebral, Ophthalmic
( Blindness), Aorta ( Aneurysm)
• Age, Sex & Ethnicity :
>50 yrs, M=F, Nordic people
• Clinical :Facial Pain & Headache,
Diplopia & Blindness (most
dangerous, Sudden, permanent)
• Pathology / Morphology : intimal
thickening – reduce luminal
diameter.
Granulomas in vessel walls, Giant
cells, Segmental involvement,
Fragmentation of Internal Elastic
Lamina (IEL)
• Diagnosis: Biopsy is important
Treatment: Steroids save vision

42. Takayasu ( Pulse less )
Arteritis
• Systemic Vasculitis : granulomatous vasculitis of
Medium and large size vessels
• Sites :Aorta ( Aneurysm), Temporal
( Head ache & Facial Pain), Vertebral, Ophthalmic
( Blindness),
• Age, Sex & Ethnicity
<40 yrs., F>M, Japanese, HLA (A24, B52, DR2)
• Clinical :Pulses Weak & Low BP in Hands ( Just
opposite to Coarction of Aorta)
• Pathology / Morphology : transmural fibrous thickening
of aorta.
Granulomas in vessel walls, Giant cells, Fibrosis and
Lymphocytic infiltration
• Diagnosis :Biopsy
Treatment :Steroids
• Complications :MI, Aortic Regurgitation

43. Polyarteritis Nodosa (PAN)
• Systemic Vasculitis of Small or Medium -sized
vessels
• Sites: Kidneys (not the Glomerular capillaries),
Heart, Liver, and GIT (NOT LUNGS)
• Age, Sex & Ethnicity :
Young Adults, M>F , no special risk groups
• Clinical :
Ulcers, Infarcts, Hemorrhages, HBsAg Positive
• Clinical course : Relapses & Remissions
• Pathology / Morphology :segmental transmural
necrotising inflammation.
acute (inflammation, Fibrinoid Necrosis,
Thrombosis), Chronic (nodularity, Fibrosis )
• Diagnosis: Biopsy is important, No ANCA
Positive
• Treatment :corticosteroids and
Cyclophosphamide
• Complications : Renal Failure, CNS lesions
Idiopathic PAN
Cutaneous forms of PAN
PAN asso. with chronic hepatitis.

44. PAN
• Small & Medium size
Vessels
• Different stages of disease
in same or different vessels
• HBsAg Positive
• ANCA Negative
• Capillaries (Pulmonary,
Glomerular) not involved,
• Large infarcts seen
• Bad prognosis
4. mPAN( micro)
• Smallest vessels( Arterioles,
capillaries, Venules)
• Same stage of disease in all
vessels
• Negative
• P-ANCA Positive
• Involved (Necrotizing
Glomerulonephritis,
Hemoptysis)
• No Large infarcts
• Better Prognosis

45. Kawasaki Disease
Muco Cutaneous Lymph node syndrome
• Systemic Vasculitis :of Small &
Medium size vessels
• Sites :coronary, cutaneous vessels
• Age, Sex & Ethnicity : Very
young (<4yrs. Age), North
America, Japan
• Clinical : Fever, Muco
(conjunctival, oral erythema,
erosions), cutaneous (erythema of
palms, soles, & Skin rash), Lymph
node syndrome ( cervical)
• Clinical course :spontaneous
Remissions in most of them
• Treatment :aspirin,
Immunoglobulins
• Complications: coronary
aneurysms
Acute febrile, usually self-limited
illness of infancy & childhood ( 80%
are 4 yrs old or younger)

46. Microscopic polyangiitis (microscopic
polyarteritis (m PAN),
Hypersensitivity or Leukocytoclastic
Vasculitis)

47. Churg – Strauss
Syndrome• Systemic Vasculitis : of Medium and large size
vessels
• Sites : Pulmonary, Coronary, Cutaneous,
• Age: 40- 50 yrs.
• Clinical : Allergic Rhinitis, Bronchial Asthma,
Eosinophilia, skin rash
• Pathology / Morphology :Eosinophilic
Granulomas in vessel walls, Necrosis,
Eosinophilic infiltration of organs
• Diagnosis: Biopsy
• Treatment : Steroids
• Complications : Myocarditis, Coronary Vasculitis

48. Wegener’s Granulomatosis
• Systemic Vasculitis :of small & Medium
size vessels.
• Sites: Pulmonary, renal, nasal & Para nasal
• Age:40yrs, M>F,
• Clinical: Pneumonitis & Nodular Pul.
Infiltrates (MC), Ch. Sinusitis,
Glomerulonephritis, Nasal ulcers
• Pathology / Morphology =
Granulomatous Necrotizing Vasculitis,
Crescentic Glomerulonephritis, Nasal
Granulomas
• Diagnosis: Biopsy, C-ANCA positive,
Triad (Vasculitis, Respiratory, Renal)
• Treatment: Cyclophosphamide
• Complications: RPGN, Pulmonary and
upper airway obstruction

49. Thromboangiitis Obliterans
( Buerger’s disease)
• Limited Vasculitis
• Sites :Tibial & Radial arteries
• Age: <35yrs, M>F, Smokers, Asians
• Clinical: intermittent claudication, rest
pain ( neural involvement), ulcerations of
Toes, Fingers
• Pathology / Morphology: Granulomatous
inflammation, Thrombi with central micro
abscess (Pus)
• Diagnosis :Biopsy,
• Treatment :Avoidance of smoking,
Surgery, Prostaglandin analogues
• Complications:ulcers, gangrene, infection
need of amputation