Peripheral Arterial Disease Aortic Aneurysms / Vasculitis

Peter B. Baker, MD

Objective for Part 1

1. Describe aneurysms of the peripheral vessels by type and morphology

2. Differentiate atherosclerotic aneurysm, syphilitic aneurysm and dissecting hematoma by pathology, clinical presentation and prognosis

3. Describe the life threatening cardiovascular manifestations of Marfan syndrome

Types of AneurysmsHandout I.A

True aneurysm

Aneurysm wall has all 3 layers False aneurysm

Aneurysm wall is adventitia only

Types of Aneurysms

Vascular Aneurysms

Etiologies Atherosclerosis Syphilis Vasculitis (ie PAN) Infection (mycotic) Trauma Congenital defect

Atherosclerotic Aortic AneurysmHandout I.C

Men > Women - familial Abdominal aorta most common site Pathogenesis involves medial atrophy Complications emboli (athero- or thrombo-) branch occlusion compression of adjacent structure risk of rupture increases with aneurysm size

4 – 4.9 cm, 1% per year5 – 5.9 cm, 11% per year> 6 cm, 25% per year

Atherosclerotic Aneurysm

AtheroscleroticAneurysm

AbdominalAorta

Atherosclerotic Aneurysm - HistologyAtherosclerotic Plaque

Atherosclerotic Aortic Aneurysm

Syphilitic Aortic AneurysmHandout I.D

Thoracic aorta Pathology inflammation of vasa vasorum obliterative endarteritis ischemic necrosis of media fibrosis (“tree bark”) of intima Complications compression of adjacent structures aortic valve regurgitation

Syphilitic Aortic Aneurysm

Syphilitic Aortitis

Vasa Vasorum

Syphilitic Aortitis

Obliterative EndarteritisObliterative Endarteritis in Syphilitic Aortitis

Dissecting Aortic HematomaHandout I.E

Pathology intimal tear split between middle and outer third of the media media may be normal or show degenerationComplications rupture – hemorrhage branch obstructionPredisposing conditions hypertension connective tissue disorders with medial degeneration

Aortic Dissection Classification Based on Extent of Involvement

Dissecting Aortic Aneurysm Gross Specimen

H

Aorta

PA

Dissecting Hematoma Extending Into Common Iliac Arteries

H

H

Dissecting Hematoma Extending Into Common Iliac Arteries

Dissecting Hematoma of the Aorta – Histologic Section

Lumen

MediaDissection

Dissecting Hematoma - Aorta

Aorta – Normal Media (Elastic Stain)Media of Normal Aorta

Aorta with Severe Medial DegenerationAorta with Medial Degeneration

Aorta with Severe Medial Degeneration – Colloidal Iron Stain

Aorta with Medial Degeneration – Colloidal Iron Stain

Objective for Part 2

Describe the etiology, pathology and selected clinical presentations of vasculitides involving large, medium size and small arteries

Causes of VasculitisHandout II.A

Infection Immunologic mechanisms Radiation Trauma Caustic substances Unknown

Vasculitis – PathogenesisHandout II.A - B

Immune complexes circulating or form in-situ Antineutrophilic cytoplasmic antibodies (ANCA) perinuclear (pANCA, Myeloperoxidase-ANCA) – microscopic polyangiitis cytoplasmic (cANCA, Proteinase3-ANCA) – WegenerAntiendothelial antibodiesCell-mediated immunity

Vasculitis-Classification

Large Vessel Giant cell (temporal) TakayasuMedium – sized vessel Polyarteritis nodosa KawasakiSmall – sized vessel Microscopic polyangiitis Wegener granulomatosis

Temporal ArteritisHandout II.C.1

Etiology – unknown ?T-cell mediated injury Clinical – rare before age 50, F > M, headache,

visual disturbances, fever, weight loss, swelling over temporal artery

Pathology - Granulomatous or nonspecific chronic inflammation

- Intimal proliferation / fibrosis with luminal narrowing

- Segmental distribution

Temporal Arteritis - Histology

L

Temporal Arteritis

Temporal Arteritis - HistologyTemporal Arteritis

Takayasu ArteritisHandout II.C.2

Etiology – unknown Clinical – age < 40 years, visual disturbances,

weak arm pulses, neurologic manifestations, hypertension

Pathology - Involves aortic arch and branches

- May involve descending aorta and pulmonary artery

- Intimal fibrosis

- Granulomatous or nonspecific chronic inflammation

Takayasu Arteritis with Severe Narrowing of the Carotid Artery

Takayasu Arteritis - Histology

A

Takayasu Arteritis

Polyarteritis NodosaHandout II.D.1

Etiology – unknown Clinical

- most often in young adults, occasionally in pediatric

age or older adults

- can be acute, relapsing or chronic

- manifestations include hypertension, abdominal pain,

renal failure, GI hemorrhage, muscle pain, neuritis,

fever, weight loss, infarcts

- 30% have circulating HBsAg-HBsAb immune

complexes

Polyarteritis NodosaHandout II.D.1

Pathology

Medium to small muscular arteries involved

Vasculitis is haphazard and segmental

Frequency: kidney > liver > heart > GI

Early findings - fibrinoid necrosis, neutrophils

Vasculitis heals by fibrosis

May develop thrombosis, aneurysm formation

Polyarteritis Nodosa in a Small Muscular Artery

Polyarteritis Nodosa

Polyarteritis Nodosa in a Small Muscular Artery

Polyarteritis Nodosa

Polyarteritis Nodosa with Aneurysm and Thrombosis

Thrombus

Polyarteritis Nodosa with Aneurysm and Thrombus

Hemorrhagic Small Bowel Infarction in Polyarteritis Nodosa

Polyarteritis Nodosa with Early Healing

Intima

Lumen

Polyarteritis with Early Healing

Allergic Granulomatosis (Churg-Strauss)Handout II.D.1.d

Pathology similar to PAN and microscopic polyangiitis Bronchial asthma / allergic rhinitis / eosinophilia / pANCA

in <50% Granulomas / infiltration of vessels by eosinophils Involves lung, heart, spleen, peripheral nerves, skin

Kawasaki DiseaseMucocutaneous Lymph Node SyndromeHandout II.D.2 Etiology – ?T-cell response to an infection Clinical – Infants and children, fever, oral mucosa

erythema, skin rash, lymphadenopathy, erythema of palms and soles

Pathology

Coronary artery vasculitis (accounts for fatalities in 1 – 2%)

Microscopic PolyangiitisHandout II.E.1

Etiology – reaction to an antigen / pANCA Clinical – skin rash, other organs Specific disorders – H-S purpura, cryoglobulinemia,

malignancy Pathology Involves microvasculature Fibrinoid necrosis Karyorrhexis of PMN’s (leukocytoclastic)

Skin Biopsy with Microscopic Polyangiitis

Skin Biopsy with Microscopic PolyangiitisMicroscopic Polyangiitis

Wegener GranulomatosisHandout II.E.2

Etiology – cANCA Clinical – sinusitis, pneumonitis, renal failure,

glomerulonephritis Pathology

- Distribution - kidneys / upper and lower

respiratory tract

- Necrotizing granulomas

- Vasculitis with fibrinoid necrosis

Wegener’s granulomatosis – Small Artery with Fibrinoid Necrosis

Wegener Granulomatosis

Wegener Granulomatosis

Thromboangiitis Obliterans Buerger DiseaseHandout II.E.3

Etiology – unknown / ? genetic influence Clinical – cigarette smoking, < 35 years, claudication of

extremities, ischemic ulcers, gangrene Pathology

Vasculitis with thrombosis

PMN collections in thrombi

Wegener Granulomatosis

Aneurysms Vasculitis Quiz

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If you have any questions or feedback, please contact me:

Peter.Baker@ChildLab.com

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