Vascular disease

The article covers vascular disease, i.e. diseases of blood vessels. Vasculitides are covered in a separate article called vasculitides.

Normal blood vessels

Comparing arteries and veins:

Feature	Artery	Vein
Internal elastic lamina	prominent/thick, usu. complete	thin & incomplete
External elastic lamina	present, thick	absent
Shape	circular / lumen wide open	collapsed
Wall thickness	thick	thin

Great vessels

When things go wrong here, you see a cardiac surgeon.

Atherosclerosis

General

• A leading cause of death, esp. in the Western world.
• May have multi-system manifestations.

Location and associated pathology:

• Coronary artery atherosclerosis (AKA coronary artery disease) -> myocardial infarction +/-coronary thrombosis.
• Atherosclerotic peripheral vascular disease -> leg amputations.
• Carotid artery atherosclerosis -> thrombotic stroke.
• Superior mesenteric artery atherosclerosis -> ischemic enteritis or ischemic colitis or ischemic enterocolitis.
• Penile artery atherosclerosis -> impotence.

Clinical risk factors:

• Age.
• Blood pressure (high) - modifiable (antihypertensives).
• Cholesterol - modifiable (statins, diet).
• Diabetes mellitus - modifiable (hypoglycemic medications, diet, lifestyle).
• Smoking - modifiable (cessation).
• Family history.

Microscopic

Features:

• Intimal hyperplasia.
• Lipid deposition.
• Foamy macrophages within intima & media.
• Cholesterol clefts
• Luminal narrowing.

Notes:

• Considered "complex" if any of the following are present:
  • Calcifications.
  • Thrombosis.
  • Haemorrhage.

Image

• 

  Right coronary artery with atherosclerosis. (WC/Nephron)

Stains

• Elastic trichrome stain or Movat stain - highlights duplication of internal elastic lamina, allows on to identify with ease intimal thickening.

Aortic dissection

• Abbreviated AoD.

General

Risk factors:

• Hypertension.
• Atherosclerosis.
  • Smoking.
• Cardiac surgery - rare, well-known complication.

Note:

• Diabetes uncommon in AoD.

Associations

Heritable:

• Marfan's syndrome.
• Loeys-Dietz syndrome - a Marfan-like syndrome
• Ehlers-Danlos syndrome.
• Bicuspid aortic valve.

Others:

• Tertiary syphilis.
• Turner syndrome.

Classification

Two classification exist:

• DeBakey.
• Stanford.

Stanford dissection classification:

• Type A - aortic root to the left subclavian artery.
  • Considered a surgical emergency.
• Type B - distal to (left) subclavian artery.
  • Generally, treated conservatively.

Gross

• Entry intimal tear +/- exit intimal tear.
  • Blood between layers of the vessel wall.

Images

• 

  Aortic dissection. (WC)

www:

• Aortic dissection (utah.edu).
• Aortic dissection (brown.edu).

Microscopic

See: cystic medial degeneration.

Images

• 

  Aortic dissection. Victoria blue-H&E. (WC/KGH)

www:

• Aortic dissection - autopsy (upmc.edu).

Cystic medial degeneration

• AKA cystic medial necrosis.

General

• Nonspecific finding - may be seen in a number of conditions.

Note about cystic medial necrosis:

• Often not cystic and not necrotic.

Microscopic

Features:

• Basophilic ground substance in the media (seen on Movat's stain).
• Disruption of the elastic lamina (seen on elastic trichrome stain).
• +/-Focal necrosis.

Images

• 

  Cystic medial degeneration - low mag. (WC/Nephron)

• 

  Cystic medial degeneration - high mag. (WC/Nephron)

• 

  Cystic medial degeneration - movat - low mag. (WC/Nephron)

• 

  Cystic medial degeneration - movat - intermed. mag. (WC/Nephron)

www:

• Marfan's syndrome (radiographics.rsna.org).

Stains

• Elastin stains (e.g. elastic trichrome stain) - disruption of the elastic lamina.
• Movat's stain - basophilic ground substance in the media.

Medial calcific sclerosis

• AKA Moenckeberg medial calcific sclerosis, calcific medial sclerosis of Monckeberg, and Monckeberg's arteriosclerosis.

General

• Usually of no clinical consequence.

Microscopic

Features:

• Medial calcification (purple irregular stuff on H&E -- calcium phosphate).

Note:

• Lumen unaffected.

Images

www:

• Moenckeberg medial calcific sclerosis (med.utah.edu).

Hyperplastic arteriolosclerosis

General

• Associated with:
  • Malignant hypertension.
  • Scleroderma.
• May be a consequence of thrombotic microangiopathy.^{[citation needed]}

Note:

• Hyperplasia = proliferation of cells.

Microscopic

Features:

• Onion-skin appearance of intima & media due to:
  • Intimal hyperplasia.
  • Smooth muscle hyperplasia.

Image: Hyperplastic arteriolosclerosis (utah.edu).

Fibromuscular dysplasia

• Abbreviated FMD.

General

Etiology:

• Unknown, possibly genetic.

Gender:

• Women > men.

• May be seen in virtually any artery.
• Reported as a cause of sudden death with involvement of the artery supplying the AV node.

Gross/radiologic

• Segmental - thinning and thickening.

Classical locations:

• Renal artery - leading to hypertension.
• Carotid artery.

Microscopic

Features:

• Smooth muscle hyperplasia - key feature.
• Elastic fibre fragmentation.
• Luminal narrowing.

Images:

• FMD (brown.edu).
• FMD of AV nodal artery (kams.or.kr).

Stains

• Elastic trichrome or Movat stain - to demonstrate elastic fibre fragmentation.

Thromboangiitis obliterans

• AKA Buerger disease.
  • Should not be confused with Berger disease (IgA nephropathy).

General

• Strong association with smoking.
• Small and medium-sized vessels of the extremities.

Diagnosis - clinical:

• Corkscrew vessels on angiography.

Treatment:

• Stop smoking.

Microscopic

Features:

• Acute inflammation:
  • Endarteritis - inner layers of blood vessels.
  • Periarteritis.

Thrombosis

See also: Cerebral venous thrombosis.

General

Definition:

• Blood clot formation within a vessel.

Complications:

• Embolism - see: Pulmonary thromboembolism.

Risk factors:

• The classic pimping question is what "Virchow's triad?"
  • Stasis, hypercoagulability, endothelial injury.
• A long list is found in: risk factors for VTE.

Gross

See: Pulmonary embolism - gross features.

Microscopic

Features:

• Lines of Zahn.
• Fibrin - pink acellular stuff on a H&E stain.

Image

• 

  Intravascular fibrin - high mag. (WC/Nephron)

Cholesterol embolism

• Abbreviated CE.

General

• Strong association with atherosclerosis - found in ~3% of individuals in an autopsy series of 267 older individuals (mean age ~65 years).
• Significant CEs are often iatrogenic.
  • Known complication of coronary catherization (incidence ~ 1%).
  • May complicate any vascular surgery, CABG.

Microscopic

Features:

• Intravascular cholesterol clefts (biconvex white spaces) - key feature.
  • Typically ~ 100-500 micrometers (long axis) x 50-100 micrometers (short axis). (?)
• +/-Macrophages and giant cells.
• +/-Eosinophils.

Note:

• May be associated with ischemic changes and necrosis.
• Usually in the context of severe atherosclerosis.

Note (trivia):

• Cholesterol crystals dissolve with routine processing (paraffin embedding); this is why one talks of "cholesterol clefts".

Images

• 

  Cholesterol embolus - intermed. mag. (WC)

• 

  Cholesterol embolus - high mag. (WC)

Coarctation of the aorta

• AKA aortic coarctation.

General

• Uncommon.

Classification:

• Preductal.
• Postductal.

Associations:

• Bicuspid aortic valve.
• Turner syndrome.

Clinical

Presentation:

• Heart failure.
• Hypertension - esp. upper extremity vs. lower extremity.

Gross

• Narrowing (stenosis) of the aorta proximal or distal to the ductus arteriosis.

Image

• 

  Pre- and postductal coarctation of the aorta - schematic (WC)

Intracranial berry aneurysm

Main article: Berry aneurysm

See also

• Cardiovascular pathology.
• Heart.
• Hypertension.
• Vasculitides.