Diseases of thoracic aorta

Question 1

Name the three layers of the thoracic aorta

Answer 1

Tunica intima
Tunica media
Tunica adventitia

Question 2

What is the tunica intima comprised of?

Answer 2

Endothelial cells

Subendothelial layer - elastic fibres and collagen

Question 3

How is the tunica intima separated from the tunic media?

Answer 3

By the internal elastic membrane

Question 4

What is the tunica media comprised of?

Answer 4

Smooth muscle cells

Secrete elastin in sheets, lamellae

Question 5

What is the tunica adventitia comprised of?

Answer 5

Thin CT layer

Collagen and elastic fibres (not lamellae)

Question 6

Function of collagen in tunica adventitia

Answer 6

Prevent stretch beyond physiological limit in systole

Question 7

Risk factors for atherosclerosis

Answer 7

Hypertension
Hypercholesterolaemia
Smoking
Diabetes
Family history
Male

Question 8

What is the key event in atherosclerosis?

Answer 8

Endothelial dysfunction

Question 9

Describe the process of atherosclerosis according to age

Answer 9

1st decade - foam cells form fatty streak
3rd decase - intermediate lesion forms atheroma
4th decade- fibrous plaque forms complicated lesion which can rupture vessel

Question 10

What risks are associated with atherosclerosis?

Answer 10

Stroke
MI
Aneurysm

Question 11

Classification of aneurysms

Answer 11

Saccular
Fusiform
False
Dissecting

Question 12

Which types of aneurysms are true aneurysms?

Answer 12

Saccular#Fusiform

Question 13

Classification of aortic aneurysm according to site

Answer 13

Ascending
Aortic arch
Descending
Abdominal

Question 14

Signs and symptoms of aneurysmal disease in aorta

Answer 14

Asymptomatic
Dyspnoea
Heart failure
Dysphasia
Hoarseness
Sharp chest pain radiating to back and shoulders
Pulsatile mass
Hypotension

Question 15

Classfication of aortic Dissection

Answer 15

DeBakey
I - originates in ascending to arch
II- confined to ascending
III- originates in descending, extends distally or retrograde to arch, ascending

Stanford
A- Any ascending involvement
B-No ascending involvement

Question 16

Aetiological factors for aortic dissection

Answer 16

Trauma
Connective Tissue disease- Marfans
Atherosclerosis
Hypertension

Question 17

What sign of aortic dissection is shown in hisotlogy?

Answer 17

Cystic medial necrosis

Question 18

Signs and symptoms of aortic dissection

Answer 18

Tearing, severe chest pain radiating to back
Collapse (tamponade, acute (NEW)Aortic regurgitation, external rupture)
Hypotension
Tachycardia
Signs of end organ hypoperfusion

Question 19

Aortic dissection must be excluded when patient is presenting with signs of which condition?

Answer 19

Inferior stemi with back pain

Question 20

Signs of aortic dissection on examination

Answer 20

Reduced peripheral pulse (BP mismatch)
Hypo/hypertension
Soft early diastolic murmur (AR)
Pulmonary oedema
Chest X ray - widened mediastinum
Confirm by ECHO and CT

Question 21

Treatment of aortic dissection

Answer 21

Type A Surgery

Type B - BP control, sodium nitroprusside and B blocker

Question 22

Which other conditions can present with aortic aneurysm/dissection?

Answer 22

Takayasu’s vasculitis

Syphilis

Question 23

Treatment of takayasu’s vasculitis

Answer 23

Steroids#Surgery

Question 24

Three types of presentation in third degree syphilis

Answer 24

Late neurological
Gummatous
Cardiac - syphilitic aortitis, aortic regurgitation

Question 25

2 types of congenital aortic aneurysm

Answer 25

Bicuspid aortic valve | Coarctation of aorta

Question 26

3 shunts in immature heart

Answer 26

Ductus arteriosus Foramen ovale Ductus venosus

Question 27

3 types of coarctation of aorta

Answer 27

Pre ductal Ductal Post ductal

Question 28

Which type of coarctation is most common in adults?

Answer 28

Post ductal

Question 29

What are the signs associated with post ductal aortic coarctation?

Answer 29

Hypertension in upper extremeties Weak pulse in lower limbs Rib notching - seen on CXR (collateral circulation) Radial/Radial/Radial Femoral delay Heart failure, FTT in infancy Hypertension in later life

Question 30

Which genetic mutation occurs in Marfan's syndrome?

Answer 30

Fibrillin I Gene

Question 31

Which murmur is associated with Marfan's syndrome?

Answer 31

Regurgitation

Question 32

Signs of marfan's syndrome

Answer 32

``` Skeletal system affect Eyes - cataracts, lens dislocation Aneurysm dissection Hyperexpanded lungs prone to pneumothorax Arm span exceeeds height Pectus excavatum Arachnodactyly of hands and feet Steinberg sign - tips of thumb protrude when folded in fist ```

Question 33

What is aortic dissection?

Answer 33

A tear in the intimal layer of the aortic wall. | Blood flows between and splits apart the tunica intima and tunica media

Question 34

When is aortic dissection diagnosed as acute or chronic?

Answer 34

Acute - less than 14 days | Chronic - more than 14 days

Question 35

Name some signs of end-organ hypoperfusion

Answer 35

``` Reduced urine output Paraplegia Lower limb ischaemia Abdominal pain secondary to ischaemia Deteriorating conscious level ```

Question 36

Differential of aortic dissection

Answer 36

MI PE Pericarditis Musculoskeletal back pain

Question 37

How to differentiate pericarditis from thoracic aortic dissection

Answer 37

Pleuritic chest pain ST elevation on ECG Pericardial rub on auscultation

Question 38

Investigations for aortic dissection

Answer 38

``` Bloods - FBC, U&Es, troponin, LFTs, coagulation ABG ECG CT angiogram Transoesophageal ECHO ```

Question 39

Why are Type B dissections managed medically instead of surgically?

Answer 39

Endovascular repair carries risk of retrograde dissection

Question 40

When is surgery considered in Type B dissections?

Answer 40

``` rupture renal visceral or limb ischaemia refectory pain uncontrollable hypertension ```

Question 41

What is the most common complication of chronic Type B dissection?

Answer 41

Aneurysm

Question 42

Complications of aortic dissection

Answer 42

``` Aortic aneurysm rupture Aortic regurgitation Myocardial ischaemia Cardiac tamponade Stroke Paraplegia ```

Question 43

Mortality rate of aortic dissection

Answer 43

20% before reaching hospital