Aortic Dissection

Question 1

What is an aortic dissection?

Answer 1

Tear in the tunica intima in wall of aorta

Question 2

What is the biggest RF for aortic dissection?

Answer 2

HTN

Question 3

List 6 risk factors other than HTN for aortic dissection

Answer 3

Trauma
Bicuspid aortic valce
CTD: Marfan’s, EDS
Turner’s + Noonan’s
Pregnancy
Syphillis

Question 4

Recall 2 ways in which aortic dissection can be classified and what these entail

Answer 4

Stanford classification
Type A: ASCENDING aorta (2/3 cases)
Type B: DESCENDING aorta (1/3 cases)

De Bakey classification
Type 1 originates in ASCENDING aorta, EXTENDs to arch + possibly beyond
Type 2: confined to ASCENDING aorta
Type 3: originates in DESCENDING aorta

Question 5

What is the main symptom of aortic dissection?

Answer 5

Tearing chest/ back pain
Maximal at onset

Question 6

Describe classic pain in type A and B dissection?

Answer 6

Type A: Chest pain more common
Type B: Upper back pain more common
(overlap + often both present)

Question 7

What signs may be found in aortic dissection?

Answer 7

Pulse deficit
Aortic regurgitation
HTN

Question 8

What pulse deficit is seen in aortic dissection?

Answer 8

Weak/ absent carotid, brachial or femoral pulse
Variation >20mmHg in SBP between arms

Question 9

List 3 features caused by involvement of specific arteries in aortic dissection

Answer 9

Coronary arteries: Angina
Spinal arteries: Paraplegia
Distal aorta: limb ischaemia

Question 10

What ECG changes are seen in aortic dissection?

Answer 10

Majority: none/ non-specific changes
Minority: ST elevation in inferior leads

Question 11

What would be seen on CXR in aortic dissection?

Answer 11

Widened mediastinum

Question 12

How should aortic dissection be imaged?

Answer 12

Stable: CT CAP (Ix of choice)- false lumen
Unstable: Transoesophageal echo

Question 13

Describe management of Type A aortic dissection

Answer 13

Surgical emergency: refer to surgeons
Meanwhile: control BP + analgesia

Question 14

What is used to control BP in Type A aortic dissection?

Answer 14

IV Labetalol
If AR/ CI: Verapamil/ Diltiazem

Then vasodilate: Sodium nitroprusside

Question 15

Why must B-blockers be avoided in aortic regurgitation?

Answer 15

B-blockers can inhibit compensatory tachycardia.

Question 16

What analgesia is given in aortic dissection?

Answer 16

Morphine sulfate
To reduce pain + stress that increases HTN + tachycardia

Question 17

What surgical intervention is performed in Type A aortic dissection?

Answer 17

Open surgery: replacement of dissection with graft

Question 18

In which type of aortic dissection is emergency surgery not indicated?

Answer 18

Descending

Question 19

Describe management of Type B aortic dissection

Answer 19

Conservative: watchful waiting + medication unless complications occur
B-blocker to reduce BP + prevent progression
+/- ARB/ ACEi
Lifestyle: avoid contact sports, smoking cessation

Question 20

When is surgical repair of type B aortic dissection performed?

Answer 20

Electively: Open replacement + graft implantation/ endovascular aortic stent implantation
If complications arise: open

Question 21

Name 5 complications of type A aortic dissections

Answer 21

MI (coronary artery occlusion; inferior pattern often seen due to RCA involvement)
Aortic regurgitation
Cardiac tamponade
Pericarditis
Stroke (extension of dissection into carotids)

Question 22

Name 2 complications of both type A and B aortic dissections

Answer 22

Aortic rupture + acute blood loss
Arterial occlusion followed by ischaemia of downstream organs

Question 23

What occurs secondary to ischaemia of the celiac trunk/ superior/ inferior mesenteric artery?

Answer 23

Acute abdomen
Ischaemic colitis

Question 24

What occurs secondary to ischaemia of the renal arteries?

Answer 24

Acute renal failure

Question 25

What occurs secondary to ischaemia of the spinal arteries?

Answer 25

Weakness of lower extremities or acute paraplegia

Question 26

What occurs secondary to complete occlusion of the distal aorta?

Answer 26

Leriche syndrome (Aortoiliac occlusive disease)
Classic triad of:
Bilateral buttock, hip, or thigh claudication
Erectile dysfunction
Absent/ diminished femoral pulses.