Aortic dissection

1. Acute Aortic
Dissection
Dr Mubarik Ahmed Jan

2. Definition
• The Aortic Dissection is a
condition that occurs due to
tear in tunica intima, which is
the innermost layer of the
aorta.
• The blood flowing in the
wall dissects the layers of the
aorta, that may lead to
aneurysm, bleeding, end-
organ damage and even death.

3. Epidemiology:
The Aortic dissection is a rare diagnosis with an
incidence of around 3 - 4 per 100,000 person -
years.
The Aortic dissection is more common in men
than women with a ratio of ~2:1.
The average age of diagnosis is in the 60’s,
although patients with connective tissue
disorder have a much lower age of presentation
often in their 30’s.

4. Predisposing
Factors:
History of previous dissection
Hemodynamic Stressors like
Hypertension and Cocaine use.
Connective Tissue Disorders (Marfan
Syndrome, Ehlers-Danlos Syndrome)
Anatomic Abnormalities that cause
abnormal flow (Bicuspid aortic valve)
Questionable predisposing factors: PCOS,
Pregnancy, Family History

5. Marfan’s
syndrome:
Famous People With Marfan Syndrome
Look - The patient doesn’t always know they have
Marfan’s so need to look for the signs.
Arachnodactyly - Elongated fingers.
Pectus excavatum : sternal excavation
Lanky limbs

6. Classification: Stanford and Debakey’s
Type A
● Involves
ascending aorta.
● Can extend
distally ad
infinitum.
● Surgery is usually
indicated.
Type B
● Involves aorta
beyond left
subclavian
artery only.
● Often managed
medically with
BP control.
Stanford’s - More commonly used

7. Classification:
• DeBakey’s
• Type 1: Involves ascending
aorta, aortic arch, and
descending aorta
• Type 2: Ascending aorta
only
• Type 3: Descending aorta
only

8. Aortic
Dissection
Variants
Intramural thrombus
• An infarction in the aortic media, most often due
to an injury to the vaso vasorum, that results in a
thrombus formation within the aortic wall, which
may extend or resolve spontaneously.
• Often a precursor to dissection

9. AD Variants
Penetrating ulcer
• Ulcer formation due to
atherosclerosis which
can lead to intramural
thrombus, dissection or
aortic perforation

10. Signs and
Symptoms

11. Signs and
Symptoms
• Although cardiac tamponade is a relatively rare
presentation of AD (~4%), it is the most common cause
of death in AD

12. History + Physical Examination:
• Classic presentation:
• Sudden onset of tearing chest pain radiating to the back.
• However, dissection may occur anywhere along the aorta and thus the
presentation may be broad and mimic other common disorders
• Variant presentations include: (Due to associated end organ damage)
• Chest pain or back pain + vomiting
• Chest pain or back pain with neurologic findings (may be due to dissection into the
carotid arteries)
• Chest pain or back pain + limb ischemia
• Cardiac tamponade
• Only 51% of AD patients have the classic tearing chest pain

13. History +
Physical
Examination:
• Presenting blood pressure
• Hypertension: 49%
• Normotension: 33%
• Hypotension: 18%
• Classic Risk Factors (Hagan 2000)
• 9% of patient’s have Marfan syndrome,
these patients are often young.
• 72% had a history of HTN.
• 9% had prior cardiac surgery.
• Physical Examination (Hagan 2000)
• Pulse deficit: Present in only 28%. Defined
as >20 SBP point difference between arms

14. Work-Up
• CBC - Leukocytosis
• INR/PTT
• Renal function - Cr elevation with renal artery
involvement.
• Troponin elevated if dissection causes
myocardial ischaemia.
• D-dimer – If negative dissection is very unlikely,
but not sufficient to rule out
• Cross-match - (Possible surgery and need for
blood products).
• Various biomarkers are being investigated (e.g.
elastin fragments, smooth muscle myosin
heavy-chain protein).

15. ECG:
Normal - >30% of patients have no ECG changes (Hagan 2000).
40% will show non-specific ST-T wave changes.
Inferior ST elevation (right coronary dissection) but can also be any STEMI (0.1% of STEMIs are dissections)
Pericarditis changes, electrical alternans (tamponade).

16. CXR
~ 60% will have a wide
mediastinum on CXR, while
~16% will have a
completely normal CXR.
Large dilated tortuous aortic arch and descending aorta with mass effect on the
trachea (displacing it to the right and mildly narrowing it).

17. CXR
• Loss of the
aortic
knob/aortic-
pulmonary
window

18. • Look for a white line of calcium
within the aortic knob. Then
measure the distance from there
to the outer edge of the aortic
knob.
• A distance > 0.5cm is considered
a positive calcium sign and a
distance > 1.0cm is considered
highly suspicious for aortic
dissection.

19. Trans Thoracic ECHO:
• May be helpful in identifying cardiac
tamponade in an unstable patient.
• Tamponade is the common cause of
hypotensive presentation of AD
• ACEP Level B guideline:
• Do not rely on abnormal bedside TTE
result to establish diagnosis of thoracic
aortic dissection.

20. Trans Esophageal ECHO:
• Excellent option in
patients with CKD or
where CTA may not be
an available.
• It has a great sensitivity
98%.

21. The ADD Risk Score: Grading the pretest probability
• The Aortic Dissection
Detection Risk Score (ADD-RS)
is a clinical decision tool that
aids in grading the pretest
probability of an acute aortic
dissection.
• Scores range from 0-3,
• where 0 is classed as low risk,
• 1 is moderate risk and
• 2-3 is high risk

22. CT Angio
Modality of choice with high specificity and
sensitivity.
Can identify a false lumen,
location of dissection flap,
extension into the great vessels,
signs of aortic rupture and end-organ damage
CTA of Chest/Abdomen/Pelvis should be done in
patients with high suspicion to visualise the entire
length of dissection

23. Type A Aortic
Dissection

24. • Type B Aortic Dissection

25. MRA:
● This is the best
imaging study
for AD but is
limited by
availability and
time.
● Sensitivity and
specificity 98%.

27. ACC/ AHA-
Aortic-
Dissection-
Guideline
Acute AoD
Evaluation
Pathway

28. Treatment depends on the type of
dissection whether Type A or Type B.
Type A dissections almost always require
open surgical repair.
Mobilize consultants as early as possible
(Cardiothoracic surgery, interventional
radiology).
Mortality increases by 1-2% for every
hour from symptom onset to definitive
treatment.
Type A Dissection:

29. Management
• Type B dissections can often be managed
medically, if uncomplicated, or with
endovascular repair.
• Thoracic Endo Vascular Aortic Repair
(TEVAR) is now favored compared to open
repair of Type B dissections as this has been
shown to reduce morbidity and mortality.

30. Stepwise
treatment :
• The initial treatment is the same for both
type A and type B and includes a stepwise
fashion of:
• Treating Pain,
• Then Heart Rate,
• Then Blood Pressure,
• With consultation to Cardiothoracic
surgery or vascular surgery depending
on the site.

31. Treat Pain:
One of the best ways to control BP in these
patients is to aggressively treat pain.
The pain is severe, and to effectively treat
BP, first need to control the pain.
Treat anything that can increase Blood
Pressure or cause Valsalva
Nausea can also be an issue and should be
dealt with antiemetics.

32. Treat HR:
• Treat HR first to avoid the shear force caused
by the stroke volume of each beat.
• Start with rate control because
antihypertensive agent may cause reflex
tachycardia which can worsen shear force.
• Esmolol is the preferred agent for controlling
heart rate with a goal HR<60.
• Esmolol is given as a 500 mcg/kg bolus
over 1 min, started at 50 mcg/kg/min
infusion and increased gradually.
• Max infusion for esmolol is 200
mcg/kg/min.

33. Treat HR:
Labetalol IV 10 or 20 mg is also an
option if esmolol infusion is not readily
available and need HR control fast.
Also consider Labetalol in cases with
cocaine as provides both alpha and
beta-blockade.
Labetalol is also available as an
infusion with rates from 30 to 120 mg
/ hour.

34. Treat Blood
Pressure:
• The goal SBP is <110. If unable to achieve the goal
SBP after maxing esmolol to goal HR<60, then
nicardipine or nitroprusside can be added.
• Nicardipine is typically started as an infusion
of 5 mg/hr and increased gradually until max
of 30 mg/hr.
• Nitroprusside: is a pure vasodilator.
• Infusion rate is 0.3-0.5 mcg/kg/min to
start.
• Typical dose for BP control is 3-4
mcg/kg/min infusion.

35. Consult
surgeon:
Type A: Immediately to be pushed
to Operation Theatre.
Type B: Surgery may be needed.
Patient will be admitted to ICU for
• Conservative management if
uncomplicated,
• Analgesia,
• Optimizing hemodynamics and
• Managing post operative complications.

36. Post-operative
complications:
• The most common post-operative complications
following endovascular repair of type B
dissection includes:
• Stent Graft migration,
• Stent Graft fracture,
• Endoleak,
• Retrograde dissection,
• Stroke,
• Paraplegia and
• Lower limb ischemia.

37. ACC/ AHA-
Aortic-
Dissection-
guideline
Acute AoD Management
Pathway

38. Historical Fact:
Dr. Michael Debakey
This is Dr. Michael Debakey of Debakey Classification fame, born in
1908.
He pioneered the first aortic repairs of aortic dissection which bears
his name.
At age 97, he actually suffered from an aortic dissection himself.
Initially, he opted for medical management, but after becoming
unresponsive, it was decided to proceed with surgical intervention.
After a complicated post-op course and 8 months in the hospital, he
returned to good health and continued to practice medicine until
his death at age 99.

39. References:
● https://www.ahajournals.org/doi/full/10.1161/cir.0b013e3181d4739e
● https://emupdates.com/accaha-aortic-dissection-guideline/
● https://litfl.com/acute-aortic-dissection/
● https://rushemergencymedicine.org/2020/01/21/aortic-dissection/
● http://www.emdocs.net/core-em-aortic-dissection/