1. THE DOCTORS GUIDE TO PATIENT SURVIVAL AFTER ACUTE AORTIC DISSECTION
Mark J. Russo, MD, MS
Co-Director, Center for Aortic Diseases
University of Chicago

2. THE NUMBERS Incidence - uncertain 5,000 – 15,000 cases/year in U.S.
Likely higher (not reportable condition, few autopsies now)
Autopsy series – 0.2% autopsies
Males 2-5x > females
Ascending dissections: years old
<40 years: Marfan, pregnancy, AV disease
Descending dissections: years old

3. NATURAL HISTORY

4. NATURAL HISTORY 1934 Shennan: >300 cases autopsies reviewd
40% acute ascending dissections died suddenly
None lived > 5 weeks
1972 Anagnostopoulos : 973 pts w untreated proximal and distal dissections
50% died with 48 hours
84% died within 1 month

5. NATURAL HISTORY As many as 40% die before reaching the hospital
Mortality increases 1-3% per hour
At 48 hours, 50% are dead
At 2 weeks 75-90% are dead

6. MECHANISM

7. MECHANISM
Initiating event may be is a primary rupture of the intima with secondary dissection of the media
-- OR --
Hemorrhage within the media and subsequent rupture of the overlying intima.

9. MECHANISM
Blood flow is redirected from the “true lumen” of the aorta into a “false lumen”

10. MECHANISM
As a result, dissection propagates in “dissection plane” separating the intima from the overlying adventitia
Usually the dissection proceeds distally/ retrograde/direction of blood flow

11. MECHANISM
Dissection may shear off or extend into branch arteries -> complications

12. COMPLICATIONS - MALPERFUSION
Stroke
(3-13%)
arm ischemia
(25-60%)
arm ischemia
(25-60%)
Paralysis
(2-9%)
kidney dysfunction
(25%-75%)
bowel ischemia
(10%-20%)
MI (5-10%)
Tamponade (10%)
leg ischemia (25-60%)

13. CLASSIFACTION
Debakey I II IIIa IIIb
Stanford A A B B

14. LOCATION OF DISSECTION

15. Type A vs B Determines Management, but . . .

16. It Is Not Your Role To Differentiate Type A vs B

17. YOUR ROLE Diagnosis Suspicion Treatment Medical Management - Always
Consult a Surgeon - Always

18. TIME MATTERS As many as 40% die before reaching the hospital
Mortality increases 1-3% per hour
At 48 hours, 50% are dead
At 2 weeks 75-90% are dead

19. DIAGNOSIS

20. leading to a correct diagnosis is a high clinical suspicion
Most important factor
leading to a correct diagnosis is
a high clinical suspicion

21. PRESENTATION Pain - severe chest, back, and/or limb – 90%
Severe uncontrolled hypertension – 50-60%
Loss of consciousness (syncope) – 15%
Weakness
Difficulty walking
Slurred speech
Blurry/loss or vision

22. PAIN CHARACTERISTICS Occurs in 90% of cases Ripping, tearing Migratory
Never experienced before
Restless, sense of doom
Most Severe at Onset
Anterior Pain: Proximal Dissection
Posterior Pain: Distal Dissection
Migratory Pain

23. PAIN CHARACTERISTICS Chest pain – 2/3 Back pain – 1/2
Abdominal pain – 1/3
Painless dissection is relatively uncommon (6.4%)
Presenting symptoms of syncope, heart failure, or stroke were seen more often in this group.
Pain in these locations usually due to other more common disorders (MI, pneumonia, pleurisy, pulmonary embolism, pneumothorax, ulcer, cholecystitis, pancreatitis) BUT….

24. Must consider aortic dissection in cases without other confirmed cause of pain

25. RISK FACTORS
Hypertension - Present in 70-90% of dissections, but 20-40% of adults
Aortic aneurysm – 13%
Family history of aortic disease – 19%
Connective tissue diseases - Marfans (2%), Ehlers-Danlos, Lowy-Dietz
Bicuspid aortic valve – 1%
Aortic coarctation
Turner syndrome
Cardiac intervention – CABG, AVR, Cath (2%)
Pregnancy
Trauma
High Intensity weightlifting
Crack – 37% in an inner city population, usually < 12 hours after last use

26. PHYSICAL EXAMINATION Acutely ill Tachycardia
Hypertension – particularly if severe HTN
Results catecholamines, renal ischemia
Hypotension (20%)
Due to acute complications
Widen Pulse Pressure
Aortic insufficiency: (50-60% ascending dissections)
Differential pressure from Left to Right Arm (when dissection is distal to BCA)
Pulse deficits: (60% ascending dissections)
May change over time

27. D-DIMER
D-Dimer is an important and well-known marker for pulmonary embolism (PE), especially in outpatients and the emergency department.
Also a biomarker for aortic dissection, because of the associated large intramural hematoma often present in aortic dissections.
Initial D-Dimer value in symptomatic patients with concerns for aortic dissection:
D-Dimer < 0.5 μg/ml: Thoracic Ascending Aortic Dissection unlikely
D-Dimer >1.6 μg/ml: Thoracic Ascending Aortic more likely,
proceed with aortic imaging with CT C/A/P with IV contrast or TEE
Thoracic Ascending Aortic Dissection (TAAD) elevates D-Dimer Earlier Than Pulmonary Embolus

28. CXR Mediastinal widening - 63% w type A dissections
Pleural effusion - 19% of dissections
Other findings:
widening of the aortic contour,
displaced calcification,
aortic kinking, and
opacification of the aorticopulmonary window
Normal - 11%

29. CXR
Features of acute type A dissection,

30. CXR
Features of acute type A dissection,
Widened mediastinum

31. CXR Features of acute type A dissection, Widened mediastinum
Rightward tracheal displacement

32. CXR Features of acute type A dissection, Widened mediastinum
Rightward tracheal displacement
Irregular aortic contour with loss of the aortic knob

33. CXR Features of acute type A dissection, Widened mediastinum
Rightward tracheal displacement
Irregular aortic contour with loss of the aortic knob
Indistinct aortopulmonary window
Left pleural effusion

34. A diagnosis of dissection should not rest on a CXR

35. IMAGING - PURPOSE Dissection flap Dilated aorta Aortic insufficiency
Pericardial effusion
Involvement of the ascending aorta
Branch vessel or coronary artery involvement
Extent of dissection and the sites of entry and reentry
Thrombus in the false lumen

36. IMAGING - OPTIONS Most have multiple imaging studies performed
mean of 1.83 per patient
Transthoracic echocardiogram – 33%
Transesophageal echocardiogram - 33%
Computed tomography - 61%
Aortography – 4%
Magnetic resonance imaging – 2%

37. CT SCAN Sensitivity - 83 and 98%; specificity - 87 and 100% Advantages
Availability at most hospitals
Identification of intraluminal thrombus and pericardial effusion
Disadvantages
Intimal flap is seen in < 75%
Site of entry is rarely identified
Nephrotoxic iodinated contrast is required
No capability to assess for aortic insufficiency

38. CT
False Lumen
True Lumen
[tear]

39. CT

40. Transthoracic Echo
Sensitivity and specificity inferior to CT, MRI, and TEE
Advantages
Noninvasive
Fast, low risk
Intimal flap may be seen in the proximal aorta in some patients
Useful for the assessment of cardiac complications of dissection, including aortic insufficiency, pericardial effusion/tamponade, and RV function.
Disadvantages - inability to adequately visualize the distal ascending, transverse, and descending aorta in a substantial majority of patients

41. Transesophageal Echo
Sensitivity 97 to 99 percent; , the specificity 77 to 85 percent
Advantages
Rapid; useful in patients too unstable for CT/MRI
True and false lumens can be identified
Intimal dissection flaps can be identified
Thrombosis in the false lumen, pericardial effusion, concomitant aortic regurgitation, and the proximal coronary arteries can be readily visualized.
Disadvantages
Requires esophageal intubation
Requires the availability of experienced operators (both physicians and technicians)
Inability to visualize the upper portion of the ascending aorta due to the interposed trachea (between the aorta and esophagus).

42. MRI Sensitivity and specificity of MRI were both 98% Advantages
85% sensitivity for identification of the site of entry
MR contrast agents have a more favorable safety profile than iodinated contrast agents.
ability to assess branch vessels.
Disadvantages
Long study
limited applicability (MRI cannot be performed in patients with claustrophobia, pacemakers, or certain types of aneurysm clips or metallic ocular/auricular implants).
not readily available on an emergency basis at many institutions
concerns about patient monitoring and relative patient inaccessibility during prolonged scanning
Unable to assess for aortic insufficiency

43. MANAGEMENT Mean arterial pressure of 60-75 mmHg:
1st line treatment: Beta blockers (eg esmolol, propranolol, or labetalol)
If there is a contraindication to beta blockers, calcium-channel blockers (eg verapamil and diltiazem) can be used
For refractory hypertension: Nitroprusside, in addition to a beta- or calcium-channel blockers.
DO NOT USE: Hydralazine or minoxidil or beta-blockers with intrinsic sympathomimetic action (eg, acebutolol, pindolol)

44. MANAGEMENT It is not your job to make a definitive diagnosis
If you suspect….call a surgeon
Call a surgeon

46. RITTERS RULES
Life-saving reminders to recognize, treat and prevent thoracic aortic dissection
Named for actor John Ritter, who died of a thoracic aortic dissection, Ritter Rules combine knowledge with action.
Address urgency, symptoms, who is most at risk and which imaging tests

47. URGENCY Thoracic aortic dissection is a medical emergency.
The death rate increases 1% every hour the diagnosis and surgical repair are delayed.

48. PAIN Severe pain is the #1 symptom.
Sudden onset of severe pain in the chest, stomach, back or neck.
is likely to be sharp, tearing, ripping, moving or so unlike any pain you have ever had that you feel something is very wrong.

49. MISDIAGNOSIS Aortic dissection can mimic heart attack.
If a heart attack or other important diagnosis is not clearly and quickly established, then aortic dissection should be quickly considered and ruled out,
particularly if a patient has a family history or features of a genetic syndrome that predisposes the patient to an aortic aneurysm or dissection.

50. IMAGING Get the right scan to rule out aortic dissection.
Only three types of imaging studies can identify aortic aneurysms and dissections: CT, MRI and transesophageal echocardiogram.
A chest X-ray or EKG cannot rule out aortic dissection.

51. RISK FACTOR Aortic aneurysm Family history
Genetic Syndromes: Marfan syndrome, Loeys-Dietz syndrome, Turner syndrome and vascular Ehlers-Danlos syndrome
Bicuspid aortic valve

52. TRIGGER Trauma Extreme straining associated with body building
Illicit drug abuse
Poorly controlled high blood pressure or by discontinuing necessary blood pressure medications.
Pregnancy

53. PREVENTION
Medical management is essential to preventing aortic dissection. If you have thoracic aortic disease, medical management that includes optimal blood pressure control, aortic imaging and genetic counseling is strongly recommended. Talk with your physician.