1. Grand Rounds Presentation April 1st Guidelines For The Diagnosis And Management Of Patients With Thoracic Aortic Disease

2. Acknowledgments
Julia Rissmiller MD
Diana Litmanovich MD
Satya Rao MD

3. A Report Of The American College Of Cardiology Foundation/American Heart Association Task Force On Practice Guidelines
Endorsed by American College Of Radiology, Society Of Interventional Radiology, North American Society For Cardiovascular Imaging

4. Introduction Clinical practice guidelines for thoracic aortic disease
Recommendations from expert panel
Evidence based report

5. Key Topics Appearance of normal thoracic aorta
Recommended imaging modalities
Standards for reporting

6. Key Topics Acute aortic syndromes
Special considerations in pregnant patients
Atherosclerosis
Future directions

7. Thoracic Aortic Anatomy
4 Parts
Root
Ascending
Arch
Descending

8. Aortic Terminology Sinuses of Valsalva Sinotubular junction
Ascending aorta
Proximal aortic arch
Mid aortic arch
Proximal descending TA
Mid descending TA
Aorta at diaphragm
Abdominal aorta
The thoracic aorta is divided into 4 parts: the aortic root
(which includes the aortic valve annulus, the aortic valve
cusps, and the sinuses of Valsalva); the ascending aorta
(which includes the tubular portion of the ascending aorta
beginning at the sinotubular junction and extending to the
brachiocephalic artery origin); the aortic arch (which begins
at the origin of the brachiocephalic artery and is the origin of
the head and neck arteries, coursing in front of the trachea and
to the left of the esophagus and the trachea); and the
descending aorta (which begins at the isthmus between the
origin of the left subclavian artery and the ligamentum
arteriosum and courses anterior to the vertebral column, and
then through the diaphragm into the abdomen).

9. Standards of Reporting
Measurement
Reproducible anatomic landmarks
Aortic root measured at the mid-sinus level

10. Normal Thoracic Aortic Diameter
Gender
Body size
Age

11. Normal Diameter Thoracic aorta Mean (cm) Root (F) 3.5 - 3.72 Root (M)
Mid-descending (F)
Mid-descending (M)

12. Normal Diameter in Males
Root < 4 cm
Descending < 3 cm

13. Normal Diameter in Females
Root < 3.8 cm
Descending < 2.8 cm

14. Aortic Diameter and Age
Diameter increases with age
Those with genetic syndromes or abnormal tissue morphology may have normal aortic diameter
at time of aortic rupture

15. Standards Of Reporting
Measurement
Perpendicular to flow
External diameter

16. Standards Of Reporting
Abnormalities of morphology should be reported even if diameter is normal
Dissection, aneurysm, traumatic injury, rupture should be communicated immediately
Techniques to minimize radiation exposure should be utilized

17. Essential Elements Of Reports
Location and length
At risk patients need measurements
Sinuses of Valsalva
Sinotubular junction
Ascending aorta
Presence of thrombus or atheroma
Presence of IMH, PAU, or calcification
Involvement of branch vessels
End-organ injury
Evidence of aortic rupture
Comparison with previous imaging
, including periaortic and mediastinal hematoma, pericardial and pleural fluid, and contrast extravasation from the aortic lumen. Direct image comparison to determine if there has been any increase in diameter.

18. Diagnostic Approach to Acute Aortic Syndromes

19. Approach To Suspected Dissection
© 2010 American Heart Association, Inc. Published by American Heart Association. 19

20. Step 1: Establishing Risk
© 2010 American Heart Association, Inc. Published by American Heart Association. 20

21. Aortic Dissection Selecting The Correct Test
Based on patient variables and institutional capabilities
If a high clinical suspicion exists but initial aortic imaging is negative, a second imaging study should be obtained 21

22. Suspected Aortic Dissection
EKG
Chest radiograph
In high risk patients:
Transesophageal echocardiogram CT
MRI
A negative chest x-ray should not delay definitive aortic imaging in high risk patients 22

23. Selecting The Correct Test: The Evidence
1996
Nonhelical CT
0.5 T MR
TEE
100% sensitivity for all modalities
Better specificity of CT (100%)
2006
Helical CT MR
All 3 imaging techniques equally reliable
*Sommer T, Fehske W, Holzknecht N, et al. Aortic dissection: a comparative study of diagnosis with spiral CT, multiplanar transesophageal echocardiography, and MR imaging. Radiology. 1996;199:347–52.
**Shiga T, Wajima Z, Apfel CC, et al. Diagnostic accuracy of transesophageal echocardiography, helical computed tomography, and magnetic resonance imaging for suspected thoracic aortic dissection: systematic review and meta-analysis. Arch Intern Med. 2006;166:1350–6. 23

24. Step 2: Expedited Aortic Imaging
© 2010 American Heart Association, Inc. Published by American Heart Association. 24

25. Transesophageal Echocardiography
Advantages
Non-ionizing
Portable
Rapid imaging time
Cardiac complications identifiable
Disadvantages
Operator dependent
Blind spot
Inability to visualize abdominal aorta

26. CT Advantages Disadvantages
Images entire aorta
Identify anatomic variants
Branch vessel involvement
Short imaging time
Triple rule out
Disadvantages
Ionizing radiation
Iodinated contrast
After intervention/surgery to detect pseudoaneurysm or leak, Suspected acute aortic dissection, distinguish among types of acute aortic syndromes (IMH, PAU, dissection)
Advantages
Image entire aorta, including lumen, wall, periaortic regions
Identify anatomic variants and branch vessel involvement
Short imaging time

27. MR Multiplanar evaluation Advantages Disadvantages
Identify dissection, IMH, PAU
Assess branch artery involvement
Dynamic imaging
Aortic valve pathology and LV dysfunction
No radiation, no iodinated contrast
Disadvantages
Long acquisition time
Contraindications
Use of gadolinium
: metallic implants, pacemakers, specifically the coronary arteries

28. When to use MR Allergy to iodinated contrast
Mild and moderate renal failure: GFR > 30
Severe renal failure – non-contrast MRI
Annual follow-up of young patients
Lohan et al. MRI Clinic N Am.2008

29. Acute Aortic Syndromes

30. Intimal Tears I: Classic Dissection II: Intramural Hematoma
III: Limited Dissection
IV: Penetrating Atherosclerotic Ulcer
V: Iatrogenic
© 2010 American Heart Association, Inc. Published by American Heart Association. 30

31. Aortic Dissection
Disruption of the media with bleeding within the wall
Prevalence: 60’s
Male predominance
More common cause of death than AAA
At sites of aneurysmal dilatation
Treatment of aneurysm before dissection important to long-term survival
40% die immediately
1% mortality per hour after
5-20% perioperative mortality 31

32. Aortic Dissection

33. Aortic Dissection
Traditionally urgent operative management for Stanford type A
Delayed surgery/medical management considered
Shock, ARF, prior repair, advanced age
Patient factors are protective
Prior valve repair
Delayed presentation

34. Intramural Hematoma 10-20% of acute aortic syndromes
Descending aorta; > 60 years
Pain
Imaging criteria
Thrombus in wall
Crescentic thickening (> 7 mm)
No intimal flap, tear or longitudinal flow in false lumen
No enhancement
High Risk
Ascending aorta > 4.8 cm
Ascending aorta involvement
Thickness > 11 mm
* Song JM, Kim HS, Song JK, et al. Usefulness of the initial noninvasive imaging study to predict the adverse outcomes in the medical treatment of acute type A aortic intramural hematoma. Circulation. 2003; 108(suppl 1):II324 –II328. 34

35. Intramural Hematoma

36. Penetrating Atherosclerotic Ulcer
Atherosclerotic lesion with ulceration
penetrates internal elastic lamina
hematoma formation
Can predispose to dissection, IMH or rupture
Descending aorta
Elderly
Chest pain 36

37. Penetrating Atherosclerotic Ulcer
© 2010 American Heart Association, Inc. Published by American Heart Association.

38. Ascending Aortic Aneurysm

39. Ascending Aortic Aneurysm
Permanent localized dilatation
At least a 50% increase in diameter compared with the expected normal diameter

40. Diagnostic Approach

41. Determine Need For Urgent Repair
© 2010 American Heart Association, Inc. Published by American Heart Association. 41

42. Ascending Aortic Aneurysm Surveillance

43. Special Considerations in Pregnancy

44. Pregnant Patients With Aortic Dilatation
Increased
Maternal blood volume
Heart rate
Blood pressure
Stroke volume
Cardiac output
Arterial dissection/rupture highest incidence
3rd trimester (50%)
Peripartum (33%)
Marfan syndrome
4.4% developed aortic dissection
*Pacini L, Digne F, Boumendil A, et al. Maternal complication of pregnancy in Marfan syndrome. Int J Cardiol. 2009;136:156–61. 44

45. Pregnant Patients With Aortic Dilatation
If known aortic root or ascending aortic dilatation
Monthly or bimonthly echocardiographic measurements of the ascending aortic dimensions until birth
If aortic arch, descending, or abdominal aortic dilatation, MRI preferred to CT
TEE also an option 45

46. Atherosclerosis Of Aortic Arch
Risk factor for stroke
Plaques proximal to left subclavian artery
Independent predictor of stroke, MI and vascular death
Embolization more likely in the presence of
Ulceration
Lack of calcification
plaques 4 mm or
greater in thickness proximal to the origin of the left subclavian
artery are associated with stroke and constitute one third
of patients with otherwise unexplained stroke.

47. Atherosclerosis Of Aortic Arch
Imaging
TEE
Plaque mobility, composition
Anatomic relationships CT
Vascular calcification
MRI
Morphology
Composition

48. Aortic Atherosclerosis
Porcelain Aorta
Severe and diffuse calcification, causing an eggshell appearance
Interferes with aortic surgery
Surgeons use alternative techniques to reduce adverse events
cannulation of the aorta , crossclamping,
and placement of coronary bypass grafts

50. Porcelain Aorta Interferes with surgery Increases risk of Stroke
Irreparable aortic injury
Distal embolization
Surgeons use alternative techniques to reduce adverse events

51. Future Directions Risks and benefits of imaging technologies
Radiation, contrast
Surveillance in the young
Biomarkers for dissection
Quantification of risk in atherosclerosis

52. Summary Aortic diameter varies by age and gender
Measurements should be consistent and reproducible
Reporting should be consistent

53. Summary Acute Aortic Syndromes Pregnancy Future Directions Dissection
TEE/CT/MRI equally accurate
Aneurysm
5.5cm/5mm growth/symptoms = surgery
Graded surveillance
Pregnancy
Routine echocardiographic surveillance
Future Directions